Chemoprevention of Herbal Compound Dongju on Tongue Carcinogenesis in Rats

Clinical trials of the herbal preparation” DongJu” have demonstrated substantial responses in patients with oral leukoplakia, but its chemopreventive mechanism remains largely undefined. Objectives: To examine the inhibitory effect of Chinese herbal Compound Dongju on 4-nitroquinoline 1-oxide (4NQO)-induced tongue carcinogenesis in rats. Methods: A total of 85 Wistar rats were divided into four groups: model group(n=35), administration group(n=35), normal control group(n=5) and herb control group(n=10). 4NQO dissolved in drinking water was administered orally to induce tongue carcinogenesis in rats. The herb compound was injected into the stomach of the rats during oral carcinogenesis. Rats were sacrificed at 9, 13, 20, 24 and 32 weeks from the beginning of the experiment. The tongues of the rats were dissected for gross and histological assessment, and SP immunohistochemical method was also employed to detect the expression of cyclinD1,IΚBα and NF-ΚBp65 in the specimens. Results: Administration of 4NQO produces a successive carcinogenesis progression model that demonstrate multiple dysplastic, preneoplastic, and neoplastic lesions following treatment with 9, 13, 20, 24 and 32 weeks. The labeling index of NF-ΚBp65, IΚBα and CyclinD1 increased gradually during the course of carcinogenesis. Administration of herbal Compound Dongju significantly inhibited the oral carcinogenesis as revealed by decreased expression of NF-ΚBp65 and CyclinD1, the positive rates of NF-ΚBp65 and CyclinD1 in administration group were markly evelated compared with model group(P<0.05). Administration of herbal Compound Dongju did not significantly influence the expression of IΚBα compared to model group (P>0.05). Conclusions: Administration of Compound Dongju effectively suppressed 4NQO induced tongue carcinogenesis. It may exert the chemopreventive effects by blocking the expression of NF-ΚB signaling pathway-related proteins.