Tags

Type your tag names separated by a space and hit enter

Plasma and urinary kinetics of the isoflavones daidzein and genistein after a single soy meal in humans.
Am J Clin Nutr. 1998 May; 67(5):867-72.AJ

Abstract

The aim of this study was to determine the pharmacokinetics and urinary excretion patterns of the soy isoflavones daidzein and genistein in humans. Six healthy men with a mean age of 37 y and a mean body mass index (in kg/m2) of 24 consumed a soybean flour-based meal on two occasions approximately 6 d apart. Blood samples and total urine were collected at intervals for the measurement of daidzein and genistein with HPLC. Isoflavone concentrations rose slowly and reached maximum values of 3.14 +/- 0.36 micromol/L at 7.42 +/- 0.74 h for daidzein and 4.09 +/- 0.94 micromol/L at 8.42 +/- 0.69 h for genistein. Elimination half-lives were 4.7 +/- 1.1 and 5.7 +/- 1.3 h for daidzein and genistein, respectively. The slow increase in plasma concentrations is consistent with the facilitation of absorption by hydrolysis in the small and large intestines of the glycosidic forms of the isoflavones present in soybean-containing foods to their corresponding aglycones. The rate of urinary excretion of daidzein was greater than that of genistein throughout the postmeal period, with mean recoveries of 62 +/- 6% and 22 +/- 4% (P < 0.001) for daidzein and genistein, respectively. However, the ratio of the areas under the plasma concentration versus time curves for genistein and daidzein was equal to the ratio of the concentrations of the respective isoflavones in the soy meal. It is concluded that the bioavailabilities of daidzein and genistein are similar, not withstanding the difference in urinary excretion.

Authors+Show Affiliations

CSIRO Division of Human Nutrition, and the Faculty of Medicine, University of Adelaide, North Terrace, South Australia. roger.king@dhn.csiro.auNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

9583843

Citation

King, R A., and D B. Bursill. "Plasma and Urinary Kinetics of the Isoflavones Daidzein and Genistein After a Single Soy Meal in Humans." The American Journal of Clinical Nutrition, vol. 67, no. 5, 1998, pp. 867-72.
King RA, Bursill DB. Plasma and urinary kinetics of the isoflavones daidzein and genistein after a single soy meal in humans. Am J Clin Nutr. 1998;67(5):867-72.
King, R. A., & Bursill, D. B. (1998). Plasma and urinary kinetics of the isoflavones daidzein and genistein after a single soy meal in humans. The American Journal of Clinical Nutrition, 67(5), 867-72.
King RA, Bursill DB. Plasma and Urinary Kinetics of the Isoflavones Daidzein and Genistein After a Single Soy Meal in Humans. Am J Clin Nutr. 1998;67(5):867-72. PubMed PMID: 9583843.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Plasma and urinary kinetics of the isoflavones daidzein and genistein after a single soy meal in humans. AU - King,R A, AU - Bursill,D B, PY - 1998/5/16/pubmed PY - 1998/5/16/medline PY - 1998/5/16/entrez SP - 867 EP - 72 JF - The American journal of clinical nutrition JO - Am. J. Clin. Nutr. VL - 67 IS - 5 N2 - The aim of this study was to determine the pharmacokinetics and urinary excretion patterns of the soy isoflavones daidzein and genistein in humans. Six healthy men with a mean age of 37 y and a mean body mass index (in kg/m2) of 24 consumed a soybean flour-based meal on two occasions approximately 6 d apart. Blood samples and total urine were collected at intervals for the measurement of daidzein and genistein with HPLC. Isoflavone concentrations rose slowly and reached maximum values of 3.14 +/- 0.36 micromol/L at 7.42 +/- 0.74 h for daidzein and 4.09 +/- 0.94 micromol/L at 8.42 +/- 0.69 h for genistein. Elimination half-lives were 4.7 +/- 1.1 and 5.7 +/- 1.3 h for daidzein and genistein, respectively. The slow increase in plasma concentrations is consistent with the facilitation of absorption by hydrolysis in the small and large intestines of the glycosidic forms of the isoflavones present in soybean-containing foods to their corresponding aglycones. The rate of urinary excretion of daidzein was greater than that of genistein throughout the postmeal period, with mean recoveries of 62 +/- 6% and 22 +/- 4% (P < 0.001) for daidzein and genistein, respectively. However, the ratio of the areas under the plasma concentration versus time curves for genistein and daidzein was equal to the ratio of the concentrations of the respective isoflavones in the soy meal. It is concluded that the bioavailabilities of daidzein and genistein are similar, not withstanding the difference in urinary excretion. SN - 0002-9165 UR - https://www.unboundmedicine.com/medline/citation/9583843/Plasma_and_urinary_kinetics_of_the_isoflavones_daidzein_and_genistein_after_a_single_soy_meal_in_humans_ L2 - https://academic.oup.com/ajcn/article-lookup/doi/10.1093/ajcn/67.5.867 DB - PRIME DP - Unbound Medicine ER -