Effect of total saponins from marsdenia tenacissima on the proliferative inhibition of human liver cancer HepG2 cells / 肿瘤研究与临床

ABSTRACT

Objective To investigate the proliferative inhibition effect and mechanism of total saponins from marsdenia tenacissima on human liver cancer HepG2 cells. Methods Human liver cancer HpeG2 cells cultured conventionally were divided into the marsdenia tenacissima saponins A control group, the experimental group and the blank control group. The experimental group was treated with different mass concentrations of total saponins from marsdenia tenacissima (0.14, 0.29, 0.58, 1.15, 2.13 mg/ml), while the marsdenia tenacissima saponins A control group was treated with marsdenia tenacissima saponins A (1.0 mg/ml), and the blank control group was established stimultaneously. The methyl thiazolyl tetrazolium (MTT) method was used to detect the effect of total saponins from marsdenia tenacissima on the activity of HepG2 cells, and the cell morphology was observed by using inverted microscopy. The cell apoptosis rate was detected by using flow cytometry from Annexin V-FITC/PI staining. The expressions of bcl-2, bax and p53 were analyzed by using Western blot after the drug effect. Results The results of cell activity test showed that total saponins from marsdenia tenacissima could inhibit the proliferation of HepG2 cells at the concentration of 0.29, 0.58, 1.15, 2.13 mg/ml, which was positively correlated with the concentration. The half maximal inhibitory concentration (IC 50) of cell growth inhibition of total saponins from marsdenia tenacissima on HepG2 cells was 0.75 mg/ml. Under inverted microscopy, the adherent cells were significantly reduced, the cells fell off into clusters and the debris was increased after the effect of total saponins from marsdenia tenacissima. Moreover, flow cytometry showed that total saponins from marsdenia tenacissima could increase the late apoptosis rate of HepG2 cells (P< 0.01). Western blot showed that the expression of bcl-2 was 0.62±0.16, 0.31±0.15, 0.84±0.09 and 1.00±0.11 respectively in the experimental group (total saponins from marsdenia tenacissima 0.58 mg/ml and 2.13 mg/ml), the marsdenia tenacissima saponins A control group and the blank control group;the expression of bax protein was 0.75±0.10, 0.83±0.12, 1.00±0.14 and 0.15±0.02, respectively in the above four groups; the expression of p53 protein was 0.63±0.08, 0.78±0.11, 1.00±0.13 and 0.18±0.02 respectively in the above four groups. The protein expression of bcl-2 was decreased and the protein expressions of bax and p53 were increased in the experiment group, and there was a statistical difference between the experiment group and the blank control group (P< 0.05). Conclusions Total saponins from marsdenia tenacissima can upregulate the expression of bax by upregulating the expression of p53 gene, and inhibit the expression of bcl-2, which would cause the cascade reaction to induce the apoptosis of HepG2 cells. Its inhibitory effect can be realized through mitochondrial pathmay to induce apoptosis.