Resveratrol, a phytoestrogen found in red wine, down-regulates protein S expression in HepG2 cells.
Thromb Res. 2011 Jan;127(1):e1-7. PMID: 20926118
Graduate School of Health and Nutrition Sciences, Nakamura Gakuen University, Fukuoka, Japan.
UNLABELLED: INTRODUATION: Resveratrol, a phytoestrogen present at a high concentration in red wine, has been reported to possess many health benefit effects that are protective against age-related diseases. Protein S (PS), an important anticoagulant factor in the protein C (PC) anticoagulant pathway, is mainly synthesized by hepatocytes, and its plasma level is decreased in high-estrogen conditions such as pregnancy and oral contraceptive use. The aim of this study was to investigate whether resveratrol affects PS expression in HepG2 cells.
MATERIALS AND METHODS: The secreted and intracellular levels of PS were determined by an enzyme-linked ligandsorbent assay and Western blotting. The mRNA expressions of PS, PC andβ chain of C4b-binding protein (C4BP-β) were analyzed by reverse transcription-polymerase chain reaction. The PS gene promotor activities in HepG2 cells transiently expressing estrogen receptor (ER) α were examined by a luciferase reporter assay.
RESULTS: Resveratrol dose- and time-dependently down-regulated the PS expression in HepG2 cells at a transcriptional level, resulting in a significant decrease in secreted PS; however, the PC and C4BP-β mRNA expressions were not affected. This action of resveratrol was not mediated through either the ER signaling or those of mitogen-activated protein kinases and protein kinase C. Piceatannol, a hydroxylated metabolite of resveratrol, and genistein, an isoflavone found in soy products, also down-regulated the PS expression.
CONCLUSIONS: Resveratrol down-regulates the PS expression in HepG2 cells in an ER-independent manner, and the two phenolic hydroxyls at carbon-3 and -5 of resveratrol may be involved in this function.