[Factors of antioxidant and prooxidant activities of carotenoids].

The effectiveness of carotenoids as antioxidants is dependent on a number of influencing factors. It is likely that carotenoids exhibit a tendency to lose their effectiveness as antioxidants or act as prooxidants. In this paper, factors influencing the antioxidant or prooxidant activities of carotenoids such as the molecule structure of carotenoids, the location or site of action of the carotenoid molecule within the cell, the concentration of carotenoids, the properties of reactants, the partial pressure of oxygen and the interaction with other antioxidants were reviewed.