ABSTRACT
The present study was designed to investigate the antihypertensive effect of methanolic extract of the whole plant of Passiflora nepalensis Walp., Passifloraceae, (MPN) in renal hypertensive and normotensive rats. The blood pressure, pulse pressure, and heart rate fell dose-dependently in renal hypertensive and normotensive rats after intravenous administration of 75, 150, and 225 mg/kg MPN, suggesting that MPN possesses antihypertensive, hypotensive and negative chronotropic effects. The effect at doses of 150 and 225 mg/kg of MPN were more pronounced than that of 75 mg/kg body weight. Thus, the present study reveals that MPN exerts antihypertensive effect against renal hypertension.
ABSTRACT
BACKGROUND: The present study investigates the cardioprotective effects of Hibiscus rosa sinensis in myocardial ischemic reperfusion injury, particularly in terms of its antioxidant effects. METHODS: The medicinal values of the flowers of Hibiscus rosa sinensis (Chinese rose) have been mentioned in ancient literature as useful in disorders of the heart. Dried pulverized flower of Hibiscus rosa sinensis was administered orally to Wistar albino rats (150-200 gms) in three different doses [125, 250 and 500 mg/kg in 2% carboxy methyl cellulose (CMC)], 6 days per week for 4 weeks. Thereafter, rats were sacrificed; either for the determination of baseline changes in cardiac endogenous antioxidants [superoxide dismutase, reduced glutathione and catalase] or the hearts were subjected to isoproterenol induced myocardial necrosis. RESULTS: There was significant increase in the baseline contents of thiobarbituric acid reactive substances (TBARS) [a measure of lipid per oxidation] with both doses of Hibiscus Rosa sinensis. In the 250 mg/kg treated group, there was significant increase in superoxide dismutase, reduced glutathione, and catalase levels but not in the 125 and 500 mg/kg treated groups. Significant rise in myocardial thiobarbituric acid reactive substances and loss of superoxide dismutase, catalase and reduced glutathione (suggestive of increased oxidative stress) occurred in the vehicle treated hearts subjected to in vivo myocardial ischemic reperfusion injury. CONCLUSION: It may be concluded that flower of Hibiscus rosa sinensis (250 mg/kg) augments endogenous antioxidant compounds of rat heart and also prevents the myocardium from isoproterenol induced myocardial injury.
