Angelica dahurica ameliorates the inflammation of gingival tissue via regulation of pro-inflammatory mediators in experimental model for periodontitis

Ethnopharmacological relevance Anti-inflammatory effects of Angelica dahurica (AD) have been reported in previous studies. In this study, we investigated the anti-inflammatory effects of AD on periodontitis. Materials and methods Male Sprague-Dawley rats aged 7 weeks (n=7) were subjected to ligature around bilateral mandibular first molars. 1 and 100 mg/mL of AD were topically applied to first molars for 14 days. Histological changes were observed in gingival epithelial layer, and the thickness of the gingival epithelial layer as well as the number of epithelial cells were quantified. To investigate the mRNA expression of pro-inflammatory cytokines in gingival tissues, reverse transcriptase polymerase chain reaction was performed. To confirm the anti-inflammatory effects of AD, pro-inflammatory mediators including cytokines and NF-kB, COX-2, and iNOS were analyzed in LPS-stimulated Raw 264.7 cells. Results Topical application of AD attenuated not only the thickness of epithelial layer, also the number of epithelial cells in gingival tissue. The expressions of IL-1β, IL-6, IL-8, and IFN-γ in gingiva were significantly reduced by AD treatment. Additionally, the expressions of IL-1β, IL-6, IL-8 and IFN-γ mRNA were inhibited by AD in LPS-treated RAW264.7 macrophage cells. Furthermore, AD treatment decreased LPS-induced elevation of NF-κB, COX-2 and iNOS protein levels in RAW264.7 cells. Conclusion Taken together, AD application ameliorated the hyperplasia of gingival epithelial layer by down-regulating pro-inflammatory mediators. AD might have therapeutic potentials for periodontal diseases.