Triple-action of the standardized antidiabetic polyherbal extract; Synacinn™ through upregulation of GLUT4 and inhibition of DPP(IV), a-amylase, and a-glucosidase activity

Abstract

Introduction: Synacinn™ is a standardized polyherbal supplement for diabetes mellitus which is formulated from Andrographis paniculata, Curcuma xanthorrhiza, Cinnamomum zeylanicum, Eugenia polyantha, and Orthosiphon stamineous. Materials and Methods: This study aimed to elucidate the antidiabetic potential of Synacinn™ on three specific actions, including 1) the insulin sensitivity and glucose transport on dexamethasone-induced insulin-resistance 3T3-L1 adipocytes, 2) the inhibitory capacity on postprandial enzyme activity (a-amylase and a-glucosidase), and 3) the inhibitory activity of hepatic DPP(IV) enzyme. Results: Results showed that insulin resistance of 3T3-L1 adipocytes may be developed by prolonging the exposure of 1µg/ml of dexamethasone for >48 hours. The insulin-resistance condition was minimized by the treatment of 10 µg/ml of Synacinn™ which significantly improved the insulin-stimulated glucose utilization by 10.6%. Meanwhile, insulin-stimulated glucose utilization in normal adipocytes was also attenuated by 9.2%. At the cellular level, Synacinn™ attenuated glucose utilization mainly by upregulating GLUT4 protein expression by 1.71 fold. Additionally, Synacinn™ is a potent inhibitor for the activity of a-amylase and a-glucosidase with IC50 of 0.467 mg/mL and 0.245 mg/mL, respectively. Synacinn™ also controlled the glycemic index through inhibition of hepatic DPP(IV) enzyme with IC50 of 1.11 mg/mL. Conclusion: Results suggested that Synacinn™ reduced diabetes mellitus through sensitizing the cellular glucose utilization, reducing the postprandial carbohydrate degradation, and inhibiting the hepatic DPP(IV) enzyme function.