Effects of Pomegranate and Onion Peels Extracts on reducing weight and controlling diabetes in Obese Diabetic Rats

The current study aimed to evaluate the effects of pomegranate peel extract (PPE) and onion peel extract (OPE) on body and fat weights; serum levels of liver enzymes, lipid profile, glucose, insulin and leptin hormones and on activities of renal tissue antioxidant enzymes and histopathology of kidneys in obese diabetic rats. Forty nine male Sprague Dawley rats were randomized into 7 equal groups (n=7). Group 1 (negative control) was fed on basal diet, while the other 6 groups were fed on high-fat diet (HFD) for 4 weeks to induce acute obesity and hyperlipidemia. The obese rats were then rendered diabetic by intraperitoneal injection of alloxan (120 mg/kg/day) for 5 days. On becoming diabetic, group 2 was kept obese diabetic as positive control and groups 3, 4, 5 and 6 were orally given PPE in doses 100 and 200 mg /kg b.wt and OPE in doses 100 and 200 mg/kg b.wt, respectively for 6 weeks. Group 7 was orally treated with Glibenclamide (standard antidiabetic drug) in a daily dose 5 mg/kg b.wt for 6 weeks. Blood samples were collected for biochemical analyses. Kidneys were dissected out for histopathology and renal homogenates were prepared to assay activities of tissue antioxidant enzymes. The results showed that oral administration of PPE and OPE to obese diabetic rats significantly reduced body and fat weights; decreased serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total cholesterol, triglycerides and low density lipoprotein. It also decreased blood urea, creatinine, glucose and leptin hormone and increased in insulin levels. Both extracts increased activities of superoxide dismutase, glutathione peroxidase and catalase antioxidant enzymes in renal tissues and alleviated kidney histopathological lesions induced by diabetes. The results denote that pomegranate and onion peel extracts possess anti-obesity, antidiabetic effects, and consequences in obese diabetic rats. The study recommends that pomegranate and onion peels as waste products may be economically used for manufacture of safe and beneficial product for trials on obese diabetics patient.