A trimer plus a dimer-gallate reproduce the bioactivity described for an extract of grape seed procyanidins
ABSTRACT The relationship between grape seed-derived procyanidin extract components and their bioactivity was explored. The monomeric and dimeric structures only acted as anti-inflammatory agents. Similarly, pure C1 trimer was highly effective on LPS-activated macrophages. To reproduce all of the bioactivities of the total extract, a fraction enriched with trimeric structures was needed. This trimeric-enriched fraction was divided into subfractions, the most bioactive of which contained two compounds with a molecular weight equal to a trimer (865) and a dimer-gallate (729), according to spectrometric analysis. Thus, it may be concluded that a mixture of both molecules reproduces the bioactivity in glucose metabolism (3T3-L1), lipid metabolism (HepG2) and macrophage functionality (RAW 264.6).
Article: Lipogenesis is decreased by grape seed proanthocyanidins according to liver proteomics of rats fed a high fat diet.[show abstract] [hide abstract]
ABSTRACT: Bioactive proanthocyanidins have been reported to have several beneficial effects on health in relation to metabolic syndrome, type 2 diabetes, and cardiovascular disease. We studied the effect of grape seed proanthocyanidin extract (GSPE) in rats fed a high fat diet (HFD). This is the first study of the effects of flavonoids on the liver proteome of rats suffering from metabolic syndrome. Three groups of rats were fed over a period of 13 weeks either a chow diet (control), an HFD, or a high fat diet supplemented for the last 10 days with GSPE (HFD + GSPE). The liver proteome was fractionated, using a Triton X-114-based two-phase separation, into soluble and membrane protein fractions so that total proteome coverage was considerably improved. The data from isobaric tag for relative and absolute quantitation (iTRAQ)-based nano-LC-MS/MS analysis revealed 90 proteins with a significant (p < 0.05) minimal expression difference of 20% due to metabolic syndrome (HFD versus control) and 75 proteins due to GSPE treatment (HFD + GSPE versus HFD). The same animals have previously been studied (Quesada, H., del Bas, J. M., Pajuelo, D., Díaz, S., Fernandez-Larrea, J., Pinent, M., Arola, L., Salvadó, M. J., and Bladé, C. (2009) Grape seed proanthocyanidins correct dyslipidemia associated with a high-fat diet in rats and repress genes controlling lipogenesis and VLDL assembling in liver. Int. J. Obes. 33, 1007-1012), and GSPE was shown to correct dyslipidemia observed in HFD-fed rats probably through the repression of hepatic lipogenesis. Our data corroborate those findings with an extensive list of proteins describing the induction of hepatic glycogenesis, glycolysis, and fatty acid and triglyceride synthesis in HFD, whereas the opposite pattern was observed to a large extent in GSPE-treated animals. GSPE was shown to have a wider effect than previously thought, and putative targets of GSPE involved in the reversal of the symptoms of metabolic syndrome were revealed. Some of these novel candidate proteins such as GFPT1, CD36, PLAA (phospholipase A(2)-activating protein), METTL7B, SLC30A1, several G signaling proteins, and the sulfide-metabolizing ETHE1 and SQRDL (sulfide-quinone reductase-like) might be considered as drug targets for the treatment of metabolic syndrome.Molecular & Cellular Proteomics 03/2010; 9(7):1499-513. · 7.40 Impact Factor