Preventive effects of a Kampo medicine, Shosaikoto, on inflammatory responses in LPS-treated human gingival fibroblasts

In the present study, we investigated the anti-inflammatory effects of a Kampo medicine Shosaikoto (TJ-9) using in vitro periodontal disease model, in which human gingival fibroblasts (HGFs) treated with lipopolysaccharide (LPS) from Porphyromonas gingivalis (PgLPS) produce IL-6, IL-8 and prostaglandin E-2 (PGE(2)). Treatment with PgLPS (10 ng/ml), TJ-9 (up to 1 mg/ml) and their combinations for 24 h did not affect the viability of HGFs. Moreover, TJ-9 did not alter LPS-induced IL-6 and IL-8 productions. However, TJ-9 significantly suppressed LPS-induced PGE(2) production in a dose-dependent manner but TJ-9 alone did not affect basal PGE(2) level. Western blotting demonstrated that TJ-9 decreased cyclooxygenase-2 (COX-2) expression in a dose-dependent manner but not phospholipase A(2). Moreover, TJ-9 selectively and dose-dependently inhibited COX-2 activity. These results suggest that TJ-9 decreased PGE(2) production by inhibition of both COX-2 expression and activity and that TJ-9 may be useful to improve gingival inflammation in periodontal disease.