The effect of triclosan on mediators of gingival inflammation

Triclosan (2,4,4',-trichloro-2'-hydroxydiphenylether) is a well-known and widely used nonionic antibacterial agent which has recently been introduced in toothpastes and mouthrinses. The efficacy of triclosan-containing toothpaste and mouthrinse to reduce both plaque and gingivitis in long-term clinical trials has been well documented. Until recently, it was generally assumed that triclosan's effect on gingival inflammation was due to its antimicrobial and anti-plaque effect. It has now become apparent that triclosan may have a direct anti-inflammatory effect on the gingival tissues. Several in vitro studies were conducted to evaluate the effect of triclosan on 4 primary enzymes of the pathways of arachidonic acid metabolism, cyclo-oxygenase 1, cyclo-oxygenase 2, 5-lipoxygenase and 15-lipoxygenase. These pathways lead to the production of known mediators of inflammation such as the prostaglandins, leukotrienes and lipoxins. Triclosan inhibited both cyclooxygenase 1 and cyclo-oxygenase 2 with IC-50 values of 43 microM and 227 microM, respectively. Triclosan also inhibited 5-lipoxygenase with an IC-50 of 43 microM. The 15-lipoxygenase was similarly inhibited by triclosan with an IC-50 of 61 microM. Hence, triclosan has the ability to inhibit both the cyclo-oxygenase and lipoxygenase pathways of arachidonic acid metabolism with similar efficacy. In cell culture experiments, it was found that triclosan inhibited IL-1 beta induced prostaglandin E2 production by human gingival fibroblasts in a concentration dependent manner, and at relatively low concentrations. These data, taken together, indicate that triclosan can inhibit formation of several important mediators of gingival inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)