Ganoderic Acid A Enhances Tumor Suppression Function of Oxaliplatin via Inducing the Cytotoxicity of T Cells

BACKGROUND: Various natural products have been demonstrated for their anti-tumor activities. As a natural triterpenoid, the effects of ganoderic acid A on oxaliplatin chemotherapy for cancer treatment remain unclear. METHODS: A xenograft mouse model of colon cancer was constructed using the HT-29 cells. Ganoderic acid A was intravenously administered with or without oxaliplatin. The CCK-8 method was performed to assess cell viability. Flow cytometry was used to determine cell apoptosis and subtyping of T cells. Cytotoxicity of the T cells was assayed using a lymphocyte-tumor co-culture system in vitro. RESULTS: Ganoderic acid A enhanced tumor suppression of oxaliplatin in the xenograft model, while single administration showed no obvious anti-tumor effect. Ganoderic acid A didn't affect cell proliferation and apoptosis of HT-29 cells treated by oxaliplatin in vitro. Additionally, ganoderic acid A co-administered with oxaliplatin didn't impact T cell subtyping in the xenograft model. Cytotoxicity of T cells in co-administered mice was remarkably enhanced compared with oxaliplatin-treated mice. CONCLUSION: Our findings reveal that ganoderic acid A synergistically enhances tumor suppression of oxaliplatin possibly via increasing the cytotoxicity of T cells.