Effect of GBRE supplement on the insulin level (a) and insulin resistance; (b) in the experimental rats. C: Control, LD: Low dose of GBRE to naïve rat, HD: High dose of GBRE to naïve rat, DM: Diabetes Mellitus induced rat, Pre-DM-LD: Low dose of GBRE to naïve rat and induced DM, Pre-DM-HD: High dose of GBRE to naïve rat and induced DM; Post-DM-LD: Low dose of GBRE to DM rat, Post-DM-HD: High dose of GBRE to DM rat. The significant difference between groups (a = when compared with control group; b = when compared with DM group; c = when compared with the drug group) were represented as * (p < 0.05), and ** (p < 0.01).