Therapeutic Efficacy of Polyphenol-Rich Fraction of Boesenbergia rotunda in Diabetic Rats: A Focus on Hypoglycemic, Antihyperlipidemic, Carbohydrate Metabolism, Antioxidant, Anti-Inflammatory and Pancreato-Protective Activities

Introduction: Boesenbergia rotunda is a famous culinary/medicinal herb native to Southeast Asia region and it is traditionally used in the treatment of several diseases. This study investigated the anti-diabetic properties of Boesenbergia rotunda polyphenol extract (BRE) in high fructose/streptozotocin-induced diabetic rats. Method: The in vitro antioxidant activity was evaluated using DPPH and ABST colorimetric assays, while the Folin-Ciocalteu method was used for the total phenolic content of BRE. For diabetes induction, a combination of high fructose solution and streptozotocin was administered to the rats and diabetic rats were orally administrated with BRE (100 and 400 mg/kg) for 5 weeks. The fasting blood glucose, body weight gain, food and water consumption were determined during the treatment period. Results: BRE showed excellent in vitro DPPH and ABTS scavenging activity with high phenolic content. BRE significantly lowered fasting blood glucose level, HbA1c, lipid profile, hepatorenal biochemical parameters and ameliorated the IPGTT in diabetic rats. Additionally, BRE reversed body weight loss, attenuated food and water intake, serum insulin level, pancreatic ss-cell function and pancreatic cell morphology. Furthermore, fructose 1,6 biphosphatase, glucose-6-phosphatase, malondialdehyde (MDA) and proinflammatory cytokines levels were also ameliorated in the BRE-treated diabetic rats, while pancreatic antioxidant enzymes activities (GSH, SOD and CAT) were significantly increased in the treated rats. Conclusions: In conclusion, the results showed that BRE effectively displayed antidiabetic effects and has possible value for antidiabetic oral medication.