Plasma uptake of selected phenolic acids following New Zealand blackcurrant extract supplementation in humans raw data
Description
New Zealand blackcurrant (NZBC) extract is a rich source of anthocyanins and in order to exert health and/or physiological effects the anthocyanin-derived metabolites need to be bioavailable in vivo. We examined the plasma uptake of selected phenolic acids following NZBC extract supplementation alongside maintaining a habitual diet (i.e., not restricting habitual polyphenol intake). Twenty healthy volunteers (9 females), age: 28±7 years, height 1.73±0.09 m, body mass 73±11 kg) consumed a 300 mg NZBC extract capsule (CurraNZ™; anthocyanin content 105 mg) following an overnight fast. Venous blood samples were taken pre and 1, 1.5, 2, 3, 4, 5, and 6 h post-ingestion of the capsule. Plasma concentrations of vanillic acid (VA), gallic acid (GA), and protocatechuic acid (PCA) were analysed by reversed-phase high-performance liquid chromatography (HPLC) and the HPLC analysis identified two dihydroxybenzoic (VA and PCA) and one trihydroxybenzoic acids (GA) in plasma following NZBC supplementation. Habitual anthocyanin intake was 168 (95%CI:68–404) mg⋅day-1 and no associations were observed between this and VA, PCA, and GA plasma uptake. Plasma time-concentration curves revealed that VA, GA, and PCA were most abundant at 3, 4, and 1.5 h post-ingestion, representing a 79%, 261% and 320% increase above baseline, respectively, with GA and PCA still elevated above pre at 6 h. This is the first study to demonstrate that an NZBC extract supplement increases the plasma uptake of phenolic acids VA, GA, and PCA even when a habitual diet is followed in the days preceding the experimental trial, although inter-individual variability is apparent.