Protective effect of acacetin in human periodontal ligament cells via regulation of autophagy and inflammation.

Our study investigated the effects of acacetin, a natural flavonoid compound, on the survival and expression of inflammatory related cytokines in lipopolysaccharide (LPS)-stimulated human periodontal ligament (PDL) cells. Treatment with acacetin significantly promoted survival and suppressed apoptosis in LPS-stimulated PDL cells in a dose-dependent manner, as shown by CCK-8 and flow cytometry assays, respectively. Moreover, ELISA assay showed that acacetin dose-dependently attenuated LPS-induced increases of TNF-α, IL-6 and IL-1β in PDL cells. Western blot analysis showed that administration of acacetin dose-dependently increased the ratio of LC3II/LC3I, as well as the expression of beclin-1, as compared to LPS-stimulated PDL cells. Inhibition of autophagy by rapamycin, an autophagy inhibitor, increased the production of pro-inflammatory cytokines and decreased survival, abolishing the beneficial role of acacetin in LPS-stimulated PDL cells. In addition, the expression of GSK-3β, a regulator of autophagy, was suppressed by administration with acacetin in a dose-dependent manner. Acacetin treatment promotes survival and suppresses inflammation in LPS-stimulated PDL cells via regulating autophagy and GSK-3β signal in PDL cells, suggesting that acacetin may be a potential novel agent for the treatment of chronic periodontitis.