Synergistic Effect of β-Carotene and Metformin on Antihyperglycemic and Antidyslipidemic Activities in Streptozotocin-Induced Diabetic Rats

Purpose: Worldwide prevalence of diabetes mellitus (DM) has become an issue of great concern in current decades. To date, a large number of biological properties have been reported from carotenoids, particularly protective effects against cancer, cardiovascular diseases, and DM, including enhancement of insulin sensitivity.In this study, we aimed to evaluate the efficacy of β-carotene as an additive agent with metformin in ameliorating Type2 (T2)DM.

Methods: In this experiment, fasting blood glucose level (BGL), low density lipoprotein (LDL), high density lipoprotein (HDL), total cholesterol (TC) and triglycerides (TG) were measured in serum of Wister albino rats with streptozotocin (STZ)-induced diabetes and after treatment with metformin (850mg/70kg b.w.) and β-carotene (10 mg/70kg b.w.) administered orally once daily for three weeks.

Results: Metformin and β-carotene treatments individually resulted in significant (p<0.001) reversal of the diabetes induced increase in BGL, LDL, TC and TG, whereas significantly increased the STZ-induced decrease in HDL, compared to diabetic control. As compared to the monotherapy, the combination therapy with metformin and β-carotene showed a significant (p<0.001) attenuation of BGL and serum level of LDL, TC, and TG and a slight increase (p<0.05) in serum HDL level, as compared to the treatment with β-carotene, but not with metformin.

Conclusion: The combination therapy of β-carotene and metformin produced a significant antidiabetic and antihyperlipidemic effect than the monotherapy alone and provides a scientific rationale for their use in antidiabetic therapy as a potential antioxidant.