The effect of Scutellaria baicalensis Georgi on immune response in mouse model of experimental periodontitis

Background/purpose A medicinal herb Scutellaria baicalensis Georgi has been reported to possess antibacterial and anti-inflammatory activities. In this study, the effect of aqueous extracts obtained from S. baicalensis GEORGI (SbE) on the immune response in ligature-induced periodontitis of mouse models was investigated. Materials and methods Sixty mice were randomly divided into four groups. Experimental periodontitis was induced by wrapping Porphyromonas gingivalis-soaked silk ligature at the gingival margins of the left first maxillary molar, and some of them were treated with SbE from the 4th week after the ligature. There were also normal and SbE-treated controls without ligature. The histopathologic analyses of periodontia were performed at Weeks 4, 6, 8, and 10 after the ligature. Serum levels of immunoglobulin (Ig) G isotypes, e.g., IgG1 and IgG2a, were quantified by enzyme-linked immunosorbent assay. Results Compared with the experimental periodontitis group, the periodontitis + SbE-treated mice showed significantly improved histopathology of periodontal tissue at Weeks 6, 8, and 10 after the ligature (P < 0.05). Compared with the control groups, periodontitis + SbE-treated mice exhibited significant higher levels of Th2-type IgG1 at Weeks 6, 8, and 10 (P < 0.01), whereas levels of the Th1-type IgG2a were relatively unaffected in periodontitis + SbE-treatment group but significantly increased in experimental periodontitis group at Weeks 6, 8, and 10 (P < 0.01). Conclusion Our data suggest that the aqueous extract of S. baicalensis Georgi could improve the experimental periodontitis in mouse model by inducing a Th2-polarized immune response.