Study of the antidiabetic activity of Punica granatum L. fruits aqueous extract on the Alloxan-diabetic Wistar rats

Pancreatic β-cells dysfunction and impairment of insulin action usually leads to hyperglycemia. Punica granatum L. is a well-known traditional herbal remedy in Iran due to its positive effects on ameliorating blood glucose homeostasis. In this study, we aimed to investigate and compare the pomegranate fruits aqueous extract (PE) on glucose and lipid metabolisms in normal and Alloxan-induced diabetic male Wistar rats. Therefore, normal (N) and diabetic (D) rats were each divided into four groups (control, a, b and c) which were treated orally with PE at doses of 0, 100, 200 and 350 mg/kg (bw), respectively. Oral glucose tolerance test (OGTT) followed by short-term and long-term glycemic controls were performed on the experimental groups. Also, plasma insulin, free fatty acids and triglyceride levels and tissues contents of glycogen and triglyceride were evaluated. By using Real-time PCR, the possibility of modulations of the Insulin receptor substrate 1 (IRS-1), Protein kinase B (Akt), Glucose transporter 2 and 4 (Glut-2, 4) mRNAs expression levels in treated rats were investigated. The obtained data showed noticeable reduction in fasting blood glucose (FBG) by 28.1% and 67.9% in short-term and long-term treatment models, respectively, in the PE+Dc group. Also, there were marked increase in the mRNAs expression levels of IRS-1, Akt, Glut-2 and Glut-4, which results in improvement of glucose uptake and storage. Taking together, it is suggested that PE administration contributed to the modulation of both hyperglycemia and hyperlipidemia in Alloxan-diabetic Wistar rats.