Effect of Raphia hookeri Seed Extract on Blood Glucose, Glycosylated Haemoglobin and Lipid Profile of Alloxan Induced Diabetic Rats

Abstract

Aim: To examine the effect of Raphia hookeri (RH) seed extract on blood glucose, glycosylated haemoglobin and lipid profile of alloxan induced diabetic rats. Materials and Methods: In the oral glucose tolerance test (OGTT), the animals received the extract (1 g/kg) or glibenclamide (0.01 mg/kg) or vehicle and 30 min later they received oral glucose load (1 g/kg). Glucose was estimated at 30min, 1, 2, 3 and 4 h. In hypoglycaemic study, the extract was administered at doses of 100, 250 and 500 mg/kg body weight (bwt) doses. In fasting blood glucose study (FBG), diabetic Wister rats, 5 per group, received graded doses (50, 100 and 200 mg/kg) of the extract or glibenclamide (10 mg/kg) or vehicle for 15 days. Blood was collected on days 0, 3, 5, 7, 9, 11, 13, 15 for glucose estimation. Lipid profile was analyzed using modified enzymatic procedure. Insulin assay was done by Diagnostic Automation Kit and HbA1C by standard protocol. The studies lasted for three weeks. Results: The diabetic animals treated with the extract showed appreciable weight gain. In oral glucose tolerance test (OGTT), RH seed extract and glibenclamide treated rats blood glucose significantly (P<0.05) decreased in the peak values and the area under curve after 4 h of oral load with decreased values of 48.3±1.0 mg/dL (63.3%) and 62.0±0.8 mg/dL (51.6%) respectively. The hypoglycaemic activity at 250 and 500 mg/kg body weight (bwt) doses showed lowest plasma glycaemic decrease of 50.1% and 54.4% respectively after 8 h of oral administration. In FBG study, after 15 days of extract/glibenclamide treatment, the animals’ blood glucose exacerbated by alloxan challenge returned to normal glycaemia with glycaemic decrease of 87.2±2.3 (79.3%); 57.0±1.7 (86.3%) and 55.0±0.3 mg/dL (87.1%) respectively while glibenclamide showed a maximum glycaemic decrease of 167.4±1.1 mg/dL (60.1%). The tissue morphology of the extract treated showed significant beta cells survivor. The extract ameliorated dislipidaemia and exerted significant (p<0.05) decrease in plasma HbA1C while marked increase in plasma insulin level occurred. Conclusion: The extract effectively attenuated hyperglycaemia, caused marked decrease in HbAIC concentration and ameliorated dislipidaemia.