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Pharmacokinetic parameters of several dietary anthocyanins following consumption of Hibiscus sabdariffa L. extract were determined in 6 healthy volunteers. Subjects were given a single oral dose of 150 mL of Hibiscus sabdariffa L. extract yielding 62.6 mg of cyanidin-3-sambubioside, 81.6 mg of delphindin-3-sambubioside, and 147.4 mg of total anthocyanins (calculated as cyanidin equivalents). Within 7 hours, the urinary excretion of cyanidin-3-sambubioside, delphinidin-3-sambubioside, and total anthocyanins (ie, the sum of all quantifiable anthocyanidin glycosides) was 0.016%, 0.021%, and 0.018% of the administered doses, respectively. Maximumexcretion rateswere determined at 1.5 to 2.0 hours after intake. The dose-normalized plasma area under the curve estimates were 0.076, 0.032, and 0.050 ng • h/mL/mg for cyanidin-3-sambubioside, delphinidin-3-sambubioside, and total anthocyanins, respectively. The dose-normalized C max estimateswere 0.036, 0.015, and 0.023 ng/mL/mg in the same sequence. They were reached each at 1.5 hours (median) after intake. The geometric means of t 1/2 were 2.18, 3.34, and 2.63 hours for cyanidin-3-sambubioside, delphinidin-3-sambubioside, and total anthocyanins, respectively. The urinary excretion of intact anthocyanins was fast and appeared to be monoexponential. To evaluate the contribution of anthocyanins to the health-protecting effects of Hibiscus sabdariffa L. extract, it will be necessary to perform further studies on both the intact glycosides and their in vivo metabolites or conjugates in human plasma and urine. [ABSTRACT FROM PUBLISHER]

Presents a study which compared some pharmacokinetic parameters and the bioavailability of several dietary anthocyanins following consumption of red wine versus red grape juice. Materials and methods; Results; Discussion and conclusions.

Abstract: The aim of the present pilot study was to characterise the renal elimination of betalains after consumption of red beet juice (RBJ). Six healthy, non-smoking female volunteers were given a single oral dose of either 500mL of a commercial RBJ containing 362.7mg of betalains and 500mL of tap water, respectively, in a sequential manner. Urine was collected in intervals up to 24h post-dose. Renal excretion of betalains was determined spectrophotometrically and quantified as betanin-equivalents. In addition, the identity of individual compounds was confirmed by HPLC coupled with diode-array detection and positive ion electrospray mass spectrometry, respectively. The amount (mean±S.D.) of intact betalains (betanin and isobetanin) recovered in urine was 1001±273μg corresponding to 0.28±0.08% of the administered dose. Maximum excretion rates were observed after a median t max,R of 3.0h (range 2.5–8.0h) amounting to 91.7±30.1μg/h. The terminal elimination rate constant (λ z ) and the corresponding half-life were 0.097±0.021h−1 and 7.43±1.47h, respectively. Using the λ z estimates obtained the expected total betalain amount excreted in urine was 1228±291μg. Based on the results obtained it is assumed that either the bioavailability of the betalains is low or that renal clearance is a minor route of systemic elimination for these compounds. The urinary excretion rates of unmetabolised betalains were fast and appeared to be monoexponential suggesting a one-compartment model. In order to get a more complete picture of the pharmacokinetics and health-promoting properties of red beet betalains, quantitative data on betalain bioavailability should include measurements of unchanged compounds and their corresponding metabolites in plasma, urine and bile. [Copyright &y& Elsevier]