Antioxidative roles of sesamin, a functional lignan in sesame
seed, and it's effect on lipid- and alcohol-metabolism in the liver: A DNA
microarray study
Issue title: The Proceedings of the 3rd International
Conference on Food Factors (ICoFF 03)
Affiliations: Institute for Health Care Science, Suntory Ltd., 1-1-1
Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka 618-8503, Japan. Tel.: +81 75
962 6207; Fax: +81 75 962 3791; E-mail: Yoshinobu_Kiso@suntory.co.jp
Abstract: Sesamin was orally administered to rats, and blood, bile and urine
were collected periodically. Over 40% of the dose of sesamin was detected in
bile as glucuronides of 2-(3, 4-methylenedioxyphenyl)-6-(3,
4-dihydroxyphenyl)-cis-dioxabicyclo[3.3.0] octane and 2-(3,
4-dihydroxyphenyl)-6-(3, 4-dihydroxyphenyl)-cis-dioxabicyclo[3.3.0] octane by
24~hr after administration. Antioxidant activities of these metabolites were
compared and catechol metabolites showed strong radical scavenging activities
against not only superoxide anion radical but also hydroxyl radical. It was
suggested that sesamin was absorbed by the route of portal vein and metabolized
to mono- or di-catechol metabolite by drug metabolizing enzymes in the liver
cells. Both metabolites exhibited antioxidant activity in the liver and were
finally conjugated with glucuronic acid and to excrete in bile. Sesamin can be
classified as a pro-antioxidant. The profiles of gene expression of the liver in rats given sesamin
or vehicle were compared. The gene expression levels of the late stage enzymes
of β-oxidation including trifunctional enzyme, acyl-CoA
oxidase, bifunctional enzyme and 3-ketoacyl-CoA thiolase were significantly
increased by sesamin. On the other hand, the transcription of the genes
encoding the enzymes for fatty acid synthesis was decreased. Moreover, in
sesamin rats, the gene expression of aldehyde dehydrogenase was increased about
3-fold, whereas alcohol dehydrogenase, liver catalase and CYP2E1 were not
changed. These results suggested that sesamin ingestion regulated the
transcription levels of hepatic metabolizing enzymes for lipids and
alcohol.
Keywords: sesamin, antioxidant, β-oxidation enzyme, aldehyde dehydrogenase, DNA microarray, genechip
Journal: BioFactors, vol. 21, no. 1-4, pp. 191-196, 2004
