Urinary pharmacokinetics of cyanidin glycosides in healthy young men following consumption of elderberry juice.

We investigated the urinary pharmacokinetics of monomeric anthocyanins in seven healthy volunteers. The volunteers were administered a single oral dose of 3.57 g total anthocyanins contained in 150 ml of a concentrated elderberry juice under fasting conditions. Within 24 h the urinary excretion of unchanged cyanidin-3,5-diglucoside (cyanidin-3-sambubioside-5-glucoside and cyanidin-3,5-diglucoside were calculated as cyanidin-3,5-diglucoside equivalents), cyanidin-3-glucoside, cyanidin-3-sambubioside and total anthocyanins (i.e., the sum of all quantifiable anthocyanidin glycosides) was 0.16, 0.06, 0.05 and 0.06% of the administered doses, respectively. Maximum excretion rates were determined within 1.0 h after intake. The estimates (arithmetic mean +/- SD) of t1/2 were 1.25 +/- 0.25, 1.53 +/- 0.36, 1.38 +/- 0.20 and 1.35 +/- 0.18 h for cyanidin-3,5-diglucoside, cyanidin-3-glucoside, cyanidin-3-sambubioside and total anthocyanins, respectively. The urinary excretion of intact anthocyanins was fast and the decline of excretion rates appeared to be monophasic, suggesting a one-compartment pharmacokinetic model. The low urinary excretion of dietary anthocyanidin glycosides with values below 1% indicates that a large proportion of these plant pigments consumed are metabolized before entry into the circulation.

Bioavailability of anthocyanidin-3-glycosides following consumption of elderberry extract and blackcurrant juice.

Pharmacokinetic parameters and the bioavailability of several dietary anthocyanins following consumption of blackcurrant juice and elderberry extract were compared exploratorily in 6 healthy volunteers. They were given a single oral dose of either 137 ml of blackcurrant juice (144.8 mg total anthocyanins) or 30 ml of elderberry extract (147.3 mg total anthocyanins). Within 7 hours, the urinary excretion of total anthocyanins (i.e. the sum of all assayed anthocyanidin glycosides) was 0.04% and 0.37% of the administered dose following blackcurrant juice and elderberry extract ingestion, respectively. Pharmacokinetic parameters based on non-compartmental methods for plasma and urine concentrations exhibited higher variability in urinary excretion after ingestion of elderberry extract. Anthocyanin absorption was significantly greater following the intake of elderberry extract than after the intake of blackcurrant juice as shown by the 5.3- and 6.2-fold higher estimates of dose-normalized Cmax and AUC(0-tZ) of total anthocyanins, respectively. The geometric means of t(1/2) were not significantly different following elderberry extract (1.74 h) and blackcurrant juice ingestion (1.73 h, p > 0.05). The urinary excretion rate of intact anthocyanins was fast, appeared to be monoexponential for both blackcurrant juice and elderberry extract. However, in order to evaluate the contribution of anthocyanins to the health-protecting effects of blackcurrant juice and elderberry extract it will be necessary to perform further studies on the unchanged glycosides and their in vivo metabolites in human plasma and urine.

Bioactive anthocyanins detected in human urine after ingestion of blackcurrant juice.

Anthocyanins are a group of very efficient bioactive compounds that are widely distributed in plant food. Several fruits (blackcurrant, blackberry, red grape) and some vegetables (eggplant, onion, red radish) are rich sources of these natural pigments. Extracts of some of them are used as food colorants as well as components of pharmaceutical preparations and functional foods. Anthocyanins, through their ability to inhibit radical reactions, are considered to exert several protective effects in the human body. Until now there has been only a small amount of data available on their capability, in intact or metabolized form, to reach the systemic circulation of humans. The present study was designed to determine the potential bioavailability in humans of the most important anthocyanins of blackcurrants: delphinidine-3-glucoside, delphinidine-3-rutinoside, cyanidine-3-glucoside, and cyanidine-3-rutinoside. Urinary samples from 4 healthy volunteers (2 women and 2 men) were collected before (baseline) and over a period of 5 hours with intervals of 30 minutes after the ingestion of 200 mL of blackcurrant juice (containing 153 mg of anthocyanins). Using high-performance liquid chromatography (HPLC), it was possible to quantify the 4 main anthocyanins of blackcurrants, excreted unchanged in the urine (0.020-0.050% of the oral doses). We present data on the bioavailability in humans of blackcurrant anthocyanins, which are dietary antioxidants with possible biological effects.