Ascorbic acid and beta-carotene as modulators of oxidative damage.

Naturally occurring antioxidants are extensively studied for their capacity to protect organisms and cells from damage induced by oxygen reactive species. In fact, oxidative stress is considered a cause of aging, degenerative disease and cancer. We have focused our attention on two agents, ascorbic acid and beta-carotene, commonly considered to be antioxidants, but whose protective activity against cancer is insufficiently known. This paper reports on the ability of these agents to act against damage induced by H2O2 and bleomycin, in Chinese hamster ovary cells cultivated in vitro. Cytogenetic and cytofluorimetric analyses were performed. Both vitamins proved effective in reducing H2O2-induced sister chromatid exchanges, but increased H2O2- and bleomycin-induced chromosomal aberrations. Cytofluorimetric data, in contrast, showed that ascorbic acid and beta-carotene act as scavengers of endogeneous and H2O2-induced oxygen species.