Antioxidants in oxidative stress

Valko M, Rhodes CJ, Moncol J, Izakovic M, Mazur M. 2006. Free radicals, metals and antioxidants in oxidative stress-induced cancer. Chem Biol Interact 160 1-40. 

As the above mentioned studies with high supplementation dosages exemplarily show, there is no known toxicity for phylloquinone (vitamin Kl), although allergic reactions are possible. This is NOT true for menadione (vitamin K3) that can interfere with glutathione, a natural antioxidant, resulting in oxidative stress and cell membrane damage. Injections of menadione in infants led to jaundice and hemolytic anemia and therefore should not be used for the treatment of vitamin K deficiency. 

Stocker, R. and Frei, B. (1991). Endogenous antioxidant defences in human plasma. In Oxidative Stress, Oxidants and Antioxidants (ed. H. Sies) pp. 213-243, Academic Press, London. 

Figure 13.3 A rationale for considering the effect of drugs and proposed antioxidants on oxidative stress in biological systems (from Aruoma, 1994).

The development of nontransmittable chronic illnesses is associated with the presence of oxidative agents in the body. These agents are found in air, water, or food or can be produced in the body s cells. Their high content in body cells causes an imbalance that results in oxidative stress damaging proteins, DNA, and others. As a result of this deterioration, an increase in the risk of nontransmittable chronic illnesses has been noted. In order to prevent or decrease oxidative stress, the consumption of foods rich in antioxidants, such as fruits and vegetables, is recommended (van Dokkum and others 2008 Liu 2003). 

Hassoun, EA Creighton University Assess abilities of endrin to induce the formation of reactive oxygen species and lipid peroxidation and DNA single strand breaks that result in oxidative stress in fetuses of pregnant mice. The protective effects of some antioxidants will also be assessed using this model. 

Loewen, P. C. In Oxidative Stress and the Molecular Biology of Antioxidant Defenses Scandahos, J. G., ed. pp. 273-308. Cold Spring Harbor Laboratory Press Cold Spring Harbor, NY, 1997. 

Bravo, J. Fita, 1. Gouet, R Jouve, H. M. Melik-Adamyan, W. Murshudov, G. N. In Oxidative Stress and the Molecular Biology of Antioxidant Defenses Scandalios,... 

P5 Studies have shown that ebselen is an antiinflammatory and antioxidative agent. Its protective effect has been investigated in oxidative stress related diseases such as cerebral ischemia in recent years. However, experimental evidence also shows that ebselen causes cell death in several different cell types. Whether ebselen will have a beneficial or detrimental effect on cells under ischemic condition is not known. Herein, we studied the effect of ebselen... 

Tsuda, T., Horio, F., and Osawa, T., The role of anthocyanins as an antioxidant under oxidative stress in rats. Biofactors, 13, 133-139, 2000. 

Free-radicals are formed in vivo, and an imbalance between production of ROS and antioxidant defence can result in oxidative stress. This may arise either from deficiencies of natural antioxidants (e.g, glutathione, ascorbate or a-tocopherol), and/or from increased formation of ROS, Oxidative stress can result in glutathione depletion, lipid... 

Oxidative stress and free-radicals The production of free-radicals and other reactive species has been much implicated in cytotoxicity. This topic is discussed in more detail elsewhere see ANTIOXIDANTS PREE-RADICAL SCAVENGERS nitric oxide synthase inhibitors. The production of these species in oxidative stress is well established. Advances in therapy may well be in the direction of boosting and augmenting natural defence processes, for example, by superoxide dismutase (SOD), catalase, a-tocopherol, glutathione, ascorbic acid and perhaps melatonin. Surprisingly, some forms of the enzyme SOD can be administered in vivo and are protective. 

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