Toxicity and Roles of Reactive Oxygen Species

Abstract

The history of studies in biology regarding reactive oxygen species (ROS) is approximately 40 years. During the initial 30 years, it appeared that these studies were mainly focused on the toxicity or microbicidal-related agents of ROS. However, recent studies have identified another action regarding oxidative signaling, other than toxicity of ROS. Basically, it is suggested that ROS are reactive, and degenerate to biomacromolecules such as DNA and proteins, leading to deterioration of cellular functions as an oxidative stress. On the other hand, recent studies have shown that ROS act as oxidative signaling in cells, resulting in various gene expressions. For example, NADPH oxidase, a major source of superoxide radicals (O(2)(-)), expresses in various tissues such as leukocytes and cardiovascular systems, and ROS derived from the enzyme play important roles in cell proliferation, differentiation, and cell death. In this review, we have focused on and described the basic properties, toxicity, and roles of ROS.

Superoxide Anion-Scavenging Effect of 2-Amino-1,3-selenazoles

“…7) O 2 Ϫ also reacts with nitric oxide (NO · ) to generate strongly toxic ROS including peroxynitrite (ONOO Ϫ ). 2,8) Some antioxidative enzymes/substances, such as superoxide dismutases (SODs), catalase, glutathione peroxidases (GPXs), and certain vitamins (vitamin C and E), act as ROS scavengers since they quench ROS. GPX eliminates effectively H 2 O 2 in vitro and in vivo in consequence, to be an important antioxidant enzyme.…”

3-(2,6-Dimethylphenyl)-2-Selenoxo-1,3-Thiazolidin-4-One Suppresses Hydrogen Peroxide–Induced Cytotoxicity on PC12 Cells Via Activation of MAPK

“…[15][16][17]30,31 From the results shown in Table 1 A low concentration of O 2 -in the human body generally plays a beneficial role in biological defenses and intercellular signal transduction. 5 On the other hand, excessive O 2 -production is involved in the pathogenesis of a number of disorders, including inflammation, rheumatoid arthritis and asthma. 32,33 Oxidative stress may be defined as an imbalance between the cellular production of reactive oxygen species, a key component of inflammation and inflammatory disorders, and antioxidant defense mechanisms.…”

Hypoxie-induzierte Freisetzung reaktiver Sauerstoffspezies (ROS) in isoliert perfundierten und ventilierten Mauslungen

“…Begründet ist das in den freien ungepaarten Elektronen, durch die die Radikale hochreaktiv sind und sehr schnell mit Strukturen in der Zelle, z. B. DNA, Proteinen und Lipiden, interagieren (Irani, 2000;Kimura et al, 2005;Sies and de Groot, 1992;Wilborn et al, 1996). ROS in unphysiologisch hohen Konzentrationen führen zu oxidativem Stress, der durch die Akkumulation von ROS aufgrund erhöhter Radikalbildung und eingeschränktem Abbau durch intrinsische Antioxidationsmechanismen entsteht.…”