X-Message-Number: 12977 Date: Tue, 21 Dec 1999 12:20:15 -0800 (PST) From: Doug Skrecky <> Subject: could proanthocyanidins toughen up tissue enough to survive Citations: 1-5 <1> Authors Sato M. Maulik G. Ray PS. Bagchi D. Das DK. Institution University of Connecticut School of Medicine, Farmington, Connecticut 06030-1110, USA. Title Cardioprotective effects of grape seed proanthocyanidin against ischemic reperfusion injury. Source Journal of Molecular & Cellular Cardiology. 31(6):1289-97, 1999 Jun. Abstract There is increasing evidence to indicate cardioprotective effects of red wine consumption. Such cardioprotective properties of wine have been attributed to certain polyphenolic constituents of grapes. The purpose of this investigation was to examine whether proanthocyanidins derived from grape seeds possess cardioprotective properties. Rats were randomly divided into two groups: grape-seed proanthocyanidin was administered orally to one group of rats (100 mg/kg/day) for 3 weeks while the other group served as control. After 3 weeks, rats were killed, hearts excised, mounted on the perfusion apparatus and perfused with Krebs-Henseleit bicarbonate (KHB) buffer. After stabilization hearts were perfused in the working mode for baseline measurements of contractile functions. Hearts were then subjected to 30 min of global ischemia followed by 2 h of reperfusion. Coronary perfusates were collected to monitor malonaldehyde formation, a presumptive marker for oxidative stress development. At the end of each experiment, the heart was processed for infarct size determination. Peroxyl radical scavenging activity of proanthocyanidin was determined by examining its ability to remove peroxyl radical generated by 2,2'-azobis (2-amidinopropane) dihydrochloride while hydroxyl radical scavenging activity was tested with its ability to reduce 7-OH.-coumarin-3-carboxylic acid. The results of our study demonstrated that proanthocyanidin-fed animals were resistant to myocardial ischemia reperfusion injury as evidenced by improved recovery of post-ischemic contractile functions. The proanthocyanidin-fed group revealed reduced extent of myocardial infarction compared to the control group. Fluorimetric study demonstrated the antioxidant property of proanthocyanidin as judged by its ability to directly scavenge peroxyl radicals. Taken together, the results of this study showed that grape seed-proanthocyanidins possess a cardioprotective effect against ischemia reperfusion injury. Such cardioprotective property, at least in part, may be attributed to its ability to directly scavenge peroxyl and hydroxyl radicals and to reduce oxidative stress developed during ischemia and reperfusion. Copyright 1999 Academic Press. <2> Authors Bouhamidi R. Prevost V. Nouvelot A. Institution Laboratoire de neurosciences, UMR 6551 du CNRS, universite de Caen, France. Title High protection by grape seed proanthocyanidins (GSPC) of polyunsaturated fatty acids against UV-C induced peroxidation. Source Comptes Rendus de l Academie des Sciences - Serie Iii, Sciences de la Vie. 321(1):31-8, 1998 Jan. Abstract The antioxidative effects of grape seed proanthocyanidins (GSPC) were studied in three in-vitro models in which polyunsaturated fatty acids (PUFAs) in aqueous solution and mice liver or brain microsomes were used as oxidative substrates, and UV-C irradiation as the pro-oxidant system. Analysis of UV-C induced lipid peroxidation was carried out by two methods: gas liquid chromatography of residual PUFAs and release of thiobarbituric acid-reactive substances (TBARs) measured by TBA reaction. Results indicate that PUFAs are more radiosensitive when incorporated in single component micelles than in mixed component micelles or microsomes. In every case, PUFA peroxidation was inhibited by low concentrations of GSPC (2 mg/L) while epigallocatecin (EGC) and epigallocatechin gallate (EGCG) monomers, at an equivalent level of epicatechin, exhibited no efficacy in our experimental conditions. This latter effect might be explained by a synergistic action of flavan-3-ol monomers, dimers and oligomers contained in the grape seed extract. <3> Authors Bagchi D. Garg A. Krohn RL. Bagchi M. Bagchi DJ. Balmoori J. Stohs SJ. Institution Creighton University School of Pharmacy, Omaha, Nebraska, USA. Title Protective effects of grape seed proanthocyanidins and selected antioxidants against TPA-induced hepatic and brain lipid peroxidation and DNA fragmentation, and peritoneal macrophage activation in mice. Source General Pharmacology. 30(5):771-6, 1998 May. Abstract 1. The comparative protective abilities of a grape seed proanthocyanidin extract (GSPE) (25-100 mg/kg), vitamin C (100 mg/kg), vitamin E succinate (VES) (100 mg/kg) and beta-carotene (50 mg/kg) on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced lipid peroxidation and DNA fragmentation in the hepatic and brain tissues, as well as production of reactive oxygen species by peritoneal macrophages, were assessed. 2. Treatment of mice with GSPE (100 mg/kg), vitamin C, VES and beta-carotene decreased TPA-induced production of reactive oxygen species, as evidenced by decreases in the chemiluminescence response in peritoneal macrophages by approximately 70%, 18%, 47% and 16%, respectively, and cytochrome c reduction by approximately 65%, 15%, 37% and 19%, respectively, compared with controls. 3. GSPE, vitamin C, VES and beta-carotene decreased TPA-induced DNA fragmentation by approximately 47%, 10%, 30% and 11%, respectively, in the hepatic tissues, and 50%, 14%, 31% and 11%, respectively, in the brain tissues, at the doses that were used. Similar results were observed with respect to lipid peroxidation in hepatic mitochondria and microsomes and in brain homogenates. 4. GSPE exhibited a dose-dependent inhibition of TPA-induced lipid peroxidation and DNA fragmentation in liver and brain, as well as a dose-dependent inhibition of TPA-induced reactive oxygen species production in peritoneal macrophages. 5. GSPE and other antioxidants provided significant protection against TPA-induced oxidative damage, with GSPE providing better protection than did other antioxidants at the doses that were employed. <4> Authors Arpentin GN. Valuiko GG. Sushkova VV. Kas'ianova NN. Gul'i MF. Title [Effect of catechins and proanthocyanidins on the initial stage of protein biosynthesis]. [Russian] Source Ukrainskii Biokhimicheskii Zhurnal. 67(4):104-7, 1995 Jul-Aug. Abstract Catechins and proanthocyanidins have been studied for their effect on initial stage of the protein biosynthesis. It has been found that (+)-catechin in all concentrations studied does not influence the intensity of t-RNA aminoacylation by 14C-glycine and 14C-arginine. Proanthocyanidins, namely, dimers B-3, B-6 and trimer C2 in the concentration of 10(-3) M completely inhibit the initial stage of the protein biosynthesis. <5> Authors Hagerman AE. Butler LG. Title The specificity of proanthocyanidin-protein interactions. Source Journal of Biological Chemistry. 256(9):4494-7, 1981 May 10. Abstract The proanthocyanidins or condensed tannins, phenolic polymers which are synthesized by many plants, characteristically bind and precipitate proteins. The specificity of the interaction was investigated using a competitive binding assay to compare directly the affinities of various proteins and synthetic polymers for the tannin obtained from Sorghum bicolor (Lin.) Moench. At pH 4.9, the relative affinities range over more than 4 orders of magnitude, indicating that this proanthocyanidin interacts quite selectively with protein and protein-like polymers. The affinity for tannins is an inverse function of the size of the polymer, and peptides with less than six residues interact very weakly with tannin. Proteins are precipitated by proanthocyanidins most efficiently at pH values near their isoelectric points. Proline-rich proteins and polymers have very high affinities for tannin. Tightly coiled globular proteins have much lower affinities for tannin than conformationally loose proteins. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=12977