Tormentic acid inhibits LPS-induced inflammatory response in human gingival fibroblasts via inhibition of TLR4-mediated NF-κB and MAPK signalling pathway

Objective: Periodontal disease is one of the most prevalent oral diseases, which is associated with inflammation of the tooth-supporting tissues. Tormentic acid (TA), a triterpene isolated from Rosa rugosa, has been reported to exert anti-inflammatory effects. The aim of this study was to investigate the anti-inflammatory effects of TA on lipopolysaccharide (LPS)-stimulated human gingival fibroblasts (HGFs). Methods: The levels of inflammatory cytokines such as interleukin (IL)-6 and chemokines such as IL-8 were detected by enzyme-linked immunosorbent assay (ELISA). The expression of Toll-like receptor 4 (TLR4), nuclear factor kappa B (NF-kappa B), I kappa B alpha, p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) was determined by Western blotting. Results: The results showed that Porphyromonas gingivalis LPS significantly upregulated. the expression of IL-6 and IL-8. TA inhibited the LPS-induced production of IL-6 and IL-8 in a dose-dependent manner. Furthermore, TA inhibited LPS-induced TLR4 expression; NF-kappa B activation; I kappa B alpha degradation; and phosphorylation of ERK, JNK, and P38. Conclusion: TA inhibits the LPS-induced inflammatory response in HGFs by suppressing the TLR4-mediated NF-kappa B and mitogen-activated protein kinase (MAPK) signalling pathway. (C) 2015 Elsevier Ltd. All rights reserved.