Background: Thea viridis extract (TVE) has long been employed clinically to treat cancer patients. We aimed to investigate the therapeutic effects of TVE on colorectal cancers, as well as the underlying mechanisms, which have not previously been explored.
Materials and methods: We first tested the effects of TVE on colorectal cancer cells HCT- 116 or Caco-2 growth, apoptosis and invasion by MTT, flow cytometry analysis and transwell assay in vitro. Next, mice received three doses (200, 400 and 800 mg/kg/day, gastric perfusion) of TVE to evaluate the effects on tumor growth and lung metastasis in mouse xenograft models which inoculated with HCT-116 or Caco-2 cells. The expression of p-ERK and p-MEK were evaluated by western blot analysis in HCT-116 and Caco-2 cells with or without TVE treatment in vitro.
Results: Our results show that TVE significantly inhibits colorectal cancer cell growth and induces apoptosis or cell cycle arrest at the G1- and S-phase in HCT-116 cells and Caco-2 cells in a dose dependent manner. Moreover, TVE effectively retards tumor cell migration and invasion through ERK/MAPK signaling pathway suppression.
Conclusion: These findings demonstrate that TVE has an anti-tumor effect in colorectal cancer by inactivating ERK/MAPK signaling pathway.