[ODP-062] Dual inhibitory activity of compound-X enriched in fennel against Porphyromonas gingivalis
Increasing evidence has shown that Porphyromonas gingivalis triggers oral dysbiosis leading to deterioration not only of periodontal health, but also of several systemic conditions. In the present study we identified remarkable anti-P. gingivalis activity of fennel by screening of 92 edible plants extracts. The n-hexane-extracted fennel (HEF) showed a rapid lethal action toward P. gingivalis, while it was rather ineffective with a wide range of other oral commensal bacterial species. Morphological analysis using both HS-AFM and FE-SEM revealed that HEF induced bacteriolysis with overproduction of OMVs. Interestingly, HEF treatment resulted in deprivation of two outer membrane transporter proteins, RagA and RagB, which is essential for nutrient acquisition in P. gingivalis, by extracellularly releasing RagA/RagB-enriched OMVs. Furthermore, HEF showed gingipain-inhibitory activity towards gingipains, resulting in blocking oral epithelial cell rounding and the subsequent detachment from culture dishes. Finally, we isolated Compound-X as a major bactericide as well as a gingipain inhibitor from HEF. Taken together, our findings suggest the clinical applicability of HEF and Compound-X for periodontitis therapy to eliminate P. gingivalis and its major virulence factors on the basis of the dual inhibitory activity.