Analysis of gene expression changes in relation to toxicity and tumorigenesis in the livers of Big Blue transgenic rats fed comf

Background: Comfrey is consumed by humans as a vegetable and a tea, and has been used as an herbal medicine for more than 2000 years. Comfrey, however, is hepatotoxic in livestock and humans and carcinogenic in experimental animals. Our previous study suggested that comfrey induces liver tumors by a genotoxic mechanism and that the pyrrolizidine alkaloids in the plant are responsible for mutation induction and tumor initiation in rat liver. Results: In this study, we identified comfrey-induced gene expression profile in the livers of rats. Groups of 6 male transgenic Big Blue rats were fed a basal diet and a diet containing 8% comfrey roots, a dose that resulted in liver tumors in a previous carcinogenicity bioassay. The animals were treated for 12 weeks and sacrificed one day after the final treatment. We used a rat microarray containing 26,857 genes to perform genome-wide gene expression studies. Dietary comfrey resulted in marked changes in liver gene expression, as well as in sign...

• Type: Journal
• Year: 2006
• Where: BMCBI
• Authors: Nan Mei, Lei Guo, Lu Zhang 0013, Leming M. Shi, Yongming Andrew Sun, Chris Fung, Carrie L. Moland, Stacey L. Dial, James C. Fuscoe, Tao Chen
• Keywords: BMCBI 2006, Comfrey, Gene Expression, Liver Tumors