Cardioprotective effect of grape seed proanthocyanidins on isoproterenol-induced myocardial injury in rats.
International Journal of Cardiology. 2006 July 5
The aim of this in-vivo study on rats was to investigate the protective activity of grape seed proanthocyanidins against injury of heart muscles, induced by isoproterenol. Myocardial injuries of rats, which received grape seed proanthocyanidins during a period if 5 weeks, were compared with those of a control group, following a treatment with isoproterenol. The researchers found that the administration of grape seed proanthocyanidins maintained the levels of the marker enzymes. Rats treated with isoproterenol showed a significant increase in TBARS (index of lipid peroxidation and oxidative stress) and a significant decrease in glutathione, glutathione peroxidase, glutathione S-transferase, superoxide dismutase and catalase when compared to the control group. The enzyme levels kept the normal levels when the rats were given grape seed proanthocyanidins, indicating that grape seed proanthocyanidins reduced oxidative stress. The study concluded that grape seed proanthocyanidins have a cardioprotective effect and protect the heart against myocardial injuries induced by isoproterenol.
Regulation of proliferation and gene expression in cultured human aortic smooth muscle cells by resveratrol and standardized grape extracts.
Biochemical and Biophysical Research Communications. 2006 July 21;346(1):367-76
Epidemiologic studies associate the consumption of red wine with reduced risk of coronary heart disease. Other studies have shown that resveratrol, the main polyphenol of red wine has cardioprotective properties. The aim of this in-vitro study was to investigate the cardioprotective activity of standardized grape extracts. The study was carried out on cultured human aortic cells, which were subject to different levels of the grape extract and resveratrol. The researchers found that resveratrol reduced the cell growth of the aortic cells, increased the tumor suppressor gene and heat shock protein and increased the expression of quinone reductases. The grape extract also reduced the cell growth but the expression of genes was different from those observed for resveratrol. The study concluded that resveratrol and grape extract regulate growth and gene expression of aortic cells in a different way.
Concord grape juice attenuates platelet aggregation, serum cholesterol and development of atheroma in hypercholesterolemic rabbits.
Atherosclerosis. 2006 June 13
Studies have shown that the consumption of concord grape juice inhibits platelet aggregation, thereby reducing the risk of cardiovascular disease. Concord grape is a dark coloured grape of which the juice is very rich in polyphenols. The aim of this study was to investigate the effect on platelet aggregation and atheroma (abnormal inflammatory accumulation of macrophage white blood cells within the walls of arteries) of the intake of concord grape juice on rabbits fed with a hypercholesterolemic diet. The rabbits were divided in a placebo group and a group receiving concord grape juice (225 ml per day) for 48 days. The researchers found that both groups showed an increase in platelet aggregation as a result of the high cholesterol diet. The group supplemented with concord grape juice showed significant less platelet aggregation and less development of atheroma. The consumption of concord grape juice also resulted in lower cholesterol levels and lower blood pressure. The study concluded that daily consumption of concord grape juice reduces hypercholesterolemia-enhanced platelet aggregation, blood pressure, cholesterol level and development of atheroma in rabbits.
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