Protective effects of Buchholzia coriacea seeds extract and fractions on blood glucose and hyperlipidemia in diabetic rats

Background: The Buchholzia coriacea seeds (Capparaceae) are used in Nigerian ethnomedicine for treatment of hyperglycemia. Our aim, therefore, is to evaluate antihyperglycemic and hypolipidemic effects of extract and fractions of Bulcholzia coriacea seeds.Methods: The cut, dried and pulverized seeds were extracted with a mixture of methanol-dichloromethane (1:1) which yielded the crude extract, MDE. The MDE was fractionated using bioactive guided procedure and yielded hexane fraction (HF), ethylacetate fraction (EF) and methanol fraction (MF). Alloxan-induced diabetes, normoglycemic test and oral glucose tolerance test (OGTT) were the antidiabetic models employed, while hypolipidemic study was performed using standard assay kits to determine the serum total cholesterol (TC) triglycerides (TG) and low density lipoproteins (LDL). Acute toxicity test of the extract was performed using Lorke’s method while qualitative and quantitative phytochemical analyses were also performed using standard procedures.Results: The results showed an oral median lethality dose (LD50) greater than 5000mg/kg. The extract and fractions showed significant antihyperglycemic effect comparable and in synergy to metformin, a standard agent. The extract (200mg/kg) showed the highest percentage blood glucose reduction (PBGR) of 52.89% while ethylacetate fraction (EF, 400mg/kg) showed PBGR of 50.84%. Also, the MDE and hexane fraction (HF) showed a significant reduction of TC, TG and LDL and related increase in HDL-C levels in diabetic treated rats.Conclusions: The extract and the fractions of Buchholzia coriacea seeds possess antihyperglycemic and antihyperlipidemic effects and showed same mechanism of action as metformin, thus providing scientific rationale for its folkloric use