The effect of dietary and topical celecoxib on 4-nitroquinoline-1-oxide-induced lingual epithelium alternations in rat.

Objective: To compare the preventive effect of dietary and topical Celecoxib(CCB), a potent inhibitor of COX-2 on 4-NQO-induced tongueSCC in rat. Methods: Fifty male Sprague Dawley adult 3- 3.5 months old rats were used as animal model in this study. The tongueSCC was induced by a daily administration of 30 ppm 4-NQO, in drinking water, for 8 months. The rats in case groups received dietary or topical CCB. TongueSpecimens were prepared for histopathological and immunohistochemical (Ki-67) staining and or TUNEL assaywere examined. Values are expressed as mean ± SEM and analyzed with Npar Kruscal Wallis and one-way ANOVA tests. p < 0.05 was considered significant. Results: The incidence of tongueprecancer lesions, judged by morphological and morhometrical criteria and apoptosis/proliferation ratio, was significantly (p<0.01) reduced by CCB. The effect of topical CCB use, at high doses, was comparable to the effect of dietary CCB. Conclusion: Both topical and dietary CCB have inhibitory effect on 4-NQO induced SCC on tongue. The effect of CCB is probably mediated by suppression of cell proliferation and induction of apoptosis.