Preventive effects of tomato pulp on oral pre-neoplastic changes induced by 4-Nitroquinoline-1-oxid in the rat

ABSTRACT

Squamous cell carcinoma [SCC] is the most frequent oral cancer. Protective effects of the consumption of vegetables and fruits on various forms of cancer including oral cancer have been determined. Tomato [Solanum lycopersicum L.] because of its lycopene and bioflavonoids contents possesses anti-carcinogenic properties. The aim of this study was to evaluate the preventive effects of tomato pulp on pre-neoplastic changes induced by 4-Nitroquinoline-1-oxid [4-NQO] in epithelial cells of lingual mucosa in the rats. Forty-eight male Wistar rats were randomly allocated into four equal groups. Group 1 served as control. Groups 2 to 4 assigned to receive 30 ppm 4-NQO in drinking water for 12 consecutive weeks. When the feeding of 4-NQO was started to the rats of groups 3 and 4, they received tomato pulp [20 and 40 ml/kg bw] daily through the oral gavage. Finally, histological evaluations for carcinogenesis were performed for tongues epithelial tissue. There were no pathological alterations in epithelial tissue of lingual mucosa in control rats. In the epithelial cells of lingual mucosa of 4-NQO treated rats, premalignant alterations appeared after 12 weeks of the last application of the drug. Administration of tomato pulp at both doses [20 and 40 ml/kg bw] during the experiment reduced the severity of the lesions, as well as caused a significant reduction in the frequency of pre-neoplastic lesions of tongue epithelial cells [P= 0.024 and P= 0.008]. The incidence of severe epithelial cells dysplasia of lingual mucosa in the high dose treatment group was significantly smaller than of low dose treatment group [P= 0.037]. The results obtained showed that tomato pulp is effective in inhibiting the development of neoplasms in epithelial cells of lingual mucosa induced by 4-NQO in the rat