Effects of 10% Dietary Incorporation of Gnetum africanum in High-Fat Diet on Lipid Profile and Some Markers of Insulin Resistance in Wistar Rats

Abstract

Aims: The present study aimed to investigate the effects of Gnetum africanum leaves on the lipid profile and insulin resistance of albino rats fed a high-fat diet incorporating 10% G. africanum leaves. Study Design: After six days of acclimatisation, twenty-five (25) male albino rats were divided into five groups, with five rats in each group. The groups were as follows: Group 1 (negative control) received a basal diet and water; Group 2 (high-fat diet only) received a high-fat diet and water; Group 3 (basal + Gnetum africanum) received a high-fat diet incorporating 10% Gnetum africanum and water; Group 4 (HFD + Gnetum africanum) received a control diet incorporating 10% Gnetum africanum and water; and Group 5 (orlistat + HFD) received a high-fat diet, a daily intraperitoneal injection of orlistat (10 mg/kg body weight) and water. Place and Duration of Study: Experimental animals were maintained in metabolic cages under standard environmental conditions at the animal house of the Faculty of Veterinary Medicine, Michael Okpara University of Agriculture, Umudike. They were provided with feed and clean drinking water and allowed to acclimatise for six days before receiving their assigned diets for four (4) weeks. Methodology: Following an overnight fast, fasting blood glucose concentrations were measured each morning using an Accu-Chek Active glucometer. At the end of four (4) weeks of feeding, during which the positive control group also received intraperitoneal injections of orlistat, the animals were sacrificed, and blood samples were collected by cardiac puncture using a 19G needle and syringe. The blood samples were centrifuged at 4,000 rpm for 10 minutes, and the separated serum was used for lipid profile analysis. Results: The lipid profile results showed a significant decrease (p>0.005) in the serum concentrations of total cholesterol, triglycerides, low-density lipoprotein and VLDL in animals in the test group compared with animals in the control group, as well as a significant decrease (p>0.005) in insulin resistance (TyG index) in the test group compared with the control group. Conclusion: The results of this feeding study suggest that Gnetum africanum leaves possess pharmacological properties and may therefore be useful in the management and treatment of diseases associated with hyperglycaemia and hyperlipidaemia.