Gamellia sinensis O.Ktze extract shows anti-colorectal cancer activity via MAPK/ERK signaling pathway

Purpose: To investigate the therapeutic effects of Gamellia sinensis O.Ktze extract (GSOE) on colorectal cancers, as well as the underlying mechanisms. Methods: The effect of GSOE on colorectal cancer cells HCT-116 or Caco-2 growth was tested, and then the apoptosis and invasion was analyzed by MTT, flow cytometry and Transwell assay in vitro. Next, the mice received three doses (200, 400 or 800 mg/kg/day, gastric perfusion) of GSOE to evaluate its effects on tumor growth. Lung metastasis in mouse xenograft models which were inoculated with HCT-116 or Caco-2 cells were also investigated. The expression of p-ERK and p-MEK were evaluated by western blot analysis in HCT-116 and Caco-2 cells with or without GSOE treatment in vitro. Result: GSOE significantly inhibited colorectal cancer cell growth and induced apoptosis or cell cycle arrest at G1- and S-phases in HCT-116 cells and Caco-2 cells in a dose-dependent manner. Moreover, GSOE effectively retarded tumor cell migration and invasion through ERK/MAPK signaling pathway suppression. Conclusion: These findings demonstrate that GSOE has an anti-tumor effect in colorectal cancer by inactivating ERK/MAPK signaling pathway.