Effects of ethyl acetate leaf extract of Annona muricata on some enzymes of carbohydrate metabolism in streptozotocin-induced diabetic wistar rats

Abstract

Diabetes is a chronic metabolic disease of multiple etiologies characterized by high blood sugar levels. The management of diabetes is taken as a global problem and curative treatment is yet to be uncovered. The leaf, root and bark of Annona muricata have been reportedly used locally as an antidiabetic agent. This study aimed to evaluate the effects of ethylacetate leaf extract of Annona muricata (AMLE) on selected enzymes of carbohydrate metabolism in diabetic rat model. Twenty male rats weighing 180 to 220 g were randomly assigned into four groups. Groups A and B were non-diabetic and diabetic rats respectively, treated with 5% dimethyl sulfoxide saline respectively. Groups C and D were diabetic rats treated with 200 mg/kg body weight (b.wt) AMLE and 5 mg/kg b.wt glibenclamide respectively for 14 days. Diabetes was induced by a single dose of 45 mg/kg b.wt streptozotocin (STZ) intraperitoneally. Rats with blood glucose values above 13.9 mmol/l 48 hours after STZ injection were considered diabetic. Animals were sacrificed on day 15 and hepatic activities of glucose-6-phosphate dehydrogenase, glucokinase, glucose-6-phosphatase and lactate dehydrogenase were assayed. The levels of hepatic lactate dehydrogenase, glucose-6-phosphate dehydrogenase and glucokinase activities in AMLE treated diabetic rats were significantly (p˂0.05) reduced compared to untreated diabetic rats. However, the activity of glucose-6-phosphatase was only slightly inhibited in the diabetic rats treated with AMLE. Ethylacetate leaf extract of A. muricata inhibited the activities of glucose-6-phosphatase and lactate dehydrogenase in this study. These findings partially support the use of this plant in the treatment of diabetes.