Antioxidants against environmental factor-induced oxidative stress

Abstract

Reactive oxygen species (ROS) are ubiquitously produced within the cell as natural by-products of aerobic respiration and energy production. Human-made pollutants present in our environments also add additional burden to biological systems and could lead to enhanced ROS production. Overproduction of ROS and/or inadequate antioxidant defense mechanisms can induce oxidative damage to a wide range of biomolecules including lipids, proteins, and nucleic acids that adversely affect organ function and health outcome. Exposure to environmental factors such as ultraviolet light, ionizing radiation, heavy metals, pesticides, and air pollutants is thought to adversely impact the function of biological systems by virtue of ROS generation. These factors are important contributor of a wide range of diseases, such as respiratory, neurological, heart, and reproductive diseases, as well as cancer. Although there are several antioxidant enzymes within cells of biological tissues that scavenge ROS, some important antioxidants cannot be synthesized by cells and must be taken in the diet to counteract oxidative damage. In this chapter, we discuss the protective roles of dietary antioxidants in the prevention of oxidative injuries induced by environmental pollutants, the scope and limitation of antioxidant therapies used against environmental factor-induced oxidative stress, and the discrepancies between the results of experimental models and epidemiologic studies. The overarching focus of this chapter is to stress the importance of nutrition and dietary antioxidants as potential modulators of disease risks associated with exposure to multiple environmental pollutants.