Endogenous Antioxidants and Radical Scavengers

Abstract

All living organisms are constantly exposed to oxidant agents deriving from both endogenous and exogenous sources capable to modify biomolecules and induce damages. Free radicals generated by oxidative stress exert an important role in the development of tissue damage and aging. Reactive species (RS) derived from oxygen (ROS) and nitrogen (RNS) pertain to free radicals family and are constituted by various forms of activated oxygen or nitrogen. RS are continuosly produced during normal physiological events but can be removed by antioxidant defence mechanism: the imbalance between RS and antioxidant defence mechanism leads to modifications in cellular membrane or intracellular molecules. In this chapter only endogenous antioxidant molecules will be critically discussed, such as Glutathione, Alpha-lipoic acid, Coenzyme Q, Ferritin, Uric acid, Bilirubin, Metallothioneine, L-carnitine and Melatonin.

Chemical–Physical Changes in Cell Membrane Microdomains of Breast Cancer Cells After Omega-3 PUFA Incorporation

“…Moreover observations also from our laboratory indicate very low levels of omega-3 PUFA in blood of breast and colon cancer patients [36].…”

Naturally Occurring Hydroxytyrosol: Synthesis and Anticancer Potential

“…Intracellular ROS can be generated by various enzyme systems, including the mitochondrial electron transport chain, cytochrome P450 in the endoplasmic reticulum, lipoxygenase, cyclooxygenase (COX), the NADPH oxidase complex, xanthine oxidase and peroxisomes [58]. Endogenous ROS can derive from innate immune cells (e.g.…”

Smoking Cessation Is Followed by Increases in Serum Bilirubin, an Endogenous Antioxidant Associated With Lower Risk of Lung Cancer and Cardiovascular Disease

“…Although it is widely known that unconjugated bilirubin can be elevated in hemolytic diseases and can be neurotoxic at very high levels in newborns (Watchko & Tiribelli, 2013), unconjugated bilirubin, the primary form of bilirubin circulating in healthy individuals, is also a powerful antioxidant (Rizzo et al, 2010;Stocker, Yamamoto, McDonagh, Glazer, & Ames, 1987) at levels within the normal reference range. Thus, while seemingly counterintuitive, bilirubin has been inversely associated with risk of a number of disorders, including pulmonary disease (Horsfall et al, 2011), cardiovascular disease (Hopkins et al, 1996;Madhavan, Wattigney, Srinivasan, & Berenson, 1997), diabetes , rheumatoid arthritis , colon cancer risk (Zucker, Horn, & Sherman, 2004), and all-cause and cancer mortality (Temme, Zhang, Schouten, & Kesteloot, 2001).…”