The bioavailability and disposition kinetics of genistein in cats

N. J. Cave, R. C. Backus, Stanley L Marks, K. C. Klasing

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


The absorption and disposition kinetics of the soy isoflavone genistein were determined in cats (n = 6). An oral dose of 100 mg/kg was administered, which has previously been demonstrated to be the minimum oral estrogenic dose, and was administered intravenously at a dose of 20 mg/kg, being the largest practical dose that could be safely administered. Plasma free, and total (conjugated + free) genistein concentrations were determined by HPLC following organic extraction. Noncompartmental analysis revealed a half-life of 21.67 ± 7.9 h (free) and 9.95 ± 2.7 h (conjugated), volume of distribution 31.94 ± 10.38 L/kg (free) and 11.82 ± 3.96 L/kg (conjugated) following intravenous administration. Following oral administration the half-lives were determined to be 17 ± 4.8 h (free) and 8.56 ± 4.65 h (conjugated), with tmax = 4.4 ± 0.6 h (free) and 4.42 ± 0.99 h (conjugated), and Cmax = 0.276 ± 0.1 μg/mL (free) and 6.24 ± 6.58 μg/mL (conjugated). Oral bioavailabilities were 1.379 ± 0.9% (free) and 29.85 ± 22.61% (conjugated). The ratio of total:free genistein ranged from 25.9 to 5.5. Poor oral absorption and efficient conjugation explain the low bioavailability of free genistein. Accumulation of genistein in peripheral lipophilic compartments may occur.

Original languageEnglish (US)
Pages (from-to)327-335
Number of pages9
JournalJournal of Veterinary Pharmacology and Therapeutics
Issue number4
StatePublished - Aug 2007

ASJC Scopus subject areas

  • Pharmacology
  • veterinary(all)


Dive into the research topics of 'The bioavailability and disposition kinetics of genistein in cats'. Together they form a unique fingerprint.

Cite this