Effect of Crude Oil Exposure on Diabetic Rats Treated with Metformin and Allium sativum

Abstract

Diabetes mellitus is rapidly increasing in prevalence and petroleum hydrocarbons contribute to its pathogenesis. This study investigates the effect of crude oil exposure on management of diabetes mellitus. A total of 54 adult male albino rats were used. Diabetes was induced by a single intra-peritoneal injection of 65 mg/kg streptozotocin dissolved in citrate buffer using insulin syringe and confirmed after 7 days.  Rats were exposed to crude oil by preparing 5% v/v and 1% v/v and treated with extract and metformin for a period of four weeks. Effects of fasting blood glucose, lipid profile, antioxidant enzymes, insulin resistance, β cell function and inflammatory markers were evaluated and histological studies carried out.  The results indicated decreased in body weight with significant (p<0.05) increase in fasting blood glucose, total cholesterol, triglyceride and low density lipoprotein cholesterol in all diabetic rats and diabetic rats exposed to crude with significant (p<0.05) decrease in the mentioned parameters in rats treated with Allium sativum extract plus metformin. There was significant (p<0.05) increase in SOD activity, GSH concentration and MDA level in all diabetic rats and diabetic rats exposed to crude oil compared to diabetic rats treated with ASE plus metformin. Inflammatory markers (IL-6, TNFα, VEGF), Insulin resistance and β cell dysfunction were significantly (p<0.05) low in diabetic rats treated with ASE plus metformin. Histological examination of pancreas revealed changes in the cyto-architecture of pancreas of all diabetic rats. Treatment with the extract of Allium sativum plus metformin had improved the structure of pancreas. Exposure to crude oil therefore affects diabetes management with metformin by increasing hyperglycemia, oxidative stress indices, inflammatory markers and insulin resistance. Therefore, treatment with Allium sativum extract plus metformin would help improve or maintain glucose metabolism and homeostasis in people living in areas of crude oil exposure.