In vitro anti-gastric tumor activities and possible mechanisms of action of paederosidic acid from paederia scandens (Lour) Merrill

Abstract

Purpose: To evaluate the anti-tumor activity and explore the possible mechanisms of action of paederosidic acid isolated from Paederia scandens (Lour.) Merrill. Methods: Paederosidic acid (PA) was isolated from P. scandens and identified by spectroscopic methods. The cytotoxic effects of PA in gastric cancer cell lines (MGC-803, BGC-823, and SGC-7901 cells) were assayed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT). Apoptosis of PA in SGC-7901 cells was evaluated by DAPI staining. To investigate the possible mechanisms of apoptosis, the effect of PA on C-caspase-3, C-caspase-9, Bcl-2 and Bax expressions in SGC-7901 cells were assayed by Western blot analysis. Results: PA exerted significant inhibitory effects on MGC-803, BGC-823, and SGC-7901 cells with 50% inhibitory concentration (IC50) values of 42.2, 43.7, and 30.5 μM, respectively, and in a concentration-dependent manner. Subsequently, SGC-7901 cells were selected for further studies. After treatment with PA, obvious condensation of the nucleus was observed in fluorescence photomicrographs, which is a characteristic of apoptosis. In addition, caspase-3, caspase-9 proteins and Bax were significantly up-regulated (p < 0.05), whereas Bcl-2 was significantly down-regulated (p < 0.05) by PA in a concentration-dependent manner. Conclusion: PA has significant anti-tumor activity on SGC-7901 cells in vitro, and the possible mechanism of action may be related to PA-induced apoptosis via mitochondria-mediated apoptosis pathway.