Antiperiodontitis Impact of Extract from Edible Herb Aster Glehni and Its Bioactive Compound, 3,5-Dicaffeolyquinic Acid

Periodontitis is a chronic oral disease caused by periodontal pathogenic bacteria, such as Porphyromonas gingivalis. The lipopolysaccharide of P. gingivalis (PgLPS) is a crucial virulence factor that contributes to the pathogenesis of periodontitis. The present study investigated the anti-inflammatory effects of extract from Aster glehni (AGE), a region-specific edible herb in Korea, and its main bioactive compound, 3,5-dicaffeolyquinic acid (3,5-DCQA), on PgLPS-induced inflammatory responses and the associated intracellular mechanisms. AGE significantly suppressed the expression of interleukin (IL)-1β and IL-6, while moderately inhibiting monocyte chemoattractant protein-1 (MCP-1) expression at both mRNA and protein levels in RAW 264.7 cells stimulated by PgLPS. Furthermore, AGE effectively attenuated mitogen-activated protein kinase (MAPK) phosphorylation and nuclear factor-κB (NF-κB) activation induced by PgLPS. In contrast, 3,5-DCQA partially inhibited the expression of IL-1β, IL-6, and MCP-1 at both mRNA and protein levels. Additionally, 3,5-DCQA appeared to attenuate MAPK phosphorylation and NF-κB activation without exhibiting clear dose-dependency. Moreover, AGE dose-dependently attenuated TLR2 and TLR4 expression, while 3,5-DCQA decreased both TLR2 and TLR4 expression without clear dose-dependency. AGE demonstrated effective inhibition of PgLPS-induced inflammatory responses, with 3,5-DCQA playing a partial role in the inhibitory potential of AGE.