Comparison of oral bioavailability of genistein and genistin in rats.
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.
Kwon
Suk Hyung
SH
Division of Pharmaceutical Sciences, College of Pharmacy, Chung-Ang University, 221 Heuksuk-dong, Dongjak-gu, Seoul 156-756, South Korea.
Kang
Myung Joo
MJ
Huh
Jin Seo
JS
Ha
Kyung Wook
KW
Lee
Jeong Rai
JR
Lee
Sang Kil
SK
Lee
Bong Sang
BS
Han
In Hee
IH
Lee
Min Suk
MS
Lee
Min Won
MW
Lee
Jaehwi
J
Choi
Young Wook
YW
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
D000975:Antioxidants; D020719:Glucuronides; D007529:Isoflavones; D048789:Phytoestrogens; D013431:Sulfates; C040641:genistin; D019833:Genistein; D013429:Sulfatases