First Author | Tyagi A | Year | 2007 |
Journal | Mol Cancer Ther | Volume | 6 |
Issue | 12 Pt 1 | Pages | 3248-55 |
PubMed ID | 18089718 | Mgi Jnum | J:141639 |
Mgi Id | MGI:3819060 | Doi | 10.1158/1535-7163.MCT-07-2006 |
Citation | Tyagi A, et al. (2007) Chemopreventive effects of silymarin and silibinin on N-butyl-N-(4-hydroxybutyl) nitrosamine induced urinary bladder carcinogenesis in male ICR mice. Mol Cancer Ther 6(12 Pt 1):3248-55 |
abstractText | Effective strategies are lacking for the management of urinary bladder cancer for which smoking is a potential risk factor. Herein, we evaluated chemoprevention of urinary bladder cancer by natural chemopreventive agents, silymarin and silibinin, in a preclinical animal (ICR mouse) model of bladder cancer induced by tobacco smoke carcinogen N-butyl-N-(4-hydroxybutyl) nitrosamine (OH-BBN). Mice were fed p.o. with saline or OH-BBN (0.05%, w/v) in drinking water for 6 weeks or with silymarin or silibinin (200 mg/kg body weight for both) starting 1 week before OH-BBN exposure for 51 weeks. Silymarin and silibinin strongly arrested OH-BBN-induced tumor progression at the stage of mucosal dysplasia with a striking reduction in papillary nodular dysplasia as well as invasive carcinoma. Some silymarin- or silibinin-treated mice developed no urothelial lesions in spite of OH-BBN exposure. Immunohistochemical analyses at study conclusion revealed that silymarin and silibinin decreased cell proliferation by 42% (P < 0.001) and 44% (P < 0.001) and increased apoptosis by 4-fold (P < 0.05) and 6-fold (P < 0.05) in OH-BBN-induced urothelium, respectively. Antiproliferative and apoptotic effects of silymarin and silibinin were associated with decreases in (a) cyclin D1 protein level and extracellular signal-regulated kinase-1/2 phosphorylation and in (b) protein levels of survivin and nuclear phospho-p65 (Ser(276) and Ser(536)), respectively. Together, these results suggest that silymarin and silibinin inhibit chemically induced urinary bladder tumor growth and progression possibly by inhibiting cell proliferation and enhancing apoptosis. |