Assessment of the roles of vitamin C, vitamin E, and beta-carotene in the modulation of oxidant stress mediated by cigarette smoke-activated phagocytes.

Phagocyte-derived reactive oxidants have been increasingly implicated in inflammation-related tissue injury and carcinogenesis. Cigarette smoking is a useful human model of chronic inflammation since it is uncomplicated by chemotherapy. It has been utilized to investigate both the involvement of phagocyte-derived reactive oxidants in the pathogenesis of pulmonary dysfunction and carcinogenesis, as well as the possible role of nutritional antioxidants in the prevention of oxidant-mediated tissue damage. Reactive oxidants generated by activated phagocytes appear to be primary mediators of spirometric abnormalities in cigarette smokers. Cigarette smoking is also associated with decreased plasma levels of ascorbate and beta-carotene, which indicates that the smoking-related chronic inflammatory response leads to an imbalance of oxidant/antioxidant homeostasis and possible predisposition to oxidant-inflicted tissue damage and disease.