Mineral and/or milk supplementation of fruit beverages helps in the prevention of H2O2-induced oxidative stress in Caco-2 cells.

Abstract

Fruit beverages are commonly supplemented with milk, vitamins and/or minerals in order to improve their healthy effects by providing some bioactive components that can act additively or synergistically against oxidative stress. To test whether iron, zinc, and milk added to fruit beverages do not affect the cytoprotective effect against oxidative damage to Caco-2 cells through GSH-related enzymes induction and cell cycle progression preservation, in comparison with non-supplemented fruit beverage. Caco-2 cells were incubated 24 h with the bioaccessible fraction (BF) of eight fruit beverages with/without iron and/or zinc, and/or milk, and then challenged with H2O2 (5 mmol L-1 -2 h). Mitochondrial enzyme activities (MTT test), GSH-Rd and GSH-Px enzyme activities, cell cycle progression and caspase-3 activity were measured. Fruit beverages prevented the deleterious effect of H2O2 on cell viability, with almost all samples reaching control basal levels. Only independent iron or zinc supplementation with/without milk exerted positive effects upon GSH-Rd activity. Both minerals with milk, afforded improved preservation of GSH-Px activity. All samples prevented the decrease in the G1 phase of cell cycle induced by H2O2, except iron supplemented samples with/without milk, but none of them avoided the increase in sub-G1 phase. However, this fact was not associated to caspase-3 activity, with a probable positive effect of zinc upon this parameter. Mineral and/or milk supplementation of fruit beverages helps in the prevention of oxidative stress in Caco-2 cells based on cell viability maintenance, GSH-related enzymes activation, cell cycle distribution preservation and inhibition of caspase-3 activation.