Objectives: Evaluation of therapeutic potentials of α-lipoic acid (α-LA), L-carnitine, Nigella sativa (N. sativa) or combination of them in carbohydrate and lipid metabolism of DM type I.
Methods: Rat model of diabetes was induced by single i.p injection of Streptozocin (STZ) 65 mg/kg. The rats were randomly assigned to 6 groups (G): healthy reference (HR), diabetic (DM), DM treated with α-lipoic acid, DM treated with L-carnitine, DM treated with N. sativa, and DM treated with combination of the 3 compounds. After 30 days from onset of diabetes, serum and tissue homogenate were obtained for evaluation of glucose metabolism as fasting blood glucose, insulin, insulin sensitivity, HOMA, C-peptide, and pyruvate dehydrogenase (PDH) activity. For lipid metabolism evaluation, total cholesterol and triacylglycerol (TG) were determined. Markers of antioxidants and oxidative status as total antioxidant capacity (TAC), glutathione-S-transeferase (GST), 8-hydroxy-2-deoxyguanosine (8-OH-dG) were measured.
Results: Either α-LA or N. sativa significantly reduced the elevated blood glucose level. The combination of 3 compounds significantly increased the level of insulin and C-peptide. Also, increased the antioxidant activity measured by TAC and decreased the oxidative damage of DNA as measured by 8-OH-dG. HOMA- β increased in G3 and G6 compared to G2. However, the decrease in TG, and total cholesterol levels were non-significant in all groups.
Conclusion: Combination of α-LA, L-carnitine and N. sativa will contribute significantly in improvement of the carbohydrate metabolism and to less extent lipid metabolism in diabetic rats, thus increasing the rate of success in management of DM. Also, this combination will have implications in clinical studies and clinical applications.
Keywords: DM; Nigella sativa; carnitine; lipoic acid.