Evaluation of the Effect of Two Different Systemic Doses of Viola Odorata on Prevention of Induced Tongue Dysplasia in Rats

Statement of the problem: oral cancer is among the ten most common cancers worldwide. it affects the life quality of patients in many ways. purpose: the aim of this study was to compare the effects of two different systemic doses of viola odorata syrup on the prevention of 4-nitroquinoline-1-oxide (4- nqo) induced tongue dysplasia in rats. materials and method: forty-eight male wistar rats were divided into four groups of a, b, c and d. group a served as the control group. the rats in groups b to d received 30 ppm of 4-nqo in drinking water for 12 weeks. additionally, the rats in groups b and c received viola odorata syrup at doses of 15 and 5 ml/kg, respectively, 3 times a week. body weights were measured three times a week. at the end, the rats were euthanized and the tongue was removed. histological evaluations for carcinogenesis were carried out under a light microscope. results: the mean body weight of the rats in groups b, c, and d were lower than that in group a (p< 0.01). after 12 weeks of treatment, microscopically no histological changes of the tongue base epithelia were observed in the control group. the rats in group b did not show severe dysplastic changes; only mild to moderate histological changes including hyperplasia and hyperkeratosis were evident. these incidences were significantly more apparent in groups c with moderate to severe changes (p< 0.05) and group d with severe dysplastic changes (p< 0.01). almost all rats in group d had hyperplasia and manifested all of the stages of dysplasia. conclusion: viola odorata extract has dose-dependent inhibitory effects on the development of tongue induced dysplasia.