In recent years, phytochemicals as cancer chemopreventive treatment of colorectal cancer have been widespread concerned.In this study, we used cranberry extract, which is one of phytochemicals, to prepare Colon-available cranberry extract(CACE), and to observe protection effect of CACE on the DNA damage induced by H₂O₂.The effects of CACE on colorectal cancer cell proliferation and invasive ability were observed.Moreover, the molecular mechanisms of CACE in colorectal cancer cell proliferation and invasion were detected.

By imitating the environment of upper gastrointestinal tract digestion and absorption, cranberry extract was prepared into CACE.First of all, the effect of CACE on growth inhibition was detected in colorectal cancer Lovo cell line determined by the MTT methood.Single cell gel electrophoresis experiment was used to test the protective effects of nucleus by CACE in colorectal cancer cells induced by hydrogen peroxide damage.Next, the Matrigel basement membrane invasion experiment was carried to exam CACE influence on Lovo cell invasive ability.Flow cytometry technique was also used to observe the influence of CACE on Lovo cell cycle.Western blot was further used to detect CACE impact on Lovo cell P53 and VEGF protein expression.Meanwhile, real-time fluorescent quantitative PCR method was used to detect CACE VEGF expression in Lovo cells.

The MTT experiment results showed that, with CACE concentr ation increasing from 20 ug/ml to 120 ug/ml, proliferation rate of Lovo cells falls from 90.64±3.11% to 38.54±3.13%.Single cell gel electrophoresis experiment showed that DNA damage of Lovo cells significantly reduces in the CACE intervention group compared to the control group after the cells were damaged with the same concentration of H₂O₂.Moreover, with increase in the CACE concentration the damage further reduced.The cell cycle was identified by Flow cytometry, and the results showed that CACE increased the proportion of Lovo cells in G1 phase.However, there was no discernible statistical significance(P>0.05). The Matrigel basement membrane invasion experiment showed that membrane cells reduced with the increase of concentration of CACE.CACE can significantly reduce the expression of colorectal cancer Lovo cells P53 and VEGF protein by Western blot results.With the increasing of concentration, the effect was further strengthened.The Real-time PCR experimental results showed that CACE inhibits VEGF mRNA expression.

The CACE can significantly inhibit the proliferation and invasion of colorectal cancer in Lovo cell line, and CACE plays a protective role in DNA damage.The anti-proliferation mechanisms of CACE may be through inhibiting the expression of P53 and VEGF.