['To investigate the effects of icariin on cardiac functions and mitochondrial oxidative stress in streptozotocin (STZ)-induced diabetic rats.', 'Male SD rats were randomly divided into normal control group, icariin control group, diabetic group, and diabetic groups administered with a low dose (30 mL x kg(-1) x d(-1), ig) or a high dose (120 mL x kg(-1) d(-1), ig) of icariin for 8 weeks. The body weight, blood glucose, cardiac functions, left ventricular weight, and myocardial collagen level were assayed. The cardiac mitochondrial reactive oxygen species (ROS) level, malondialdehyde (MDA) level, and superoxide dismutase (SOD) activity were measured.', 'Treatment with icariin reduced the losing of body weight in diabetic rats. Icariin markedly reduced the ratio of ventricular weight and body weight, increased the left ventricular develop pressure and +/- dp/dt(max), and decreased the left ventricular end diastolic pressure in diabetic rats. The myocardial collagen and the level of cardiac mitochondrial ROS in diabetic rats were all markedly reduced by icariin. Furthermore, high dose of icariin significantly decreased the mitochondrial MDA level and increased SOD activity in diabetic rat hearts.'] Does [ Icariin reduce mitochondrial oxidative stress injury in diabetic rat hearts ]?