Effect of Ozone on Response to Ovalbumin & Its Modulation by Vitamins C & E in Sensitized Guinea Pigs (Report)
Outdoor air pollution levels have been associated with a broad spectrum of adverse health effects in individuals with asthma (1). Ozone is a potent inflammatory outdoor air pollutant that mediates many of its toxic effects through free radical reactions (2). Increased oxidative stress has been well documented to play a significant role in the initiation and perpetuation of the airway inflammation in asthma (3,4). Thus, combined ozone exposure and allergen exposure may have a synergistic effect. Ozone exposure has been shown to adversely affect asthmatics and enhance the response to allergen exposure (5-9) in asthmatics and in animal models though other workers have failed to corroborate these findings (10). Vitamin C or L-ascorbate is an important watersoluble antioxidant, capable of scavenging a variety of free radicals and oxidants, including ozone (11). Ozone-induced lung damage is potentiated in ascorbate-depleted guinea pigs (12). Vitamin E is another antioxidant scavenges peroxyl radicals derived from ozone-polyunsaturated fatty acids (PUFA) interactions (13). Ozone exposure studies on vitamin E deficient animals have provided evidence of protective role of vitamin E (13). These vitamins, together, may therefore offer protection against ozone-allergen interaction. We therefore carried out a study to investigate whether exposure to ozone in concentrations that are often found in the ambient air enhances the response to allergen inhalation in sensitized guinea pigs and whether dietary supplementation with vitamins C and E offers any protection.