An Acute, Placebo-Controlled, Single-Blind, Crossover, Dose-Response, Exploratory Study to Assess the Effects of New Zealand Pine Bark Extract (Enzogenol®) on Glycaemic Responses in Healthy Participants

An acute, placebo-controlled, single-blind, crossover, dose-response, exploratory study was designed to investigate the hypoglycaemic effects of New Zealand pine bark extract (Enzogenol (R)). Twenty-five healthy participants categorised into having a monophasic or complex (biphasic or triphasic) glucose curve shape at the control visit consumed a placebo and Enzogenol (R) (50 and 400 mg) on three separate occasions before an oral glucose tolerance test (OGTT). In the monophasic group, 50 and 400 mg of Enzogenol (R) significantly reduced the mean glucose incremental area under the curve (iAUC) compared to control 241.3 +/- 20.2 vs. 335.4 +/- 34.0 mmol/L.min, p = 0.034 and 249.3 +/- 25.4 vs. 353.6 +/- 31.5 mmol/L.min, p = 0.012, respectively. The 400 mg dose further reduced the percentage increment of postprandial glucose (%PG) 31.4% +/- 7.9% vs. 47.5% +/- 8.6%, p = 0.010, glucose peak 7.9 +/- 0.3 vs. 8.9 +/- 0.3 mmol/L, p = 0.025 and 2h-OGTT postprandial glucose (2hPG) 6.1 +/- 0.3 vs. 6.7 +/- 0.3 mmol/L, p = 0.027. Glucose iAUC was not significantly different in the complex group, except for reductions in %PG 28.7% +/- 8.2% vs. 43.4% +/- 5.9%, p = 0.012 after 50 mg dose and 27.7% +/- 5.4% vs. 47.3% +/- 7.2%, p = 0.025 after 400 mg dose. The results suggest that Enzogenol (R) may have hypoglycaemic effects in healthy participants, especially those exhibiting monophasic shapes.