Luteolin ameliorates cardiac failure in type I diabetic cardiomyopathy

Objective: The study aimed to determine whether luteolin can confer cardioprotective effects against diabetic cardiomyopathy in relation to specific and quantitative markers of oxidative stress. Methods: We examined diabetic cardiomyopathy by left ventricular hemodynamic analysis. Myocardial oxidative stress was assessed by measuring the activity of superoxide dismutase (SOD) as well as the level of malondialdehyde (MDA). Hypolipidaemic effects of luteolin were also investigated in STZ-induced diabetic rats. Myocardial Akt/PKB phosphorylation, heme oxygenase-1 (HO-1) and connective tissue growth factor (CTGF) protein levels were measured by Western blot in all rats at the end of the study. Results: This study showed a significant increase in serum triacylglycerol (TG), total cholesterol (TC), lower density lipoprotein (LDL), MDA content, creatine kinase (CK), lactate dehydrogenase (LDH), and myocardial CTGF and a significant decrease in high density lipoprotein (HDL), SOD and Akt phosphorylation level in the diabetic group compared to the control group. Luteolin treatment induced a significant decrease in serum TG, TC, LDL, MDA, CK, LDH, and myocardial CTGF and a significant increase in HDL, SOD and Akt phosphorylation levels in comparison with the diabetic group. Conclusion: These results show that luteolin protects against the progression of diabetes mellitus-induced cardiac dysfunction by attenuation of myocardial oxidative stress probably through its antioxidant properties. (C) 2012 Elsevier Inc. All rights reserved.