Synergistic Effect of Vitamin C with Cisplatin for Inhibiting Proliferation of Gastric Cancer Cells

Background: Ascorbic acid, known as vitamin C, has been used in combination with a number of cytotoxic agents in vitro and in vivo with contradictory results on its effectiveness. It is believed that vitamin C can sensitize different cancer cells to common therapy strategies such as chemotherapy and radiotherapy. During current research, the combination effect of vitamin C with cisplatin was evaluated against gastric cancer cells. Methods: MTT-based proliferation assay, combination index method, and flow cytometry technique were employed for the assessment of cell cycle and determination of apoptosis/necrosis on the AGS cell line. Results: Co-treatment of gastric cancer cells with vitamin C in its IC₅₀ dose in addition to cisplatin in both IC₅₀ (10 µg/ml) and five times less (2 µg/ml) doses could increase the cytotoxicity effect of cisplatin in a synergistic manner. Moreover, the pointed co-treatment approach could induce the cell count in sub-G0 phase while reducing it in the G0/G1, G2/M, and S phases. Further findings showed that the combined dose of vitamin C and cisplatin could increase the percentage of apoptotic and necrotic cells in comparison with a single dose of cisplatin. Conclusion: This study introduces a possible approach for the treatment of gastric cancer with more potency and less amount of administered cisplatin to induce toxicity.