Antioxidant Mechanisms of Enzymes and Proteins

Ahmad, Sami

doi:10.1007/978-1-4615-9689-9_7

Cited by 60 publications

(42 citation statements)

References 100 publications

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“…The latter compounds, by a selfon the essential -S-S-bridges within a protein molecule, propagating process, may cause further oxidative damage to many cellular systems and biologically important molecules 3.4. NADPH-dependent lipid peroxidation and PE synthesis via [38]. The characteristic feature of the phospholipid BE reacthe BE reaction tion studied in this report is that the above-mentioned moleIn a reconstituted system composed of microsomal cytocular species of phospholipids serve both as membranous subchrome P450 reductase/cytochrome P450 and Fe 3+, NADPH strates and reaction products.…”

Section: Inhibition Of Enzyme Activity (% Of Control)mentioning

confidence: 82%

Nonenzymatically evoked and cytochrome P450‐dependent lipid peroxidation inhibits synthesis of phosphatidylethanolamine via the ethanolamine base exchange reaction in rat liver microsomes

et al. 1996

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In the present study the relationship between lipid sole pathway for PS formation. Sundler et al. [3] reported that peroxidation, changes in the redox state of membrane and in isolated rat hepatocytes, at physiological concentrations of phosphatidylethanolamine (PE) synthesis via base exchange ethanolamine (25 ~tM), 8-9% of the total PE synthesis could reaction in rat liver microsomes was investigated. It was found be attributed to Ca2+-dependent incorporation of ethanolthat PE synthesis is enhanced in the presence of antioxidants, amine via the BE reaction. The reaction does not result in a butylated hydroxytoluene (BHT), or unsaturated free fatty acids, net increase of the total PE content, but is rather responsible Prooxidants, tert-butyl hydroxyperoxide (BHP), ferrous ions for significant remodelling of preexisting membrane phosphocombined with ascorbate or NADPH (via cytochrome P450-lipids. The most abundant molecular species of PS and PE are dependent proteins), increased the amount of lipid peroxidation known to contain long-chain polyunsaturated fatty acids: araproducts in the membrane, and in consequence inhibited the chidonic (20:4), docosatetraenoic (22:4)and docosahexaenoic reaction. The effect of BHP was fully reversed by reduced (22:6) in the sn-2 position of their glycerol moiety [4]. glutathione and dithiothreitol (DTT), whereas the effect of other compounds could be reversed only by BHT. In contrast, a Furthermore, Ellingson and Seenaiah [5] have documented reversal of the inhibitory effect of cadmium ions on base that stearoyl-polyunsaturated molecular species of PE and exchange activity was observed in the presence of DTT, but PC are preferentially converted to PS by the phospholipid not BHT. Therefore, both the -SH/-S-S-ratio in the membrane, BE reaction in rat liver microsomes. affected by BlIP and cadmium ions, and the lipid hydroxyper-PE, kept in a bilayer configuration by interactions with oxides (rather than aldehydes), generated by ferrous ions and other membrane phospholipid molecules, is able to induce ascorbate or NADPH, are equally responsible for the inactivalocal nonbilayer structures by creating hexagonal phases [6]. tion of the ethanolamine base exchange enzyme in rat liverThis property of PE may be responsible for regulation of the microsomes. This may suggest that the synthesis of PE via the activity of many membranous enzymes, for example cytobase exchange reaction may be considered an element of the chrome P450 [7]. The latter class of enzymes participates in superfine cellular machinery involved in the repair of damage to unsaturated fatty acid chains of phospholipids caused by reactive hydroxylation processes of different hydrophobic molecules, oxygen species under oxidative stress, like fatty and bile acids, phospholipids, steroid hormones and/or xenobiotics [8]. Moreover, the PE hexagonal phase

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Section: Inhibition Of Enzyme Activity (% Of Control)mentioning

confidence: 82%

Nonenzymatically evoked and cytochrome P450‐dependent lipid peroxidation inhibits synthesis of phosphatidylethanolamine via the ethanolamine base exchange reaction in rat liver microsomes

et al. 1996

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“…In addition, photosynthesis produces singlet oxygen ('O2) through several photochemical and chemical pathways (Asada & Takahashi 1987). Higher plants possess several enzymatic and non-enzymatic scavenging systems for minimizing damage (Ahmad 1995;Dalton 1995). Ascorbate has a central position as an antioxidant in the chloroplast stroma; furthermore, it is essential for the regeneration of a-tocopherol and the deepoxidation of the xanthophyll violaxanthin to zeaxanthin in the thylakoid membrane (Foyer 1993).…”

Section: Introductionmentioning

confidence: 99%

Acclimation by suboptimal growth temperature diminishes photooxidative damage in maize leaves

Leipner

Fracheboud

Stamp

1997

Plant Cell & Environment

109

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Leaves of Zea mays L. seedlings which developed at optimal (25 °C) or suboptimal (15 °C) temperature were exposed to high irradiance (1000/imoI m~^ s~') and a severe chilling temperature (5 °C) for up to 24 h to investigate their ahility to withstand photooxidative stress. During this stress, the degradation of the endogenous antioxidants ascorbate, glutathione and a-tocopherol was delayed and less pronounced in 15 °C leaves. Similarly, the decline in chlorophyll a, chlorophyll b, 3-carotene and lutein was slower throughout the stress period. Faster development and a higher level of non-photochemical quenching (NPQ) of chlorophyll fluorescence, related to a stronger de-epoxidation of the larger xanthophyll cycle pool in 15 °C leaves, could act as a defence mechanism to reduce the formation of reactive oxygen species during severe chilling. Furthermore, plants grown at suboptimal temperature exhibited a higher amount of the antioxidants glutathione and a-tocopherol. The higher a-tocopherol content in leaves (double based on leaf area; 4-fold higher based on chlorophyll content) which developed at suboptimal temperature may play an especially important role in the stabilization of the thylakoid membrane and thus prevent lipid peroxidation.

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“…GST in insects can be considered a primary antioxidant enzyme, in as much as it is effective in metabolizing lipid peroxides. 44 However significantly decreased GST activity occurred in cypermethrin+melatonin treated samples as compared with control. Our studies suggest that there was an decreased level in synthetic pyrethroid against melatonin in lepidopteran insects.…”

Section: Discussionmentioning

confidence: 87%

Effect of Cypermethrin Induced Antioxidant Enzymes Systems in Response to Melatonin Administration in Drosophila Melanogaster

Vasuki

Karthi²,

Shivakumar

2016

FRA

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Introduction: Melatonin, the main hormonal product of the pineal gland, has pleiotropic bioactivity that encompasses numerous endocrinological and behavioral processes. Melatonin and several of its metabolites function as free radical scavengers and broad-spectrum antioxidants. Due to their small size and amphiphilic nature they can easily reach all cellular compartments. The aim of the present study was to investigate the effect of melatonin on cypermethrin induced free radical damage in Drosophila melanogaster. Methods: The pro-or antioxidant enzyme activities of superoxide dismutase (SOD), glutathione-S-transferase (GST), lipid peroxidation (LPO), peroxidase (POX), catalase (CAT) and cytochrome P450 were assayed. Results: SOD and cytochrome P450 enzymes show significant increase in the melatonin+synthetic pyrethroid treated group, while GST shows significantly decreased activity in melatonin+synthetic pyrethroid group with respect to control. Lipid peroxidation activity was significantly increased in the synthetic pyrethroid group and also in melatonin+synthetic pyrethroid treated groups. Conclusion: In conclusion, melatonin administered the resulted in activation/increased expression of Cyt P450, GST and SOD titers, showing that melatonin in addition to being an antioxidant molecules, it also participates in eliciting other antioxidant systems in insects.

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Antioxidant Mechanisms of Enzymes and Proteins

Cited by 60 publications

References 100 publications

Nonenzymatically evoked and cytochrome P450‐dependent lipid peroxidation inhibits synthesis of phosphatidylethanolamine via the ethanolamine base exchange reaction in rat liver microsomes

Nonenzymatically evoked and cytochrome P450‐dependent lipid peroxidation inhibits synthesis of phosphatidylethanolamine via the ethanolamine base exchange reaction in rat liver microsomes

Acclimation by suboptimal growth temperature diminishes photooxidative damage in maize leaves

Effect of Cypermethrin Induced Antioxidant Enzymes Systems in Response to Melatonin Administration in Drosophila Melanogaster

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