Introduction: Oral squamous cell carcinoma (OSCC) has the highest mortality rates among all carcinomas and is the most common head and neck cancer. Several natural compounds and micronutrients have been under investigation for their efficacy in head and neck cancer chemoprevention. Green tea contains various cancer preventive catechins that have a role in preventing cancer recurrence in various organs in humans. Curcumin, a natural polyphenol, is one of the most investigated biomolecules from Mother Nature. Curcumin has been shown to exert significant growth inhibitory effect on oral precancerous and carcinoma cell lines, and the effect is synergistic with epigallocatechin gallate, the most abundant polyphenol in tea.
Objectives: To assess the chemopreventive effects of green tea and curcumin through induction of hamster buccal pouch carcinoma by using an apoptotic marker and compare their effect each alone and in combination.
Materials and methods: Squamous cell carcinoma was chemically induced in fifty Syrian golden hamsters divided into 5 groups (10 each). The first group was used as normal control group. The second group received the carcinogenic agent only. The other three groups received green tea, curcumin and combination of both, respectively.
Results:Normal control group (A) revealed neither pathological nor inflammatory changes in the buccal pouch with 1.72%of the cells underwent apoptosiswhile the cells of positive control group (B) resulted in 11.57% apoptosis. In the study groups, treatment of the cells with green tea (C), curcumin (D) and both of them (E) resulted in 82.22 %, 78.91%, 96.63% apoptosis respectively. The fluorescent image by confocal laser scanning in group B showed increase of the red fluorescence in the nucleus and cytoplasm of the squamous cell carcinoma cells indicating high proliferating cells while the fluorescent image of group C, D and E showed decrease of the red florescence in the nuclei of the squamous cell carcinoma cells indicating low proliferation.
Conclusions: Green tea and curcumin have a significant chemopreventive effect against oral carcinogenesis and the combination of both agents has a better effect.