Abstract
OBJECTIVE: To investigate the effect of solasonine, an active component of Solanum nigrum, on proliferation and apoptosis of non-small cell lung cancer PC9 cells. METHODS: PC9 cells were treated with 2, 5, 10, 15, 20, or 25 μmol/L solasonine, and the changes in cell proliferation were examined using CCK-8 assay. Tetramethyl rhodamine ethyl ester (TMRE) was used to detect the changes in mitochondrial membrane potential, and caspase-3/7 detection kit and GreenNuc(TM) caspase-3/Annexin V-mCherry kit for live cell were used to analyze the changes in caspase-3 of the cells. Annexin V-FITC/PI double staining was employed to analyze the apoptosis rate of the cells. The effect of PTEN inhibitors on solasonine-induced cell apoptosis was examined by detecting apoptosis-related protein expressions using Western blotting. RESULTS: Solasonine treatment for 24, 48, and 72 h significantly lowered the viability of PC9 cells. The cells treated with solasonine for 24 h showed significantly decreased mitochondrial membrane potential and increased cell apoptosis with enhanced caspase-3/7 and caspase-3 activities and expression of cleaved caspase-3. Solasonine treatment significantly decreased phosphorylation levels of PI3K and Akt, increased the protein expressions of PTEN and Bax, and lowered the expression of Bcl-2 protein in the cells. CONCLUSION: Solasonine inhibits proliferation and induces apoptosis of PC9 cells by regulating the Bcl-2/Bax/caspase-3 pathway and its upstream proteins.