title: N-acetylcysteine and S-methylcysteine inhibit MeIQx rat hepatocarcinogenesis in the post-initiation stage.
abstract: N-acetylcysteine (NAC) and S-methylcysteine (SMC), water soluble organosulfur compounds contained in garlic, were evaluated for chemoprevention of hepatocarcinogenesis after 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) initiation in rats. Intergastric treatment with NAC or SMC five times a week resulted in decreased numbers and areas of preneoplastic, glutathione S-transferase placental form (GST-P) positive foci of the liver in a dose-dependent manner. Moreover, cell proliferation was reduced in GST-P positive foci by NAC and SMC. Insulin-like growth factor I (IGF-I) and inducible nitric oxide synthase (iNOS) mRNA expressions were found downregulated in the liver by NAC. The studies indicate that NAC can serve as a chemopreventive agent for rat hepatocarcinogenesis induced by MeIQx by reducing cell proliferation, which may involve IGF-I and iNOS downregulation.
authors.affiliation: Department of Pathology, Osaka City University Medical School, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Motome
authors.initials: M
authors.lastname: Nishikawa-Ogawa
authors.forename: Hideki
authors.initials: H
authors.lastname: Wanibuchi
authors.forename: Keiichirou
authors.initials: K
authors.lastname: Morimura
authors.forename: Anna
authors.initials: A
authors.lastname: Kinoshita
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nishikawa
authors.forename: Shuji
authors.initials: S
authors.lastname: Hayashi
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Yano
authors.forename: Shoji
authors.initials: S
authors.lastname: Fukushima
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology; D002273:Carcinogens; D049109:Cell Proliferation; D003545:Cysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015536:Down-Regulation; D005982:Glutathione Transferase / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008113:Liver Neoplasms / Q000139:chemically induced / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010920:Placenta / Q000378:metabolism; D011810:Quinoxalines; D051381:Rats; D016622:Silver Staining; D013997:Time Factors
chemical_list: D016588:Anticarcinogenic Agents; D002273:Carcinogens; D011810:Quinoxalines; D007334:Insulin-Like Growth Factor I; C036990:2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline; C008425:S-methylcysteine; D052247:Nitric Oxide Synthase Type II; D005982:Glutathione Transferase; D003545:Cysteine; D000111:Acetylcysteine