Effects of an ethanolic extract of Garcinia kola on glucose and lipid levels in streptozotocin induced diabetic rats

The effect of Garcinia kola on glucose and lipid levels in streptozotocin-induced diabetic rats was investigated. Ethanolic extract of G. kola was prepared and used for animal treatments. Diabetes was induced by a single intraperitoneal injection of streptozotocin (40 mg/kg body weight). Acute effects of G. kola on glucose were investigated by giving a single dose of distilled water or 300 mg/kg G. kola extract or metformin 300 mg/kg. Glucose levels were measured 2, 4 and 6 h after treatment. To investigate the long term effects, animals were treated daily for four weeks with either distilled water (controls) or 300 mg/kg G. kola extract. At termination, serum glucose, low density lipoprotein (LDL) and high density lipoprotein (HDL) levels were measured. There was no significant difference (P>0.05) in single dose glucose levels, long term HDL levels and body weights compared to the controls. However, in the four week treated rats, glucose (mmol/L) was significantly lower (16.2±2.9; P<0.05) than in the controls (21.6±3.6) and the LDL levels were significantly decreased by 66% in the treated group compared to controls (P<0.01; 86.8±18.2 versus 29.8±10.9). This confirms the hypoglycaemic and especially the hypolipidemic effects of G. kola in a diabetic rat model.Keywords: G. kola, ethanolic extract, hyperglycemia, low density lipoprotein (LDL), high density lipoprotein (HDL), streptozotoci