Exercise‐Induced Reductive Stress Is a Protective Mechanism against Oxidative Stress in Peripheral Blood Mononuclear Cells

Abstract

Eccentric exercise is a well-studied modality that induces oxidative stress and muscle damage. Furthermore, it promotes inflammatory response in which peripheral blood mononuclear cells (PBMCs) are the major mediators. Although free radicals are necessary in a specific range of concentrations, yet unknown, it remains unclear whether reductive redox status (i.e., increased antioxidant defenses and impaired free radical generation) is beneficial or not. Thus, the aim of the present investigation was to examine the effects of reductive stress and the impact of reduced glutathione (GSH) baseline values on the ability of PBMCs to counteract oxidative stress induced by a potent oxidative agent. PBMCs were isolated from the blood of subjects who performed eccentric exercise and treated with t-BOOH for 24 h. The subjects were clustered in the reductive and the oxidative group on the basis of increased or decreased GSH concentration postexercise compared to preexercise values, respectively. According to our results in PBMCs, lipid peroxidation levels as depicted by thiobarbituric acid reactive substances (TBARS) remained unchanged in the reductive group contrary to the observed enhancement in the oxidative group. In addition, GSH concentration and catalase activity increased in the reductive group, whereas they were not affected in the oxidative group. In conclusion, the effects of an oxidizing agent on the redox status of PBMCs isolated from the blood of athletes after acute eccentric exercise are dependent on the baseline values of GSH in erythrocytes. Otherwise, reductive stress defined by increased GSH levels is a protective mechanism, at least when followed by an oxidative stimulus.

Influence of Long-Term Fasting on Blood Redox Status in Humans

“…In addition, we also analyzed the role of GSH baseline values on the effects of fasting. This could be an important issue since the therapeutic efficiency of any redox-altering intervention depends on the baseline levels of endogenous antioxidants, also called antioxidant status [ 36 ].…”

“…We cannot exclude that the cut-off at ten days does not reflect the changes in all subjects. Furthermore, the reductive stress induced by exercise, although generally known to be beneficial, can be detrimental for individuals with low GSH values, but not for those individuals with increased baseline GSH values [ 36 ]. The effects of redox-altering stimuli, such as antioxidant administration and exercise, on blood redox status, are highly dependent on the baseline values of the intrinsic antioxidant mechanisms.…”

The Effects of Aerobic Exercise on Oxidative Stress in Older Adults: A Systematic Review and Meta-Analysis

“…Exercise is a known strategy to modulate levels of OS in older adults, but the relationship between exercise and OS is extremely complex, depending on the mode, intensity, and duration of exercise. Studies have shown that regular exercise with light to moderate intensity could gradually strengthen endogenic antioxidant defense mechanism and diminish level of OS (De Sousa et al, 2017;Spanidis et al, 2018). Conversely, acute exercise and high-intensity exercise lead to increased level of OS (Pingitore et al, 2015).…”

Influence of Acute Exercise on DNA Repair and PARP Activity before and after Irradiation in Lymphocytes from Trained and Untrained Individuals

“…Furthermore, exercise training induces an increased activity of mitochondrial 8-oxoguanine DNA glycosylase (OGG1), which is responsible for the excision of the mutagenic base byproduct 8-oxoguanine, in the nuclei of red fibers but a decreased activity in nuclei of white fibers [33]. Interestingly, the protective effects of exercise have been reported not only in skeletal muscle [34,35] but also in the liver [36,37], kidney [38], brain [39,40,41], and blood [42,43]. Regarding the protective potential of training on blood cells, DNA damage is lower in peripheral blood mononuclear cells of trained individuals compared to untrained individuals after exposure to oxidative stress [12].…”