THE EFFECT OF RESVERATROL AND ZINC ON INTRACELLULAR ZINC STATUS IN NHPrE CELLS

Abstract

To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated in 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 µM) and 4 levels of zinc [0, 4, 16 and 32 µM or zinc deficient (ZD), zinc normal (ZN), zinc adequate (ZA) and zinc supplemented (ZS), respectively]. Among each zinc treatment, a progressive reduction in cell growth or increase in cellular total zinc was observed with increases of resveratrol from 2.5, 5 and 10 µM or from 5 and 10 µM, respectively. In ZS cells, a much higher increase in cellular total zinc was observed as early as 1 µM resveratrol. A flow cytometry study revealed that the resveratrol (10 µM) induced G2/M arrest was responsible for the depressed cell growth. Data from an in vitro experiment using zinquin, as an indicator of intracellular free Zn(II) status, demonstrated complex formation between resveratrol and zinc ion. Zinquin ethyl ester fluorescence spectrofluorimetry and microscope imaging revealed that intracellular labile free zinc decreased in ZD and ZN NHPrE cells but increased in high zinc (ZA and ZS) cells. Furthermore, increases in cellular zinc status induced enhanced levels of reactive oxygen species (ROS) as well as senescence detected by morphological and histochemical changes in cells treated with 2.5 or 10 µM resveratrol, especially in ZA and ZS cells. Thus, increases in free labile zinc may induce ROS and senescence.Grant Funding SourceUNIV. MARYLAND