title: Antioxidant activity in cells and organs.
abstract: Antioxidant activity in cells occurs at several levels. The present work focuses on some aspects of enzymatic antioxidant defense. In particular, the so-called ancillary enzymes and transport systems are presented. Recent aspects on the control of the levels of antioxidant enzymes include the oxyR regulon in microorganisms as well as the response to DNA hypomethylation in livers of mice. Ebselen is a novel selenoorganic compound with antioxidant activity capable of conferring protection against oxidative challenge. Its activity to catalyse the GSH-peroxidase reaction is thought to mediate the effect in intact cells. The nonenzymatic antioxidant defense (e.g., vitamins E and C and other natural or chemically synthesized compounds) form an important complementary part of cellular antioxidant defense.
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001393:Azoles / Q000494:pharmacology; D004798:Enzymes / Q000378:metabolism*; D005978:Glutathione / Q000096:biosynthesis / Q000502:physiology; D054833:Isoindoles; D009249:NADP / Q000502:physiology; D016566:Organoselenium Compounds; D012643:Selenium / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D001393:Azoles; D004798:Enzymes; D054833:Isoindoles; D016566:Organoselenium Compounds; C042986:ebselen; D009249:NADP; D005978:Glutathione; D012643:Selenium