Molecular analysis on the chemopreventive properties of resveratrol, a plant polyphenol microcomponent.

As a plant microcomponent, resveratrol is a polyphenolic compound produced by several species and found especially in Polygonum roots, peanuts seeds, berries and also grape and therefore can be present in human diet or beverages (red wine, for instance). Traditional chinese medicine and more recent epidemiological studies strongly suggested that resveratrol may act as a cancer chemopreventive compound. The biochemical mechanism by which resveratrol inhibits cell proliferation was provided by studies in numerous human cell lines including our work in hepatoblastoma HepG2 and colorectal tumor SW480 cells. The results show that resveratrol strongly inhibits cell proliferation at the micromolar range in a time- and dose-dependent manner. Resveratrol appears to block the cell cycle at the transition S to G2/M since there is no inhibition of [3H]-thymidine incorporation observed, while there is an increase of the cell number in S phase. On the other hand, in order to evaluate if the amount of resveratrol taken up during food or drink consumption is sufficient to ensure in the whole body the in vitro described beneficial effects, we evaluated the ratio between plasmatic level of resveratrol and its cell bioabsorption. Our study reports a higher uptake of resveratrol in the human hepatic derived HepG2 cells than in colorectal derived SW480 cells. In contrast, resveratrol is conjugated in these cells and derivatives are released in large amounts in the cell medium. Based on present knowledge, resveratrol appears to be a promising bioactive natural molecule with potential applications in phytotherapy, pharmacology or in nutriprotection (nutraceutic food) area.