Diet enriched with procyanidins enhances antioxidant activity and reduces myocardial post-ischaemic damage in rats.

Aim of this work was to study the efficacy of procyanidins from Vitis vinifera seeds, a standardized mixture of polyphenol antioxidants, on cardiac mechanics following ischemia/reperfusion stunning in the rat, after 3 weeks supplementation. Young and aged male rats were fed a diet enriched with procyanidins complexed (1:3 w/w) with soybean lecithin (2.4%); control animals (CTR-young and CTR-aged) received an equal amount of lecithin and 2 additional groups of animals the standard diet. At the end of the treatment, the total plasma antioxidant defense (TRAP), vitamin E, ascorbic acid and uric acid were determined in plasma and the hearts from all groups of animals subjected to moderate ischemia (flow reduction to 1 ml/min for 20 min) and reperfusion (15 ml/min for 30 min). In both young and aged rats supplemented with procyanidins the recovery of left ventricular developed pressure (LVDP) at the end of reperfusion was 93% (p < 0.01) and 74% (p < 0.01) of the preischemic values and the values of coronary perfusion pressure (CPP) were maintained close to those of the preischemic period. Also creatine kinase (CK) outflow was restrained to baseline levels, while a 2-fold increase in prostacyclin (6-keto-PGF1alpha) in the perfusate from hearts of young and aged rats was elicited during both ischemia and reperfusion. In parallel, procyanidins significantly increased the total antioxidant plasma capacity (by 40% in young and by 30% in aged rats) and the plasma levels of ascorbic acid, while tend to reduce vitamin E levels; no significant differences were observed in uric acid levels. The results of this study demonstrate that procyanidins supplementation in the rat (young and aged) makes the heart less susceptible to ischemia/reperfusion damage and that this is positively associated to an increase in plasma antioxidant activity.