title: Isoflavone-free soy protein prepared by column chromatography reduces plasma cholesterol in rats.
abstract: To know whether isoflavones are responsible for the hypocholesterolemic effect of soy protein, the effect on plasma cholesterol of isoflavone-free soy protein prepared by column chromatography was examined in rats. Five-week-old male Sprague-Dawley rats were fed cholesterol-enriched AIN-93G diets containing either 20% casein (CAS), 20% soy protein isolate (SPI), 20% isoflavone-free SPI (IF-SPI), 19.7% IF-SPI + 0.3% isoflavone-rich fraction (isoflavone concentrate, IC), or 20% CAS + 0.3% IC for 2 weeks. Plasma total cholesterol concentrations of rats fed SPI and IF-SPI were comparable and were significantly lower than that of rats fed CAS. The addition of IC to the CAS and IF-SPI did not influence plasma cholesterol level. Fecal steroid excretion of the three SPI groups was higher than that of the two CAS groups, whereas the addition of IC showed no effect. Thus, a significant fraction of the cholesterol-lowering effect of SPI in rats can be attributed to the protein content, but the isoflavones and other minor constituents may also play a role.
authors.affiliation: New Ingredients Research Institute and Soybean Health Foods Laboratory, Fuji Oil Company, Ltd., 1 Sumiyoshi-cho, Izumisano, Osaka 598-8540, Japan. 910293@so.fujioil.co.jp
authors.forename: Kensuke
authors.initials: K
authors.lastname: Fukui
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Tachibana
authors.forename: Satoshi
authors.initials: S
authors.lastname: Wanezaki
authors.forename: Shinichi
authors.initials: S
authors.lastname: Tsuzaki
authors.forename: Kiyoharu
authors.initials: K
authors.lastname: Takamatsu
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Yukio
authors.initials: Y
authors.lastname: Hashimoto
authors.forename: Tadahisa
authors.initials: T
authors.lastname: Shimoda
mesh_terms: D000818:Animals; D002364:Caseins / Q000008:administration & dosage; D002784:Cholesterol / Q000097:blood*; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D002845:Chromatography / Q000379:methods*; D004435:Eating; D005243:Feces / Q000737:chemistry; D007529:Isoflavones / Q000032:analysis*; D008297:Male; D009929:Organ Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D030262:Soybean Proteins / Q000008:administration & dosage* / Q000737:chemistry*; D013256:Steroids / Q000032:analysis; D015430:Weight Gain
chemical_list: D002364:Caseins; D002791:Cholesterol, Dietary; D007529:Isoflavones; D030262:Soybean Proteins; D013256:Steroids; D002784:Cholesterol