Sinomenine inhibits proliferation of SGC-7901 gastric adenocarcinoma cells via suppression of cyclooxygenase-2 expression

Sinomenine (SIN) is a bioactive alkaloid extracted from the Chinese medicinal plant Sinomenium acutum. Results of studies have shown that the anti-inflammatory, immunosuppressive and anti-arthritic effects of SIN are partially attributed to the inhibition of cyclooxygenase-2 (COX-2) expression. COX-2 overexpression is associated with enhanced proliferation and angiogenesis of gastric cancer (GC). SGC-7901 cells were treated with different concentrations of SIN in order to observe its effect on the proliferation of human gastric adenocarcinoma cells and to explore the potential underlying molecular mechanism via the detection of COX-2 expression. Celecoxib was used as the positive control. Morphological alterations of the cells were observed microscopically. Cell proliferation was evaluated using MTT assay. COX-2 expression was detected using semi-quantitative RT-PCR and Western blotting. The results showed that SIN inhibited the proliferation of SGC-7901 cells in a time- and dose-dependent manner. In the presence of SIN or celecoxib, SGC-7901 cells became round and detached morphologically, indicating cell apoptosis. The expression of COX-2 was inhibited by SIN in a dose-dependent manner at both the mRNA and protein levels. Our findings indicate that the protective effects of SIN are mediated through the inhibition of COX-2 expression. These findings suggest a novel therapy to treat inflammation-mediated gastric adenocarcinomata.