Chemopreventive Potential Of CFT-1 (Camellia Sinensis (L.) O. Kuntze) Against DEN-induced Hepatocellular Carcinoma In Rats And Its Underlying Mechanism

This study aims to investigate the effects of common tea and high EGGC tea(CFT-1)on rat liver cancer induced by diethyl nitrosamine(DEN),and on anti-cancer related genes PCNA,Bcl-2 and Bax.The content of EGGC in CFT-1 tea is 13.42%,only 4.32%in common tea,especially the synergistic anticancer component content is also higher(ECG3.58%,C 3.0%,total catechin 22.49%,caffeine 5.38%).We used 25mg/kg,50mg/kg DEN to establish rat liver cancer model,and chose an optimal dose.We divided 40 wistar rats into four groups:control group,model group,commom tea group and CFT-1 tea group.The rats of model group and tea groups were injected with DEN,and rats of tea groups were intervened with tea water.After treatment,we detected the liver function indicators.The methods of immunohistochemistry,Western blotting and fluorescence quantitative were used to detect the expressions of PCNA,Bcl-2,Bax for researching the anti-cancer mechanism.The results are as follows:1)In the study of DEN dose,the incidence of liver cancer in two model groups were 100%,the mortality rate of 25mg/kg group was 10%,the mortality rate of 50mg/kg group was 40%,so we used the dose of 25mg/kg in the next experiment.2)Proliferating cell nucleus antigen(PCNA)exists in the tumor cells mainly,reflecting the state of proliferation.Bcl-2 gene suppresses cell apoptosis,and Bax promotes cancer cell apoptosis.The result of immunohistochemistry showed that the positive expressions of PCNA and Bcl-2 in model group were significantly higher than control,and the positive expression of Bcl-2 in CFT-1 tea group was lower than model group and common tea group.The positive expression of Bax in CFT-1 group was the highest.The positive expression of Bax in model group was the lowest.3)The result of Western blotting showed that the expressions of PCNA and Bcl-2 in CFT-1 tea were significantly lower than model group and common tea group,the expression of PCNA was reducing 24.85%,8.87%respectively(P<0.05)and the expression of Bcl-2 was reducing 41.79%,32.63%respectively(P<0.05);The expression of Bax in CFT-1 tea group was higher than model group and common tea,enhancing 71.63%,59.73%respectively(P<0.05).4)The result of fluorescence quantitative showed that the mRNA expressions of PCNA and Bcl-2 in model group was significantly higher than control and tea groups;The mRNA expressions of PCNA and Bcl-2 in CFT-1 tea group were significantly lower than model group and common tea group,the mRNA expression of PCNA was reducing 25.03%,15.72%respectively(P<0.05)and the mRNA expression of Bcl-2 is reducing 53.15%,47.22%respectively(P<0.05).The mRNA expression of Bax in CFT-1 tea group was higher than model group and common tea group,enhancing 98.43%,64.37%respectively(P<0.05);In conclusion,we establish the model of rat liver cancer successfully.CFT-1 tea can reduce the expression of Bcl-2 and elevate the expression of Bax,to inhibit the development of liver cancer.And the CFT-1 tea is better than common tea in protecting the liver effectively and preventing the development of cancer.