Chemoprevention and therapy of tea polyphenol of colorectal cancer in colorectal cancer rats and cells: a systematic review

Abstract

Objective To evaluate the chemoprevention and therapy of tea polyphenol of colorectal cancer in colon cancer rats and cells. Methods Such database as CBM, CNKI, VIP, Wanfang, PubMed, Medline, EMBase, Cochrane Library were searched for collecting the papers including using tea polyphenol as a therapy and chemoprevention of colorectal cancer in colorectal cancer rats and colorectal cells, from their establishment to June 1, 2014, and the references of those related papers were also searched by hand. After studying selection, assessment and data extraction were conducted by two reviewers. RevMan5.2 software was used for Meta-analyze. Results Seventeen studies were included. Three hundred and five rats and 5 colorectal cell lines were used to the research, they were divided into the study group (received the tea treatment) and the control group (not received the tea treatment). The results of meta-analyses showed that: ① Aberrant crypt foci (ACF): standardized mean difference SMD=-3.69(95%CI为-5.85~-1.54, Z=3.40, P=0.000 8), which indicated that tea polyphenol could reduce the number of ACF. ② The average number of tumors per rat: SMD=-0.83 (95%CI: -1.14~-0.51, Z=5.18, P=0.000 01), which indicated that tea polyphenol could reduce the average number of tumors per rat. ③ Cell cycle G1 phase: SMD=1.85(95%CI: 0.03~3.66, Z=1.99, P=0.05), which indicated that tea polyphenol could increase the cell in G1 phase. ④ Cell cycle S phase: SMD=-2.64(95%CI: -4.38~-0.90, Z=2.98, P=0.003), which indicated that tea polyphenol could decrease colon cancer cell in S phase. Conclusion Tea polyphenol has a positive effect on colon cancer cell and colon cancer rats. Key words: Tea; Colorectal neoplasms; Cell cycle; Aberrant crypt foci