A synergistic insulinotropic effect of green tea extract and pomegranate extract with rosiglitazone: both in vivo and in vitro experiment

Objective: Scientists have growing interest in traditional medicinal plants as they contain active ingredients for the treatment of various diseases. Tea is one of the most popular beverages worldwide. The variety of tea and tea extracts in the market has different polyphenol profiles, which are the bioactive chemical entities. We performed a direct comparison between Thea sinensis, green tea extracts (GTEs), and Punica granatum peel powder (PGPP), which have been chemically well characterized in a type II diabetic mouse model. Methods: We conducted both in vivo and in vitro experiments in the present paper. In vivo studies were carried out on male Swiss albino rats having type II diabetes, induced by single intravenous injection of streptozotocin (0.7 mg/Kg i.m.) and IDDM rats received either PGPP (200 mg/kg) or GTE (100 mg/kg) as a single oral dose. After the above result, the extracts were further subjected to know the effect of insulin secretion by RIN-5F cells providing confirmation of insulinotropic effect. Results: The results revealed that both PGPP and GTE substantially lowered blood glucose levels and ameliorated glucose intolerance, both were effective in antihyperglycemic activity and in lowering body weight gain. Serum insulin levels significantly increased in GTE group as well as in PGPP group, suggesting that they were exerting hypoglycemic effects through different pathways. Conclusion: Synergistic action of PGPP and GTE is an effective alternative for the treatment of type II diabetes through the regeneration of ß cells of pancreas.