title: Antagonistic effect of the Ainu-selected traditional beneficial plants on the transformation of an aryl hydrocarbon receptor.
abstract: Transformation of an aryl hydrocarbon receptor (AhR) is the initial step to express the multiple toxicity of halogenated and polycyclic aromatic hydrocarbons (HAHs and PAHs) including dioxins. Therefore, it has been suggested that suppression of the transformation induced by HAHs and PAHs leads to reduce their toxicological effects. In this study, the antagonistic effect of 110 indigenous plants (192 plant parts) used as medicine and/or food by the Ainu on the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced AhR transformation was investigated. Of these, a stalk of Aralia elata (Miq.) Seemann and a bark of Fraxinus mandshurica Rupr. var. japonica Maxim. exhibited the strong antagonistic effect in a dose-dependent manner. An antioxidative activity and polyphenol content were also measured, and the strong correlation (r= 0.96) between these two parameters could be confirmed. However, correlation coefficients of the antagonistic effect of 192 extracts compared to their antioxidative activity and polyphenol content were 0.17 and 0.20, respectively. These results suggest that the Ainu-selected traditional beneficial plants are useful source for findings of novel AhR antagonists, and the antagonistic activity of these plants may be independent on their antioxidative activity and polyphenol content.
  
  
  CONCLUSIONS
  Our findings lead to discovery of the valuable plants used by the Ainu and the novel active compounds useful for human's life, and furthermore, may contribute to the development of new medicines and functional foods.
authors.affiliation: Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Hyogo, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Nishiumi
authors.forename: Keizo
authors.initials: K
authors.lastname: Hosokawa
authors.forename: Masaki
authors.initials: M
authors.lastname: Anetai
authors.forename: Toshiro
authors.initials: T
authors.lastname: Shibata
authors.forename: Rie
authors.initials: R
authors.lastname: Mukai
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Yoshida
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ashida
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D027983:Aralia / Q000737:chemistry; D044466:Asian People; D002474:Cell-Free System / Q000187:drug effects / Q000378:metabolism; D004032:Diet / Q000208:ethnology; D055808:Drug Discovery; D004785:Environmental Pollutants / Q000037:antagonists & inhibitors / Q000494:pharmacology; D005527:Food, Fortified / Q000032:analysis; D031661:Fraxinus / Q000737:chemistry; D006801:Humans; D007564:Japan; D008099:Liver / Q000378:metabolism; D008518:Medicine, East Asian Traditional; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010945:Plants, Edible / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D000072317:Polychlorinated Dibenzodioxins / Q000037:antagonists & inhibitors / Q000494:pharmacology; D051381:Rats; D018336:Receptors, Aryl Hydrocarbon / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D020218:Response Elements / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D004785:Environmental Pollutants; D010636:Phenols; D010936:Plant Extracts; D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon