The acute effects of Montbretin A (MbA), an á‐glucosidase inhibitor, on plasma glucose levels in the Zucker Diabetic Fatty rat

Postprandial hyperglycemia is a risk factor for cardiovascular disease in diabetic patients. Acarbose and Miglitol, current therapeutic α‐glucosidase inhibitors, reduce postprandial hyperglycemia but, due to side effects, are not well tolerated. Research is ongoing to develop products that will minimize side effects and improve patient compliance. MbA, a purified glycosylated acyl flavonol, was isolated from extracts of the plant, Crocosmia crocomiflora. In vitro studies have shown MbA to be an inhibitor of both exquisite specificity and affinity for human pancreatic α‐amylase. The objective of this study was to determine if MbA was an orally effective glucose lowering agent in an animal model of type 2 diabetes. Animals were challenged with a starch load (2 g/kg) immediately followed by MbA (dose range: 0.5 to 10 mg/kg) administered by oral gavage. Plasma glucose levels were measured immediately prior to and at 30, 60, 90 and 120 minutes post‐administration. Acarbose 10 mg/kg was used as a control for glucose response. MbA prevented the starch‐induced increase in glucose levels at doses greater than 5 mg/kg. MbA (10 mg/kg) reduced plasma glucose levels by 38±3% as compared to 26±2% for acarbose in fatty treated animals. These data show that MbA was effective in lowering plasma glucose levels in vivo . Future studies will examine the chronic effects of oral MbA treatment on diabetes mellitus. Supported by CDRD and CIHR.