stilbenes and ethyl-gallate

Vascular smooth muscle cell (VSMC) proliferation contributes to the development of atherosclerosis. Red wine consumption due to the polyphenol content has been reported to counteract atherosclerosis progression possibly through inhibition of VSMC proliferation, among other mechanisms. In this study we investigate the antiproliferative activity of four wine polyphenols: resveratrol, quercetin, ethyl gallate, and (+)-catechin in rat aortic VSMC. All four polyphenols inhibited serum-induced VSMC proliferation when applied as a single treatment. To further address a potential synergistic action of the investigated polyphenols, the antiproliferative effect of different combinations in equimolar, as well as equipotent ratios were quantified. The IC₅₀ values of single polyphenols regarding the inhibition of VSMC proliferation ranged from 49.58 µM to 86.06 µM. However, apparent inhibitory efficacy of each compound increased by a factor of 10.4 in the quadruple equipotent mixture, as calculated from the dose-reduction index. Thus, the effective IC₅₀ values of each of the four mixture constituents ranged from 4.76 µM to 8.27 µM. The calculated combination index (CI, where CI <, =, or > 1 indicate synergy, additivity, or antagonism, respectively) values of equimolar combinations of the polyphenols indeed indicated mainly synergy (CI ranging from 0.24 ± 0.01 to 1.51 ± 0.13). Optimized equipotent mixture showed enhanced synergy (CI ranging from 0.18 ± 0.04 to 1.36 ± 0.26). In conclusion, we show for the first time that four major polyphenols from wine synergistically inhibit VSMC proliferation.

Topics: Animals; Catechin; Cell Proliferation; Drug Synergism; Gallic Acid; Muscle, Smooth, Vascular; Quercetin; Rats; Rats, Sprague-Dawley; Resveratrol; Stilbenes

To study the chemical constituents of Lysidice brevicalyx.. Various chromatographic techniques were used to isolate and purify the constituents such as column chromatography on silica gel, Rp-silica gel, Sephadex LH-20 and HPLC. The structures were elucidated by chemical evidence and spectroscopic methods.. Seven compounds were isolated from the 95% ethanol extract of the leaves of L. brevicalyx and these compounds were elucidated as 2-0-[1-(3-methylbutyryl)phloroglucin-ol]-beta-D-glucopynanoside (1), 3-beta-D-glucopyranosyloxy-4, 5-dimethoxy-benzoic acid (2), benzyl alcohol O-beta-D-glucopyra noside (3), polydatin (4), quercetin-3-alpha-L-rhamnopyranoside (5), ethyl gallate (6), benzyl 6-O-alpha-L-arabinofurano syl-beta-D-glucopynanoside (7).. All Compounds were isolated from this plant for the first time. Compounds 2, 3, 5-7 were obtained from this genus for the first time.

Topics: Chromatography, High Pressure Liquid; Fabaceae; Gallic Acid; Glucosides; Glycosides; Monosaccharides; Plant Extracts; Plant Leaves; Quercetin; Stilbenes