title: Comparison of oral bioavailability of genistein and genistin in rats.
abstract: Genistein (GT) is an isoflavone from Leguminosae and has received much attention as a phytoestrogen. Genistin is a glycoside form of GT (genistein-7-O-beta-D-glucopyranoside, GT-glu) is mainly found in soy-derived foods. In this study, we examined the pharmacokinetic properties and bioavailability of GT in rats and compared with those of GT-glu. In order to characterize and compare the pharmacokinetics of GT and GT-glu, these compounds were administered intravenously and orally. The plasma concentration of GT was determined by HPLC after enzymatic hydrolysis. After oral administration of GT with various doses (4, 20, 40 mg/kg), the bioavailability of GT was 38.58, 24.34 and 30.75%, respectively. The T(max), C(max) and AUC(0-infinity) of GT after oral administration of GT (40 mg/kg), were 2h, 4876.19 ng/ml, 31,269.66 ng h/ml, respectively. When smaller amount of GT was administered, the faster T(max) was observed. Oral administration of GT-glu resulted in longer T(max), lower C(max), and greater bioavailability than that of GT. The pharmacokinetic parameters of GT following oral administration of GT-glu (64 mg/kg as GT-glu, 40 mg/kg as GT) were obtained as follows: 8h (T(max)), 3763.96 ng/ml (C(max)), 51,221.08 ng h/ml (AUC(0-infinity)) and 48.66% (absolute bioavailability), respectively. These results indicate that the oral bioavailability of GT-glu is greater than that of GT.
authors.affiliation: Division of Pharmaceutical Sciences, College of Pharmacy, Chung-Ang University, 221 Heuksuk-dong, Dongjak-gu, Seoul 156-756, South Korea.
authors.forename: Suk Hyung
authors.initials: SH
authors.lastname: Kwon
authors.forename: Myung Joo
authors.initials: MJ
authors.lastname: Kang
authors.forename: Jin Seo
authors.initials: JS
authors.lastname: Huh
authors.forename: Kyung Wook
authors.initials: KW
authors.lastname: Ha
authors.forename: Jeong Rai
authors.initials: JR
authors.lastname: Lee
authors.forename: Sang Kil
authors.initials: SK
authors.lastname: Lee
authors.forename: Bong Sang
authors.initials: BS
authors.lastname: Lee
authors.forename: In Hee
authors.initials: IH
authors.lastname: Han
authors.forename: Min Suk
authors.initials: MS
authors.lastname: Lee
authors.forename: Min Won
authors.initials: MW
authors.lastname: Lee
authors.forename: Jaehwi
authors.initials: J
authors.lastname: Lee
authors.forename: Young Wook
authors.initials: YW
authors.lastname: Choi
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001682:Biological Availability; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D019833:Genistein / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D020719:Glucuronides / Q000378:metabolism; D006868:Hydrolysis; D007275:Injections, Intravenous; D007408:Intestinal Absorption; D007529:Isoflavones / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D008297:Male; D008657:Metabolic Clearance Rate; D048789:Phytoestrogens / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D013429:Sulfatases / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism
chemical_list: D000975:Antioxidants; D020719:Glucuronides; D007529:Isoflavones; D048789:Phytoestrogens; D013431:Sulfates; C040641:genistin; D019833:Genistein; D013429:Sulfatases