Delphinol® standardized maqui berry extract reduces postprandial blood glucose increase in individuals with impaired glucose regulation by novel mechanism of sodium glucose cotransporter inhibition

Abstract

Aim: The impetus of our study was to investigate the effects of a nutritional supplement Delphinol®, an extract of maqui berries (Aristotelia chilensis) standardised to ≥25% delphinidins and ≥35% total anthocyanins, on postprandial blood glucose and insulin levels and identify the physiologic mechanism involved.

Methods: Postprandial blood glucose and insulin were investigated in double-blind, placebo-controlled, cross-over fashion in ten volunteers with moderate glucose intolerance. Longer term effects on blood sugar levels were investigated in streptozotocin-diabetic rats over a four months period. Effects of maqui berry delphinidins on sodium-glucose symport were examined in rodent jejenum of the small intestine.

Results: Delphinol® intake prior to rice consumption statistical significantly lowered post prandial blood glucose and insulin as compared to placebo. We identified an inhibition of Na+-dependant glucose transport by delphinidin, the principal polyphenol to which Delphinol® is standardised. In a diabetic rat model the daily oral application of Delphinol® over a period of four months significantly lowered fasting blood glucose levels and reached values indistinguishable from healthy non-diabetic rats.

Conclusion: Our results suggest a potential use of Delphinol® for naturally controlling post-prandial blood glucose owed to inhibition of sodium glucose co-transporter in small intestine.