Apoptotic mechanism of gastric carcinoma cells induced by matrine injection

OBJECTIVE: To investigate the mechanism of gastric carcinoma cells apoptosis induced by matrine injection in vitro. METHODS: Effects of 24, 48, 72, 96 h incubation with different concentrations (0.25-1.5 g/L) of matrine injection on proliferation of SGC-7901 cells were evaluated using 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT) assay. The cellular morphology of SGC-7901 cells was observed by transmission electron microscope (EM). Flow cytometry was used to analyze the apoptosis of SGC-7901 cells by staining with annexin V-FITC/PI. The expression of Fas/FasL was examined by flow cytometry using specific antibody. The activity of caspase-3 was measured by spectrofluorometry. RESULTS: Matrine injection could inhibit the proliferation of SGC-7901 cells in a dose- and time-dependent manner. The typical morphological changes of apoptosis were observed after incubation with 1.0 g/L matrine injections for 48 h. The apoptosis rates of 0.5 g/L, 1.0 g/L and 1.5 g/L groups were 39.80%, 58.11% and 79.00% respectively. The apoptotic cells in matrine injection group were mainly early apoptotic cells, and those in 5-FU group were mainly late apoptotic cells and necrotic cells. Spectrofluorometry revealed FI levels of Fas and FasL were equal, which were both correlated with apoptosis rate. The activity of caspase-3 increased with the elevation of matrine concentration, and was correlated with the apoptosis rate. CONCLUSION: Matrine injection can induce apoptosis of SGC-7901 cells through the up-regulation of Fas/FasL expression and activation of caspase-3.