Antimutagenic activity and preventive effect of black tea on buccal mucosa cancer

A black tea product was evaluated for anti-mutagenic and in vivo anticancer effects. At concentrations of 1.25 and 2.5 mg/plate, black tea exhibited anti-mutagenicity with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the Salmonella typhimurium TA100 strain. A Kunming (KM) mouse buccal mucosa cancer model was established by injecting mice with U14 squamous cell carcinoma cells. Following injection, the wound at the injection site was smeared with black tea. It was observed that the tumor volumes for the groups treated with different concentrations of black tea were smaller than the control groups. The sections of buccal mucosa cancer tissue showed that cancer development in the black tea groups was weaker compared with that in the control group. Similar results were observed in the lesion section of the cervical lymph. Using reverse transcription polymerase chain reaction (RT-PCR), the black tea groups demonstrated an increase in Bcl-2-associated X protein (Bax) and a decrease in B cell lymphoma-2 (Bcl-2) expression, compared with the control groups. The results demonstrated that black tea had an improved antimutagenic effect and in vivo buccal mucosa cancer preventive activity compared with the untreated control in mice.