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The fruit and root parts of Paeonia anomala L. are used for the treatment of many kinds of disorders in Mongolian traditional medicine. The protective effect of a fruit extract from P. anomala against tert-butylhydroperoxide-induced cell damage was evaluated in human hepatoma HepG2 cells and compared to that of a root extract from P. anomala on the basis of cell viability, generation of intracellular reactive oxygen species, cellular total glutathione concentration, and anti-genotoxicity. The fruit extract of P. anomala showed excellent protection against the oxidative stress when compared to the root extract, through free radical scavenging, enhancing cellular glutathione concentration, and inhibiting DNA damage. Chemical constituents in the fruit extract of P. anomala were investigated and two novel compounds, 2-hydroxy-6-methoxy-4-O-(6'-O-α-L-arabinofuranosyl-β-D-glucopyranosyl)acetophenone (1) and 3,3'-di-O-methyl-4-O-(3''-O-galloyl-β-D-glucopyranosyl)ellagic acid (2), along with 18 other known compounds were identified. Compound 2 showed better cytoprotection against tert-butylhydroperoxide than compound 1. Among other compounds isolated from the fruit extract, ellagic acid, methyl gallate, ethyl gallate, fischeroside B, and quercetin derivatives showed potent protective effects against tert-butylhydroperoxide-induced oxidative stress via inhibiting reactive oxygen species generation and increasing total glutathione levels in HepG2 cells.

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, =, or1 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.

Piptadenia pervillei Vatke (Fabaceae) was selected from a screening programme devoted to the search of naturally-occuring antimalarial compounds from plants of Madagascar. Bioassay-guided fractionation of the ethyl acetate extract of the leaves led to the isolation of four phenolic compounds, (+)-catechin ( 1), (+)-catechin 5-gallate ( 2), (+)-catechin 3-gallate ( 3) and ethyl gallate ( 4). Structures were determined by NMR and mass spectroscopy. Compounds 2 and 3 displayed the highest in vitro activity against the chloroquine-resistant strain FcB1 of Plasmodium falciparum with IC (50) values of 1.2 microM and 1.0 microM, respectively, and no significant cytotoxicity against the human embryonic lung cells MRC-5 was measured (IC (50) values > 75 microM). Five analogues ( 5 - 9) of (+)-catechin 5-gallate ( 2) were synthesized and evaluated for their antiplasmodial activity.

A new ellagitannin, methyl (S)-flavogallonate (14) along with fourteen known compounds, gallic acid, methyl gallate, ethyl gallate, 2,3-di-O-[( S)-4,5,6,4',5',6'-hexahydroxybiphenyl-2,2'-diyldicarbonyl]-(alpha/beta)-D-glucopyranose (4), vitexin, isovitexin, orientin, iso-orientin, kaempferol 3-O-beta-D-rutinoside, rutin, neosaponarin, ellagic acid, flavogallonic acid (13), and (alpha/beta)-punicalagin (15) have been isolated from the leaves of Terminalia myriocarpa Heurck. Protective effect of the major and structurally related compounds 4, 13, 15 and the new compound 14 against CCl 4 -induced hepatotoxicity has been evaluated and compared, using adult male rats weighing 200-250 g. Serum levels of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), lipid peroxide and nitric oxide production were significantly increased by administration of CCl 4 to rats and then reduced significantly only by treatment with compounds 4, 14 and 15 in a dose-dependent manner. Comparison of the protective properties of these compounds showed that compound 14 is more potent than compound 15 than 4 and that compound 13 has a non-significant effect at the used two dose levels.