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Evidence-Based Complementary and Alternative Medicine
Volume 2013 (2013), Article ID 589169, 9 pages
http://dx.doi.org/10.1155/2013/589169
Research Article

Melinjo (Gnetum gnemon L.) Seed Extract Decreases Serum Uric Acid Levels in Nonobese Japanese Males: A Randomized Controlled Study

1Department of Aging Control Medicine, Juntendo University Graduate School of Medicine, Bunkyo-Ku, Tokyo 113-0033, Japan
2Institute for Bee Products & Health Science, Yamada Bee Company, Inc., 194 Ichiba, Kagamino-cho, Okayama 708-0393, Japan

Received 27 September 2013; Accepted 24 November 2013

Academic Editor: Syed Ibrahim Rizvi

Copyright © 2013 Hiroyuki Konno et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Melinjo (Gnetum gnemon L.) seed extract (MSE) containing trans-resveratrol (3,5,4′-trihydroxy-trans-stilbene) and other derivatives exerts various beneficial effects. However, its mechanism of action in humans remains unknown. In this study, we aimed to investigate beneficial effects of MSE in healthy adult males. In this double-blind, randomized controlled study, 30 males aged 35–70 years with ≤10% flow-mediated dilatation received placebo or 750 mg MSE powder for 8 weeks, and twenty-nine males ( years old) completed the trial. There was a significant difference in the melinjo and placebo groups. Compared with the placebo control, MSE significantly reduced serum uric acid at 4 weeks and 8 weeks ( and 15, resp.). HDL cholesterol was significantly increased in the melinjo group. To clarify the mechanism of MSE for reducing uric acid, we investigated xanthine oxidase inhibitory activity, angiotensin II type 1 (AT1) receptor binding inhibition rate, and agonistic activities for PPARα and PPARγ. MSE, trans-resveratrol, and a resveratrol dimer, gnetin C (GC), significantly inhibit AT1 receptor binding and exhibit mild agonistic activities for PPARα and PPARγ. In conclusion, MSE may decrease serum uric acid regardless of insulin resistance and may improve lipid metabolism by increasing HDL cholesterol.