Compound Radix Sophorae Flavescentis exerts antitumor effects by inhibiting the proliferation and inducing the apoptosis of esophageal carcinoma TE-8 cells

The aim of this study was to examine the effects of compound Radix Sophorae Flavescentis on the proliferation of esophageal carcinoma TE-8 cells and to elucidate the mechanisms involved. For this purpose, we incubated TE-8 cells in medium containing various concentrations (0, 0.0125, 0.025, 0.05, 0.1, 0.2, 0.4 and 0.8 mg/ml) of the compound Radix Sophorae Flavescentis injection and its effects on the proliferation of TE-8 cells were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, we observed the morphological changes and measured the expression levels of apoptosis-related genes (caspase-3, Bcl-2 and Bax) in the cells treated with different doses of the compound (low-dose group, 0.05 mg/ml; medium-dose group, 0.2 mg/ml; and high-dose group, 0.8 ng/ml) by reverse transcription-quantitative PCR (RT-qPCR). The apoptotic index of the cancer cells treated with different doses of the compound was determined by TUNEL assay. Our results revealed that compared with the control group (untreated cells), the proliferation of the cancer cells treated with the compound was significantly inhibited (P≤0.05); the inhibition of the proliferation of the cancer cells occured in a dose-dependent manner. Compared with the control group, the apoptotic rate of the cells in the low-dose, medium-dose and high-dose groups increased significantly (P<0.05) in a dose-dependent manner. In addition, compared with the control group, the mRNA expression of caspase-3 and Bax increased significantly in the cells treated with the compound. However, the mRNA expression of Bcl-2 markedly decreased (P<0.05). With the gradual increase in the drug concentration, the mRNA expression levels of caspase-3, Bcl-2 and Bax in the cancer cells were altered in a dose-dependent manner. In conclusion, our data demonstrate that compound Radix Sophorae Flavescentis injection significantly enhances the expression of pro-apoptotic genes in esophageal carcinoma TE-8 cells by increasing apoptosis and inhibiting cell proliferation. Thus, this study provides a theoretical basis for the clinical treatment of esophageal carcinoma.