H Parikh, CB Tripathi, P Shah, V Ghori, RK Goyal. Investigation of the cardioprotective effects of Crataegus oxycantha and its molecular mechanism. Curr Res Cardiol 2015;2(4):161-167. BaCKGRound:Crataegus oxycantha has been used as a cardiotonic for the treatment of early stage congestive heart failure; however, there are few authentic investigational studies addressing its cardioprotective use. oBJECTIVE: To investigate the cardioprotective effect of C oxycantha and to elucidate its possible mechanism of action. METHodS:The effects of C oxycantha was studied using a rat model of isoproterenol (ISO) (100 mg/kg subcutaneous for two days) -induced myocardial necrosis. Cardiac damage was assessed using various biochemical enzymes and histological studies. Various oxidative parameters and Na + -K + ATPase activity were studied to elucidate the mechanism of action. RESulTS: Pretreatment with C oxycantha significantly prevented the increase in serum levels of cardiac troponin-I, creatine kinase-MB, lactate dehydrogenase, glutamate oxalotransaminase, glutamate pyruvate transaminase and uric acid in ISO-treated (100 mg/kg) rats. The increased serum levels of cholesterol, triglyceride, low-density lipoprotein cholesterol and atherogenic index after ISO administration were decreased to nearly normal levels by C oxycantha extract. Pretreatment with C oxycantha in ISOtreated animals produced significant decrease in lipid peroxidation and significant increase in endogenous antioxidant superoxide dismutase, catalase and reduced glutathione in myocardial tissue. C oxycantha extract significantly inhibited Na + -K + ATPase enzyme present in heart homogenate by virtue of presence of ursolic acid as evidenced by high-performance thin layer chromatography analysis of C oxycantha extract, which may be a possible mechanism of cardiotonic activity of C oxycantha. ConCluSIon: C oxycantha may be viewed as potentially cardiotonic, cardioprotective and antioxidant.