EFFECT OF ROSELLE CALYX EXTRACT ON GINGIPAIN ACTIVITY, PRODUCTION OF INFLAMMATORY CYTOKINES, AND ORAL BACTERIAL MORPHOLOGY

This study to investigate the effect of roselle calyx extract on gingipain activity, production of inflammatory cytokines, and oral bacterial morphology. The inhibitory effect of roselle calyx extract (RCE) on Arg- (Rgp) and Lys-gingipain (Kgp) was evaluated using synthetic substrate colorimetric assay with a 96-well microtiter plate. RCE with various concentrations was tested for determination of interleukin (IL)-6 and IL-8 produced from KB cells stimulated with heat-inactivated P. gingivalis. The production of IL-6 and IL-8 was quantified using an ELISA kit. The morphological alterations in cells of S. mutans and P. gingivalis after treatment with RCE were studied using scanning electron microscopy (SEM). RCE could inhibit both Rgp (90%) and Kgp (70%) activities significantly at concentrations lower than the minimum inhibitory concentration (MIC) (2.2 mg/mL). Furthermore, the production of IL-6 and IL-8 from KB cells stimulated with P. gingivalis was significantly inhibited by RCE at 6 h after exposure, in a dose-dependent manner. After treatment with RCE, the morphological alterations were observed in cells of S. mutans and P. gingivalis by using SEM. The ability of RCE to inhibit gingipain activity and production of inflammatory cytokines indicates that RCE could be considered for prevention and clinical treatment for periodontitis.