title: Presence of orally administered rice bran oil γ-oryzanol in its intact form in mouse plasma.
abstract: Although the beneficial effects (e.g., lipid-lowering activity) of γ-oryzanol (OZ), a mixture of ferulic acid esters of plant sterols and triterpene alcohols, have been extensively investigated, few studies have evaluated the absorption and metabolism of OZ. Moreover, it is unclear whether OZ, once ingested, is directly absorbed by the intestine into the bloodstream at a sufficient level to exhibit activity. Here, we prepared OZ concentrate from purified rice bran oil (Rice Oil OZ), determined the concentration of OZ in the preparation (cycloartenyl ferulate equivalent concentration; 52.2%), and then carried out chromatography-mass spectrometry analysis of plasma samples from mice after oral administration of Rice Oil OZ. The OZ concentrations of plasma from the control (vehicle-treated) mice were low (trace levels); however, at 5 h after a single oral administration of the Rice Oil OZ (600 mg per kg body weight), the levels significantly increased, reaching 17.6 ng mL-1for cycloartenyl ferulate, 28.2 ng mL-1for 24-methylenecycloartanyl ferulate isomers, 15.6 ng mL-1for campesteryl ferulate, and 5.1 ng mL-1for β-sitosteryl ferulate, respectively, expressed in equivalence of cycloartenyl ferulate in plasma. These results provided the first mass spectrometric evidence suggesting that a portion of orally administered OZ is directly absorbed by the intestine and is present in the intact form in plasma. The presence of a significant amount of OZ in its intact form in plasma may explain the beneficial effects of OZ in vivo.
authors.affiliation: Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi 981-8555, Japan. nkgw@m.tohoku.ac.jp.
authors.forename: Eri
authors.initials: E
authors.lastname: Kobayashi
authors.affiliation: Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi 981-8555, Japan. nkgw@m.tohoku.ac.jp.
authors.forename: Junya
authors.initials: J
authors.lastname: Ito
authors.affiliation: Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi 981-8555, Japan. nkgw@m.tohoku.ac.jp.
authors.forename: Shunji
authors.initials: S
authors.lastname: Kato
authors.affiliation: Tsuno Food Industrial CO., LTD., Ito-Gun, Wakayama 649-7194, Japan.
authors.forename: Kazue
authors.initials: K
authors.lastname: Sawada
authors.affiliation: Tsuno Food Industrial CO., LTD., Ito-Gun, Wakayama 649-7194, Japan.
authors.forename: Midori
authors.initials: M
authors.lastname: Matsuki
authors.affiliation: Tsuno Food Industrial CO., LTD., Ito-Gun, Wakayama 649-7194, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hashimoto
authors.affiliation: Food and Biotechnology Innovation Project, New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai, Miyagi 980-8579, Japan and Food and Health Science Research Unit, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi 981-8555, Japan.
authors.forename: Teruo
authors.initials: T
authors.lastname: Miyazawa
authors.affiliation: Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi 981-8555, Japan. nkgw@m.tohoku.ac.jp.
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Nakagawa
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D015394:Molecular Structure; D010666:Phenylpropionates / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D000073879:Rice Bran Oil / Q000008:administration & dosage* / Q000737:chemistry* / Q000378:metabolism; D053719:Tandem Mass Spectrometry
chemical_list: D010666:Phenylpropionates; D000073879:Rice Bran Oil; C013172:gamma-oryzanol