See discussions, stats, and author profiles for this publication at: http://www.researchgate.net/publication/50418508 Comparative Absorption of a Standardized Curcuminoid Mixture and Its Lecithin Formulation ARTICLE in JOURNAL OF NATURAL PRODUCTS · MARCH 2011 Impact Factor: 3.8 · DOI: 10.1021/np1007262 · Source: PubMed CITATIONS READS 70 151 8 AUTHORS, INCLUDING: John Cuomo Giovanni Appendino USANA Health Sciences, Inc Amedeo Avogadro University of Eastern Pied… 18 PUBLICATIONS 274 CITATIONS 363 PUBLICATIONS 7,303 CITATIONS SEE PROFILE SEE PROFILE Stefano Togni Indena S.p.A. 21 PUBLICATIONS 262 CITATIONS SEE PROFILE Available from: Stefano Togni Retrieved on: 27 November 2015 ARTICLE pubs.acs.org/jnp Comparative Absorption of a Standardized Curcuminoid Mixture and Its Lecithin Formulation ,† ,‡ † † † John Cuomo,* † Giovanni Appendino,*§ Adam S. Dern,† Erik Schneider, Toni P. McKinnon, Mark J. Brown, Stefano Togni, and Brian M. Dixon † USANA Health Sciences, Inc., 3838 West Parkway Boulevard, Salt Lake City, Utah 84120, United States ‡ Dipartimento di Scienze Chimiche, Alimentari, Farmaceutiche e Farmacologiche, Universita degli Studi del Piemonte Orientale, Via Bovio 6, 28100, Novara, Italy § Indena S.p.A., Viale Ortles 12, 20139 Milano, Italy ABSTRACT: The relative absorption of a standardized curcu- minoid mixture and its corresponding lecithin formulation (Meriva) was investigated in a randomized, double-blind, cross- over human study. Clinically validated dosages were used for both products, and plasma levels of all three major curcumi- noids [curcumin (1a), demethoxycurcumin (1b), and bisde- methoxycurcumin (1c)] were evaluated. Total curcuminoid absorption was about 29-fold higher for Meriva than for its corresponding unformulated curcuminoid mixture, but only phase-2 metabolites could be detected, and plasma concentrations were still significantly lower than those required for the inhibition of most anti-inflammatory targets of curcumin. Remarkably, phospholipid formulation increased the absorption of demethoxylated curcuminoids much more than that of curcumin (1a), with significant differences in plasma curcuminoid profile between Meriva and its corresponding unformulated curcuminoid mixture. Thus, the major plasma curcuminoid after administration of Meriva was not curcumin (1a), but demethoxycurcumin (1b), a more potent analogue in many in vitro anti-inflammatory assays. The improved absorption, and possibly also a better plasma curcuminoid profile, might underlie the clinical efficacy of Meriva at doses significantly lower than unformulated curcuminoid mixtures. ver the past few decades, preclinical and clinical evidence poorly bioavailable, with only conjugates being generally detect- Ohas been accumulating that the pathological mechanisms able in plasma even after dosages as high as 12 g/day.8,10 involved in chronic diseases are multifactorial and that these Two major strategies have been pursued to improve the conditions are therefore better addressed with a multitargeted bioavailability of curcumin.8 The first is a combination with À rather than a monotargeted therapy.1 3 The promiscuous target- adjuvants capable of increasing the absorption of curcumin, like 9 ing of multiple cellular end-points has therefore become a piperine, quercetin, or turmeric oil. The curcuminÀpiperine therapeutic virtue,4 and agents that can modulate multiple formulation is the best documented and has been shown to almost 11 cellular targets, once dismissed as unselective ligands, are now double the human bioavailability of curcumin. However, it has 4 been argued that this improvement comes at the expense of an considered attractive research leads. In this context, no com- 12 pound better than curcumin (1a) exemplifies the biomedical increased potential of interaction with mainstream drugs, since relevance of promiscuous agents.5 With over 100 molecular piperine is an inhibitor of phase-1 and phase-2 xenobiotic meta- bolizing enzymes,13 and curcumin has also been shown to inhibit targets identified and almost 3000 preclinical investigations,6 various classes of cytochromes (including CPYP3A4) as well as this compound is, undoubtedly, one of the best investigated P-glycoprotein activity.12,14 The second strategy has been the natural products to date. Curcumin features a unique blend of inclusion of curcumin in a lipophilic matrix (liposomes, Phyto- Michael acceptor, metal chelating, and antioxidant properties 7 somes, and lipid micro- and nanoparticles) or encapsulation with that has so far substantially eluded all attempts of dissection. micellar surfactants or casein.8 Many of these formulations have The promiscuous binding properties of curcumin make it led to dramatic improvement in the absorption of curcumin in difficult to explore the chemical space around the pharmaco- animal experiments,8 but little human data exist. phore of the natural product, since analogues would have to be Commercially available natural curcumin is a mixture of three assayed against multiple rather than single molecular end-points. curcuminoids: curcumin (1a, ca. 70À75%), demethoxycurcumin Therefore, a large share of the medicinal chemistry research on (1b, ca. 15À20%), and bisdemethoxycurcumin (1c, ca. 5À10%). curcumin has focused on improving the dismally low oral Most published literature on curcumin does not make a clear absorption of the natural product by suitable formulation.8 9 Curcumin has a high hydrolytic instability at physiological pH Received: October 11, 2010 and an inherently low intestinal absorption.8 It is therefore very Copyright r XXXX American Chemical Society and American Society of Pharmacognosy A dx.doi.org/10.1021/np1007262 | J. Nat. Prod. XXXX, XXX, 000–000 Journal of Natural Products ARTICLE Table 1. Curcuminoid Content of the Study Capsules Meriva reference high dose low dose reference curcuminoid (mg per capsule) (mg per capsule) (mg per dose) (mg per dose) (mg per dose) curcumin (1a) 33 259 297 165 1295 demethoxycurcumin (1b) 8 79 68 38 396 bisdemethoxycurcumin (1c) 1 22 11 6 108 total curcuminoids 42 360 376 209 1799 distinction between pure 1a (monomolecular curcumin, gener- curcuminoid mixture used for the formulation with lecithin. The ally obtained by synthesis) and the mixture of the three curcu- dosages were inspired by previous clinical studies for inflamma- minoids obtained by extraction from turmeric. In this study, two tory conditions, where active dosages of around 1À2 g/day of formulations of a mixture of natural curcuminoids, a noncom- nonformulated curcuminoid mixtures20 and around 200À300 plexed powder and a phospholipid formulation (Meriva), were mg of curcuminoids as Meriva were used,1 while the choice of the compared. Both materials had a similar ratio of all three natural first time point was done in accordance to previous data that 15 10 curcuminoids (see below). Curcumin is sparingly soluble in showed tmax values for curcumin around 4 h. For this study, both water and lipophilic organic solvents, but has polar groups subjects consumed, in random order and on separate study days, that make it a good candidate for phospholipid complexation via five (low-dose) or nine (high-dose) capsules of Meriva, corre- hydrogen bonding and dipole interactions with the polar head sponding to 209 and 376 mg total curcuminoids, or, alternatively, groups of phosphatidylcholine.16 As a result, phospholipid five capsules of the corresponding nonformulated curcuminoid particles bearing curcumin at their surface can be formed,17 mixture (reference) containing 1799 mg of total curcuminoids. and curcumin has indeed been shown to strongly bind to The composition of the two types of capsules is listed in Table 1. phospholipid micelles, positioning the water-labile β-diketone Free curcumin (1a) could not be detected in any plasma moiety into the lipid bilayer and shielding it from hydrolytic samples, in accordance with previous studies that have mostly retro-Claisen fragmentation, the major mechanism of degrada- failed to detect unconjugated curcumin in human plasma even tion in water.16 Based on this previous research, a novel curcumin after the administration of megadoses of curcumin.8 Conse- formulation was developed under the brand name Meriva by quently, all plasma samples were treated with Helix pomatia combining a standardized mixture of natural curcuminoids and glucuronidase/sulfatase before HPLC-MS/MS analysis. The lecithin in a 1:2 ratio, with 2 parts of microcrystalline cellulose peak plasma total curcuminoid concentration (cmax) reached being also added to improve the physical state.18 A comparative with the high dosage of Meriva was 206.9 ( 164.7 ng/mL, and analysis of the hydrolytic stability of Meriva and noncomplexed the corresponding time of the peak plasma curcuminoid con- ( curcumin showed a dramatic increase in stability in the pH range centration (tmax) was reached at 2.7 1 h after the administra- À ( of the small intestine (pH 7 8), the major site of absorption for tion. For the low dosage, cmax was 68.9 50.8 ng/mL and tmax polyphenolic compounds (Giori, A.; Franceschi, F.; Appendino, was 3.3 ( 1 h. For the reference curcuminoid mixture, these G. Unpublished data). Apart from hydrolytic stabilization, phos- values were 14.4 ( 12.5 ng/mL and 6.9 ( 6.7 h. Within the pholipid formulation could also increase the absorption of context of curcumin human absorption, the >200 ng/mL con- curcumin in a direct way, since phospholipids can be rapidly centration of conjugated curcuminoids is still lower than the low taken up into biomembranes