Influence of Alpha-Lipoic Acid on Streptozotocin Induced Diabetic Cardiomyopathy in Adult Male Albino Rats

Abstract

Introduction: Cardiovascular disease is responsible for 80% of deaths among diabetic patients. Diabetic patients may suffer from cardiac insult termed ‘diabetic cardiomyopathy’. Aim of the Work: Investigation of biochemical structural and ultrastructural changes of the diabetic hearts and effect of supplementation with alpha-lipoic acid (ALA). Materials and Methods: Thirty adult male albino rats were divided into: group I control rats, group II diabetic rats and group III diabetic rats receiving ALA. Diabetes was induced in rats of groups II and III by streptozotocin drug. The animals were sacrificed after 16 weeks. The hearts and sera were prepared for biochemical and microscopical studies. Results: Diabetic (Group-II) animals showed significant increase in levels of serum; glucose, malondialdehyde (MDA), cholesterol and hepatic glucose -6-phosphatase enzyme (G-6-Pase) activity in addition to a significant decrease in tissue glutathione (GSH). Structurally, cardiac muscle fibers appeared swollen with areas devoid of fibers, with collagen deposition among them. Ultrastructurally, diabetic hearts showed poorly organized myofibrils and sarcomeres, disrupted Z lines, dilated sarcoplasmic reticulum, abnormal mitochondria with heterogonous electron dense matrix and disrupted mitochondrial membranes. Some mitochondria showed vacuoles and fusion with each other. The wall of blood vessels was irregular. Secondary lysosomes and myelin bodies in between myofibrils were detected. In diabetic (Group-III) animals, ALA partially prevented biochemical, structural and ultrastructural changes. Conclusion: Different structural, ultrastructural and biochemical changes were evident in diabetic rats after 16 weeks. The supplementation of ALA in diabetic rats partially prevented such changes, suggesting its possible protective effect against the risk of the progression of cardiovascular diseases during diabetes.