Blood Glucose – Lowering Potentials of Annona muricata Leaf Extract in Alloxan–Induced Diabetic Rats

Abstract

The blood glucose- lowering potentials of ethanol leaf extract of Annona muricata were studied. Thirty wistar albino rats were divided into six groups of five rats per group. Group 1 served as “Normal control” animals and received normal rat pellets and water. Diabetes mellitus was induced in Groups 2, 3, 4, and 5 by intraperitoneal injection of alloxan (130 mg/kg). Group 6 rats were administered with 400 mg/kg daily of the extract without induction; group 3 rats were treated with glibenclamide (5 mg/kg body weight), groups 4 and 5 received 200 mg/kg and 400 mg/kg body weight of A. muricata leaf extract daily respectively throughout the duration of the experiment of 14 days. Group 2 rats were induced but not treated with any drug, thus it served as the “Negative control” group. Quantitative phytochemical analysis of the leaf extract was carried out using the Association of Official Analytical Chemists (AOAC) methods. Acute toxicity test of the leaf extract of A. muricata was determined using 12 rats by Lorke’s toxicity testing method. The blood glucose levels of the animals in each group were determined using Accu-chek test strip method. The weights of the animals were determined using a standard electronic weighing balance. The result of the quantitative phytochemical analysis of the leaf showed that the ethanol leaf extract contains the following: phenols (74 mg/100 g), flavonoids (3.70 mg/100 g), tannins (2.95 mg/100 g), oxalate (6.48 mg/100 g), terpenoid (13.88 mg/100 g), phytates (130 mg/100 g), saponins (6800 mg/100 g), alkaloids (570 mg/100 g), cardiac glycoside (1690 mg/100g). Acute toxicity studies showed that LD50 was 3807.89 mg/kg body weight. The results of the average blood glucose levels (mg/dl) of the rats in each group were group 1, 82.6071±7.7524, group 2, 309.3571±163.6923, group 3, 226.7143±132.8182, group 4, 146.5000±140.1465, group 5, 150.4783±81.8340, and group 6, 83.4643±12.5329 for each group respectively. The average body weights of the rats in each group were group 1, 192.8571±22.5844, group 2, 185.7143±33.6759, group 3, 177.1429±36.67500, group 4, 219.2857±21.2908, group 5, 119.5455±23.5993, and group 6, 191.7857±25.2475. The findings from this study suggest that ethanolic leaf extract of A. muricata has notable effect in lowering blood glucose levels in diabetic rats and is a more potent drug in the treatment and management of diabetes mellitus and oxidative stress- related diseases.