Oxidative Stress and Reactive Oxygen Species

Abstract

This article discusses different aspects concerning classification/nomenclature, biochemical properties and pathophysiological roles of reactive oxygen species (ROS) which are pivotal to interpret the concept of oxidative stress. In vitro studies in both the prokaryotes and eukaryotes clearly demonstrate that exogenous or constitutive and inducible endogenous sources of ROS together with cofactors such as transition metals can damage virtually all the biomolecules. This adverse chemistry is at the origin of structural and metabolic defects that ultimately may lead to cell dysfunction and death as underlying mechanisms in tissue degeneration processes. The same biomolecular interpretation of aging has been proposed to embodies an oxidative stress-based process and oxidative stress may virtually accompany all the inflammatory events. As a consequence, ROS have proposed to play several roles in the pathogenesis of chronic-degenerative conditions, such as athero-thrombotic events, neurodegeneration, cancer, some forms of anemia, auto-immune diseases, and the entire comorbidity of uremia and diabetes. Nowadays, the chance to investigate biochemical and toxicological aspects of ROS with advanced biomolecular tools has, if needed, still more emphasized the interest on this area of biomedicine. These technological advancements and the huge information available in literature represent in our time a challenge to further understand the clinical meaning of oxidative stress and to develop specific therapeutic strategies.

Assessment of antioxidant enzymes and free radical scavenging activity of selected medicinal plants

“…[7] Oxidative stress plays a role in inflammation, accelerates aging and contributes in variety of degenerative conditions as cardiovascular diseases, atherosclerosis, cancer, cataract, central nervous system disorders, rheumatoid arthritis, diabetes, liver diseases and AIDS. [8] Cells manifest potent antioxidant defenses against oxidative stress, counting detoxifying enzymes and exogenous free radical scavengers. The major enzymes that convert reactive oxygen species to less reactive molecules are superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase.…”

Oxidative Status And Plasma Prolidase Activity In Patients With Gallstones

“…[5] It is well known that, in chronic diseases such as cholelithiasis, the active inflammatory response is induced with neutrophilic infiltration. These neutrophils, macrophages and/or monocytes produce ROS which may cause DNA damage to the adjacent cells [6,7] Oxidative stress provoked by ROS plays an important role in the pathogenesis of many diseases such as hepatitis, cholecystitis, gallstones, gastroduodenal mucosal inflammation, peptic ulcer disease, and probably even gastric cancer. [7][8][9] The organism has enzymatic and non-enzymatic antioxidant systems neutralizing the harmful effects of the endogenous ROS products.…”

“…These neutrophils, macrophages and/or monocytes produce ROS which may cause DNA damage to the adjacent cells [6,7] Oxidative stress provoked by ROS plays an important role in the pathogenesis of many diseases such as hepatitis, cholecystitis, gallstones, gastroduodenal mucosal inflammation, peptic ulcer disease, and probably even gastric cancer. [7][8][9] The organism has enzymatic and non-enzymatic antioxidant systems neutralizing the harmful effects of the endogenous ROS products. Under certain conditions, the oxidative or anti-oxidative balance shifts towards the oxidative status as a result of increase in ROS and/or impairment in antioxidant mechanism.…”

In vivo evaluation of graded fresh leave extracts of vernoniaamygdalina and ocimumgratissimum on some oxidative stress indicators in rats

“…Oxidative stress plays a role in causation of several disease conditions, through the involvement of free radicals which produce structural damage to tissues and contribute to disease generation via activation of gene regulatory proteins (Galli et al, 2005;Van Wijk et al, 2008). Herbs are sources of various phytochemicals, many of which possess powerful antioxidant activity which have a role in antioxidant defence and redox signalling (Dragland et al, 2003).…”