title: Null anticarcinogenic effect of silymarin on diethylnitrosamine-induced hepatocarcinogenesis in rats.
abstract: The aim of this study was to investigate the anticarcinogenic effects of silymarin in diethylnitrosamine (DEN)-induced hepatocarcinogenic rat models. Severe and mild models of hepatocellular carcinoma (HCC) were generated by the intraperitoneal administration of 40 mg/kg DEN once a week for 18 weeks and 100 mg/kg DEN every 2 weeks for 6 weeks in male Wistar rats, respectively. In the severe and mild models of HCC, the rats were treated with 0.1 and 0.5% silymarin for 18 weeks and with 0.1% silymarin for 5 weeks, respectively. Serum transaminase levels were not significantly decreased by the silymarin treatment in either model. Macroscopic and microscopic features indicated that the silymarin-containing formulations did not significantly inhibit the hepatic tumor formation induced by DEN. Furthermore, immunohistochemical and western blot analyses demonstrated that the expression levels of proliferating cell nuclear antigen and glutathioneS-transferase P, which are hepatocarcinogenic markers, were not significantly modified by the silymarin treatment. These results indicate that silymarin may not be considered as a candidate agent against hepatocarcinogenesis.
authors.affiliation: Second Department of Internal Medicine, Tottori University School of Medicine, Yonago, Tottori 683-8504, Japan.
authors.forename: Ryu
authors.initials: R
authors.lastname: Imamoto
authors.affiliation: Second Department of Internal Medicine, Tottori University School of Medicine, Yonago, Tottori 683-8504, Japan.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Okano
authors.affiliation: Second Department of Internal Medicine, Tottori University School of Medicine, Yonago, Tottori 683-8504, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Sawada
authors.affiliation: Second Department of Internal Medicine, Tottori University School of Medicine, Yonago, Tottori 683-8504, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Fujise
authors.affiliation: Second Department of Internal Medicine, Tottori University School of Medicine, Yonago, Tottori 683-8504, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Abe
authors.affiliation: Second Department of Internal Medicine, Tottori University School of Medicine, Yonago, Tottori 683-8504, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Murawaki
keywords: diethylnitrosamine; hepatocellular carcinoma; silymarin