Activated polymorphonuclear neutrophils (PMN) generate extremely high amounts of reactive oxygen species (ROS), but these are normally targeted at pathogens inside intracellular phagosomes. These same beneficial antimicrobial functions can cause significant local tissue injury and lead to the development of pathologic systemic inflammatory conditions. PMN apoptosis is a major mechanism associated with the resolution of inflammatory reactions. Caspase 3 activation is the first step in the execution phase of apoptosis. The goals of the present study was to investigate the in vitro effect of beetroot (Beta vulgaris var. rubra) and chokeberry (Aronia melanocarpa Elliot) juice on oxidative metabolism and apoptosis in human polymorphonuclear granulocytes. PMN oxidant production, in response to phorbol myristate acetate, was characterized by a dichlorofluorescin oxidation assay and luminol- dependent chemiluminescence. Caspase 3 activation was assayed by the method of DEVD-AMC cleavage in PMN cultured up to 24 hours. The results of our study showed: 1/ beetroot and chokeberry juice affected the concentration dependent inhibition of H₂O₂ production and chemiluminescence response by PMN, 2/ we also observed their proapoptotic effects. These natural products could be an important adjunct in cancer chemoprevention.