Ameliorating effect of betanin, a natural chromoalkaloid by modulating hepatic carbohydrate metabolic enzyme activities and glycogen content in streptozotocin – nicotinamide induced experimental rats

Abstract

Betanin, a chromoalkaloid of beetroot, has shown significant biological effects of antioxidants, anti-inflammatory and anticarcinogenic activities. So, we attempted to determine whether betanin (a natural pigment) would be protective against hyperglycemia in streptozotocin (STZ) - nicotinamide (NA) induced diabetic rats. Rats were injected with STZ (40mg/kgb.w.) 15 mins after the administration of NA (110mg/kgb.w.) by intraperitonially (i.p.) 30days for the induction of experimental diabetes mellitus. After 72h diabetic rats were treated with betanin orally at a doses of 10, 20 and 40mg/kg b.w., respectively in a dose dependent manner and glibenclamide (600μg/kgb.w.). The promising character of betanin against diabetic rats was evaluated by performing the various biochemical parameters and histomorphological changes in liver and pancreas. Among the three doses, 20mg/kgb.w. of betanin was able to positively regulate plasma glucose, insulin, glycosylated hemoglobin (HbA1c) and hemoglobin (Hb) levels by significantly increasing the activity of glycolytic enzyme (glucokinase and pyruvate kinase), glucose-6-phosphate dehydrogenase and significantly decreasing the activity of gluconeogenic enzymes (glucose-6-phosphatase and fructose-1,6-bisphosphatase) thereby increasing the glycogen content in the liver. We put forward that betanin could significantly restore the levels of carbohydrate metabolic key enzymes to near normal in diabetic rat. Immunohistochemical observation of pancreas revealed that betanin treated diabetic rats showed increased insulin immunoreactive β-cells, which confirmed the biochemical findings. Taken together, present study suggests that betanin modulates the carbohydrate metabolism and has beneficial effects in glucose homeostasis.