Abstract: Objective To observe protective effect of blueberry anthocyanins on cyclophosphamide-induced cardiotoxicity in rats and to explore the mechanism of the effect.Methods Thirty-two male Sprague Dawley rats were randomly divided into control group,model group and blueberry anthocyanins group(20 mg/kg and 80 mg/kg).All animals in treatment groups were administerted with blueberry anthocyanins by gavage once a day for 14 days continuously.The rats in the model group and treatment group were injected with cyclophosphamide(100 mg/kg)at 8th day of the experiment.Myocardial histopathology change was observed.Malondialdehyde(MDA) content and superoxide dismutase(SOD) activity in serum of the rats were detected by using kit assay automaticbiochemical analyzer.Bcl-2 and Bax protein levels of myocardial cells were detected with Western blot method.Results The rats in the model group showed cardiac myocyte hypertrophy,degeneration/necrosis,apoptosis,and infiltration.Whereas the extent of cardial myocyte degeneration and necrosis,apoptosis,and infiltration were alleviated in blueberry anthocyanins group.Myocardial cell injury indices such as lactate dehydrogenase(314.7±9.2 U/L),aspartate aminotransferase(772.5±18.3 U/L),and creatine kinase(501.5±13.6 U/L) increased significantly in model groups,while the indexes decreased significantly in blueberry anthocyanins treatment group(127.7±7.4,411.5±10.3,and 268.6±8.4).The content of SOD decresead and MDA content increased significantly in myocardial tissue of model group,wheras in blueberry anthocyanins group,SOD level increased and MDA content decreased significantly.Conclusion Blueberry anthocyanins have protective effect on cyclophosphamide-induced cardiac toxicity in rats and the mechanism of the effect may be related to antioxidant capacity of blueberry anthocyanins.