Current Molecular Pharmacology, 2009, 2, 1-14 1

Mechanisms of Non-Opioid Analgesics Beyond Cyclooxygenase Enzyme Inhibition

May Hamza1,2 and Raymond A. Dionne*,1

1National Institute of Nursing Research, NIH, Bethesda, MD, USA; 2Department of Pharmacology, Faculty of Medicine, Ain Shams University, Cairo, Egypt Abstract: Non-opioid analgesics including both selective and non-selective cyclooxygenase (COX) inhibitors and acetaminophen are the most widely used treatments for pain. Inhibition of COX is thought to be largely responsible for both the therapeutic and adverse effects of this class of drugs. Accumulating evidence over the past two decades has demonstrated effects of non-opioids beyond the inhibition of COX and prostaglandin synthesis that might also explain their therapeutic and adverse effects. These include their interaction with endo- cannabinoids, nitric oxide, monoaminergic, and cholinergic systems. Moreover, the recent development of microarray technology that al- lows the study of human gene expression suggests multiple pathways that may be related to the analgesic and anti-inflammatory effects of non-opioids. The present review will discuss the multiple actions of non-opioids and their interactions with these systems during in- flammation and pain, suggesting that COX inhibition is an incomplete explanation for the actions of non-opioids and proposes the in- volvement of multiple selective targets for their analgesic, as well as, their adverse effects. Keywords: NSAIDs, endocannabinoids, monoaminergic systems, cholinergic system, nitric oxide, interleukin-6, matrix metalloproteinases, inflammatory pain.

INTRODUCTION The introduction and eventual recognition of an increased risk of cardiovascular adverse effects attributed to selective COX-2 Non-opioid analgesics are among the most widely used medica- inhibitors [10] also challenges the COX-inhibition hypothesis. It tions due to their efficacy for a wide range of pain and inflamma- was proposed that selective COX-2 inhibitors, in contrast to non- tory conditions. In the United States alone, over 172 million pre- selective ones, affect the balance between prothrombotic and anti- scriptions for cyclooxygenase (COX) inhibitors (both selective and thrombotic eicosanoids, thereby shifting the balance to a prothrom- non-selective) were dispensed in the year 2004 [1]. Inhibition of botic state [11]. However, to date, this proposed mechanism of prostaglandin (PG) synthesis has been widely accepted since the cardiovascular risk has not been confirmed [12]. In fact, several 1970s as the mechanism underlying the pharmacological actions of findings argue against this assumption. In healthy volunteers, thera- both the therapeutic and adverse effects of this group of drugs. The peutic doses of rofecoxib that are known to inhibit vascular PGI application of new molecular-genetic technologies to classic anal- 2 production, do not result in significant changes in endothelial vaso- gesic paradigms has resulted in compelling evidence to question the unitary COX-inhibition hypothesis of non-opioids. We review here dilator responses [13]. In another clinical study, rofecoxib neither evidence that suggests alternative mechanisms of non-opioids ac- affected the levels of both PGI2 and thromboxane A2 metabolites, tions that may hold promise for new strategies for analgesic drug nor did it have an effect on bleeding time, platelet aggregation or development. thrombin generation after 7 days of treatment in an ex-vivo model of microvascular injury [14]. Further, internal mammary and radial arteries and saphenous veins donated by individuals with ongoing IS INHIBITION OF PROSTAGLANDIN SYNTHESIS THE cardiovascular disease (during standard coronary artery bypass SOLE MECHANISM UNDERLYING THE PHARMACOL- surgery) showed detectable levels of COX-1 but not COX-2 [15]. OGICAL ACTIONS OF NON-OPIOID ANALGESICS? Interestingly, in bovine aortic endothelial cells, prostacyclin syn- The inhibition of PG synthesis has been reported in almost thase and COX-1 were colocalized to the nuclear envelope and every study that has used a non-opioid. We have shown in several endoplasmic reticulum. However, there was a lack of colocalization studies a temporal association between decreased PGE2 levels at the of COX-2 with prostacyclin synthase [16]. Taken together, these site of extraction in the oral surgery model of acute inflammatory studies argue against the role of vascular COX-2 in PGI2 mediated pain and the analgesic effects of NSAIDs and coxibs [2-4]. How- vasodilation. Recent epidemiologic reports suggest that cardiovas- ever, observations dissociating the analgesic and the anti- cular risk associated with COX-2 inhibitors extends to some non- inflammatory activities of non-opioids have also been reported. At selective NSAIDs and to acetaminophen, particularly with higher analgesic doses, sodium salicylate does not inhibit urinary excretion doses or higher frequency of use [17], further lack of evidence for of PGE2 or PGI2 metabolites in human volunteers [5]. Furthermore, COX-2 mediated imbalance resulting in a prothrombotic state. though the COX inhibitory activities of salicylate and acetylsali- The recent development of microarray technology allows study cylic acid (ASA; aspirin) differs markedly [6], they show similar of gene expression across the whole human genome, adding further anti-inflammatory potencies [7]. The same discrepancy applies to R- and S-enantiomers of flurbiprofen, without possible explanation possibilities to explore drug effects. We have recently shown in two based on pharmacokinetics or chiral inversion. While S- different studies [18, 19] the effect of both ibuprofen and rofecoxib on gene expression in the oral surgery model of acute inflammatory flurbiprofen has anti-inflammatory activity and inhibits PGE2 syn- thesis, R-flurbiprofen at equianalgesic doses is devoid of both prop- pain. Both drugs induce over 3-fold up-regulation of more tran- erties [8]. Furthermore, a meta-analysis reported that the analgesic scripts than did the placebo 48 hours after surgery. Among the efficacy of different non-opioids in the clinical dental pain model, upregulated genes identified in these studies are interleukin-6 (IL- does not correspond to the degree of inhibition of PG synthesis in 6), suppressor of cytokine signaling 3 (SOCS3), and matrix metal- vitro [9], which suggests that other molecular mechanisms contrib- loproteinases (MMPs), which we will discuss in detail here. Taken ute to the analgesic effects of NSAIDs. together, it appears plausible that multiple mechanisms contribute to non-opioids’ therapeutic and adverse effects. Indeed COX-

independent mechanisms have been reported for the antiprolifera-

tive and antineoplastic effects of NSAIDs and coxibs [20, 21]. The *Address correspondence to this author at the Building 10, CRC, Room 2-1339, Na- present review will focus on the interaction of non-opioids with tional Institutes of Health, Bethesda, MD 20892, USA; Tel: 301-496-0294; Fax: 301- endocannabinoids, nitric oxide (NO) and monoaminergic and cho- 480-1413; E-mail: [email protected]

1874-4672/09 $55.00+.00 © 2009 Bentham Science Publishers Ltd. 2 Current Molecular Pharmacology, 2009, Vol. 2, No. 1 Hamza and Dionne linergic pathways in relation to their analgesic effect, and their ef- As shown in Fig. (1), the increase in endocannabinoids levels fect on IL-6 and MMPs regulation. following non-opioids treatment could be explained based on ei- ther: 1) the inhibition of their metabolism by FAAH; several non- ENDOCANNABINOID SYSTEM AND ITS RELATION TO opioids, including indomethacin, ibuprofen and flurbiprofen, inhibit NON-OPIOIDS the activity of FAAH [33-35], particularly at low pH [35-37], often a characteristic of the site of inflammation. 2) Inhibition of their Cannabinoids, including endogenous ones, have been impli- oxidative metabolism by COX-2; at least in vitro COX-2 can me- cated in the modulation of a large number of behavioral processes, tabolize AEA [30]. 3) Increase endocannabinoid synthesis as a including pain and inflammation [22, 23]. Anandamide (AEA), the result of shunting of free AA away from PG synthesis [38, 39]. 4) amide of arachidonic acid (AA) with ethanolamine and 2- In case of acetaminophen after being metabolized into N- arachidonyl glycerol (2-AG) are the most widely studied endocan- acylphenolamine (AM-404) in the brain and spinal cord, inhibition nabinoids, even though several other have been identified. The of the cellular uptake of AEA thus preventing its inactivation and synthesis, release and metabolism of endocannabinoids have been enhancing its potency [40]. 5)
nhibition of NO synthesis and thus discussed in detail elsewhere [24, 25]. Important targets in the me- inactivating the endocannabinoid transporter [41, 42]. tabolism of endocannabinoids are AEA membrane transporter In vivo studies support the involvement of endocannabinoids in (AMT), which facilitates the transport of AEA into the cells [26] to the analgesic and anti-inflammatory effects of non-opioids. The be hydrolyzed by fatty acid amidohydrolase enzyme (FAAH) [27, selective cannabinoid CB1 receptor (CB1) antagonist AM-251 an- 28]. AEA may also be metabolized by COX-2 and to a less extent tagonizes the antinociceptive activity of indomethacin in the mouse COX-1 into PGE2-ethanolamide. However, AEA is a significantly formalin test and zymosan-induced heat hyperalgesia [38] and that poorer substrate than AA for COX-2. 2-AG is selectively metabo- of flurbiprofen in the rat formalin test [39]. Other observations sup- lized by COX-2 at a much higher rate than AEA and the products of porting the role of endocannabinoids include: 1) failure of intrathe- its oxygenation closely parallel those for AA oxygenation [29, 30]. cal indomethacin to induce an antinociceptive effect in CB1- The involvement of endocannabinoids in the analgesic anti- receptor knockout mice [38]. 2) Both ibuprofen and rofecoxib in- inflammatory effects of non-opioids is suggested by both in vitro duce a synergistic antinociceptive effect when injected with AEA and in vivo evidence. In a macrophage cell line, indomethacin in- into the rat paw before the formalin test and CB1 and CB2 antago- duced AEA synthesis in the presence of a calcium ionophore [31]. nists completely antagonize their effects [32, 43]. 3) The 6-methyl- In vivo, ibuprofen and rofecoxib injected with AEA increased the pyridin-2-yl analogue of ibuprofen, which is equipotent as a COX levels of the endocannabinoids AEA, oleoylethanolamide and inhibitor yet more potent as FAAH inhibitor [44] was more effica- palmitoylethanolamide in inflamed paw tissues. Interestingly, cious than ibuprofen in the acetic acid writhing test [45]. 4) The higher levels were produced by rofecoxib. Paw level of AEA was CB1 receptor antagonists (AM-281 and SR141716A) prevent the also elevated non-significantly after injection of either ibuprofen or analgesic effects of acetaminophen in the hot plate test [46], and the rofecoxib alone. [32]. CB1 receptor antagonist AM-251 blocks the antinociceptive effect

Fig. (1). A hypothetical diagram of possible sites of interaction between non-opioids and the endocannabinoid system. Endocannabinoids including anan- damide are proposed to be released from the post-synaptic neurons upon depolarization, diffuse or actively transported via AMT (anandamide membrane transporter) to the presynaptic neuron and activate cannabinoid CB1-receptors. AMT, which is activated by nitric oxide (NO), is also responsible for the cellu- lar uptake of AEA where it is hydrolyzed by either FAAH (fatty acid amidohydrolase) into arachidonic acid (AA) and ethanolamine, or by cyclooxygenase 2

(COX2) into PGE2 ethanolamide. Non opioids are known to inhibit COX2 and some of them can inhibit FAAH. Non-opioids also modulate NO synthesis and AMT might be inhibited by acetaminophen. Finally, inhibition of COX might result in a shift of AA metabolism towards the synthesis of endocannabinoids. Mechanisms of Non-Opioid Analgesics Beyond Cyclooxygenase Current Molecular Pharmacology, 2009, Vol. 2, No. 1 3 of acetaminophen in the mouse formalin test
. Where not all studies acetaminophen possesses no binding affinity to any type of 5-HT show reversal of non-opioids antinociceptive effects after CB1 re- receptor or transporter [65], a direct effect on 5-HT receptors or ceptor blockade [47, 48], the discrepancy might be due to the dif- transporters is unlikely and the exact mechanism of acetaminophen ferences in pain models used. The preponderance of evidence is effects on 5-HT signaling is yet to be determined. Based on behav- strongly suggestive that endocannabinoids contribute to the analge- ioral studies using naloxone, activation of opiate receptors has been sic effects of non-opioids. suggested as a mechanism for increasing 5-HT levels, at least in the cerebral cortex and pons [66]. However, acetaminophen has little NON-OPIOIDS AND MONOAMINERGIC PATHWAYS affinity for opioid receptors [66]. The involvement of opiate recep- tors has been suggested also for ASA [50], diclofenac, indometha- The antinociceptive effects of non-opioids might also be related cin and sodium salicylates [67]. to their effects on the monoaminergic pathways, namely the The molecular mechanism underlying acetaminophen–induced noradrenergic and the serotonergic systems. analgesia via the serotonergic system was recently studied [68]. Acetaminophen modulated the expression of four genes in the lum- The Serotonergic System and its Relation to Non-Opioids bar enlargement of the rat spinal cord following the formalin test, The regulation of spinal nociceptive processing by serotonin (5- but not in naive rats. The gene and protein expression of the low- NTR HT) may induce facilitation or inhibition of nociception due to the affinity neurotrophin receptor (p75 ), insulin-like growth factor-1 different classes of 5-HT receptors and their location on facilitating receptor alpha subunit (IGF-1R
) and growth hormone receptor (primary afferent fibers, projection neurons, excitatory interneu- (GHR) were upregulated, while gene expression of the somatostatin rons) and attenuating (inhibitory interneurons) neurons in the super- 3 receptor (sst3R) was down-regulated. The changes in the gene expression of these four transcripts were dependent on spinal 5- ficial laminae of the spinal cord [49]. HT1A receptor stimulation, since they were completely blocked by The involvement of the serotonergic system in the antinocicep- WAY-100635. While a GHR antagonist partially reversed the anti- tive effects of non-opioids has been extensively studied. In rats, nociceptive effect of acetaminophen in the second phase, an IGF- ASA increases 5-HT content in the cerebral cortex and pons [50, 1R antagonist completely antagonized its effect in both phases im- 51], as does acetaminophen in the striatum, posterior cortex, hypo- plying that these cellular events are important for the antinocicep- thalamus, hippocampus and brain stem but not the spinal cord of tive activity of acetaminophen. Acetaminophen also increases the rats [52]; while rofecoxib increases 5-HT in the frontal cortex [53]. activity of both extracellular signal-regulated kinases 1 and 2 Lysine ASA increases concentrations of 5-hydroxyindole acetic (ERK1/2), an effect that was again blocked by the 5-HT1A receptor acid, in several areas of the brain in rats [54]. This increase in 5-HT antagonist WAY-100635. The down-regulation of sst3R mRNA levels is accompanied by down-regulation of 5-HT2 receptors ex- depends on an acetaminophen-induced 5-HT1A receptor dependent pression in several studies [50, 51, 53]. Furthermore, administration increase in neuronal ERK1/2 activities that mediate antinociception. of acetaminophen for 15 days results in a dose-dependent U0126, a specific inhibitor of mitogen-activated protein kinases 1/2 downregulation of the 5-HT2A receptor in the frontal cortex of rats. (MAPK1/2), which are kinases upstream of ERKs, totally pre- These effects were accompanied by an increase in 5-HT levels in vented the augmentation of phosphorylation and activities of platelets [55], which might reflect a parallel change in 5-HT level in ERK1/2 elicited by acetaminophen, and the down-regulation of the central nervous system [56]. sst3R mRNA. U0126 only partially blocks acetaminophen-induced The increase in 5-HT in acetaminophen-treated rats is not due antinociception in the formalin test. While further studies are to increased synthesis since quantitative determination of 5- needed to test the effect of other non-opioids on these targets, col- hydroxytryptophan accumulation after aromatic L-amino acid de- lectively these observations suggest that the antinociceptive activity carboxylase blockade showed no changes, nor does the increase in of non-opioids is mediated at least in part through interaction with 5-HT is due to blockade of its catabolizing enzyme, MAO A, as 5- the serotonergic system. hydroxyindoleacetic acid levels do not decrease concomitantly with the increases in 5-HT levels [52]. In vitro, acetaminophen exerts no Noradrenergic System and its Relation to Non-Opioids direct effect on MAO A activity. It increases K+-evoked [3H]5-HT overflow from slices of the posterior cortex, but not the striatum, The noradrenergic system is involved in nociception at spinal the brain stem or the hypothalamus, eliminating the possibility that and supraspinal levels. Its effects are mediated through activation of changes in 5-HT release/reuptake might account for the increased
-adrenoceptors and descending inhibitory pathways. At the spinal levels of 5-HT in these areas [52]. level, norepinephrine produces potent analgesia through activation of
2 adrenoceptors. It is likely that norepinephrine modulates noci- In vivo studies support the involvement of a central serotonergic ception via indirect control of the activity of other descending mechanism in the antinociceptive activity of non-opioids. Depletion pathways including histaminergic and serotonergic pathways [49, of central 5-HT antagonizes the antinociceptive activity of ASA, 69]. The role of
adrenoceptors subtypes in nociception is re- acetaminophen, diclofenac, ketoprofen, metamizol, acetaminophen, viewed in detail elsewhere [49]. piroxicam, meloxicam and rofecoxib in several pain models [53, 57-59]. Furthermore, the analgesic effect of ASA is enhanced by PGE2 causes a significant reduction of the stimulation-induced central administration of either 5-HT or its precursor 5- overflow from peripheral noradrenergic nerve terminals and a small hydroxytryptophan [57]. There is considerable controversy on iden- yet significant reduction from central noradrenergic nerve terminals tifying the role of different 5-HT receptor subtypes in the mecha- in vitro [70]. This action may contribute to the pronociceptive ef- nism of action of acetaminophen, e.g. [60-62]. Recently, Pickering fects of PGE2, and consequently, to the antinociceptive effect of et al. [63] reported the reversal of the analgesic effect of aceta- non-opioids. In-vivo studies support this hypothesis; both destruc- tion of bulbospinal noradrenergic projection neurons by intracere- minophen by the 5-HT3 antagonists, tropisetron or granisetron in a pain self-evaluation test based on the electrical stimulation of the broventricular injection of 6-hydroxy dopamine and intrathecal median nerve in man. At least in case of acetaminophen, central injection of phentolamine (a non selective
-adrenoceptor antago- serotonergic effects appears to be primarily supraspinal [64]. Since nist) prevents the pronociceptive effect of PGE2 and the antinoci- ceptive effect of indomethacin in the rat tail-flick and mechanical Randall-Selitto paw-withdrawal tests [71]. Similarly, the
2 adreno-
Hamza, M. Role of transient receptor potential vanilloid-1 (TRPV1) and cannabinoid ceptor antagonist yohimbine, but not the
1 adrenoceptor antagonist CB1 receptors in paracetamol induced antinociception and hypothermia in mice. prazosin antagonizes the antinociceptive effects of the non-opioids FASEB J. 2008, 22, 1125.11. 4 Current Molecular Pharmacology, 2009, Vol. 2, No. 1 Hamza and Dionne ketoprofen, diclofenac and piroxicam in the mouse tail flick test level NO plays an important role in the development and mainte- [72]. In addition, the
2 adrenoceptor antagonist atipamezole pre- nance of inflammatory hyperalgesia. Its role in the periphery is not vents the analgesic effects of systemic ketoprofen on mechanical as well studied [83, 84]. noxious stimulation in sheep [73]. Yohimbine, however, did not Non-opioids inhibit NO production in different clinical and ex- antagonize the antinociceptive effect of diclofenac in the mouse perimental studies. Ibuprofen (2400 mg p.o.) decreases alveolar NO writhing test [74], which might be due to the different nature of the flow rates and urinary excretion of nitrite and nitrate, in both endo- inflammatory stimulus and the predominant role of COX inhibition toxemic and normal subjects [85]. Similarly, ibuprofen-arginine as an anti-inflammatory mechanism in this model. In the same (400 mg) reduces NO metabolites in serum twenty minutes after model, systemic combination of
1- and
2-adrenoceptor agonists oral intake [86]. In spinally microdialyzed mice, indomethacin re- (phenylephrine and clonidine, respectively) with diclofenac or ke- duces NO metabolites in dialysate [38]. The inhibitory effect of toprofen showed a synergistic antinociceptive effect, suggesting indomethacin on NO production and or iNOS induction was re- that they induce antinociception by activating different mechanisms ported in several other studies [87-89]. Acetaminophen also inhibits (COX inhibition and
2-adrenoceptor activation). On the other NO synthesis in murine spinal cord slices [90]. In RAW 264.7 hand, intrathecal administration of the same drug combinations macrophages, acetaminophen, ASA and sodium salicylate inhibits resulted in an additive rather than synergistic interaction [74, 75]. NO production and iNOS protein expression in a dose dependent Similarly, the concurrent intraperitoneal administration of clonidine manner. Further, acetaminophen inhibits iNOS mRNA expression with metamizol, nimesulide, acetaminophen, piroxicam or [91]. Although the main body of evidence supports the inhibitory naproxen results in synergistic interactions. The intrathecal effect of ASA on NO synthesis, sporadic studies suggest a stimula- administration of these combinations, however, resulted in an tory role e.g. [92, 93]. The discrepancies could be explained additive interaction [76]. Taken together, these data clearly point based on the difference of cell types and/or inflammatory model. to an interaction between non-opioids and the adrenergic system. Non-opioids may activate supraspinal mechanisms that indirectly PG inhibition does not seem to contribute to this inhibitory cause descending inhibitory influences on the spinal transmission of process, since the effect of different non-opioids varies under the nociceptive inputs [71-73], beside their COX inhibitory action. same experimental setting. For example, therapeutic concentrations of ASA, but not indomethacin inhibits the protein expression of CHOLINERGIC SYSTEM AND ITS RELATION TO NON- iNOS and the production of nitrite in lipopolysaccharide (LPS) OPIOIDS activated RAW 264.7 murine macrophages, while only ASA inhib- its the catalytic activity of iNOS in cell free extracts [94]. Likewise,

Acetylcholine in the dorsal horn of the spinal cord is released ASA, but not indomethacin or acetaminophen inhibits cytokine- from both intrinsic neurons and supraspinal structures. Possible induced nitrite production in cardiac fibroblasts [95]. Furthermore, cholinergic mechanisms of antinociception may include the activa- there was no significant difference between the S- and R- pure tion of non-cholinergic descending inhibitory pathways, mediation enantiomers of flurbiprofen and ketoprofen as regards the reduction of descending inhibition following its own release from descending of NO release from IL-1 stimulated human chondrocytes [96], and pathways and the induction of antinociception following release exogenous PGE2 did not reverse the inhibitory effects of celecoxib from inhibitory interneurons in the dorsal horn. Pharmacological on NO production by activated human articular chondrocytes [97]. studies have suggested that antinociceptive effects of acetylcho- Ryu et al. [91] suggests that acetaminophen inhibits iNOS ex- line in the dorsal horn are mediated through both nicotinic and pression at the transcriptional level by suppression of nuclear factor muscarinic receptors. The mechanism of this analgesia, however, is kappa B (NF-B) binding activity, whereas salicylates exerts their not well defined as nicotinic receptor activation at the spinal level effects by inhibiting iNOS expression at the translational or post- may affect several modulatory transmitters including inhibitory translational level [94]. NF-B expression is one of the integral amino acids, norepinephrine and serotonin [49, 69]. contributors to iNOS transcription and expression [98]. LPS or ASA administered subcutaneously, but not spinally, increases cytokines were shown to activate the phosphatidyinositol 3- intraspinal acetylcholine release in anesthetized rats [77], which kinase/Akt (PI3K-Akt) pathway, which in turn activates the NF-B might contribute to its analgesic activity. In line with that, choliner- pathway, and results in upregulation of iNOS expression in vascular gic depletion by intracerebroventricular hemicholinium-3 or sys- smooth muscle cells [99]. In human articular chondrocytes, NO temic administration of the muscarinic antagonist atropine antago- production is mediated via NF-B, Jun NH2-terminal kinase (JNK) nizes the antinociceptive effect of both intraperitoneally and in- and p38, with celecoxib inactivating NF-B and JNK [97]. Simi- trathecally administered clonixin, diclofenac, piroxicam, ketoprofen larly, acetaminophen inhibits NF-B binding to the promoter region and meloxicam in the mouse tail flick test [78]. In support of the of the iNOS gene [91]. Since non-opioids regulate NF-B, JNK, above theory, the cholinergic agonist carbachol shows a synergistic p38 and Akt [100], this might represent the molecular mechanism antinociceptive effect in the acetic acid writhing test when co- by which they regulate iNOS expression. injected intraperitoneally with meloxicam, diclofenac, piroxicam or In agreement with the pronociceptive role of NO at the spinal ketoprofen. Intrathecal administration, however, shows only an level and the inhibitory effect of acetaminophen on its production, additive effect [79]. These studies point to a possible role for cen- L-arginine, but not D-arginine, antagonizes the antinociceptive tral cholinergic modulation of the antinociceptive effects of non- effect of acetaminophen in NMDA and substance P-induced noci- opioids, yet further investigations are needed to identify and local- ception, suggesting that the analgesic effect of acetaminophen is ize the exact mechanism of this modulation. related to inhibition of NO generation [101]. Further, intrathecal treatment with LG-nitro-L-arginine, a non-selective NOS inhibitor, NON-OPIOIDS AND NITRIC OXIDE or with 7-nitroindazole, a selective nNOS inhibitor, potentiates the antinociceptive activity of submaximal doses of acetaminophen in NO has been recognized as an important intra- and intercellular Randall-Selitto and writhing tests [102]. In the periphery, however, messenger molecule in the central nervous system [80]. Its release the picture is not as clear. Several studies show inhibition of the depends on its synthetic enzyme, nitric oxide synthase (NOS), antinociceptive effects of non-opioids by local administration of L- which exist in three isoenzymes termed NOSs [81] and many of its NAME in inflammatory pain models, including ketorolac, dipyrone effects are mediated by cyclic guanosine monophosphate (cGMP) [103], indomethacin [104], rofecoxib [105], nimesulide [106], [82]. NO is implicated in many physiological and pathological meloxicam [107] and lumiracoxib [108]. These effects range from processes including nociception, inflammation and regulating the partial inhibition to complete reversal of the analgesic activity of contractile activity of vascular smooth muscle cells. At the spinal Mechanisms of Non-Opioid Analgesics Beyond Cyclooxygenase Current Molecular Pharmacology, 2009, Vol. 2, No. 1 5 the non-opioids used. However, in all these studies the dose of L- methacin on IL-6 gene expression in human dental pulp cells [127] NAME used did not have any effect on the nociceptive threshold. and in IL-1-stimulated human gingival fibroblasts [120]. This The controversy might be due to type and intensity of the noxious could explain the variable effects of non-opioids in different in- stimuli, rat strain and the dose or concentration reached at the active flammatory models, since IL-6 production is differentially modu- site [108]. The contradictory roles NO plays in nociception [109, lated by PG receptor agonists: in IL-1 stimulated human gingival 110] might contribute to this complexity. fibroblasts, a selective EP2 agonist, butaprost, inhibited IL-6 pro- In vascular endothelium, ASA elicits NO release by direct ace- duction in a concentration dependent manner, while 17-phenyl-- tylation of the eNOS protein. This effect is independent of COX trinor PGE2, a selective EP1 agonist, upregulated IL-6 production inhibition [111]. Further studies are needed to elucidate the effect of [120]. Different roles of PGE2 receptor subtypes was also seen in different non-opioids on the NO/cGMP pathway in vessels, as this human periodontal ligament cells [119], murine bone marrow may be one of the mechanisms of cardiovascular adverse effects denderitic cells [126] and in RAW 264.7 macrophages [128]. It is recently associated with the use of this group of drugs. therefore suggested that PGE2 induces variable regulatory effects on IL-6 production through different subtypes of EP receptors, the NON-OPIOIDS AND IL-6 selectivity of which depends on expression of EP subtypes of PGE2 receptors [119, 120]. IL-6 is a pleiotropic cytokine that modulates a variety of EP2 and EP4 are G-protein-coupled receptors that activate physiological functions including cell proliferation, differentiation, adenylyl cyclase upon ligand binding and result in increased cyclic survival, inflammation and apoptosis. IL-6 gene transcripts are adenosine monophosphate (cAMP) levels, while EP1 receptor acti- expressed in human atherosclerotic lesions [112] and circulating IL- vation results in an increase in intracellular calcium levels [129]. In 6 levels may predict the risk of future cardiovascular events [113, cloned osteoblast-like MC3T3-E1 cells, PGE2 stimulates IL-6 syn- 114]. With the recent recognition of the cardiovascular adverse thesis through Ca2+ mobilization from the extracellular space via events of non-opioids, their relation to IL-6 becomes of special EP1 receptors [130]. The effect of cAMP on IL-6 production varies interest. between studies [119, 120, 131]. Many non-opioids also affect We recently reported an increase in gene and protein expression cAMP level, but different studies show varying results [132-134]. of IL-6 in response to both rofecoxib and ibuprofen in the oral mu- We have recently reported downregulation of gene and protein cosa, after tissue injury and 48 hours of acute inflammation in the expression of phosphodiesterase type IV (PDE4D) enzyme by ro- oral surgery model [18]. As seen in Table (1), the effect of non- fecoxib and ketorolac in oral mucosal biopsies, 3 hours after third opioids vary remarkably in a variety of inflammatory models and at molar tooth extraction [135]. Fig. (2) summarizes the possible sites different time points; some non-opioids even induce variable effects of interactions between non-opioids and IL-6 regulatory pathways. on IL-6 production in the same experimental setting [115, 116]. Not NF-B, also plays an important role in the upregulation of IL-6 only the drug used, but the sample tested could contribute to these in response to several inflammatory mediators [136, 137]. It is discrepancies. In a clinically relevant rat model of polymicrobial known that different non-opioids produce variable effects on the peritonitis and sepsis, induced by cecal ligation and puncture, the activation of NF-B; for review see [100]. A binding site for tran- levels of IL-6 were significantly higher in ascetic fluid than in cir- scription factor NF-B is present in the 5’ promoter region of the culating blood both after 6 and 24 hours, a finding that may indicate IL-6 gene [138]. NF-B inhibition lowers peptidoglycan- and more activity at the local site of inflammation and infection than PGE2-induced IL-6 production in RAW 264.7 macrophages and systemically [116]. The same finding was reported in a clinical IKK
-dependent NF-B activation occurs downstream of the sig- setting [117]. naling pathway of COX-2-generated PGE2 and PKA activation The effect of non-opioids on IL-6 production could be due to stimulated by peptidoglycan [128]. In the same study, the selective inhibition of PGs synthesis. The regulatory effect of PGE2 on IL-6 COX-2 inhibitor, NS398, inhibited the peptidoglycan-induced NF- has been reported in many studies e.g. [119, 120, 126, 127]. Fur- B-specific DNA protein complex formation from 2–12 h of treat- thermore, exogenous PGE2 reverses the stimulatory effect of indo- ment, but not in the first 60 min, suggesting that NF-B activation

Table 1. Effect of Different Non-Opioids on IL-6 Expression

Drug Duration Effect Biomarker Model Ref.

Rofecoxib (50 mg) Gene & protein expression in oral Acute inflammation following oral 48 hours Elevated [18] mucosal biopsies surgery Ibuprofen (1600 mg) Ibuprofen (600 &1200 mg) 48 hours Elevated Protein level in serum Athletes competing in a 160-km race [118] Stimulated human gingival fibroblast Indomethacin (1μ
) 25 hours Elevated Protein level in the supernatant [119, 120] and human periodontal ligament cells Protein level in the supernatant and IL-1 stimulated human chondrocytes Rofecoxib & piroxicam 12 days No change [115] cellular matrix cultured in alginate beads Indomethacin (75 mg/d) 5 days Lowered Protein level in serum 2-h of experimental exercise [121]

1 week [122] Rofecoxib (25 mg) 1 month, but not Patients with acute coronary event, Lowered Protein level in serum [123] at 3 months taking aspirin 6 months [124] Oncostatin and IL-1
stimulated hu- Indomethacin (1 μ
) 18 hours Lowered Gene expression level [125] man lung or synovial fibroblasts Aceclofenac, sodium diclofenac, Protein levels in the supernatant, and IL-1 stimulated human chondrocytes indomethacin, nimesulide, cele- 12 days Lowered [115] cellular matrix cultured in alginate beads coxib and ibuprofen 6 Current Molecular Pharmacology, 2009, Vol. 2, No. 1 Hamza and Dionne

Fig. (2). A hypothetical diagram of possible sites of action of non-opioids in the regulatory pathway of IL-6. IL-6 binds to IL-6 receptor forming a hexadimer with intracellular gp-130 molecule. This activates (phosphorylates) JAK-1 (Janus kinase 1), which leads to the phosphorylation of gp-130 and subsequently the activation of STAT1 and STAT 3 (signal transducers and activators of transcription). The activation of this signaling cascade results in the induction of

SOCS3 formation that ultimately inhibits the signaling transduction of IL-6. PGE2 via EP2 and EP4 receptors activates adenylyl cyclase leading to the forma- tion of cAMP that activates (protein kinase A) PKA and subsequently NFkB (nuclear factor kappa B). NFB activation results in further IL-6 expression and it also interferes with activation of STAT. Non-opioids interfere with synthesis of PGE2, the degradation of c-AMP and also regulates SOCS 3and NFB. It should be noted that non-opioids have different effects on these targets in different cells and under different experimental conditions.

may be PGE2/cAMP dependent [128]. Furthermore, activation of COX-2 seems to have a key role in the signaling pathway leading to NF-B blocks IL-6-induced late phase STAT3 activation in Mock- increased proteinase expression [155]. transfected HepG2 cells [139]. We also reported an increase in gene and protein expression of Possible Factors Contributing to Non-Opioids Effects on MMPs SOCS3 in response to both rofecoxib and ibuprofen in the oral mu- Inhibition of PGs Synthesis cosa, 48 hours after tissue injury and acute inflammation in the oral surgery model [18]. To our knowledge, the effect of other non- Accumulating data have revealed that PGs are involved in the opioids on the expression of SOCS3 has not been reported. Over regulation of MMP pathways in various cell types [156, 157]. The expression of SOCS3 blocks the proinflammatory effects of IL-6 use of selective EP receptors subtypes agonists and antagonists, signaling through gp130 [140, 141]. Thus, even if non-opioids un- however, do not show a consistent pattern for the role of each sub- type [158-160]. How much inhibition of PGE production contrib- der certain conditions might upregulate IL-6 production, an accom- 2 panying over expression of SOCS3 might in fact block its proin- utes to the final effect of non-opioid analgesics on MMP production is far from clear, particularly considering the differential effects of flammatory effects. non-opioid analgesics on MMPs. The variable response to different non-opioid analgesics on MMP-1 and MMP-3 production in bovine NON-OPIOIDS AND MATRIX METALLOPROTEINASES chondrocytes cultured in alginate gel beads [161] argues against the possibility of a common mode of action. The use of the pure enan- The matrix metalloproteinases (MMPs) are a family of enzymes tiomers of flurbiprofen and ketoprofen can help answer this ques- that cleave the various components of the extracellular matrix. tion, since the S-enantiomer inhibits PGE synthesis, while the R- MMPs are activated by tissue plasminogen activator (tPA)/plasmin, 2 enantiomer is devoid of this property. Panico et al. [96] showed in and are inactivated by their endogenous protein inhibitors, tissue human chondrocytes that S-flurbiprofen and S-ketoprofen inhibits inhibitors of metalloproteinases (TIMPs). The dynamic interaction IL-1
induced MMP-3 production to a greater extent than R- between MMPs and their endogenous inhibitors, the TIMPs, deter- flurbiprofen and R-ketoprofen. However, R-flurbiprofen and R- mine their overall activity (for review, see [142, 143]). MMPs can ketoprofen significantly inhibited IL-1
induced MMP-3 produc- be both pro-inflammatory and anti-inflammatory and the same tion, suggesting that inhibition of PGE2 production, though partici- MMP might have opposite roles in different conditions. They con- pating in this process, is not the sole player. The ability of exoge- tribute to the vulnerability of atherosclerotic plaques [144], which nous PGE2 to reverse the effect of COX-inhibitors on MMPs shows on rupture could be a predisposing factor to acute coronary syn- variable results [146, 162-165]. Thus it is likely that the effects of drome. This adds to the importance of their relation to non-opioids. non-opioid analgesics on MMPs are both PG dependent and inde- As seen in Table (2) non-opioids have different effects on pendent. It is suggested that the PGE2 requirement in MMP synthe- MMPs and TIMPs in different inflammatory models. Both COX-1 sis may vary with different cell types as well as duration of expo- and COX-2 seem to be involved in MMP-9 induction [155], though sure [163]. Mechanisms of Non-Opioid Analgesics Beyond Cyclooxygenase Current Molecular Pharmacology, 2009, Vol. 2, No. 1 7

Table 2. Effect of Different Non Opioids on MMPs 1,2,3,9 and TIMPs 1,3

Non-opioids Time Point Effect Clinical Condition or Inflammatory Model Biomarker Ref.

MMP-1 Rofecoxib, ibuprofen 48 hrs  Acute inflammation following oral surgery Gene expression [19] IL-1 stimulated chondrocytes or unstimulated chondro- Celecoxib 48 hrs NC Protein in supernatant [145] cytes from arthritic patients LPS-stimulated or LPS- plus H O -stimulated human Protein expression in super- Indomethacin (20 μM) 48 hrs  2 2 [146] primary monocytes natant MMP-2 Activity and protein expres- ASA (500 mg) 1 hr NC Activated platelets in vivo in humans sion in plasma from blood of a [147] skin wound

Human umbilical vein endothelial cells Protein expression in culture ASA (0.1 mM) 1-4 days  [148] media and activity Diclofenac sodium, nimesulide, celecoxib, Articular cartilage, meniscus and synovium of os- 4 days  Activity [149] valdecoxib, rofecoxib and teoarthritis patients etoricoxib MMP3 Rofecoxib, ibuprofen 48 hrs  Acute inflammation following oral surgery Gene expression [19] Nimesulide (200 mg)  28 days Patients with osteoarthritis Protein expression in serum [150] Ibuprofen (1200 mg)  IL-1 stimulated chondrocytes or unstimulated chondro- Celecoxib 48 hs NC Protein in supernatant [145] cytes from arthritic patients MMP-9 Indomethacin (10 mg/kg) 24 hrs  TNF-
-induced neuroinflammation in rat Protein expression and activity [151] Protein expression in culture ASA (0.1 mM) 1-4 days  Human umbilical vein endothelial cells [148] media and activity Indomethacin (1 μM) 24 hrs NC Human cultured monocytes Protein expression [152] TIMP1 Nimesulide (200 mg), 28 days NC Patients with osteoarthritis Protein expression in serum [150] ibuprofen (1200 mg) Indomethacin (10 μM) 24 hours  Cytokine stimulated pulp fibroblast Gene expression [153] Indomethacin & di- 72 hours  Synovial fibroblasts from rheumatoid arthritis patients Protein expression [154] clofenac (0.1-10 μM) TIMP3 Rofecoxib (50 mg) 48 hrs  Acute inflammation following oral surgery Gene expression [19]

Transcriptional Regulation of MMPs NF-B [100]. (3) Non-opioids inhibit AP-1 activation by different The molecular mechanisms of MMP regulation have been ex- stimuli [100]. The inhibition of AP-1 activation together with inhi- tensively studied (for review see [166, 167]). Cytokines are key bition of NF-B by ASA and sodium salicylate results in reduction regulators of MMP expression, and the concentrations and combi- of MMP-9 levels [176]. nations of cytokines may determine the extent of matrix degrada- MMP Activators and Inhibitors tion [168]. Different cytokines may lead to the activation of at least As mentioned earlier MMPs are activated by tPA/plasmin, and are one of the MAPK pathways (ERK1/2, JNK, and p38 MAPK), inactivated by TIMPs. Therefore, affecting any of these activators which may result in upregulation of secondary mediators such as or inhibitors would alter the activity of MMPs (Fig. 4). In bovine IL-6 or PGE2 that contribute to the upregulation of MMP-1 and articular chondrocytes, ASA, diclofenac, indomethacin, meloxicam, MMP-3 expression [169]. Translocation of activated MAPKs to the naproxen, and tiaprofenic acid dose dependently inhibited the gne nucleus results in phosphorylation of the components of activator expression of tPA. However, only indomethacin and tiaprofenic protein 1 (AP-1) [170]. The interplay between different transcrip- acid reduced the expression of uPA [161]. The effect of non-opioids tion factors contributes to the control of MMP expression. The NF- on plasminogen activators was reported in other studies including B pathway also contributes to the regulation of MMP-1, -3, -9 and [149, 177, 178]. TIMPs, on the other hand, have been extensively -11 expression [167, 171]. studied; a few examples of the effect of non-opioids on TIMPs are The interaction of non-opioids with the MMP regulatory path- shown in Table (2). way is expected at different levels (Fig. 3). (1) Non-opioids are IL-8 and Monocyte Chemoattractant Protein-1 (MCP-1) known to differentially affect cytokine expression, including TNF-
, IL-1 and IL-6, all of which are major regulators of MMP expres- IL-8 is another target for non-opioids that may affect the overall sion [18, 172-175]. (2) They regulate different MAPKs as well as activity of MMPs. IL-8 downregulates TIMP-1 expression in cho- lesterol-loaded human macrophages [179], and induces the gene 8 Current Molecular Pharmacology, 2009, Vol. 2, No. 1 Hamza and Dionne

Fig. (3). A hypothetical diagram of possible sites of action of non-opioids in the regulatory pathway of MMPs. TNF-
and IL-1 activates the MAPKs ERK1/2, p38, and JNK, which results in phosphorylation of the components of AP-1, and the upregulation of MMPs. Activation of MAPKs also may result in upregula- tion of secondary mediators such as, IL-6 or PGE2. IL-6 via the JAK/STAT pathway may upregulate MMPs. PGE2 via EP4 receptors activates adenylyl cyclase leading to the formation of cAMP that interfere with the activation of ERK. NFB is also involved in the regulation of MMPs expression. Non-opioids interfere with synthesis of PGE2, the degradation of c-AMP and also regulate various cytokines. They regulate AP-1, NFB and MAPKs. It should be noted that non- opioids have different effects on these targets in different cells and under different experimental conditions.

Fig. (4). A hypothetical diagram of possible regulatory mechanisms of non-opioids on MMPs. It should be noted that non-opioids have different effects on these targets in different cells and under different experimental conditions. Abbreviations: NO, nitric oxide; IL-6, Interleukin-6; MCP-1, Monocyte Chemoat- tractant Protein-1; MMPs, matrix metalloproteinases; SOCS3, suppressor of cytokine signaling 3; IL-8, Interleukin-8; IL-1, Interleukin-1; PGE2, prostaglandin

E2; TIMPs, tissue inhibitors of metalloproteinases; t-PA, tissue plasminogen activator; u-PA, urokinase; TNF
, tumor necrosis factor
. Mechanisms of Non-Opioid Analgesics Beyond Cyclooxygenase Current Molecular Pharmacology, 2009, Vol. 2, No. 1 9

Fig. (5). Possible targets that contribute to the analgesic effects, anti-inflammatory action or adverse effects of non-opioids in the central nervous system, the peripheral sites of inflammation or the blood vessels. expression of MMP-2 and MMP-9 in cultured neurons [180] and in preciated alternatives to a unitary COX-inhibition hypothesis may tumor cells [181]. Again, IL-8 is differentially regulated by non- form the basis for the development of new analgesics and anti- opioids [19, 182]. inflammatory medications with more favorable safety profiles. MCP-1 also causes an increase in MMP-1 in cytokine stimu- lated monocytes [183], and MMP-9 secretion by primary isolated ACKNOWLEDGMENTS rat brain microglia in vitro [184] and non-opioids differentially modulate the expression of MCP-1 [18, 185, 186]. This work was supported by Division of Intramural Research, NINR/NIH. Nitric Oxide The modulatory role of NO on MMPs and TIMP expression ABBREVIATIONS and/or activity has been shown in rat aortic smooth muscle cells [187], rat primary astrocytes [188] and murine macrophages [189]. 2-AG = 2-Arachidonyl glycerol Since non-opioids modulate NO synthesis (as discussed earlier), 5-HT = 5-Hydroxy treptamine (serotonin) this may represent another mechanism by which non-opioids regu- late MMP production and activity. AA = Arachidonic acid Mechanical Regulation of MMPs AEA = Arachidonoylethanolamide (anandamide) MMPs are regulated by changes in mechanical forces applied to AP-1 = Activator protein 1 tissues (for review see [190]). NSAIDs are known to increase blood ASA = Acetylsalicylic acid (aspirin) pressure [191], and acetaminophen was reported to have the same cAMP = Cyclic adenosine monophosphate effect [192, 193]. Thus, non-opioids might upregulate vascular production of MMPs by elevating blood pressure. CB1 = Cannabinoid CB1 receptor cGMP = Cyclic guanosine monophosphate CONCLUDING REMARKS AND FUTURE DIRECTIONS COX = Cyclooxygenase enzyme Inhibition of eicosanoids synthesis represents an important as- EP = Prostaglandin E receptor pect of non-opioid action, yet accumulating data points to several ERK1/2 = Extracellular signal-regulated kinases 1 and 2 other targets (reviewed here) that contribute either to their analgesic effects, anti-inflammatory actions or to their adverse effects (Fig. FAAH = Fatty acid amidohydrolase enzyme 5). The interaction between non-opioids and these targets can be GHR = Growth hormone receptor prostanoid-dependent or independent, and in many cases these mechanisms are interactive. The studies cited in this review demon- IL = Interleukin strate the wide variability in response to non-opioids in a variety of IL-6R = Interleukin-6 receptor cells and tissues under different experimental conditions. These JNK = Jun NH -terminal kinase observations suggest that except for a common action as COX in- 2 hibitors, these drugs have diverse pharmacological actions making MAPK = Mitogen-activated protein kinase it problematic to consider them as a single group. While these dis- MCP-1 = Monocyte chemoattractant protein-1 crepant observations prevent generalization about which mecha- nisms predominate in the action of non-opioids, these recently ap- MMPs = Matrix metalloproteinases 10 Current Molecular Pharmacology, 2009, Vol. 2, No. 1 Hamza and Dionne

NF-B = Nuclear factor kappa B inflammatory Drugs, Acetaminophen, and the Risk of Cardiovascular Events. Circulation 2006, 113, 1578-1587. NO = Nitric oxide [18] Wang, X. M.; Wu, T. X.; Hamza, M.; Ramsay, E. S.; Wahl, S. M.; Dionne, R. A. Rofecoxib modulates multiple gene expression pathways in a clinical NOS = Nitric oxide synthase model of acute inflammatory pain. Pain 2007, 128, 136-147. NSAIDs = Non-steroidal anti-inflammatory drugs [19] Wang, X. M.; Wu, T. X.; Lee, Y. S.; Dionne, R. A. Rofecoxib regulates the expression of genes related to the matrix metalloproteinase pathway in hu- PG = Prostaglandin mans: implication for the adverse effects of cyclooxygenase-2 inhibitors. Clin. Pharmacol. Ther. 2006, 79, 303-315. PI3K-Akt = Phosphatidylinositol 3-kinase/Akt [20] Grosch, S.; Maier, T. J.; Schiffmann, S.; Geisslinger, G. Cyclooxygenase-2 (COX-2)-independent anticarcinogenic effects of selective COX-2 inhibitors. PKA = Protein kinase A J. Natl. Cancer Inst. 2006, 98, 736-747. SOCS3 = Suppressor of cytokine signaling 3 [21] Scheper, M. A.; Sauk, J. J.; Nikitakis, N. G. COX-independent antineoplastic effects of sulindac in oral cancer are mediated by survivin down-regulation. sst3R = Somatostatin 3 receptor Anticancer Res. 2006, 26, 4103-4113. [22] Calignano, A.; La Rana, G.; Giuffrida, A.; Piomelli, D. Control of pain STAT = Signal transducers and activators of transcription initiation by endogenous cannabinoids. Nature 1998, 394, 277-281. [23] Richardson, J. D.; Kilo, S.; Hargreaves, K. M. Cannabinoids reduce hyperal- TIMPs = Tissue inhibitors of metalloproteinases gesia and inflammation via interaction with peripheral CB1 receptors. Pain TNF
= Tumor necrosis factor
1998, 75, 111-119. [24] Di Marzo, V.; De Petrocellis, L.; Bisogno, T. The biosynthesis, fate and t-PA = Tissue plasminogen activator pharmacological properties of endocannabinoids. Handb. Exp. Pharmacol. 2005, 147-185. u-PA = Urokinase [25] Bisogno, T.; Ligresti, A.; Di Marzo, V. The endocannabinoid signalling system: biochemical aspects. Pharmacol. Biochem. Behav. 2005, 81, 224- 238. REFERENCES [26] Beltramo, M.; Stella, N.; Calignano, A.; Lin, S. Y.; Makriyannis, A.;

TM Piomelli, D. Functional role of high-affinity anandamide transport, as re- [1] IMS Health, IMS National Sales Perspectives , 2/2005. vealed by selective inhibition. Science 1997, 277, 1094-1097. [2] Gordon, S. M.; Brahim, J. S.; Rowan, J.; Kent, A.; Dionne, R. A. Peripheral [27] Cravatt, B. F.; Giang, D. K.; Mayfield, S. P.; Boger, D. L.; Lerner, R. A.; prostanoid levels and nonsteroidal anti-inflammatory drug analgesia: repli- Gilula, N. B. Molecular characterization of an enzyme that degrades neuro- cate clinical trials in a tissue injury model. Clin. Pharmacol. Ther. 2002, 72, modulatory fatty-acid amides. Nature 1996, 384, 83-87. 175-183. [28] Fowler, C. J.; Jonsson, K. O.; Tiger, G. Fatty acid amide hydrolase: biochem- [3] Khan, A. A.; Brahim, J. S.; Rowan, J. S.; Dionne, R. A. In vivo selectivity of istry, pharmacology, and therapeutic possibilities for an enzyme hydrolyzing a selective cyclooxygenase 2 inhibitor in the oral surgery model. Clin. Phar- anandamide, 2-arachidonoylglycerol, palmitoylethanolamide, and oleamide. macol. Ther. 2002, 72, 44-49. Biochem. Pharmacol. 2001, 62, 517-526. [4] Lee, Y. S.; Kim, H.; Brahim, J. S.; Rowan, J.; Lee, G.; Dionne, R. A. Aceta- [29] Fowler, C. J. The contribution of cyclooxygenase-2 to endocannabinoid minophen selectively suppresses peripheral prostaglandin E2 release and in- metabolism and action. Br. J. Pharmacol. 2007, 152, 594-601. creases COX-2 gene expression in a clinical model of acute inflammation. [30] Kozak, K. R.; Prusakiewicz, J. J.; Marnett, L. J. Oxidative metabolism of Pain 2007, 129, 279-286. endocannabinoids by COX-2. Curr. Pharm. Des. 2004, 10, 659-667. [5] Rosenkranz, B.; Fischer, C.; Meese, C. O.; Frolich, J. C. Effects of salicylic [31] Pestonjamasp, V. K.; Burstein, S. H. Anandamide synthesis is induced by and acetylsalicylic acid alone and in combination on platelet aggregation and arachidonate mobilizing agonists in cells of the immune system. Biochim. prostanoid synthesis in man. Br. J. Clin. Pharmacol. 1986, 21, 309-317. Biophys. Acta. 1998, 1394, 249-260. [6] Mitchell, J. A.; Akarasereenont, P.; Thiemermann, C.; Flower, R. J.; Vane, J. [32] Guindon, J.; Loverme, J.; De Lean, A.; Piomelli, D.; Beaulieu, P. Synergistic R. Selectivity of nonsteroidal antiinflammatory drugs as inhibitors of consti- antinociceptive effects of anandamide, an endocannabinoid, and nonsteroidal tutive and inducible cyclooxygenase. Proc. Natl. Acad. Sci. USA 1993, 90, anti-inflammatory drugs in peripheral tissue: a role for endogenous fatty-acid 11693-11697. ethanolamides? Eur. J. Pharmacol. 2006, 550, 68-77. [7] Preston, S. J.; Arnold, M. H.; Beller, E. M.; Brooks, P. M.; Buchanan, W. W. [33] Fowler, C. J.; Tiger, G.; Stenstrom, A. Ibuprofen inhibits rat brain deamida- Comparative analgesic and anti-inflammatory properties of sodium salicylate tion of anandamide at pharmacologically relevant concentrations. Mode of and acetylsalicylic acid (aspirin) in rheumatoid arthritis. Br. J. Clin. Pharma- inhibition and structure-activity relationship. J. Pharmacol. Exp. Ther. 1997, col. 1989, 27, 607-611. 283, 729-734. [8] Brune, K.; Beck, W. S.; Geisslinger, G.; Menzel-Soglowek, S.; Peskar, B. [34] Fowler, C. J.; Janson, U.; Johnson, R. M.; Wahlstrom, G.; Stenstrom, A.; M.; Peskar, B. A. Aspirin-like drugs may block pain independently of pros- Norstrom, K.; Tiger, G. Inhibition of anandamide hydrolysis by the enanti- taglandin synthesis inhibition. Experientia 1991, 47, 257-261. omers of ibuprofen, ketorolac, and flurbiprofen. Arch. Biochem. Biophys. [9] Mccormack, K.; Brune, K. Dissociation between the antinociceptive and 1999, 362, 191-196. anti-inflammatory effects of the nonsteroidal anti-inflammatory drugs. A [35] Fowler, C. J.; Holt, S.; Tiger, G. Acidic nonsteroidal anti-inflammatory drugs survey of their analgesic efficacy. Drugs 1991, 41, 533-547. inhibit rat brain fatty acid amide hydrolase in a pH-dependent manner. J. En- [10] Graham, D. J.; Campen, D.; Hui, R.; Spence, M.; Cheetham, C.; Levy, G.; zyme Inhib. Med. Chem. 2003, 18, 55-58. Shoor, S.; Ray, W. A. Risk of acute myocardial infarction and sudden car- [36] Holt, S.; Fowler, C. J. Anandamide metabolism by fatty acid amide hydro- diac death in patients treated with cyclo-oxygenase 2 selective and non- lase in intact C6 glioma cells. Increased sensitivity to inhibition by ibuprofen selective non-steroidal anti-inflammatory drugs: nested case-control study. and flurbiprofen upon reduction of extra- but not intracellular pH. Naunyn Lancet 2005, 365, 475-481. Schmiedebergs Arch. Pharmacol. 2003, 367, 237-244. [11] Mukherjee, D.; Nissen, S. E.; Topol, E. J. Risk of cardiovascular events [37] Holt, S.; Nilsson, J.; Omeir, R.; Tiger, G.; Fowler, C. J. Effects of pH on the associated with selective COX-2 inhibitors. JAMA 2001, 286, 954-959. inhibition of fatty acid amidohydrolase by ibuprofen. Br. J. Pharmacol. [12] Mitchell, J. A.; Warner, T. D. COX isoforms in the cardiovascular system: 2001, 133, 513-520. understanding the activities of non-steroidal anti-inflammatory drugs. Nat. [38] Gühring, H.; Hamza, M.; Sergejeva, M.; Ates, M.; Kotalla, C. E.; Ledent, C.; Rev. Drug Discov. 2006, 5, 75-86. Brune, K. A role for endocannabinoids in indomethacin-induced spinal anti- [13] Verma, S.; Raj, S. R.; Shewchuk, L.; Mather, K. J.; Anderson, T. J. Cy- nociception. Eur. J. Pharmacol. 2002, 454, 153-163. clooxygenase-2 blockade does not impair endothelial vasodilator function in [39] Ates, M.; Hamza, M.; Seidel, K.; Kotalla, C. E.; Ledent, C.; Gühring, H. healthy volunteers: randomized evaluation of rofecoxib versus naproxen on Intrathecally applied flurbiprofen produces an endocannabinoid-dependent endothelium-dependent vasodilatation. Circulation 2001, 104, 2879-2882. antinociception in the rat formalin test. Eur. J. Neurosci. 2003, 17, 597-604. [14] Tuleja, E.; Mejza, F.; Cmiel, A.; Szczeklik, A. Effects of cyclooxygenases [40] Hogestatt, E. D.; Jonsson, B. A.; Ermund, A.; Andersson, D. A.; Bjork, H.; inhibitors on vasoactive prostanoids and thrombin generation at the site of Alexander, J. P.; Cravatt, B. F.; Basbaum, A. I.; Zygmunt, P. M. Conversion microvascular injury in healthy men. Arterioscler. Thromb. Vasc. Biol. 2003, of acetaminophen to the bioactive N-acylphenolamine AM404 via fatty acid 23, 1111-1115. amide hydrolase-dependent arachidonic acid conjugation in the nervous sys- [15] Mitchell, J. A.; Lucas, R.; Vojnovic, I.; Hasan, K.; Pepper, J. R.; Warner, T. tem. J. Biol. Chem. 2005, 280, 31405-31412. D. Stronger inhibition by nonsteroid anti-inflammatory drugs of cyclooxy- [41] Maccarrone, M. M.; Bari, M. M.; Lorenzon, T. T.; Bisogno, T. T.; Di Marzo, genase-1 in endothelial cells than platelets offers an explanation for increased V. V.; Finazzi-Agrò, A. A. Anandamide uptake by human endothelial cells risk of thrombotic events. FASEB J. 2006, 20, 2468-2475. and its regulation by nitric oxide. J. Biol. Chem. 2000, 275, 13484-13492. [16] Liou, J. Y.; Shyue, S. K.; Tsai, M. J.; Chung, C. L.; Chu, K. Y.; Wu, K. K. [42] Bisogno, T. T.; Maccarrone, M. M.; De Petrocellis, L. L.; Jarrahian, A. A.; Colocalization of prostacyclin synthase with prostaglandin H synthase-1 Finazzi-Agrò, A. A.; Hillard, C. C.; Di Marzo, V. V. The uptake by cells of (PGHS-1) but not phorbol ester-induced PGHS-2 in cultured endothelial 2-arachidonoylglycerol, an endogenous agonist of cannabinoid receptors. cells. J. Biol. Chem. 2000, 275, 15314-15320. Eur. J. Biochem. 2001, 268, 1982-1989. [17] Chan, A. T.; Manson, J. E.; Albert, C. M.; Chae, C. U.; Rexrode, K. M.; Curhan, G. C.; Rimm, E. B.; Willett, W. C.; Fuchs, C. S. Nonsteroidal Anti-

Mechanisms of Non-Opioid Analgesics Beyond Cyclooxygenase Current Molecular Pharmacology, 2009, Vol. 2, No. 1 11

[43] Guindon, J.; De Lean, A.; Beaulieu, P. Local interactions between anan- [69] Yaksh, T. L. Central pharmacology of nociceptive transmission. In Wall and damide, an endocannabinoid, and ibuprofen, a nonsteroidal anti- Melzack’s Textbook of Pain; McMahon, S. B. and Koltzenburg, M., Eds.; El- inflammatory drug, in acute and inflammatory pain. Pain 2006, 121, 85-93. sevier Churchill Livingstone, 2006, pp. 371-414. [44] Holt, S.; Paylor, B.; Boldrup, L.; Alajakku, K.; Vandevoorde, S.; Sundstrom, [70] Bergstrom, S.; Farnebo, L. O.; Fuxe, K. Effect of prostaglandin E 2 on cen- A.; Cocco, M. T.; Onnis, V.; Fowler, C. J. Inhibition of fatty acid amide hy- tral and peripheral catecholamine neurons. Eur. J. Pharmacol. 1973, 21, 362- drolase, a key endocannabinoid metabolizing enzyme, by analogues of ibu- 368. profen and indomethacin. Eur. J. Pharmacol. 2007, 565, 26-36. [71] Taiwo, Y. O.; Levine, J. D. Prostaglandins inhibit endogenous pain control [45] Cocco, M. T.; Congiu, C.; Onnis, V.; Morelli, M.; Cauli, O. Synthesis of mechanisms by blocking transmission at spinal noradrenergic synapses. J. ibuprofen heterocyclic amides and investigation of their analgesic and toxi- Neurosci. 1988, 8, 1346-1349. cological properties. Eur. J. Med. Chem. 2003, 38, 513-518. [72] Pinardi, G.; Sierralta, F.; Miranda, H. F. Adrenergic mechanisms in antinoci- [46] Ottani, A.; Leone, S.; Sandrini, M.; Ferrari, A.; Bertolini, A. The analgesic ceptive effects of non steroidal anti-inflammatory drugs in acute thermal no- activity of paracetamol is prevented by the blockade of cannabinoid CB1 re- ciception in mice. Inflamm. Res. 2002, 51, 219-222. ceptors. Eur. J. Pharmacol. 2006, 531, 280-281. [73] Lizarraga, I.; Chambers, J. P. Involvement of opioidergic and alpha2- [47] Anikwue, R.; Huffman, J. W.; Martin, Z. L.; Welch, S. P. Decrease in effi- adrenergic mechanisms in the central analgesic effects of non-steroidal anti- cacy and potency of nonsteroidal anti-inflammatory drugs by chronic inflammatory drugs in sheep. Res. Vet. Sci. 2006, 80, 194-200. delta(9)-tetrahydrocannabinol administration. J. Pharmacol. Exp. Ther. 2002, [74] Miranda, H. F.; Sierralta, F.; Pinardi, G. An isobolographic analysis of the 303, 340-346. adrenergic modulation of diclofenac antinociception. Anesth. Analg. 2001, [48] Guindon, J.; Beaulieu, P. Antihyperalgesic effects of local injections of 93, 430-435. anandamide, ibuprofen, rofecoxib and their combinations in a model of neu- [75] Pinardi, G.; Sierralta, F.; Miranda, H. F. Interaction between the antinocicep- ropathic pain. Neuropharmacology 2006, 50, 814-823. tive effect of ketoprofen and adrenergic modulatory systems. Inflammation [49] Millan, M. J. Descending control of pain. Prog. Neurobiol. 2002, 66, 355- 2001, 25, 233-239. 474. [76] Miranda, H. F.; Pinardi, G. Isobolographic analysis of the antinociceptive [50] Pini, L. A.; Vitale, G.; Sandrini, M. Serotonin and opiate involvement in the interactions of clonidine with nonsteroidal anti-inflammatory drugs. Phar- antinociceptive effect of acetylsalicylic acid. Pharmacology 1997, 54, 84-91. macol. Res. 2004, 50, 273-278. [51] Vitale, G.; Pini, L. A.; Ottani, A.; Sandrini, M. Effect of acetylsalicylic acid [77] Abelson, K. S.; Kommalage, M.; Hoglund, A. U. Spinal cholinergic in- on formalin test and on serotonin system in the rat brain. Gen. Pharmacol. volvement after treatment with aspirin and paracetamol in rats. Neurosci. 1998, 31, 753-758. Lett. 2004, 368, 116-120. [52] Courade, J. P.; Caussade, F.; Martin, K.; Besse, D.; Delchambre, C.; Hanoun, [78] Pinardi, G.; Sierralta, F.; Miranda, H. F. Atropine reverses the antinocicep- N.; Hamon, M.; Eschalier, A.; Cloarec, A. Effects of acetaminophen on tion of nonsteroidal anti-inflammatory drugs in the tail-flick test of mice. monoaminergic systems in the rat central nervous system. Naunyn Pharmacol. Biochem. Behav. 2003, 74, 603-608. Schmiedebergs Arch. Pharmacol. 2001, 364, 534-537. [79] Miranda, H. F.; Sierralta, F.; Pinardi, G. Carbachol interactions with nonste- [53] Sandrini, M.; Vitale, G.; Pini, L. A. Effect of rofecoxib on nociception and roidal anti-inflammatory drugs. Can. J. Physiol. Pharmacol. 2002, 80, 1173- the serotonin system in the rat brain. Inflamm. Res. 2002, 51, 154-159. 1179. [54] Groppetti, A.; Braga, P. C.; Biella, G.; Parenti, M.; Rusconi, L.; Mantegazza, [80] Bredt, D. S.; Snyder, S. H. Nitric oxide, a novel neuronal messenger. Neuron P. Effect of aspirin on serotonin and met-enkephalin in brain: correlation 1992, 8, 3-11. with the antinociceptive activity of the drug. Neuropharmacology 1988, 27, [81] Sakurada, C.; Sugiyama, A.; Nakayama, M.; Yonezawa, A.; Sakurada, S.; 499-505. Tan-No, K.; Kisara, K.; Sakurada, T. Antinociceptive effect of spinally in- [55] Srikiatkhachorn, A.; Tarasub, N.; Govitrapong, P. Effect of chronic analgesic jected L-NAME on the acute nociceptive response induced by low concen- exposure on the central serotonin system: a possible mechanism of analgesic trations of formalin. Neurochem. Int. 2001, 38, 417-423. abuse headache. Headache 2000, 40, 343-350. [82] Wood, P. L.; Emmett, M. R.; Rao, T. S.; Cler, J.; Mick, S.; Iyengar, S. Inhi- [56] Ostrowitzki, S.; Rao, M. L.; Redei, J.; Andres, A. H. Concurrence of cortex bition of nitric oxide synthase blocks N-methyl-D-aspartate-, quisqualate-, and platelet serotonin2 receptor binding characteristics in the individual and kainate-, harmaline-, and pentylenetetrazole-dependent increases in cerebel- the putative regulation by serotonin. J. Neural Transm. Gen. Sect. 1993, 93, lar cyclic GMP in vivo. J. Neurochem. 1990, 55, 346-348. 27-35. [83] Luo, Z. D.; Cizkova, D. The role of nitric oxide in nociception. Curr. Rev. [57] Shyu, K. W.; Lin, M. T.; Wu, T. C. Possible role of central serotoninergic Pain 2000, 4, 459-466. neurons in the development of dental pain and aspirin-induced analgesia in [84] Mcmahon, S. B.; Bennett, D. L. H.; Bevan, S. Inflammatory mediators and the monkey. Exp. Neurol. 1984, 84, 179-187. modulators of pain. In Wall and Melzack’s Textbook of Pain; McMahon, S. [58] Pini, L. A.; Sandrini, M.; Vitale, G. The antinociceptive action of paraceta- B. and Koltzenburg, M., Eds.; Elsevier Churchill Livingstone, 2006, pp. 49- mol is associated with changes in the serotonergic system in the rat brain. 72. Eur. J. Pharmacol. 1996, 308, 31-40. [85] Vandivier, R. W.; Eidsath, A.; Banks, S. M.; Preas, H. L., Ii; Leighton, S. B.; [59] Miranda, H. F.; Lemus, I.; Pinardi, G. Effect of the inhibition of serotonin Godin, P. J.; Suffredini, A. F.; Danner, R. L. Down-Regulation of Nitric Ox- biosynthesis on the antinociception induced by nonsteroidal anti- ide Production by Ibuprofen in Human Volunteers. J. Pharmacol. Exp. Ther. inflammatory drugs. Brain Res. Bull. 2003, 61, 417-425. 1999, 289, 1398-1403. [60] Courade, J. P.; Chassaing, C.; Bardin, L.; Alloui, A.; Eschalier, A. 5-HT [86] Sprott, H.; Gay, R. E.; Michel, B. A.; Gay, S. Influence of ibuprofen-arginine receptor subtypes involved in the spinal antinociceptive effect of acetamino- on serum levels of nitric oxide metabolites in patients with chronic low back phen in rats. Eur. J. Pharmacol. 2001, 432, 1-7. pain--a single-blind, placebo controlled pilot trial (ISRCTN18723747). J. [61] Sandrini, M.; Pini, L. A.; Vitale, G. Differential involvement of central 5- Rheumatol. 2006, 33, 2515-2518. HT1B and 5-HT3 receptor subtypes in the antinociceptive effect of [87] Hrabak, A.; Vercruysse, V.; Kahan, I. L.; Vray, B. Indomethacin prevents the paracetamol. Inflamm. Res. 2003, 52, 347-352. induction of inducible nitric oxide synthase in murine peritoneal macro- [62] Alloui, A.; Chassaing, C.; Schmidt, J.; Ardid, D.; Dubray, C.; Cloarec, A.; phages and decreases their nitric oxide production. Life Sci. 2001, 68, 1923- Eschalier, A. Paracetamol exerts a spinal, tropisetron-reversible, antinocicep- 1930. tive effect in an inflammatory pain model in rats. Eur. J. Pharmacol. 2002, [88] Du, Z. Y.; Li, X. Y. Inhibitory effects of indomethacin on interleukin-1 and 443, 71-77. nitric oxide production in rat microglia in vitro. Int. J. Immunopharmacol. [63] Pickering, G.; Loriot, M. A.; Libert, F.; Eschalier, A.; Beaune, P.; Dubray, C. 1999, 21, 219-225. Analgesic effect of acetaminophen in humans: first evidence of a central se- [89] Pang, L.; Hoult, J. R. Induction of cyclooxygenase and nitric oxide synthase rotonergic mechanism. Clin. Pharmacol. Ther. 2006, 79, 371-378. in endotoxin-activated J774 macrophages is differentially regulated by indo- [64] Bonnefont, J.; Alloui, A.; Chapuy, E.; Clottes, E.; Eschalier, A. Orally methacin: enhanced cyclooxygenase-2 protein expression but reduction of administered paracetamol does not act locally in the rat formalin test: inducible nitric oxide synthase. Eur. J. Pharmacol. 1996, 317, 151-155. evidence for a supraspinal, serotonin-dependent antinociceptive mechanism. [90] Godfrey, L.; Bailey, I.; Toms, N. J.; Clarke, G. D.; Kitchen, I.; Hourani, S. Anesthesiology 2003, 99, 976-981. M. O. Paracetamol inhibits nitric oxide synthesis in murine spinal cord slices. [65] Raffa, R. B.; Codd, E. E. Lack of binding of acetaminophen to 5-HT receptor Eur. J. Pharmacol. 2007, 562, 68-71. or uptake sites (or eleven other binding/uptake assays). Life Sci. 1996, 59, [91] Ryu, Y. S.; Lee, J. H.; Seok, J. H.; Hong, J. H.; Lee, Y. S.; Lim, J. H.; Kim, PL37-PL40. Y. M.; Hur, G. M. Acetaminophen Inhibits iNOS Gene Expression in RAW [66] Pini, L. A.; Vitale, G.; Ottani, A.; Sandrini, M. Naloxone-reversible antinoci- 264.7 Macrophages: Differential Regulation of NF-[kappa]B by Acetamino- ception by paracetamol in the rat. J. Pharmacol. Exp. Ther. 1997, 280, 934- phen and Salicylates. Biochem. Biophys. Res. Commun. 2000, 272, 758-764. 940. [92] Paul-Clark, M. J.; Van Cao, T.; Moradi-Bidhendi, N.; Cooper, D.; Gilroy, D. [67] Bjorkman, R. Central antinociceptive effects of non-steroidal anti- W. 15-epi-lipoxin A4-mediated Induction of Nitric Oxide Explains How As- inflammatory drugs and paracetamol. Experimental studies in the rat. Acta pirin Inhibits Acute Inflammation. J. Exp. Med. 2004, 200, 69-78. Anaesthesiol. Scand. Suppl. 1995, 103, 1-44. [93] Shimpo, M.; Ikeda, U.; Maeda, Y.; Ohya, K.-I.; Murakami, Y.; Shimada, K. [68] Bonnefont, J.; Daulhac, L.; Etienne, M.; Chapuy, E.; Mallet, C.; Ouchchane, Effects of Aspirin-Like Drugs on Nitric Oxide Synthesis in Rat Vascular L.; Deval, C.; Courade, J. P.; Ferrara, M.; Eschalier, A.; Clottes, E. Aceta- Smooth Muscle Cells. Hypertension 2000, 35, 1085-1091. minophen recruits spinal p42/p44 MAPKs and GH/IGF-1 receptors to pro- [94] Amin, A. A. R.; Vyas, P. P.; Attur, M. M.; Leszczynska-Piziak, J. J.; Patel, I. duce analgesia via the serotonergic system. Mol. Pharmacol. 2007, 71, 407- I. R.; Weissmann, G. G.; Abramson, S. S. B. The mode of action of aspirin- 415. like drugs: effect on inducible nitric oxide synthase. Proc. Natl. Acad. Sci. USA 1995, 92, 7926-7930. 12 Current Molecular Pharmacology, 2009, Vol. 2, No. 1 Hamza and Dionne

[95] Saeid Farivar, R.; Chobanian, A. V.; Brecher, P. Salicylate or Aspirin Inhib- [120] Noguchi, K.; Shitashige, M.; Endo, H.; Kondo, H.; Ishikawa, I. Binary its the Induction of the Inducible Nitric Oxide Synthase in Rat Cardiac Fi- regulation of interleukin (IL)-6 production by EP1 and EP2/EP4 subtypes of broblasts. Circ. Res. 1996, 78, 759-768. PGE2 receptors in IL-1beta-stimulated human gingival fibroblasts. J. Perio- [96] Panico, A. M.; Cardile, V.; Gentile, B.; Garufi, F.; Avondo, S.; Ronsisvalle, dontal. Res. 2002, 37, 29-36. S. "In vitro" differences among (R) and (S) enantiomers of profens in their [121] Rhind, S. G.; Gannon, G. A.; Shephard, R. J.; Shek, P. N. Indomethacin activities related to articular pathophysiology. Inflammation 2005, 29, 119- modulates circulating cytokine responses to strenuous exercise in humans. 128. Cytokine 2002, 19, 153-158. [97] Tsutsumi, R.; Ito, H.; Hiramitsu, T.; Nishitani, K.; Akiyoshi, M.; Kitaori, T.; [122] Lekakis, J. P.; Vamvakou, G.; Andreadou, I.; Ganiatsos, G.; Karatzis, E.; Yasuda, T.; Nakamura, T. Celecoxib inhibits production of MMP and NO Protogerou, A.; Papaioannou, T.; Ikonomidis, I.; Papamichael, C.; Mavrika- via down-regulation of NF-
B and JNK in a PGE2 independent manner in kis, M. E. Divergent effects of rofecoxib on endothelial function and in- human articular chondrocytes. Rheumatol. Int. 2008, 28, 727-736. flammation in acute coronary syndromes. Int. J. Cardiol. 2006, 112, 359- [98] Xie, Q.; Kashiwabara, Y.; Nathan, C. Role of transcription factor NF-kappa 366. B/Rel in induction of nitric oxide synthase. J. Biol. Chem. 1994, 269, 4705- [123] Monakier, D.; Mates, M.; Klutstein, M. W.; Balkin, J. A.; Rudensky, B.; 4708. Meerkin, D.; Tzivoni, D. Rofecoxib, a COX-2 inhibitor, lowers C-reactive [99] Hattori, Y.; Hattori, S.; Kasai, K. Lipopolysaccharide activates Akt in vascu- protein and interleukin-6 levels in patients with acute coronary syndromes. lar smooth muscle cells resulting in induction of inducible nitric oxide syn- Chest 2004, 125, 1610-1615. thase through nuclear factor-kappa B activation. Eur. J. Pharmacol. 2003, [124] Bogaty, P.; Brophy, J. M.; Noel, M.; Boyer, L.; Simard, S.; Bertrand, F.; 481, 153-158. Dagenais, G. R. Impact of prolonged cyclooxygenase-2 inhibition on in- [100] Tegeder, I.; Pfeilschifter, J.; Geisslinger, G. Cyclooxygenase-independent flammatory markers and endothelial function in patients with ischemic heart actions of cyclooxygenase inhibitors. FASEB J. 2001, 15, 2057-2072. disease and raised C-reactive protein: a randomized placebo-controlled [101] Bjorkman, R.; Hallman, K. M.; Hedner, J.; Hedner, T.; Henning, M. Aceta- study. Circulation 2004, 110, 934-939. minophen blocks spinal hyperalgesia induced by NMDA and substance P. [125] Richards, C. D.; Agro, A. Interaction between oncostatin M, interleukin 1 Pain 1994, 57, 259-264. and prostaglandin E2 in induction of IL-6 expression in human fibroblasts. [102] Bujalska, M. Effect of cyclooxygenase and NO synthase inhibitors adminis- Cytokine 1994, 6, 40-47. tered centrally on antinociceptive action of acetaminophen (Part II). Pol. J. [126] Jozefowski, S.; Bobek, M.; Marcinkiewicz, J. Exogenous but not endogenous Pharmacol. 2003, 55, 1001-1011. prostanoids regulate cytokine secretion from murine bone marrow dendritic [103] Granados-Soto, V.; Flores-Murrieta, F. J.; Castaneda-Hernandez, G.; Lopez- cells: EP2, DP, and IP but not EP1, EP3, and FP prostanoid receptors are in- Munoz, F. J. Evidence for the involvement of nitric oxide in the antinocicep- volved. Int. Immunopharmacol. 2003, 3, 865-878. tive effect of ketorolac. Eur. J. Pharmacol. 1995, 277, 281-284. [127] Lin, S. K.; Kuo, M. Y.; Wang, J. S.; Lee, J. J.; Wang, C. C.; Huang, S.; Shun, [104] Ventura-Martinez, R.; Deciga-Campos, M.; Diaz-Reval, M. I.; Gonzalez- C. T.; Hong, C. Y. Differential regulation of interleukin-6 and inducible cy- Trujano, M. E.; Lopez-Munoz, F. J. Peripheral involvement of the nitric ox- clooxygenase gene expression by cytokines through prostaglandin-dependent ide-cGMP pathway in the indomethacin-induced antinociception in rat. Eur. and -independent mechanisms in human dental pulp fibroblasts. J. Endod. J. Pharmacol. 2004, 503, 43-48. 2002, 28, 197-201. [105] Deciga-Campos, M.; Lopez-Munoz, F. J. Participation of the -arginine-nitric [128] Chen, B. C.; Liao, C. C.; Hsu, M. J.; Liao, Y. T.; Lin, C. C.; Sheu, J. R.; Lin, oxide-cyclic GMP-ATP-sensitive K+ channel cascade in the antinociceptive C. H. Peptidoglycan-induced IL-6 production in RAW 264.7 macrophages is effect of rofecoxib. Eur. J. Pharmacol. 2004, 484, 193-199. mediated by cyclooxygenase-2, PGE2/PGE4 receptors, protein kinase A, I [106] Islas-Cadena, M.; Aguirre-Banuelos, P.; Granados-Soto, V. Evidence for the kappa B kinase, and NF-kappa B. J. Immunol. 2006, 177, 681-693. participation of the nitric oxide-cyclic GMP pathway in the antinociceptive [129] Sugimoto, Y.; Narumiya, S. Prostaglandin E receptors. J. Biol. Chem. 2007, effect of nimesulide. J. Pharmacol. Toxicol. Methods 1999, 42, 87-92. 282, 11613-11617. [107] Aguirre-Bañuelos, P. P.; Granados-Soto, V. V. Evidence for the participation [130] Kozawa, O.; Suzuki, A.; Tokuda, H.; Kaida, T.; Uematsu, T. Interleukin-6 of the nitric oxide-cyclic GMP pathway in the antinociceptive action of synthesis induced by prostaglandin E2: cross-talk regulation by protein meloxicam in the formalin test. Eur. J. Pharmacol. 2000, 395, 9-13. kinase C. Bone 1998, 22, 355-360. [108] Lozano-Cuenca, J. J.; Castañeda-Hernández, G. G.; Granados-Soto, V. V. [131] Hershko, D. D.; Robb, B. W.; Luo, G.; Hasselgren, P. O. Multiple transcrip- Peripheral and spinal mechanisms of antinociceptive action of lumiracoxib. tion factors regulating the IL-6 gene are activated by cAMP in cultured Eur. J. Pharmacol. 2005, 513, 81-91. Caco-2 cells. Am. J. Physiol. Regul. Integr. Comp .Physiol. 2002, 283, [109] Tegeder, I.; Schmidtko, A.; Niederberger, E.; Ruth, P.; Geisslinger, G. Dual R1140-R1148. effects of spinally delivered 8-bromo-cyclic guanosine mono-phosphate (8- [132] Craven, P. A.; Saito, R.; Derubertis, F. R. Role of local prostaglandin synthe- bromo-cGMP) in formalin-induced nociception in rats. Neurosc. Lett. 2002, sis in the modulation of proliferative activity of rat colonic epithelium. J. 332, 146-150. Clin. Invest. 1983, 72, 1365-1375. [110] Prado, W. A.; Schiavon, V. F.; Cunha, F. Q. Dual effect of local application [133] Bevilacqua, M.; Vago, T.; Baldi, G.; Renesto, E.; Dallegri, F.; Norbiato, G. of nitric oxide donors in a model of incision pain in rats. Eur. J. Pharmacol. Nimesulide decreases superoxide production by inhibiting phosphodiesterase 2002, 441, 57-65. type IV. Eur. J. Pharmacol. 1994, 268, 415-423. [111] Taubert, D.; Berkels, R.; Grosser, N.; Schroder, H.; Grundemann, D.; [134] Lopez-Lluch, G.; Fernandez-Ayala, D. J.; Alcain, F. J.; Buron, M. I.; Que- Schomig, E. Aspirin induces nitric oxide release from vascular endothelium: sada, J. M.; Navas, P. Inhibition of COX activity by NSAIDs or ascorbate in- a novel mechanism of action. Br. J. Pharmacol. 2004, 143, 159-165. creases cAMP levels and enhances differentiation in 1alpha,25- [112] Seino, Y.; Ikeda, U.; Ikeda, M.; Yamamoto, K.; Misawa, Y.; Hasegawa, T.; dihydroxyvitamin D3-induced HL-60 cells. Arch. Biochem. Biophys. 2005, Kano, S.; Shimada, K. Interleukin 6 gene transcripts are expressed in human 436, 32-39. atherosclerotic lesions. Cytokine 1994, 6, 87-91. [135] Wang, X.; Hamza, M.; Gordon, S. M.; Wahl, S. M.; Dionne, R. A. COX [113] Biasucci, L. M.; Liuzzo, G.; Fantuzzi, G.; Caligiuri, G.; Rebuzzi, A. G.; Inhibitors Down-regulate PDE4D Expression in a Clinical Model of Inflam- Ginnetti, F.; Dinarello, C. A.; Maseri, A. Increasing levels of interleukin matory Pain. Clin. Pharmacol. Ther. 2008, 84, 39-42. (IL)-1Ra and IL-6 during the first 2 days of hospitalization in unstable angina [136] Skurk, T.; Van Harmelen, V.; Hauner, H. Angiotensin II stimulates the are associated with increased risk of in-hospital coronary events. Circulation release of interleukin-6 and interleukin-8 from cultured human adipocytes by 1999, 99, 2079-2084. activation of NF-kappaB. Arterioscler. Thromb. Vasc. Biol. 2004, 24, 1199- [114] Libby, P.; Ridker, P. M.; Maseri, A. Inflammation and atherosclerosis. Cir- 1203. culation 2002, 105, 1135-1143. [137] Fan, Z.; Bau, B.; Yang, H.; Aigner, T. IL-1beta induction of IL-6 and LIF in [115] Sanchez, C.; Mateus, M. M.; Defresne, M. P.; Crielaard, J. M.; Reginster, J. normal articular human chondrocytes involves the ERK, p38 and NFkappaB Y.; Henrotin, Y. E. Metabolism of human articular chondrocytes cultured in signaling pathways. Cytokine 2004, 28, 17-24. alginate beads. Longterm effects of interleukin 1beta and nonsteroidal antiin- [138] Matsusaka, T.; Fujikawa, K.; Nishio, Y.; Mukaida, N.; Matsushima, K.; flammatory drugs. J. Rheumatol. 2002, 29, 772-782. Kishimoto, T.; Akira, S. Transcription factors NF-IL6 and NF-kappa B syn- [116] Osterberg, J.; Ljungdahl, M.; Haglund, U. Influence of cyclooxygenase ergistically activate transcription of the inflammatory cytokines, interleukin 6 inhibitors on gut immune cell distribution and apoptosis rate in experimental and interleukin 8. Proc. Natl. Acad. Sci. USA 1993, 90, 10193-10197. sepsis. Shock 2006, 25, 147-154. [139] Albrecht, U.; Yang, X.; Asselta, R.; Keitel, V.; Tenchini, M. L.; Ludwig, S.; [117] Holzheimer, R. G.; Schein, M.; Wittmann, D. H. Inflammatory response in Heinrich, P. C.; Haussinger, D.; Schaper, F.; Bode, J. G. Activation of NF- peritoneal exudate and plasma of patients undergoing planned relaparotomy kappaB by IL-1beta blocks IL-6-induced sustained STAT3 activation and for severe secondary peritonitis. Arch. Surg. 1995, 130, 1314-1319; discus- STAT3-dependent gene expression of the human gamma-fibrinogen gene. sion 1319-1320. Cell Signal. 2007, 19, 1866-1878. [118] Nieman, D. C.; Henson, D. A.; Dumke, C. L.; Oley, K.; Mcanulty, S. R.; [140] Croker, B. A.; Krebs, D. L.; Zhang, J. G.; Wormald, S.; Willson, T. A.; Davis, J. M.; Murphy, E. A.; Utter, A. C.; Lind, R. H.; Mcanulty, L. S.; Mor- Stanley, E. G.; Robb, L.; Greenhalgh, C. J.; Forster, I.; Clausen, B. E.; row, J. D. Ibuprofen use, endotoxemia, inflammation, and plasma cytokines Nicola, N. A.; Metcalf, D.; Hilton, D. J.; Roberts, A. W.; Alexander, W. S. during ultramarathon competition. Brain Behav. Immun. 2006, 20, 578-584. SOCS3 negatively regulates IL-6 signaling in vivo. Nat. Immunol. 2003, 4, [119] Noguchi, K.; Maeda, M.; Ruwanpura, S. M.; Ishikawa, I. Prostaglandin E2 540-545. (PGE2) downregulates interleukin (IL)-1alpha-induced IL-6 production via [141] Yasukawa, H.; Ohishi, M.; Mori, H.; Murakami, M.; Chinen, T.; Aki, D.; EP2/EP4 subtypes of PGE2 receptors in human periodontal ligament cells. Hanada, T.; Takeda, K.; Akira, S.; Hoshijima, M.; Hirano, T.; Chien, K. R.; Oral Dis. 2005, 11, 157-162. Yoshimura, A. IL-6 induces an anti-inflammatory response in the absence of SOCS3 in macrophages. Nat. Immunol. 2003, 4, 551-556. Mechanisms of Non-Opioid Analgesics Beyond Cyclooxygenase Current Molecular Pharmacology, 2009, Vol. 2, No. 1 13

[142] Page-Mccaw, A.; Ewald, A. J.; Werb, Z. Matrix metalloproteinases and the glandin-Dependent and -Independent Mechanisms. J. Immunol. 1998, 161, regulation of tissue remodelling. Nat. Rev. Mol. Cell. Biol. 2007, 8, 221-233. 3071-3076. [143] Mccawley, L. J.; Matrisian, L. M. Matrix metalloproteinases: they're not just [165] Yamada, H.; Kikuchi, T.; Nemoto, O.; Obata, K.; Sato, H.; Seiki, M.; Shin- for matrix anymore! Curr. Opin. Cell. Biol. 2001, 13, 534-540. mei, M. Effects of indomethacin on the production of matrix metalloprotein- [144] Dabek, J.; Kulach, A.; Gasior, Z. The role of matrix metalloproteinases in ase-3 and tissue inhibitor of metalloproteinases-1 by human articular chon- acute coronary syndromes. Eur. J. Intern. Med. 2007, 18, 463-466. drocytes. J. Rheumatol. 1996, 23, 1739-1743. [145] Nakamura, H.; Masuko, K.; Yudoh, K.; Kato, T.; Nishioka, K. Effects of [166] Chakraborti, S.; Mandal, M.; Das, S.; Mandal, A.; Chakraborti, T. Regulation celecoxib on human chondrocytes--enhanced production of chemokines. of matrix metalloproteinases: An overview. Mol. Cell. Biochem. 2003, 253, Clin. Exp. Rheumatol. 2007, 25, 11-16. 269-285. [146] Lu, Y.; Wahl, L. M. Oxidative stress augments the production of matrix [167] Yan, C.; Boyd, D. D. Regulation of matrix metalloproteinase gene expres- metalloproteinase-1, cyclooxygenase-2, and prostaglandin E2 through en- sion. J. Cell. Physiol. 2007, 211, 19-26. hancement of NF-kappa B activity in lipopolysaccharide-activated human [168] Mauviel, A. Cytokine regulation of metalloproteinase gene expression. J. primary monocytes. J. Immunol. 2005, 175, 5423-5429. Cell. Biochem. 1993, 53, 288-295. [147] Falcinelli, E.; Giannini, S.; Boschetti, E.; Gresele, P. Platelets release active [169] Kunisch, E.; Gandesiri, M.; Fuhrmann, R.; Roth, A.; Winter, R.; Kinne, R. matrix metalloproteinase-2 in vivo in humans at a site of vascular injury: lack W. Predominant activation of MAP kinases and pro-destructive/pro- of inhibition by aspirin. Br. J. Haematol. 2007, 138, 221-230. inflammatory features by TNF alpha in early-passage synovial fibroblasts via [148] Kiran, M. S.; Sameer Kumar, V. B.; Viji, R. I.; Sudhakaran, P. R. Temporal TNF receptor-1: failure of p38 inhibition to suppress matrix metalloprotein- relationship between MMP production and angiogenic process in HUVECs. ase-1 in rheumatoid arthritis. Ann. Rheum. Dis. 2007, 66, 1043-1051. Cell Biol. Int. 2006, 30, 704-713. [170] Lee, J.; Jung, E.; Lee, J.; Huh, S.; Hwang, C. -H.; Lee, H. -Y.; Kim, E. -J.; [149] Yang, S. F.; Hsieh, Y. S.; Lue, K. H.; Chu, S. C.; Chang, I. C.; Lu, K. H. Cheon, J. -M.; Hyun, C. G.; Kim, Y. S.; Park, D. Emodin inhibits TNF [al- Effects of nonsteroidal anti-inflammatory drugs on the expression of pha]-induced MMP-1 expression through suppression of activator protein-1 urokinase plasminogen activator and inhibitor and gelatinases in the early os- (AP-1). Life Sci. 2006, 79, 2480-2485. teoarthritic knee of humans. Clin. Biochem. 2008, 41, 109-116. [171] Vincenti, M.; Brinckerhoff, C. Transcriptional regulation of collagenase [150] Bevilacqua, M.; Devogelaer, J. P.; Righini, V.; Famaey, J. P.; Manicourt, D. (MMP-1, MMP-13) genes in arthritis: integration of complex signaling H. Effect of nimesulide on the serum levels of hyaluronan and stromelysin-1 pathways for the recruitment of gene-specific transcription factors. Arthritis in patients with osteoarthritis: a pilot study. Int. J. Clin. Pract. Suppl. 2004, Res. 2002, 4, 157-164. 58, 13-19. [172] Endres, S.; Whitaker, R. E.; Ghorbani, R.; Meydani, S. N.; Dinarello, C. A. [151] Candelario-Jalil, E.; Taheri, S.; Yang, Y.; Sood, R.; Grossetete, M.; Estrada, Oral aspirin and ibuprofen increase cytokine-induced synthesis of IL-1 beta E. Y.; Fiebich, B. L.; Rosenberg, G. A. Cyclooxygenase inhibition limits and of tumour necrosis factor-alpha ex vivo. Immunology 1996, 87, 264-270. blood-brain barrier disruption following intracerebral injection of tumor ne- [173] Sirota, L.; Punsky, I.; Bessler, H. Effect of indomethacin on IL-1beta, IL-6 crosis factor-alpha in the rat. J. Pharmacol. Exp. Ther. 2007, 323, 488-498. and TNFalpha production by mononuclear cells of preterm newborns and [152] Nguyen, J.; Gogusev, J.; Knapnougel, P.; Bauvois, B. Protein tyrosine kinase adults. Acta Paediatr. 2000, 89, 331-335. and p38 MAP kinase pathways are involved in stimulation of matrix metal- [174] Poyet, P.; Doualla-Bell, F.; Levesque, D.; Ritchot, N.; Guay, J. M.; Marceau, loproteinase-9 by TNF-alpha in human monocytes. Immunol. Lett. 2006, 106, F.; Gaudreault, R. C. Down-regulation of interleukin-1beta production and 34-41. PGE2 accumulation by an indomethacin-phenylalanine derivative in human [153] Lin, S. K.; Wang, C. C.; Huang, S.; Lee, J. J.; Chiang, C. P.; Lan, W. H.; monocytes. Life Sci. 1998, 62, 2241-2247. Hong, C. Y. Induction of dental pulp fibroblast matrix metalloproteinase-1 [175] Kast, R. E. Tumor necrosis factor has positive and negative self regulatory and tissue inhibitor of metalloproteinase-1 gene expression by interleukin- feed back cycles centered around cAMP. Int. J. Immunopharmacol. 2000, 22, 1alpha and tumor necrosis factor-alpha through a prostaglandin-dependent 1001-1006. pathway. J. Endod. 2001, 27, 185-189. [176] Murono, S.; Yoshizaki, T.; Sato, H.; Takeshita, H.; Furukawa, M.; Pagano, J. [154] Takahashi, S.; Inoue, T.; Higaki, M.; Mizushima, Y. Cyclooxygenase inhibi- S. Aspirin inhibits tumor cell invasiveness induced by Epstein-Barr virus la- tors enhance the production of tissue inhibitor-1 of metalloproteinases tent membrane protein 1 through suppression of matrix metalloproteinase-9 (TIMP-1) and pro-matrix metalloproteinase 1 (proMMP-1) in human rheu- expression. Cancer Res. 2000, 60, 2555-2561. matoid synovial fibroblasts. Inflamm. Res. 1997, 46, 320-323. [177] Fibbi, G. G.; Serni, U. U.; Matucci, A. A.; Mannoni, A. A.; Pucci, M. M.; [155] Khan, K. M. F.; Howe, L. R.; Falcone, D. J. Extracellular Matrix-induced Anichini, E. E.; Del Rosso, M. M. Control of the chondrocyte fibrinolytic Cyclooxygenase-2 Regulates Macrophage Proteinase Expression. J. Biol. balance by the drug piroxicam: relevance to the osteoarthritic process. J. Chem. 2004, 279, 22039-22046. Rheumatol. 1994, 21, 2322-2328. [156] Baratelli, F. E.; Heuze-Vourc'h, N.; Krysan, K.; Dohadwala, M.; Riedl, K.; [178] Pelletier, J. J. P.; Mineau, F. F.; Fernandes, J. J.; Kiansa, K. K.; Ranger, P. Sharma, S.; Dubinett, S. M. Prostaglandin E2-Dependent Enhancement of P.; Martel-Pelletier, J. J. Two NSAIDs, nimesulide and naproxen, can reduce Tissue Inhibitors of Metalloproteinases-1 Production Limits Dendritic Cell the synthesis of urokinase and IL-6 while increasing PAI-1, in human OA Migration through Extracellular Matrix. J. Immunol. 2004, 173, 5458-5466. synovial fibroblasts. Clin. Exp. Rheumatol. 1997, 15, 393-398. [157] Pillinger, M. H.; Marjanovic, N.; Kim, S.-Y.; Scher, J. U.; Izmirly, P.; To- [179] Moreau, M.; Brocheriou, I.; Petit, L.; Ninio, E.; Chapman, M. J.; Rouis, M. lani, S.; Dinsell, V.; Lee, Y.-C.; Blaser, M. J.; Abramson, S. B. Matrix Met- Interleukin-8 Mediates Downregulation of Tissue Inhibitor of Metalloprote- alloproteinase Secretion by Gastric Epithelial Cells Is Regulated by E Pros- inase-1 Expression in Cholesterol-Loaded Human Macrophages : Relevance taglandins and MAPKs. J. Biol. Chem. 2005, 280, 9973-9979. to Stability of Atherosclerotic Plaque. Circulation 1999, 99, 420-426. [158] Pavlovic, S.; Du, B.; Sakamoto, K.; Khan, K. M.; Natarajan, C.; Breyer, R. [180] Thirumangalakudi, L.; Yin, L.; Rao, H. V.; Grammas, P. IL-8 induces ex- M.; Dannenberg, A. J.; Falcone, D. J. Targeting prostaglandin E2 receptors pression of matrix metalloproteinases, cell cycle and pro-apoptotic proteins, as an alternative strategy to block cyclooxygenase-2-dependent extracellular and cell death in cultured neurons. J. Alzheimers Dis. 2007, 11, 305-311. matrix-induced matrix metalloproteinase-9 expression by macrophages. J. [181] Inoue, K.; Slaton, J. W.; Kim, S. J.; Perrotte, P.; Eve, B. Y.; Bar-Eli, M.; Biol. Chem. 2006, 281, 3321-3328. Radinsky, R.; Dinney, C. P. N. Interleukin 8 Expression Regulates Tumori- [159] Yan, M.; Noguchi, K.; Ruwanpura, S. M.; Ishikawa, I. Cyclooxygenase-2- genicity and Metastasis in Human Bladder Cancer. Cancer Res. 2000, 60, dependent prostaglandin (PG) E2 downregulates matrix metalloproteinase-3 2290-2299. production via EP2/EP4 subtypes of PGE2 receptors in human periodontal [182] Kimura, T.; Iwase, M.; Kondo, G.; Watanabe, H.; Ohashi, M.; Ito, D.; Na- ligament cells stimulated with interleukin-1alpha. J. Periodontol. 2005, 76, gumo, M. Suppressive effect of selective cyclooxygenase-2 inhibitor on cy- 929-935. tokine release in human neutrophils. Int. Immunopharmacol. 2003, 3, 1519- [160] Fushimi, K.; Nakashima, S.; You, F.; Takigawa, M.; Shimizu, K. Prostaglan- 1528. din E2 downregulates TNF-alpha-induced production of matrix metalloprote- [183] Zhang, Y.; Wahl, L. M. Synergistic enhancement of cytokine-induced human inase-1 in HCS-2/8 chondrocytes by inhibiting Raf-1/MEK/ERK cascade monocyte matrix metalloproteinase-1 by C-reactive protein and oxidized through EP4 prostanoid receptor activation. J. Cell. Biochem. 2007, 100, LDL through differential regulation of monocyte chemotactic protein-1 and 783-793. prostaglandin E2. J. Leukoc. Biol. 2006, 79, 105-113. [161] Sadowski, T.; Steinmeyer, J. Effects of non-steroidal antiinflammatory drugs [184] Cross, A. K.; Woodroofe, M. N. Chemokine modulation of matrix metallo- and dexamethasone on the activity and expression of matrix metalloprotein- proteinase and TIMP production in adult rat brain microglia and a human ase-1, matrix metalloproteinase-3 and tissue inhibitor of metalloproteinases-1 microglial cell line in vitro. Glia 1999, 28, 183-189. by bovine articular chondrocytes. Osteoarthr. Cartil. 2001, 9, 407-415. [185] Schneider, A.; Harendza, S.; Zahner, G.; Jocks, T.; Wenzel, U.; Wolf, G.; [162] Li, L.; Akers, K.; Eisen, A. Z.; Seltzer, J. L. Activation of gelatinase A (72- Thaiss, F.; Helmchen, U.; Stahl, R. A. K. Cyclooxygenase metabolites medi- kDa type IV collagenase) induced by monensin in normal human fibroblasts. ate glomerular monocyte chemoattractant protein-1 formation and monocyte Exp. Cell. Res. 1997, 232, 322-330. recruitment in experimental glomerulonephritis1. Kidney Int. 1999, 55, 430- [163] Vaday, G. G.; Schor, H.; Rahat, M. A.; Lahat, N.; Lider, O. Transforming 441. growth factor-beta suppresses tumor necrosis factor alpha-induced matrix [186] Efsen, E.; Bonacchi, A.; Pastacaldi, S.; Valente, A. J.; Wenzel, U. O.; Tosti- metalloproteinase-9 expression in monocytes. J. Leukoc. Biol. 2001, 69, 613- Guerra, C.; Pinzani, M.; Laffi, G.; Abboud, H. E.; Gentilini, P.; Marra, F. 621. Agonist-specific regulation of monocyte chemoattractant protein-1 expres- [164] Zhang, Y.; Mccluskey, K.; Fujii, K.; Wahl, L. M. Differential Regulation of sion by cyclooxygenase metabolites in hepatic stellate cells. Hepatology Monocyte Matrix Metalloproteinase and TIMP-1 Production by TNF- 2001, 33, 713-721. {alpha}, Granulocyte-Macrophage CSF, and IL-1{beta} Through Prosta-

14 Current Molecular Pharmacology, 2009, Vol. 2, No. 1 Hamza and Dionne

[187] Gurjar, M. M. V.; Sharma, R. R. V.; Bhalla, R. R. C. eNOS gene transfer [190] Blain, E. J. Mechanical regulation of matrix metalloproteinases. Front. inhibits smooth muscle cell migration and MMP-2 and MMP-9 activity. Ar- Biosci. 2007, 12, 507-527. terioscler. Thromb. Vasc. Biol. 1999, 19, 2871-2877. [191] Armstrong, E. P.; Malone, D. C. The impact of nonsteroidal anti- [188] Shin, C. Y.; Lee, W. J.; Choi, J. W.; Choi, M. S.; Ryu, J. R.; Oh, S. J.; inflammatory drugs on blood pressure, with an emphasis on newer agents. Cheong, J. H.; Choi, E. Y.; Ko, K. H. Down-regulation of matrix metallopro- Clin. Ther. 2003, 25, 1-18. teinase-9 expression by nitric oxide in lipopolysaccharide-stimulated rat pri- [192] Egan, B. M. Nonnarcotic Analgesic Use and the Risk of Hypertension in US mary astrocytes. Nitric Oxide 2007, 16, 425-432. Women. Hypertension 2002, 40, 601-603. [189] Ridnour, L. A.; Windhausen, A. N.; Isenberg, J. S.; Yeung, N.; Thomas, D. [193] Curhan, G. C.; Willett, W. C.; Rosner, B.; Stampfer, M. J. Frequency of D.; Vitek, M. P.; Roberts, D. D.; Wink, D. A. Nitric oxide regulates matrix Analgesic Use and Risk of Hypertension in Younger Women. Arch. Intern. metalloproteinase-9 activity by guanylyl-cyclase-dependent and - Med. 2002, 162, 2204-2208. independent pathways. Proc. Natl. Acad. Sci. USA 2007, 104, 16898-16903.

Received: January 29, 2008 Revised: June 21, 2008 Accepted: June 24, 2008