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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. [ABSTRACT FROM AUTHOR]

The present study was designed to investigate the cardioprotective effects of Sundarban honey (SH) in rats with isoproterenol- (ISO-) induced myocardial infarction. Adult male Wistar Albino rats were pretreated with Sundarban honey (5 g/kg) daily for a period of 6 weeks. After the treatment period, ISO (85 mg/kg) was subcutaneously injected into the rats at 24 h intervals for 2 days. ISO-induced myocardial damage was indicated by increased serum cardiac specific troponin I levels and cardiac marker enzyme activities including creatine kinase-MB, lactate dehydrogenase, aspartate transaminase, and alanine transaminase. Significant increases in serum total cholesterol, triglycerides, and low-density lipoprotein-cholesterol levels were also observed, along with a reduction in the serum high-density lipoprotein-cholesterol level. In addition to these diagnostic markers, the levels of lipid peroxide products were significantly increased. The activities of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, and glutathione reductase were significantly decreased in the hearts after ISO-induced myocardial infarction. However, pretreatment of ischemic rats with Sundarban honey brought the biochemical parameters to near normalcy, indicating the protective effect of Sundarban honey against ISO-induced ischemia in rats. Histopathological findings of the heart tissues further confirmed the biochemical findings, indicating that Sundarban honey confers protection against ISO-induced oxidative stress in the myocardium. [ABSTRACT FROM AUTHOR]

The present study was designed to investigate the cardioprotective effects of Malaysian Tualang honey against isoproterenol- (ISO-) induced myocardial infarction (MI) in rats by investigating changes in the levels of cardiac marker enzymes, cardiac troponin I (cTnI), triglycerides (TG), total cholesterol (TC), lipid peroxidation (LPO) products, and antioxidant defense system combined with histopathological examination. Male albino Wistar rats (n = 40) were pretreated orally with Tualang honey (3 g/kg/day) for 45 days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes (creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and aspartate transaminase (AST)), cTnI, serum TC, and TG levels. In addition, ISO-induced myocardial injury was confirmed by a significant increase in heart lipid peroxidation (LPO) products (TBARS) and a significant decrease in antioxidant enzymes (SOD, GPx, GRx, and GST). Pretreatment of ischemic rats with Tualang honey conferred significant protective effects on all of the investigated biochemical parameters. The biochemical findings were further confirmed by histopathological examination in both Tualang-honey-pretreated and ISO-treated hearts. The present study demonstrates that Tualang honey confers cardioprotective effects on ISO-induced oxidative stress by contributing to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation. [ABSTRACT FROM AUTHOR]