Enhanced bioavailability of soy isoflavones by complexation with beta-cyclodextrin in rats.
In order to improve the solubility and bioavailability of a soy isoflavone extract (IFE), inclusion complexes (IFE-beta-CD) of the isoflavone extract with beta-cyclodextrin (beta-CD) were prepared and studied for their solubility and bioavailability. The aqueous solubility of the complexes of IFE with beta-CD (2.0 mg/ml) was about 26 times that of IFE itself (0.076 mg/ml). The same dosages of IFE and IFE-beta-CD were orally administered to SD rats (Sprague-Dawley) on an isoflavone glycoside (IFG) basis (daidzin, genistin and glycitin), and the plasma concentrations of daidzein, genistein and glycitein were measured over time to estimate the average AUC (area under the plasma concentration versus time curve) of the isoflavones. After the oral administration, the AUC values for daidzein, genistein and glycitein were 340, 11 and 28 microg x min/ml, respectively. In contrast, the respective AUC values after the administration of IFE-beta-CD were 430, 20 and 48 microg x min/ml. The bioavailability of daidzein in IFE-beta-CD was increased to 126% by the formation of inclusion complexes with beta-CD, compared with that in IFE. Furthermore, the bioavailability of genistein and glycitein in IFE-beta-CD formulation was significantly higher by up to 180% and 170%, respectively, compared with that of IFE p=0.008 and p=0.028, respectively). These results show that the absorption of IFE could be improved by the complexation of IFE with beta-CD (IFE-beta-CD).
Lee
Seung-Hyun
SH
R&D Center, Bioland Ltd., Ansan, Kyunggi, Republic of Korea.
Kim
Young Heui
YH
Yu
Heui-Jong
HJ
Cho
Nam-Suk
NS
Kim
Tae-Hyun
TH
Kim
Dong-Chool
DC
Chung
Chan-Bok
CB
Hwang
Yong-Il
YI
Kim
Ki Ho
KH
D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical; D019833:Genistein / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D007529:Isoflavones / Q000097:blood / Q000737:chemistry* / Q000493:pharmacokinetics; D008297:Male; D010936:Plant Extracts / Q000737:chemistry / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013025:Glycine max / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*
D007529:Isoflavones; D010936:Plant Extracts; D047392:beta-Cyclodextrins; C004742:daidzein; D019833:Genistein; C433283:glycitin