Effect of AA on oral glucose tolerance test (A); the areas under the curve (AUC) were calculated using the trapezoid method (B); comparison between the effects of streptozotocin (singly) and streptozotocin-nicotinamide (in combination) on adult rats (C). Data were expressed as mean ± SE (n = 6). *p < 0.05 compared with control group. **p < 0.01 compared with control group. #p < 0.05 compared with streptozotocin-nicotinamide treated rats. $p < 0.01 compared with streptozotocin-nicotinamide treated.