In vitro and in vivo anti-cancer activities of Kuding tea (Ilex kudingcha C.J. Tseng) against oral cancer

Abstract

Kuding tea (Ilex kudingcha C.J. Tseng) is drunk widely in China. The in vitro anticancer effects of Kuding tea were evaluated in TCA8113 human tongue carcinoma cells using a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay. At a concentration of 200 μg/ml, Kuding tea exhibited an inhibitory effect of 75% in TCA8113 cells, which was higher than that observed at concentrations of 100 and 50 μg/ml (41 and 10% inhibition, respectively). Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analyses of the apoptosis, inflammation and metastasis genes and proteins in Kuding tea-treated cancer cells were performed. Kuding tea significantly induced apoptosis in TCA8113 cancer cells (P<0.05) by upregulating Bax, caspase-3 and caspase-9 expression, and downregulating Bcl-2 expression. Expression of the NF-κB, iNOS and COX-2 genes that are associated with inflammation was significantly downregulated by Kuding tea, which demonstrated its anti-inflammatory properties. Kuding tea also exerted an anti-metastatic effect on cancer cells. This was demonstrated by the decreased expression of matrix metalloproteases (MMPs) and the increased expression of tissue inhibitors of metalloproteinases (TIMPs), and confirmed by the inhibition of the metastasis of U14 squamous cell carcinoma cells in imprinting control region (ICR) mice. The ICR mouse buccal mucosa cancer model was established by injecting the mice with U14 cells. Following injection, the wound at the injection site was topically treated with Kuding tea. It was observed that the tumor volumes for the group treated with Kuding tea were smaller than those from the control mice. Analysis of the sections of buccal mucosa cancer tissue demonstrated that the buccal mucosa cancer degrees of the Kuding tea-treated mice were weaker than that in the control mice. Similar results were observed in the lesion sections of the cervical lymph nodes. Based on these results, Kuding tea exhibited successful in vitro anticancer effects in TCA8113 cells and in vivo buccal mucosa cancer preventive activity.