Role of Free Radicals, Oxidative Stress and Xenobiotics in Carcinogenesis by Environmental Pollutants

Resumen

Carcinogenesis by many small molecular weight chemicals involves either a direct action of the chemical on cellular DNA or metabolism of the parent chemical to an active or ultimate form, which can than react with cellular DNA to produce a permanent chemical change in a DNA structure. A free radical is an atom or molecule that has one or more unpaired electron(s). These are highly reactive species capable of wide spread, indiscriminate oxidation and per oxidation of proteins, lipids and DNA which can lead to significant cellular damage and even tissue and/or organ failure. . Oxidative stress is a leading cause to damage cells by oxidation. The rate at which oxidative damage is induced (input) and the rate at which it is efficiently repaired and removed (output). Xenobiotics are a compound that is foreign to the body. Xenobiotics can produce a variety of biological effects, including pharmacologic responses, toxicity, genes, immunologic reactions and cancer. Oxidative stress is a leading cause to damage cells by oxidation. The rate at which oxidative damage is induced (input) and the rate at which it  is efficiently repaired and removed (output). This communication highlights the role of carcinogens as environmental pollutants with the possible mechanism of free radicals, oxidative stress and xenobiotics.