Seven-day supplementation with piceatannol does not improve endothelial function at rest or after exercise: a pilot...

Piceatannol, a polyphenolic compound found in high concentrations in passion fruit, has been reported to exert multiple physiological effects in preclinical studies, including vascular relaxation and increased expression of endothelial nitric oxide synthase. Despite these findings, its influence on endothelial function in humans, both at rest and in response to exercise, remains largely unknown. Therefore, this study aimed to investigate whether a 7-day regimen of piceatannol supplementation alters endothelial function at rest and following low-intensity aerobic exercise.

Eight young, healthy men participated in a randomized, double-blind, crossover trial. Each participant completed two experimental conditions: (1) a placebo trial and (2) a piceatannol trial. For seven consecutive days, they ingested tablets containing either 0 mg (placebo) or 10 mg of piceatannol daily. On the morning of the eighth day (8:00 am), they visited the laboratory for baseline assessments, followed by 60 minutes of cycling exercise at 30% of their maximal oxygen uptake. Blood pressure and brachial artery flow-mediated dilation (FMD) were measured before and after exercise.

No between-trial differences were observed in blood pressure at rest, during exercise, or after exercise. %FMD and absolute FMD likewise did not differ between the placebo and piceatannol trials. The observed effects were small (partial η² ≈ 0.05-0.06), and analysis of covariance adjusting for baseline diameter or shear rate area under the curve yielded consistent results.

Seven-day piceatannol supplementation did not enhance endothelial function at rest or after low-intensity aerobic exercise in young, healthy men.