Synergistic anticancer effect of extract from Rosa roxburghii Tratt combined with 5-fluorouracil on human hepatocellular carcinoma cell line SMMC-7721.

Objective:To investigate the synergistic antitumor effect of 5-fluorouracil(5-FU)combined with extract from Rosa roxburghii Tratt (CL) on human hepatocellular carcinoma cell line SMMC-7721. Methods:The effect of 5-FU combined with CL on the proliferation of SMMC-7721 cells was measured by MTT reduction test and analyzed by cell growth curves. The effect of 5-FU and CL on the differentiation of SMMC-7721 cells was evaluated by counting the number of nitroblue tetrazolium(NBT)-positive cells and determining the alpha-fetoprotein (AFP) level in cultured supernatant. The effect of 5-FU and CL on cell cycle and apoptosis was determined by acridine orange (AO)/ethidium bromide (EB) staining and flow cytometry (FCM).Results:The growth curves of SMMC-7721 cells were shifted towards the bottom after combined treatment,and the q values were between 0.85-1.15 in 96 h,indicating there was an additive effect between 5-FU and CL. The ratios of NBT-positive cells were elevated after being treated with either 5-FU or CL alone and in combination compared with control group (P0.05),and the percentage of NBT-positive cells was higher in combined therapy group than single CL therapy group (P0.05). CL or CL combined with 5-Fu decreased the extracellular AFP level. The AFP concentration in cultured medium was decreased with increased CL dosage,but there was no obvious difference between combined treatment group and single CL treatment group (P0.05). The apoptotic ratio was not different between CL and CL plus 5-FU treatment group (P0.05). Compared with negative control group,the ratio of heteroploid was raised after being treated with 5-FU (P0.05). The ratio of SMMC-7721 cells in G0/G1 phase was increased (P0.05) and that in S phase was decreased (P0.05) after treatment with CL or CL plus 5-FU. The percentage of SMMC-7721 cells in G2/M phase was decreased after treatment with CL plus 5-FU (P0.05). Conclusion:CL and 5-FU have synergistic anticancer effect on SMMC-7721 cells,and the machnisms are related with their synergistic effects in inducing cell differentiation and inhibiting cell proliferation.