Bitter melon protects against lipid peroxidation caused by immobilization stress in albino rats

In the present study, protective effects of bitter melon (Momordica charantia) extract on lipid peroxidation induced by immobilization stress in rats have been assessed. Graded doses of extract (50, 100, and 150 mg/kg body weight) were administered orally to rats subjected to immobilization stress for two hours for seven consecutive days. Stress was applied by keeping the rats in a cage where no movement was possible. After seven days, rats were killed by decapitation after ether anesthesia. Blood and liver were collected to measure thiobarbituric acid reactive substances, reduced glutathione, and catalase. In vitro effects of M. charantia extract on lipid peroxidation in liver homogenate of normal, control, and rats pretreated with extract were carried out against cumene hydroperoxide-induced lipid peroxidation. Results reveal that in vivo M. charantia inhibited stress-induced lipid peroxidation by increasing the levels of reduced glutathione and activities of catalase. These results were further supported by in vitro results. In vitro inhibition of lipid peroxidation was indicated by low levels of thiobarbituric acid in the liver homogenate from pretreated rats and normal rats when incubated with both cumene hydroperoxide and extract. Inhibition was also noted in the homogenate where the rats were pretreated but the mixture contained no extract. Thus this plant provides protection by strengthening the antioxidants like reduced glutathione and catalase. Inclusion of this plant in the daily diet would be beneficial.