Prospects for treatment of free radical-mediated tissue injury

Abstract

Toxic metabolites of oxygen are generated normally by aerobic metabolism in cells and this generation can significantly increase in certain pathologic conditions. When endogenous antioxidant defense capabilities are exceeded by this oxidant flux, tissue injury occurs. This process can be intercepted pharmacologically at different levels with agents that scavenge reactive oxygen metabolites, block their generation, or enhance endogenous antioxidant capabilities. In many situations, such as the treatment of post-ischaemic reperfusion injury, efficacy of antioxidant is related primarily to the proportionate magnitude of the total injury sustained that is due to an antioxidant mechanism. This approach has shown great promise in animal models of clinical problems and has been tested successfully in early, controlled clinical trials.

Oxidant status increased during fracture healing in rats

“…We believe PNL, which is one of the main cellular agents in tissue regeneration and repair, may play a major role in the development of oxidative stress injury. A significant increase in MDA during this period is comparable to the ischemiareperfusion injury seen in other types of organ and tissue trauma (Ikeda et al 1989, Bagchi et al 1990, Oda et al 1992, Rangan and Bulkley 1993. Although MDA levels 4 weeks after the fracture were slightly above basal levels, this increase was not statistically significant.…”

Sonographic Changes in Hypoxic-Ischaemic Encephalopathy

“…These infants had normal blood pressure but a very high BFV in the cerebral arteries and a very low BFV in the visceral arteries already during the first day of life with the development of severe HIE, severe renal, gastrointestinal and hepatic failure as well as cardiac failure. Animal models have indicated that reperfusion is the main mechanism of injury after intestinal or renal ischemia; however, the post-ischemic reperfusion injury is related primarily to the magnitude and time of the total ischemia (Rangan & Bulkley, 1993).…”

<b><i>Nigella Sativa</i></b> Reduces Tissue Damage in Rat Ovaries Subjected to Torsion and Detorsion: Oxidative Stress, Proinflammatory Response and Histopathological Evaluation

“…It is encountered as several degrees of tissue damage. The total damage that the tissue incurs is the sum of that caused by both ischemia and reperfusion [16,17,18,19]; as a result, the prevention of reperfusion injury increases the success of all kinds of treatments [16,17]. I/R injury results in an excessive production of reactive oxygen species (ROS) associated with a number of factors, including ROS and cytokines in tissues such as brain, kidney, heart, muscle, and ovaries [20,21,22,23,24].…”