Abstract

Background: Anisopus mannii (AM) N.E.Br. (Apocynaceae), a plant traditionally used for the treatment of diabetes mellitus in Northwestern Nigeria, is often prescribed as an adjunct to conventional treatment of diabetes mellitus. Aims and Objectives: The objective was to investigate the influence of coadministration of the stem of AM and metformin on glucose homeostasis and lipid profile in rats.
Materials and Methods: Following departmental ethics committee permission, two doses (200 mg/kg and 600 mg/kg) each of the aqueous and methanolic stem extracts of AM were administered to glucose-loaded normal rats, and the influence of the coadministration of the most effective of the doses tested (200 mg/kg of methanolic stem extract) with metformin (50 mg/kg) for 28 days on glucose homeostasis and lipid profile was investigated in streptozotocin/nicotinamide-induced diabetic rats.
Results: When coadministered, metformin reduced the fasting glucose-lowering effect of the AM extract, whereas the extract reduced the degree of elevation of the skeletal muscle glycogen content by metformin. Furthermore, both the extract and metformin, when combined in diabetic rats, reduced each other’s beneficial effects in (a) improving glucose tolerance, as evidenced by reduction in the total area under the oral glucose tolerance test curve; (b) reducing fasting blood levels of total cholesterol, low-density lipoprotein cholesterol and triglycerides; and (c) increasing hepatic glycogen content. Conclusion: This study revealed that metformin (50 mg/kg) and the methanolic stem extract of AM (200 mg/kg) had a potentially negative influence on each other’s beneficial effects on glucose homeostasis and lipid profile in diabetic rats