Effectiveness of flavonoid-rich leaf extract of Acalypha indica in reversing experimental myocardial ischemia: biochemical and histopathological evidence.

Abstract

Objective: In this study, we investigated the antimyocardial ischemic effects of flavonoid-rich methanolic leaf extract of Acalypha indica (AIE).

Methods: An animal model of myocardial ischemic injury was induced by isoproterenol (ISO) in adult rats. Albino Wistar rats were pretreated with the AIE (100 and 200 mg/kg body weight orally) for 30 d followed by ISO (85 mg/kg subcutaneously) at an interval of 24 h for 2 d. At the end of the experimental period (12 h after the second dose of ISO injection), rats were sacrificed by anaesthetization with an intramuscular injection of ketamine hydrochloride (24 mg/kg). To ensure anti-ischemic potential of AIE, the plasma lipids such as total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), free fatty acids (FFA), phospholipids (PL), myocardial lipids and hepatic lipids (TC, TG, FFA and PL) were estimated. Histopathology of heart tissue was also examined.

Results: Administration of AIE maintained the levels of plasma lipids in all the treatment groups (100 and 200 mg/kg) when compared with the ISO-injected model rats. Histopathological examination of heart tissue of ISO-administered model rat showed myofiber loss, extensive subendocardial necrosis, infiltration of inflammatory cells, marked myocellular edema and vacuolar degeneration. However, pretreatment with AIE at 200 mg/kg showed predominantly normal myocardium structure with myofibers appeared and no inflammatory cell infiltration, edema and necrosis.

Conclusion: The biochemical and histological evidence from this study shows that AIE is protective against ISO-induced myocardial ischemia.