Anti-Inflammatory Effects of Apostichopus japonicus Extract in Porphyromonas gingivalis-Stimulated RAW 264.7 Cells

Apostichopus japonicus has been used both as a food and in traditional medicine. However, its anti-inflammatory effects in periodontal diseases have not been studied. We examined the anti-inflammatory properties of Apostichopus japonicus extract in RAW 264.7 cells stimulated by Porphyromonas gingivalis. The cytotoxicity of Apostichopus japonicus extract was evaluated using the MTS assay. Its effect on NO production was then measured using the NO assay. The mRNA expression of inducible nitric oxide synthase (iNOS) and the pro-inflammatory cytokines IL-1β and IL-6 were assessed using quantitative real-time PCR (qRT-PCR). Western blotting was performed to investigate the expression of regulatory proteins involved in the NF-κB and MAPK signaling pathways. Apostichopus japonicus extract significantly inhibited NO production without cytotoxicity in RAW 264.7 cells. Following Porphyromonas gingivalis stimulation, treatment with the extract decreased iNOS mRNA expression and protein levels, which are responsible for NO production. The extract also suppressed the mRNA expression of pro-inflammatory cytokines. Additionally, Apostichopus japonicus extract inhibited NF-κB activation by regulating signaling molecules such as IKK and IκBα, while also preventing the phosphorylation of MAPK, including ERK, p38, and JNK, showing anti-inflammatory potential. Therefore, it may be a promising natural candidate for the development of new preventive and therapeutic strategies for periodontitis.