Weichang'an and 5-fluorouracil suppresses colorectal cancer in a mouse model

AIM: To examine the effect of Weichang'an ( WCA) and 5- fluorouracil ( 5- fu) on colorectal tumor and hepatic metastasis in a mouse model. METHODS: Quantitative determination of hesperidin, the effective component in WCA decoction, was performed using HPLC. In vitro cytotoxicity of WCA was determined by treating HCT- 116 cells with WCA diluents or serum extracted from rats that received WCA by oral gavage for 1 wk and MTT assays. Forty- eight nude mice received cecum implantation with tumor blocks subcutaneously amplified from human colon cancer cell line HCT- 116. Mice were randomly divided into four treatment groups: control ( CON), WCA, 5- FU and combination ( WCA + 5- FU). Pathological examination of tumors consisted of tissue sectioning and hematoxylin and eosin staining. Tumor weight and size were measured, and the number of metastatic lesions was counted. Serum carcinoembryonic antigen ( CEA) level was determined by ELISA. The expression levels of tumor genesis and metastasisrelated proteins a- catenin and matrix metalloproteinase ( MMP)- 7 were measured by real- time quantitative reverse transcriptase polymerase chain reaction ( RTPCR), immunohistochemistry and immunoblotting. Cell fractionation was used to investigate intracellular distribution of a- catenin. RESULTS: Parenchymal tumors were palpable in the abdomens of nude mice 2 wk post- implantation and orthotopic tumor formation rate was 100% in all groups. 5- FU treatment alone significantly decreased tumor weight compared to the CON group ( 1.203 0.284 g vs 1.804 0.649 g, P < 0.01). WCA treatment alone reduced the rate of metastasis ( 50% vs 100%, P < 0.05). Combination treatment of WCA + 5- FU was the most effective, reducing the tumor weight ( 1.140 0.464 g vs 1.804 0.649 g, P < 0.01) and size ( 1493.438 740.906 mm3 vs 2180.259 816.556 mm3, P < 0.05), the rate of metastases ( 40% vs 100%, P < 0.01), and serum CEA levels ( 31.263 7.421 g/ L vs 43.040 11.273 g/ L, P < 0.05). Expression of a- catenin and MMP- 7 was decreased in drug- treated groups compared to controls, as detected using realtime quantitative RT- PCR, immunohistochemistry and immunoblotting, respectively. Cell fractionation assays revealed that nuclear translocation of a- catenin was reduced by WCA and/ or 5- FU treatments. CONCLUSION: Combination of WCA with 5- FU significantly inhibited colon tumor growth and hepatic metastases. Decreased expression of a- catenin and MMP- 7 may be important. al