Ameliorating Effect of Glehnia littoralis Extract on Periodontitis Through Regulation of 11β-Hydroxysteroid Dehydrogenase Type 1 in an Experimental Periodontitis Model.

Glehnia littoralis Fr. Schmidt ex Miq. has been cultivated in China for a long time and used as a medicinal plant called "Beishashen" in traditional Chinese medicine and has been traditionally known to have antibacterial and anti-inflammatory effects, but its direct role in periodontitis has not been known. Currently used periodontal treatments require long-term administration, which causes many side effects. Therefore, in this study, we evaluated the effects of G. littoralis extract (GLE) on periodontitis in an experimental periodontitis-induced in vitro and vivo model and understood its potential molecular mechanism. The effect of GLE on periodontitis in vitro was investigated using human periodontal ligament (HPDL) cells mediated by PG-LPS. Additionally, a ligature-induced periodontitis model and a PG-LPS-induced periodontal inflammation model were used to investigate the effect of GLE in vivo. In vitro study results showed that GLE down-regulated the increased inflammatory cytokines and mediators in HPDL cells stimulated with PG-LPS, and simultaneously down-regulated the levels of 11β-HSD1 and glucocorticoid receptor (GR), thereby alleviating periodontal inflammation. At the same time, it restored the lost osteoblast differentiation potential of HPDL cells. In addition, in an in vivo model representatively used for periodontitis research, the periodontal inflammation-alleviating effect and the effect of restoring or protecting damaged periodontal tissue were confirmed. GLE can be considered as a new periodontitis treatment agent through regulating 11β-HSD1.