The Inhibitory Effects of New Zealand Pine Bark (Enzogenol (R)) on alpha-Amylase, alpha-Glucosidase, and Dipeptidyl Peptidase-4 (DPP-4) Enzymes

The New Zealand pine bark extract (Enzogenol (R)) has previously been shown to elicit acute hypoglycaemic effects in humans. The present study investigated the underlying mechanisms of Enzogenol (R) in reducing postprandial glucose in humans. The potential inhibitory action of Enzogenol (R) against digestive enzymes: alpha-amylase and alpha-glucosidase, and dipeptidyl peptidase-4 (DPP-4) enzyme was determined. Enzogenol (R) demonstrated the ability to inhibit all three enzymes: alpha-amylase enzyme activity (IC50 3.98 +/- 0.11 mg/mL), alpha-glucosidase enzyme activity (IC50 13.02 +/- 0.28 mu g/mL), and DPP-4 enzyme activity (IC50 2.51 +/- 0.04 mg/mL). The present findings indicate the potential for Enzogenol (R) to improve postprandial glycaemia by delaying carbohydrate digestion via the inhibition of digestive enzymes (alpha-amylase and alpha-glucosidase), and enhancing the incretin effect via inhibiting the dipeptidyl-peptidase-4 enzyme. The inhibitory actions of Enzogenol (R) on enzymes should therefore be further validated in humans for its potential use in type 2 diabetes mellitus prevention and management.