June 2001 Notes Biol. Pharm. Bull. 24(6) 701—703 (2001) 701 Inhibitory Effects of Anti-Inflammatory Drugs on Interleukin-6 Bioactivity a a a a b Bo-Seong KANG, Eun-Yong CHUNG, Yeo-Pyo YUN, Myung Koo LEE, Yong Rok LEE, c a ,a Ki-Sung LEE, Kyung Rak MIN, and Youngsoo KIM* College of Pharmacy, Chungbuk National University,a Cheongju 361–763, Korea, College of Engineering, Yeungnam University,b Kyongsan 712–749, Korea, and Research Center for Biomedical Resources, Pai-Chai University,c Taejon 302–735, Korea. Received November 20, 2000; accepted February 14, 2001 Interleukin-6 (IL-6) is known as a proinflammatory cytokine involved in immune response, inflammation, and hematopoiesis. Inhibitory effects of anti-inflammatory drugs on IL-6 bioactivity using IL-6-dependent hy- bridoma have been evaluated. Three out of 16 nonsteroidal anti-inflammatory drugs (NSAIDs) showed IC50 val- 5 . ues of less than 100 mM, which were in the order of oxyphenylbutazone hydrate (IC50 7.5 mM) meclofenamic acid sodium salt (31.9 mM).sulindac (74.9 mM). Steroidal anti-inflammatory drugs (SAIDs) exhibited significant inhibitory effects at 100 mM on the IL-6 bioactivity, and their inhibitory potencies were in the order of budesonide 5 . (IC50 2.2 mM) hydrocortisone 21-hemisuccinate (6.7 mM), prednisolone (7.5 mM), betamethasone (10.9 mM) dex- amethasone (18.9 mM) and triamcinolone acetonide (24.1 mM). The results would provide an additional mecha- nism by which anti-inflammatory drugs display their anti-inflammatory and immunosuppressive effects at higher concentrations. Key words anti-inflammatory drugs; IL-6 inhibitor; oxyphenylbutazone hydrate; budesonide Interleukin-6 (IL-6) is a proinflammatory cytokine which were purchased from GIBCO BRL Products (Gaithersburg, is produced by both lymphoid and nonlymphoid cells.1) The MD, U.S.A.) and rhIL-6 from Wako Pure Chemical Ind., Ltd. receptor for IL-6 is composed of two polypeptide chains (Osaka, Japan). called a-subunit and b-subunit.1,2) The a-subunit is the lig- Culture of Hybridoma MH60/BSF-2 The murine B and-binding chain with a molecular weight of approximately cell hybridoma dependent on IL-6 for its growth was cul- 80 kDa, and is also known as gp80.2,3) The b-subunit is tured in RPMI (10.4 mg/ml RPMI-1640, 2.48 mg/ml HEPES, known as gp130 and is the signal-transducing chain of the re- 100 units/ml benzylpenicillin potassium, 100 mg/ml strepto- ceptor complex.2,4) The gp130 is shared by a family of cy- mycin sulfate, pH 7.1) containing 10% FBS and 1 unit/ml 17) tokines including oncostatin M (OSM), leukemia inhibitory rhIL-6 at 37 °C with 5% CO2. factor (LIF), IL-11, cardiotrophin-1 (CT-1) and ciliary neu- IL-6 Bioassay One hundred microliter of 13104 rotrophic factor (CNTF).5—7) MH60/BSF-2 cells, 50 ml of 1.2 unit/ml rhIL-6, and 50 ml of IL-6 is a multifunctional cytokine acting in various cells. It the medium with or without sample were added to a 96-well induces the differentiation of B cells to antibody-producing microplate (Nunc, Roskilde, Denmark). After incubation at plasma cells, T-cell growth and differentiation, the differenti- 37 °C with 5% CO2 for 48 h, the cell growth was measured ation of myeloid leukemic cell lines into macrophages, by optical density (OD) at wavelength 570 nm using the megakaryocyte maturation, the neuronal differentiation of MTT method. Effect on IL-6 bioactivity by the sample is rep- PC12 cells, development of osteoclasts, and acute-phase pro- resented as inhibition %, [1-(sample OD570/control 8—14) 3 tein synthesis in hepatocytes. IL-6 acts as a growth fac- OD570)] 100, compared with the control. Data are expressed tor for myeloma/plasmacytoma, keratinocytes, mesangial as means6S.E.M., and their significant differences from the cells, renal carcinoma, and Kaposi’s sarcoma, but inhibits the controls were analyzed by Student’s t-test. growth of myeloid leukemia cell lines and certain sarcoma IL-3 Bioassay and Cytotoxicity BAF/BO3 cell line was cell lines.15,16) Thereby, IL-6 plays important roles in the cultured in RPMI containing 10% FBS and 20 units/ml pathogenesis of a variety of diseases, in particular, chronic rmIL-3. Proliferation of BAF/BO3 by rmIL-3 was measured inflammation, autoimmune diseases, viral infection, and ma- as an IL-3 bioassay.18) IL-6-independent MH60 cell line was lignancies.1,2) established by gradually decreasing IL-6 in RPMI containing In this study, inhibitory effects of anti-inflammatory drugs 10% FBS for passage of MH60/BSF-2.18) Effect on the on IL-6 bioactivity were investigated. Oxyphenybutazone hy- growth rate of IL-6-independent MH60 cells in RPMI con- drate exhibited the highest inhibitory effect among nons- taining 10% FBS without IL-6 was viewed as the cytotoxic- teroidal anti-inflammatory drugs (NSAIDs) and budesonide ity of the sample. among steroidal anti-inflammatory drugs (SAIDs). RESULTS AND DISCUSSION MATERIALS AND METHODS NSAIDs are well known as inhibitors of prostaglandin Materials Anti-inflammatory drugs, RPMI-1640, and 3- synthesis. However, the mechanism may not account for all [4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide pharmacological effects of NSAIDs. It was reported that in- (MTT) were purchased from Sigma Chemical Co., Inc. (St. domethacin and diclofenac up-regulated the production of Louis, MO, U.S.A.). Fetal bovine serum (FBS) and N-[2-hy- TNF, IFN-g and IL-2 released from Th1 cells but down-regu- droxyethyl]piperazine-N9-2-ethanesulfonic acid (HEPES) lated the production of IL-4 and IL-6 released from Th2 ∗ To whom correspondence should be addressed. e-mail: [email protected] © 2001 Pharmaceutical Society of Japan 702 Vol. 24, No. 6 cells.19) sis of new proteins. It was reported that SAIDs inhibited the Five NSAIDs of diclofenac sodium salt, sulindac, meclofe- production of TNF, IL-1, IL-2, IL-6, IFN-g chemokine, and namic acid sodium salt, mefenamic acid and oxyphenylbuta- GM-CSF, but increased the number of receptors of IL-1 and zone hydrate exhibited significant inhibitory effects at 100 IL-6.20) m M on IL-6 bioactivity (Table 1). Diclofenac sodium salts All SAIDs exhibited significant inhibitory effects at 100 and sulindac at 100 m M exhibited 42% and 79% inhibition on m M on IL-6 bioactivity (Table 1). Based on the IC50 values, the cytokine bioactivity, respectively, but etodolac, in- inhibitory potency on IL-6 bioactivity was in the order of domethacin, and tolmetin sodium salt in the acetate subfam- budesonide.hydrocortisone 21-hemisuccinate, prednisolone, ily of NSAIDs did not inhibit. Both meclofenamic acid betamethasone.dexamethasone, triamcinolone acetonide. sodium salt and mefenamic acid in the fenamate subfamily beclomethasone dipropionate. Budesonide inhibited the IL-6 exhibited .95% and 37% inhibition at 100 m M, respectively. bioactivity in a dose-dependent manner, and showed an IC50 Oxyphenylbutazone hydrate exhibited >95% inhibition at value at the concentration of 2.2 m M (Fig. 1). 100 m M on IL-6 bioactivity, but phenylbutazone in the pyra- Among anti-inflammatory drugs showing >50% inhibition zoline subfamily did not inhibit. None of NSAIDs in car- on IL-6 bioactivity at 100 m M, all except sulindac and budes- boxylate, propionate and oxicam subfamilies tested in this onide inhibited the IL-3 bioactivity with potency in the order study showed significant inhibitory effects on IL-6 bioactiv- of prednisolone, hydrocortisone 21-hemisuccinate, dexam- ity. Oxyphenylbutazone hydrate inhibited the IL-6 bioactivity ethasone.oxyphenylbutazone hydrate, triamcinolone ace- in a dose-dependent manner, and showed an IC50 value at the concentration of 7.5 m M (Fig. 1). Based on the IC50 values, inhibitory potency on IL-6 bioactivity was in the order of oxyphenylbutazone hydrate.meclofenamic acid sodium salt. sulindac.diclofenac sodium salt and mefenamic acid (Table 1). SAIDs are corticosteroids exerting profound effects on the inflammatory and immune responses.20) Corticosteroid re- sponses are initiated by binding to a specific receptor, and mediated by the cascade of cellular events involving synthe- Table 1. Inhibitory Effects on IL-6 Bioactivity Inhibition (%) Anti-inflammatory drug IC (m M) at 100 m M 50 Nonsteroidal anti-inflammatory drugs Carboxylate Aspirin ,063 .100 Acetates Diclofenac sodium salt 4262* .100 6 . Etodolac 19 3 100 Fig. 1. Dose-Dependent Inhibitory Effects on IL-6 Bioactivity by 6 . Indomethacin 19 1 100 Oxyphenylbutazone Hydrate and Budesonide Sulindac 7961* 74.9 6 . Samples are oxyphenylbutazone hydrate (open circle) and budesonide (solid circle). Tolmetin sodium salt 8 6 100 Data are represented as inhibition %, mean6S.E. of three independent tests, and their Propionates significant differences from the control are ∗ p,0.001. Fenoprofen calcium salt 1662 .100 Flurbiprofen 2663 .100 Ibuprofen ,061 .100 Table 2. Inhibitory Effects on IL-3 Bioactivity and Cytotoxic Effects on Ketoprofen ,064 .100 IL-6-independent MH60 Cells Naproxen sodium salt 1864 .100 Fenamates IC50 (m M) Meclofenamic acid sodium salt .9561* 31.9 Anti-inflammatory drug Mefenamic acid 3763* .100 IL-3 Cytotoxicity Pyrazolines Oxyphenylbutazone hydrate .9561* 7.5 Nonsteroidal anti-inflammatory drugs Phenylbutazone 2664 .100 Sulindac .100 .100 Oxicam Meclofenamic acid sodium salt 48.6 92.7 Piroxicam 1261 .100 Oxyphenylbutazone hydrate 35.2 78.5 Steroidal anti-inflammatory drugs Steroidal anti-inflammatory drugs Beclomethasone dipropionate 4562* .100 Betamethasone 51.0 .100 Betamethasone 9362* 10.9 Budesonide .100 .100 Budesonide .9564* 2.2 Dexamethasone 24.9 .100 Dexamethasone .9561* 18.9 Hydrocortisone 21-hemisuccinate 21.4 .100 Hydrocortisone 21-hemisuccinate 9262* 6.7 Prednisolone 16.0 .100 Prednisolone .9563* 7.5 Triamcinolone acetonide 39.9 .100 Triamcinolone acetonide 8664* 24.1 IL-3 bioactivity was measured by proliferation of BAF/BO3 cells in the presence of IL-6 bioactivity was measured by proliferation of hybridoma MH60/BSF-2 in the rmIL-3.