The effect of a human pancreatic α‐amylase inhibitor, montbretin A, on the chronic treatment of type 2 diabetes

Montbretin A, a purified glycosylated acyl flavonol, was isolated from extracts of the plant Crocosmia crocosmiflora. Montbretin A has been shown to be a specific inhibitor of human pancreatic α‐amylase (HPA). The objective of this study was to determine if chronic administration of montbretin A and acarbose, an inhibitor of α‐glucosidases and HPA, could prevent and/or delay the onset of diabetes in the Zucker Diabetic Fatty (ZDF) rat. Montbretin A (7.5 mg/kg/day) and acarbose (10 mg/kg/day) were administered to ZDF and lean littermate controls for 60 days. Plasma was analyzed for glucose, insulin, triglyceride, cholesterol, alanine transaminase (ALT) and 8‐isoprostane. Both montbretin A and acarbose attenuated the increase in plasma glucose levels in the ZDF rat. There was no effect of montbretin A or acarbose on lipid parameters. All ZDF animals had elevated ALT levels; however, ALT levels were significantly higher in the acarbose treated group, which may indicate an exacerbation of liver damage. This study indicates that montbretin A is as effective as acarbose in lowering plasma glucose levels; further studies are ongoing to assess the side effect profile of montbretin A. Project was funded by the Canadian Institutes of Health Research and supported by the Centre of Drug Research and Development.