polysaccharides inhibit cellular apoptosis and autophagy induced by lipopolysaccharide in A549 cells through sirtuin 1 activation.

In the present study, the role of in cellular apoptosis and autophagy induced by lipopolysaccharide (LPS) in human epithelial A549 lung-cancer cells was investigated. Initially, it was demonstrated that LPS attenuated A549 cell viability in a time- and dose-dependent manner. Furthermore, LPS induced apoptotic cell death and autophagy in A549 cells and increased reactive oxygen species (ROS) production in a time-dependent manner. In addition, LPS treatment was demonstrated to markedly suppress sirtuin 1 (SIRT1) protein expression in A549 cells. Notably, it was demonstrated that polysaccharides activate SIRT1, leading to increased p62 expression, decreased p53 acetylation and B-cell lymphoma 2-associated X protein expression, and subsequently attenuate LPS-induced apoptotic cell death and autophagy. The results of the present study demonstrated that polysaccharides activate SIRT1 and inhibit LPS-induced ROS production, apoptosis and autophagy. This may have critical implications for the treatment of infection.