Triclosan reduces prostaglandin biosynthesis in human gingival fibroblasts challenged with interleukin-1 in vitro

Abstract The effect of the toothpaste ingredient triclosan (2,4,4′-trichloro-2′-hydroxyldiphenyl ether) on the prostaglandins biosynthesis in human gingival fibroblasts challenged with interleukin-1β (IL-1β) or tumor necrosis factor α (TNFα) was studied in vitro. When gingival fibroblasts were treated simultaneously with triciosan and IL-1β, the stimulatory effect of IL-1β on prostaglandin E₂ (PGE₂) and PGI₂ formation was reduced in a dose-dependent manner by triclosan. Triclosan also reduced the PGE: formation induced by TNFα. Furthermore, the capacity of IL-1β to induce release of [³H] arachidonic acid from prelabelled gingival fibroblasts was reduced in the presence of triclosan. Addition of exogenous unlabelled arachidonic acid (AA) to the cells resulted in enhanced PGE₂ formation which was reduced by triclosan. The upregulation of the metabolism of AA to PGE₂ induced by IL-lβ, was markedly reduced in the presence of triclosan. The study indicates that the stimulatory effect of IL-1β on prostanoid formation (PGE₂, PGI₂) in human gingival fibroblasts was diminished in the presence of triciosan partly at the level of phospholipase A₂ and partly at the level of cyclooxygenase. The present data that triclosan. in vitro, inhibits the production of inflammatory mediators such as prostaglandins suggests that this can be an aspect of its clinical effect on gingivitis, in addition to its antibacterial effect.