The role of oxidative stress in lung injury induced by cigarette smoke

Abstract

Oxidative stress is a damaging process resulting from an imbalance between excessive generation of oxidant compounds and insufficient antioxidant defence mechanisms. Oxidative stress plays a crucial role in the initiation and progression of cigarette smoke-induced lung injury, deterioration in lung functions, and development of chronic obstructive pulmonary disease (COPD). In smokers and in patients with COPD, the increased oxidant burden derives from cigarette smoke per se, and from activated inflammatory cells releasing enhanced amounts of reactive oxygen and nitrogen species (ROS, RNS, respectively). Although mild oxidative stress resulting from cigarette smoking leads to the upregulation of the antioxidative enzymes synthesis in the lungs, high levels of ROS and RNS observed in patients with COPD overwhelm the antioxidant enzymes capacities, resulting in oxidant-mediated lung injury and cell death. In addition, depletion of antioxidative systems in the systemic circulation was consistently observed in such patients. The imbalance between the generation of ROS/RNS and antioxidant capacities -the state of "oxidative stress" -is one of the major pathophysiologic hallmarks in the development of COPD. Detrimental effects of oxidative stress include impairment of membrane functions, inactivation of membrane-bound receptors and enzymes, and increased tissue permeability. In addition, oxidative stress aggravates the inflammatory processes in the lungs, and contributes to the worsening of the protease-antiprotease imbalance. Several markers of oxidative stress, such as increases in lipid peroxidation products and reductions in glutathione peroxidase activity, have been shown to be related to the reductions in pulmonary functions. In the present article we review the current knowledge about the vicious cycle of cigarette smoking, oxidative stress, and inflammation in the pathogenesis of COPD.

Oxidative Stress, the Paradigm of Ozone Toxicity in Plants and Animals

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In vitro cytotoxicity and mutagenicity of mainstream waterpipe smoke and its functional consequences on alveolar type II derived cells

“…Moreover, Louhelainen et al (2008) concluded that NO may play a role in the pathogenesis and progression of COPD. It is believed that the formation of free radicals, superoxide or nitric oxide result in lung oxidant toxicity through subsequent chain reactions resulting in uncontrolled destructive oxidation (Kluchová and Tkáčová, 2006). As an inflammatory mediator, we studied the effect of WSC on the production of NO from A549 cells.…”

Catalizadores de alúminas modificadas mediante la incorporación de Fe por el método sol-gel e impregnación y su desempeño catalítico en la combustión del tricloroetileno

“…El catalizador AFI presentó un evento entre 25 a 220ºC con una pérdida de peso del 11 % relacionada con la perdida de agua físico absorbida. Posteriormente se observó un evento endotérmico a 242 ºC y uno exotérmico a 445 ºC, relacionado con la descomposición del acetato de hierro [7] y con el cambio de fase a maghemita [8] respectivamente.…”