SYNERGISTIC ANTITUMOR EFFECT OF 20-(R)-RG3 COMBINED WITH 5- FLUOROURACIL ON HCT-116 CELL
5-FU, a classical chemotherapy agent, plays an important role in treatment of colorectal cancer (CRC), However, the severe cells toxicity of 5-FU is a principal obstacle of clinical application in CRC. 20(R)-ginsenoside Rg3 (20-(R)-Rg3, GRg3), a monomer extracted from Panax ginseng roots, has been well-researched for the treatment of many cancers. Up to now, the synergism of GRg3 combination with 5-FU in CRC have not been reported in vitro. Therefore, this study aimed to explores the anti-cancer activity of GRg3 in combination with a lower dose 5-FU and further identify the mechanism for inhibiting growth of cells. Our results demonstrated that co-treatment worked synergistically and more effectively than either drug alone in decreasing viability in HCT-116 cells. 5-FU and GRg3 together exhibit greater cell cycle arrest in the S and G1/G0 than when used alone. Furthermore, two-drug combination significantly down-regulate the anti-apoptosis proteins expression levels of Bcl-2 and Bcl-xl and up-regulated significantly the expression levels of Bax, P53, cleaved-PARP and cleaved-caspase-3. Based on these data, we conclude that lower concentrations of 5-FU and GRg3 used in combination produce a synergistic anti-cancer effect that is mediated by apoptosis through a mitochondrial pathway and arresting cells in S and G0/G1 phase. Collectively, Combination of 5-FU and GRg3 could be regarded as a promising therapy for controlling the growth of CRC cells.