ABSTRACT
Objective: Okra [Abelmoschus esculentus] is a tropical vegetable that is rich in carbohydrates, fibers, proteins and natural antioxidants. The aim of the present study was to evaluate the effects of Okra powder on pancreatic islets and its action on the expression of PPAR-gamma and PPAR-alpha genes in pancreas of high-fat diet [HFD] and streptozotocin- induced diabetic rats
Materials and Methods: In this experimental study, diabetes was induced by feeding HFD [60% fat] for 30 days followed by an injection of streptozotocin [STZ, 35 mg/kg]. Okra powder [200 mg/kg] was given orally for 30 days after diabetes induction. At the end of the experiment, pancreas tissues were removed and stained by haematoxylin and Eozine and aldehyde fuchsin for determination of the number of beta-cells in pancreatic islets. Fasting blood sugar [FBS], Triglycerides [TG], cholesterol, high density lipoprotein [HDL], low density lipoprotein [LDL], and insulin levels were measured in serum. Moreover, PPAR-gamma and PPAR-alpha mRNAs expression were measured in pancreas using real time polymerase chain reaction [PCR] analysis
Results: Okra supplementation significantly decreased the elevated levels of FBS, total cholesterol, and TG and attenuated homeostasis model assessment of basal insulin resistance [HOMA-IR] index in diabetic rats. The expression levels of PPAR-gamma and PPAR-alphagenes that were elevated in diabetic rats, attenuated in okra-treated rats [P<0.05]. Furthermore, okra improved the histological damages of pancreas including vacuolization and decreased beta-cells mass, in diabetic rats
Conclusion: Our findings confirmed the potential anti-hyperglycemic and hypolipidemic effects of Okra. These changes were associated with reduced pancreatic tissue damage. Down-regulation of PPARs genes in the pancreas of diabetic rats after treatment with okra, demonstrates that okra may improve glucose homeostasis and beta-cells impairment in diabetes through a PPAR-dependent mechanism
ABSTRACT
Objective: L-carnitine [LC] has been shown to protect cardiac metabolism in diabetes patients with cardiovascular diseases [CVDs]. Apelin, a newly discovered adipocytokines, is an important regulator of cardiac muscle function; however, the role of the level of expression of Apelin axis in improvement of cardiac function by LC in diabetic patients, is not clear. In the present study, obese insulin-resistant rats were used to determine the effect of LC, when given orally with a high-calorie diet, on Apelin and Apelin receptor [Apj] expression in cardiac muscle
Materials and Methods: In this experimental study, rats were fed with high-fat/high-carbohydrate diet for five weeks and subsequently were injected with streptozotocin 30 mg/kg for induction of obesity and insulin resistance. After confirming the induction of diabetes [serum glucose above 7.5 mmol/L], the animals received LC 300 mg/kg in drinking water for 28 days. On days 0, 14 and 28 after treatment, cardiac Apelin and Apj gene expression was evaluated by real time polymerase chain reaction [PCR] analysis. Serum levels of insulin, Apelin, glucose, tumor necrosis factor-alpha [TNF-alpha], interleukin-1beta [IL-1beta] and the homeostasis model assessment of insulin resistance [HOMA-IR] were also measured using commercial kits
Results: Cardiac Apelin and Apj expression and serum Apelin were increased in obese rats, while LC supplementation decreased the serum levels of Apelin and down-regulated Apelin and Apj expression in cardiac muscle. These changes were associated with reduced insulin resistance markers and serum inflammatory factors and improved lipid profile
Conclusion: We concluded that LC supplementation could attenuate the over-expression of Apelin axis in heart of diabetic rats, a novel mechanism by which LC improves cardiovascular complications in diabetic patients