Evaluation of Anti-Hyperglycemic Effect of Aqueous Leaf Extract of Anisopus mannii (N.E Br) in Alloxan-Induced Diabetic Mice

Abstract

Background: Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia due to defects in insulin secretion, insulin action, or both.

Aim: The research aimed at evaluating the anti-hyperglycemic effect of aqueous leaf extract of Anisopus mannii alone and in combination with metformin in alloxan-induced diabetic mice.

Methodology: Phytochemical screening of the extract was carried out according to the methods of Trease and Evans. The LD₅₀ of the extract was determined using OECD Guideline 425. The anti-hyperglycemic effect of the extract was evaluated using the method of Goldener and Gomori. Hyperglycemia was induced by the injection of 150mg/kg of 0.5% alloxan monohydrate in mice. The study was conducted on seven groups of six rats each (n = 6). Group I rats were non-diabetic (administered distilled water), while alloxan-induced hyperglycemic rats were assigned accordingly to the remaining six groups. Group II rats served as diabetic control and were administered normal saline (1 mL/kg). Groups III, IV and V were hyperglycemic rats treated with Anisopus manni extract at doses of 250, 500, and 1000 mg/kg, respectively. Group VI (positive control) were hyperglycemic rats treated with metformin (250 mg/kg). We then added Group VII to observe the anti-hyperglycemic effect of this extract in combination with metformin. The doses were administered orally daily to the various groups for 28 days. Blood glucose levels, food, and water consumption were taken for each Group at the end of Day 7, 14, 21 and 28 of the experiment.

Results: The extract contained alkaloids, carbohydrates, cardiac glycosides, flavonoids, saponins, tannins, terpenes, and steroids. Anthraquinones were absent. The LD₅₀ of the extract was estimated to be greater than 5000 mg/kg. There were significant (p<0.05) dose-dependent reductions in blood glucose levels in the extract-treated groups when compared to the diabetic control group. There were also significant reductions (p<0.05) in food and water intake in the treatment groups when compared to the diabetic control group.

Conclusion: Aqueous leaf extract of Anisopus manni possesses a significant anti-hyperglycemic effect in alloxan-induced diabetic mice, supporting its traditional use in the treatment of diabetes mellitus. Further studies are recommended for the isolation and characterization of bioactive compounds responsible for the anti-hyperglycemic activity as well as the possible mechanism(s) of action.