RESUMEN
Propolis contains high concentrations of polyphenols, flavonoids, tannins, ascorbic acid, and reducing sugars and proteins. Malaysian Propolis (MP) has been reported to exhibit high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferric reducing antioxidant power (FRAP) values. Herein, we report the antioxidant properties and cardioprotective properties of MP in isoproterenol- (ISO-) induced myocardial infarction in rats. Male Wistar rats (n = 32) were pretreated orally with an ethanol extract of MP (100 mg/kg/day) for 30 consecutive days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes and cardiac troponin I levels and altered serum lipid profiles. In addition significantly increased lipid peroxides and decreased activities of cellular antioxidant defense enzymes were observed in the myocardium. However, pretreatment of ischemic rats with MP ameliorated the biochemical parameters, indicating the protective effect of MP against ISO-induced ischemia in rats. Histopathological findings obtained for the myocardium further confirmed the biochemical findings. It is concluded that MP exhibits cardioprotective activity against ISO-induced oxidative stress through its direct cytotoxic radical-scavenging activities. It is also plausible that MP contributed to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation.
RESUMEN
Although Citrus macroptera (Rutaceae), an indigenous fruit in Bangladesh, has long been used in folk medicine, however, there is a lack of information concerning its protective effects against oxidative damage. The protective effects of an ethanol extract of Citrus macroptera (EECM) against acetaminophen-induced hepatotoxicity and nephrotoxicity were investigated in rats. Rats (treatment groups) were pretreated with EECM at doses of 250, 500, and 1000 mg/kg, respectively, orally for 30 days followed by acetaminophen administration. Silymarin (100 mg/kg) was administered as a standard drug over a similar treatment period. Our findings indicated that oral administration of acetaminophen induced severe hepatic and renal injuries associated with oxidative stress, as observed by 2-fold higher lipid peroxidation (TBARS) compared to control. Pretreatment with EECM prior to acetaminophen administration significantly improved all investigated biochemical parameters, that is, transaminase activities, alkaline phosphatase, lactate dehydrogenase, γ-glutamyl transferase activities and total bilirubin, total cholesterol, triglyceride and creatinine, urea, uric acid, sodium, potassium and chloride ions, and TBARS levels. These findings were confirmed by histopathological examinations. The improvement was prominent in the group that received 1000 mg/kg EECM. These findings suggested that C. macroptera fruit could protect against acetaminophen-induced hepatonephrotoxicity, which might be via the inhibition of lipid peroxidation.
RESUMEN
We investigated the protective role of Withania somnifera leaf extract (WSLEt) on isoproterenol- (ISO-) induced myocardial infarction (MI) in rats. Subcutaneous injection of ISO (85 mg/kg body weight (b.w.)) administered to rats for two consecutive days caused a significant increase in cardiac troponin I (cTnI) levels and serum lipid profiles, as well as the activities of some marker enzymes. In addition to these diagnostic markers, there were increased levels of lipid peroxidation (LPO) and decreased activities of enzymatic antioxidants (superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRx), and glutathione-S-transferase (GST)) in the myocardium. However, oral pretreatment (100 mg/kg b.w.) with WSLEt for 4 weeks elicited a significant cardioprotective activity by lowering the levels of cTnI, lipid profiles, and marker enzymes. The levels of LPO products were also significantly decreased. Elevated activities of antioxidant enzymes were also observed in rats pretreated with WSLEt. As further confirmed histopathologically, our findings strongly suggest that the cardioprotective effect of WSLEt on myocardium experiencing ISO-induced oxidative damage may be due to an augmentation of the endogenous antioxidant system and an inhibition of LPO in the myocardial membrane. We conclude that WSLEt confers some protection against oxidative damage in ISO-induced MI in rats.