Role of Copper, Zinc, Selenium and Tellurium in the Cellular Defense against Oxidative and Nitrosative Stress

Abstract

The trace elements copper, zinc and selenium are linked together in cytosolic defense against reactive oxygen and nitrogen species. Copper, zinc-superoxide dismutase catalyzes the dismutation of superoxide to oxygen and hydrogen peroxide. The latter and other hydroperoxides are subsequently reduced by the selenoenzyme glutathione peroxidase (GPx). Cytosolic GPx can also act as a peroxynitrite reductase. The antioxidative functions of these trace elements are not confined to being constituents of enzymes: 1) copper and zinc ions may stimulate protective cellular stress-signaling pathways such as the antiapoptotic phosphoinositide-3-kinase/Akt cascade and may stabilize proteins, thereby rendering them less prone to oxidation; and 2) selenium does not only exist in the cell as selenocysteine (as in GPx) but also as selenomethionine, which is regularly present in low amounts in proteins in place of methionine. Selenomethionine catalyzes the reduction of peroxynitrite at the expense of glutathione. Also, low-molecular-weight organoselenium and organotellurium compounds of pharmacologic interest catalyze the reduction of hydroperoxides or peroxynitrite with various cellular reducing equivalents.

Antioxidants: An Overview on the Natural and Synthetic Types

“…These GPx play a significant role in protecting cells against oxidative damage from ROS and RNS, which include superoxide, hydrogen peroxide, hydroxyl radicals, nitric oxide and peroxynitrite. [86][87] The other essential antioxidant selenoenzymes are the TrxR where they use thioredoxin (Trx) as a substrate to maintain a Trx/TrxR system in a reduced state for removal of harmful hydrogen peroxide. [88][89] There are three types of TrxR that have been identified, and these include cytosolic TrxR1, mitochondrial TrxR2 and spermatozoa-specific TrxR, (SpTrxR).…”

Study on Relationships Between Dietary Mineral Intakes and Blood Pressure and Blood Lipid in TB patients

“…Such as potassium plays a main role in carbohydrate and protein metabolism. To keep the normal intracellular osmotic pressure; maintain the normal function of the nerve muscle and myocardial function and maintain cells inside and outside the acid-base balance, etc [15]. Ca was not only the main component of bones and teeth, also participate in a variety of physiological activities in the body.…”

“…P is related to the physiological function of Ca and Mg. The epidemiological studies showed that trace elements Fe, Zn and Cu were related to the incidence of coronary artery disease, and the mechanism is related to vascular cell dysfunction and inflammatory reaction [13,14,15]. It was reported that the deficiency of Mg causes the inhibition of glucose tolerance, carbohydrate and lipid metabolism, and degradation of serum high density lipoprotein [16,17].…”

Efeitos antioxidantes do selênio e seu elo com a inflamação e síndrome metabólica

“…O zinco forma parte da enzima antioxidante citosólica, Cobre-Zinco Superóxido Dismutase (CuZn-SOD) 8,26 . Moléculas de superóxido são convertidas a peróxido de hidrogênio pela CuZn-SOD, a qual ativa as vias inflamatórias 8,27 .…”