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 Hp LC. 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 l e s i o n s wa s c o u n t e d. S e r u m c a r c i n o e m b r yo n i c antigen(CEA) level was determined by ELISA. The expression levels of tumor genesis and metastasisrelated proteins β-catenin and matrix metalloproteinase(MMp)-7 were measured by real-time quantitative reverse transcriptase polymerase chain reaction(RTp CR), immunohistochemistry and immunoblotting. Cell fractionation was used to investigate intracellular distribution of β-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 μg/L vs 43.040 ± 11.273 μg/L, p < 0.05). Expression of β-catenin and MMp-7 was decreased in drug-treated groups compared to controls, as detected using realtime quantitative RT-p CR, immunohistochemistry and immunoblotting, respectively. Cell fractionation assays revealed that nuclear translocation of β-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 β-catenin and MMp-7 may be important.