Methanol Leaf Extract of Desmodium velutinum (Wild.) D.C. and Acarbose Exhibit Additive Pharmacological Effects in Diabetic Wistar Rats

Abstract

This study investigated the pharmacological effects of methanol extract of Desmodium velutinum leaves (DVE) administered alone and when co-administered with Acarbose (ACA) in diabetic Wistar rats. Preliminary phytochemical analysis and acute toxicity study were carried out on DVE using standard methods. In the pharmacological study, diabetes was induced in rats by intraperitoneal administration of 150 mg alloxan/kg b.w. Seven groups (6 groups of diabetic rats and 1 group of normoglycemic rats) of four rats each were used for the study. Groups I and II served as normoglycemic (NDC) and diabetic controls (DC) respectively and received 1ml distilled water/kg b.w. Groups III and IV were administered 400 and 800 mg DVE/kg respectively while groups V and VI were administered the same doses (400 and 800 mg/kg respectively) but co-administered with a fixed dose of ACA (150 mg/kg b.w.). Group VII was administered 150 mg ACA/ kg b.w. alone. Weekly fasting blood sugar (FBS) levels and body weight changes were estimated for 28 days. After the 28-day treatment regimen, rats were euthanized, and blood samples collected for serum biochemical analysis. Phytochemical analysis of DVE revealed the presence of alkaloids, phenols, flavonoids, tannins, steroids and terpenoids in varying proportions. Treatment with DVE alone and its co-administration with ACA significantly (p< 0.05) reduced FBS and serum biochemicals parameters of rats compared with diabetic control. DVE alone and its co-administration with ACA also significantly (p< 0.05) increased the serum total protein of rats compared with diabetic control. However, the pharmacological effects of DVE and ACA co-administration were significantly (p< 0.05) higher than that of DVE or ACA administered alone. It was concluded that DVE and ACA exhibited additive pharmacological effects in diabetic Wistar rats and as such could be useful in the management of diabetes.