Antioxidant metabolism

Relationships Between Antioxidant Metabolism and Carotenoids in the Regulation of Photosynthesis... 

Ruiz-Lozano JM, Azcon R, Pahna JM (1996) Superoxide dismutase activity in arbuscular mycorrhizal Lactuca sativa plants subjected to drought stress. New Phytol 134 327-333 Garmendia I, Goicoechea N, Aguirreolea J (2004) Antioxidant metabolism in asymptomatic leaves of Verticillium-infected pepper associated with an arbuscular mycorrhizal fungus. J Phytopathol 152 593-599... 

Due to the potency of the redox system of vitamin C s two forms, several further interactions with readily oxidizable nutrients exist. The redox system is able to protect sulfhydryl groups of proteins as well as polyunsaturated fatty acids from oxidation. The close relationship of the nutritive antioxidants vitamin C, vitamin E, and P-carotene can be seen not only in cellular antioxidative metabolism but also during absorption. In the presence of ascorbic acid the absorption of these antioxidants is improved due to the protecting characteristics of vitamin C. 

Hasanuzzaman M, Hossain MA, Fujita M (2010) Selenium in higher plants physiological role, antioxidant metabolism and abiotic stress tolerance. J Plant Sci 5 354-375. doi 10.3923/... 

Fig. 12 Natural polyamine trypanthione (45) and its oxidized form (46), which are involved in the antioxidant metabolism of T. cruzi and the inhibiting polyamine analog kukoamine A (10)...

Mineral oil and paraffins should not be used, because these are not metabolized and may irritate tissue. Various other additives are needed for stabiUty, stefihty, and isotonicity antimicrobial preservatives, antioxidants (qv), chelating agents (qv), and buffers. No parenteral container material is completely inert to parenteral solvent systems. 

DOX, as EPI seems to form fewer amounts of ROS and secondary alcohol metabolite, (ii) encapsulation of anthracyclines in uncoated or pegylated liposomes that ensure a good drug delivery to the tumor but not to the heart, (iii) conjugation of anthracyclines with chemical moieties that are selectively recognized by the tumor cells, (iv) coadministration of dexrazoxane, an iron chelator that diminishes the disturbances of iron metabolism and free radical formation in the heart, and (v) administration of anthracyclines by slow infusion rather than 5-10 min bolus (Table 1). Pharmacological interventions with antioxidants have also been considered, but the available clinical studies do not attest to an efficacy of this strategy. 

Neuromelanin, a dark colored pigment and product of the oxidative metabolism of dopamine, is found in the cytoplasm of dopaminergic neurons of the human substantia nigra pars compacta. Neuromelanin deposits increase with age, matching the age distribution of Parkinson s disease. In the absence of significant quantities of iron, neuromelanin can act as an antioxidant in... 

A specific role for vitamin E in a required metabolic function has not been found. In addition to its direct antioxidant effects, a-tocopherol has been reported to have specific molecular functions. 

Some sprays include vitamins such as tocopherols (vitamin E) or panthenol, which is metabolized in the skin to become pantothenic acid, a B vitamin. Since hair does not metabolize ( It s dead, Jim ), these sprays perform the functions of antioxidants (tocopherols). In other words, they add shine and moisture (panthenol) rather than perform their normal vitamin roles. Moisture helps prevent damage during combing. 

In the pharmaceutical industry, GA is used in pharmaceutical preparations and as a carrier of drugs since it is considered a physiologically harmless substance. Additionally, recent studies have highlighted GA antioxidant properties (Trommer Neubert, 2005 Ali Al Moundhri, 2006 Hinson et al., 2004), its role in the metabolism of lipids (Tiss et al., 2001, Evans et al., 1992), its positive results when being used in treatments for several degenerative diseases such as kidney failure (Matsumoto et al., 2006 Bliss et al., 1996 Ali et al., 2008), cardiovascular (Glover et al., 2009) and gastrointestinal (Wapnir et al., 2008 Rehman et al, 2003). 

Antioxidant potential of intermediates in phenylpropanoid metabolism in higher FEBS Letters, 368, 188-92. 

Ubiquinone, known also as coenzyme Q, plays a crucial role as a respiratory chain electron carrier transport in inner mitochondrial membranes. It exerts this function through its reversible reduction to semiquinone or to fully hydrogenated ubiquinol, accepting two protons and two electrons. Because it is a small lipophilic molecule, it is freely diffusable within the inner mitochondrial membrane. Ubiquinones also act as important lipophilic endogenous antioxidants and have other functions of great importance for cellular metabolism. ... 

Heim, K.E. et al., Flavonoid antioxidants chemistry, metabolism and structure-activity relationships, J. Nutr. Biochem., 13, 572, 2002. 

In the Unites States, the daily intake of 3-carotene is around 2 mg/day Several epidemiological studies have reported that consumption of carotenoid-rich foods is associated with reduced risks of certain chronic diseases such as cancers, cardiovascular disease, and age-related macular degeneration. These preventive effects of carotenoids may be related to their major function as vitamin A precursors and/or their actions as antioxidants, modulators of the immune response, and inducers of gap-junction communications. Not all carotenoids exert similar protective effects against specific diseases. By reason of the potential use of carotenoids as natural food colorants and/or for their health-promoting effects, research has focused on better understanding how they are absorbed by and metabolized in the human body. 

Cyanidin is the most common anthocyanin in foods. In addition, anthocyanins are stabilized by the formation of complexes with other flavonoids (co-pigmentation). In the United States, the daily anthocyanin consumption is estimated at about 200 mg. Several promising studies have reported that consumption of anthocyanin-rich foods is associated with reductions of the risks of cancers - and atherosclerosis and with preventive effects against age-related neuronal and behavioral declines. These beneficial effects of anthocyanins might be related to their reported biological actions such as modulators of immune response and as antioxidants. Knowledge of anthocyanin bioavailability and metabolism is thus essential to better understand their positive health effects. 

Explains the bioavailability, antioxidant and pro-oxidant action, and the influence of pigments on health and metabolism... 

In the previous section, we have described some of the mechanisms that may lead to the fijrmation of lipid hydroperoxides or peroxyl radicals in lipids. If the peroxyl radical is formed, then this will lead to propagation if no chain-breaking antioxidants are present (Scheme 2.1). However, in many biological situations chain-breaking antioxidants are present, for example, in LDL, and these will terminate the peroxyl radical and are consumed in the process. This will concomitandy increase the size of the peroxide pool in the membrane or lipoprotein. Such peroxides may be metabolized by the glutathione peroxidases in a cellular environment but are probably more stable in the plasma comjxutment. In the next section, the promotion of lipid peroxidation if the lipid peroxides encounter a transition metal will be considered. 

Cort, W.M. (1982). Antioxidant properties of ascorbic acid in foods. In Ascorbic Acid Chemisty, Metabolism and Uses (eds. P.A. Seib and B.M. Tolbert) Advanced Chemical Series No. 200, p. 531. American Chemical Society, Washington, DC. 

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