Effect of chronic treatment with bark of Terminalia arjuna: a study on the isolated ischemic-reperfused rat heart.

Dried pulverized bark of Terminalia arjuna Linn (TA) was administered orally to Wistar albino rats (120-150 g) in two doses [500 and 750 mg/kg in 2% carboxy methyl cellulose (CMC)], 6 days per week for 12 weeks. Thereafter, rats were sacrificed either for determination of baseline changes in cardiac endogenous antioxidant compounds [superoxide dismutase (SOD), reduced glutathione (GSH) and catalase (CAT)] or the hearts were subjected to oxidative stress associated with in vitro ischemic-reperfusion injury (IRI). There was significant increase in the baseline contents of thiobarbituric acid reactive substance (TBARS) (a measure of lipid peroxidation) with both doses of TA. However, only in the 500 mg/kg treated group, this was accompanied by a simultaneous increase in SOD, GSH and CAT levels, but not in the 750 mg/kg treated group, where only CAT was raised. Significant rise in myocardial TBARS and loss of SOD, CAT and GSH (suggestive of increased oxidative stress) occurred in the vehicle-treated hearts subjected to in vitro IRI. Only hearts, harvested from the 500 mg/kg rats treated rats, were significantly protected from oxidative stress, when subjected to in vitro IRI. The results suggest that crude bark of TA augments endogenous antioxidant compounds of rat heart and also prevents oxidative stress associated with IRI of the heart.