The biochemical basis of antioxidant therapy in critical illness

Abstract

During critical illness free radical production may increase as a result of, for example, sepsis or tissue trauma. In addition, because of a potential for increased losses, and the possibility of inadequate nutrition, the antioxidant defences of the body may become compromised. Thus, the delicate balance between free radicals and antioxidants may be disturbed. Various nutritional and pharmacological strategies to enhance antioxidant defences have been proposed, which aim either to maintain or enhance endogenous antioxidant stores or to provide alternative antioxidant agents. Trace elements and amino acids are particularly important, and their synergistic role in the maintenance of the body's antioxidant defence network will be discussed.

Protein modification as oxidative stress marker in follicular fluid from women with polycystic ovary syndrome: the effect of inositol and metformin

“…In particular, the direct evaluation of the level of oxidative stress in cell-free biological fluids is very difficult since they lack ROS producing cells. The effect of ROS, however, can be demonstrated indirectly, for example through the evaluation of the oxidative damage of proteins, as we previously did in human seminal plasma trough the analysis of free -SH groups [31] thus confirming that this methodology has to be considered as a reliable method for the indirect evaluation of the OS status [15,16]. Recently, we also reported preliminary results on the quantitative analysis of free-SH groups of proteins in human FF [32].…”

“…Free-SH groups labeling with 3-N-maleimidopropionyl biocytin (MPB) followed by two dimensional electrophoresis, and computer assisted analysis of the reactive spots may allow a quantitative and qualitative evaluation of the OS level related to the redox state of the follicular microenvironment. Cysteinyl residues are highly susceptible to oxidation, and their eventual loss may represent a sensitive and stable marker of an OS status [15,16].…”

High-dose selenium reduces ventilator-associated pneumonia and illness severity in critically ill patients with systemic inflammation

“…High concentrations of selenite inhibit DNA-binding activity of NF-jB in vitro, by reacting with its thiol groups [10,11]. As an antioxidant and antiinflammatory agent, Se is potentially important in SIRS [12][13][14][15].…”

Protein modification as oxidative stress marker in normal and pathological human seminal plasma

“…13 Labeling of free -SH groups with 3-N-maleimidopropionyl biocytin (MPB) followed by two-dimensional (2D) electrophoresis, streptavidin blotting and computer-assisted analysis of the reactive spots, may provide a quantitative and qualitative evaluation of the OS level in different biological fluids, which is unequivocally related to the redox state of the microenvironment and a very sensitive and stable marker of oxidative stress. 14,15 Prompted by the aforementioned observation, we aim to assess the degree of OS in the seminal plasma of normozoospermic, leukocytospermic, and azoospermic men by determining the amount of ROS by means of the luminol-based chemiluminescence assay. Furthermore, the overall changes in the level of protein free -SH groups, detected by MPB labeling and subsequent 2D electrophoresis, is determined as a marker of OS as revealed by protein oxidative damage.…”