Mechanisms of Cardioprotective Effect of Withania somnifera in Experimentally Induced Myocardial Infarction

Abstract

The present study was designed to evaluate the cardioprotective potential of hydro-alcoholic extract of Withania somnifera on the basis of haemodynamic, histopathological and biochemical parameters in the isoprenaline-(isoproterenol) induced myocardial necrosis in rats and to compare with Vitamin E, a known cardioprotective antioxidant. Wistar albino male rats (150-200 g) were divided into six main groups: sham, isoprenaline control, Withania somnifera/Vitamin E control and Withania somnifera/Vitamin E treatment groups. Withania somnifera was administered at doses 25, 50 and 100 mg/kg and Vitamin E at a dose of 100 mg/kg, orally for 4 weeks. On days 29 and 30, the rats in the isoprenaline control and Withania somnifera/Vitamin E treatment groups were given isoprenaline (85 mg/kg), subcutaneously at an interval of 24 hr. On day 31, haemodynamic parameters were recorded and the hearts were subsequently removed and processed for histopathological and biochemical studies. A significant decrease in glutathione (P<0.05), activities of superoxide dismutase, catalase, creatinine phosphokinase and lactate dehydrogenase (P<0.01) as well as increase in lipid peroxidation marker malonyldialdehyde level (P<0.01) was observed in the hearts of isoproterenol control group rats as compared to sham control. However, we have not observed any significant changes in activity of glutathione peroxidase and protein levels. Left ventricular dysfunction was seen as a decrease in heart rate, left ventricular rate of peak positive and negative pressure change and elevated left ventricular end-diastolic pressure in the control group was recorded. On histopathological examination, myocardial damage was further confirmed. Our data show that Withania somnifera (25, 50 and 100 mg/kg) exerts a strong cardioprotective effect in the experimental model of isoprenaline-induced myonecrosis in rats. Augmentation of endogenous antioxidants, maintenance of the myocardial antioxidant status and significant restoration of most of the altered haemodynamic parameters may contribute to its cardioprotective effect. Among the different doses studied, Withania somnifera at 50 mg/kg dose produced maximum cardioprotective effect.

Evaluation of Cardioprotective Activity of Fulvic Acid Against Isoproterenol Induced Oxidative Damage in Rat Myocardium

“…LPO is a wellestablished mechanism of cellular injury and has been used as an indicator of oxidative stress that is responsible for the pathogenesis of MI. 30 The extend of LPO has been evaluated by estimating MDA content, In our investigation, ISO treatment resulted in a significant increase in the levels of MDA content a products of lipid peroxidation in the heart tissue homogenate. The control animals who received Isoprenaline have shown raise in MDA content as a result of increase in lipid peroxidation as well as concomitant plunge in activity of antioxidant enzymes such as SOD, GSH and catalase.…”

Endogenous sulfur dioxide protects against isoproterenol-induced myocardial injury and increases myocardial antioxidant capacity in rats

“…36 More interestingly, the ventricular dysfunction, as mentioned above, could be significantly prevented by antioxidants. 35,37 An increasing body of evidence suggests that free radicals, including reactive oxygen species and reactive nitrogen species, have long been recognized to act as the major mediators of cardiac injury, and antioxidants and free radical scavengers have been shown to minimize cardiac injury, which, to some extent, verifies that oxygen radicals have a key role in cardiac injury. 38,39 Studies showed that ISO-induced cardiotoxicity was partly due to the formation of oxygen-free radicals and sulfhydryl reactivity through a variety of its oxidation products.…”

Nephroprotective Effect ofWithania somnifera:A Dose-Dependent Study

“…medicinal properties, such as immunomodulatory, [17] antiinflammatory, [18] endocrine, [19] anti-stress, [20] anti-cancer, [21 adaptogenic, [22] anti-tumor, [23] central nervous system, [24,25] cardiovascular, [26,27] and neuroprotective [28] activities, respectively. Among the other parts of this plant, the root has been considered to be the most active part for therapeutic purposes.…”