The postoperative redox status of patients with diabetes mellitus: a mini review

The human organism is exposed to variable endogenous and exogenous factors that result in the induction of free radicals. Surgeries are associated with increased inflammation and production of free radicals through various mechanisms, including ischemia, hemolysis, or endogenous antioxidant depletion. Importantly, a more oxidized redox status could lead to the condition known as "oxidative stress," which is related to alterations in insulin signaling and may lead to insulin resistance and diabetes mellitus. Therefore, patients with diabetes who undergo surgery could be more vulnerable compared with healthy individuals. Thus, this review focuses on the currently available literature regarding the link between the redox status and diabetes complications after surgery and the methods used to assess the redox status of patients, which is the first step to designing an appropriate treatment strategy. To this end, we queried PubMed for novel works published up to May 2020. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Precaution Measures for the Safety of the Personnel in the Surgical Wards during the COVID-19 Pandemic

Coronavirus disease-19 has affected million of people worldwide, constituting the biggest social, economic, and health crisis since World War 2. During this pandemic, the hospitals have become hot zones for the treatment of patients. Therefore, it is important to take the appropriate protective measures and ensure the physician's health and, especially, those who work in the intensive care units and in operating rooms. In this letter, we are trying to make a discussion regarding the measures that should be considered by the healthcare workers who are facing this invisible enemy during their effort to provide their services in the surgery rooms

A battery of translational biomarkers for the assessment of the in vitro and in vivo antioxidant action of plant polyphenolic compounds: The biomarker issue

Over the last decades, the scientific findings stressing the beneficial health implications of plant-derived compounds (i.e., plant extracts rich in polyphenols) have been increased significantly. Assessing the properties of such compounds throughout the redox continuum is a common practice for the evaluation of their dynamics in reinforcing the antioxidant and antitoxic defence of tissues and, even, whole organisms or in the refinement of free radical-related disease onset. In the present contribution we propose a battery of translational biomarkers for measuring the antioxidant, antimutagenic and antitoxic capacities of plant compounds in three levels. The level 1 is the characterization of plant-derived compounds in vitro by detecting their antiradical and reducing capacity and their antimutagenic and anticarcinogenic properties. In the level 2, the tested agents should be administered in diverse cell lines in order to be examined for their antitoxic and antioxidant capacities. Although cell lines are considered as an in vitro system, it is undisputable that they are an in vivo-like environment and, thus, a link to in vivo settings. The level 3 is the administration of plant compounds in vivo, in experimental animals or humans either individually or as food supplements. The biomarkers for oxidative damage, antioxidant capacity and reducing/oxidative potential analyzed here seem to be suitable surrogate endpoints in the effort to extrapolate in vitro evidence to in vivo models. It is recommended that the aforementioned three lines of research (i.e., in vitro, cell culture environment and in vivo) should be applied in order to holistically reveal the biological action of plant polyphenolic compounds in the frame of redox biology and toxicology. © 2018 Elsevier B.V

Variations in Oxidative Stress Levels in 3 Days Follow-up in Ultramarathon Mountain Race Athletes

Spanidis, Y, Stagos, D, Orfanou, M, Goutzourelas, N, Bar-or, D, Spandidos, D, and Kouretas, D. Variations in oxidative stress levels in 3 days follow-up in ultramarathon mountain race athletes. J Strength Cond Res 31(3): 582-594, 2017 - The aim of the present study was the monitoring of the redox status of runners participating in a mountain ultramarathon race of 103 km. Blood samples from 12 runners were collected prerace and 24, 48, and 72 hours postrace. The samples were analyzed by using conventional oxidative stress markers, such as protein carbonyls (CARB), thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC) in plasma, as well as glutathione (GSH) levels and catalase (CAT) activity in erythrocytes. In addition, 2 novel markers, the static oxidation-reduction potential marker (sORP) and the capacity oxidation-reduction potential (cORP), were measured in plasma. The results showed significant increase in sORP levels and significant decrease in cORP and GSH levels postrace compared with prerace. The other markers did not exhibit significant changes postrace compared with prerace. Furthermore, an interindividual analysis showed that in all athletes but one sORP was increased, whereas cORP was decreased. Moreover, GSH levels were decreased in all athletes at least at 2 time points postrace compared with prerace. The other markers exhibited great variations between different athletes. In conclusion, ORP and GSH markers suggested that oxidative stress has existed even 3 days post ultramarathon race. The practical applications from these results would be that the most effective markers for short-term monitoring of ultramarathon mountain race-induced oxidative stress were sORP, cORP, and GSH. Also, administration of supplements enhancing especially GSH is recommended during ultramarathon mountain races to prevent manifestation of pathological conditions. © 2016 National Strength and Conditioning Association

Exercise-induced reductive stress is a protective mechanism against oxidative stress in peripheral blood mononuclear cells

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. Copyright © 2018 Ypatios Spanidis et al

Oxidation of human serum albumin exhibits inter-individual variability after an ultra-marathon mountain race

The aim of this study was to examine the oxidation of human serum albumin (HSA) caused by oxidative stress following exhaustive and demanding exercise, such as an ultra-marathon race. For this purpose, blood samples from 12 adult runners who underwent a 103 km mountain ultra-marathon race were collected before the race, and also at 24, 48 and 72 h post-race. HSA was partially purified using affinity chromatography and consequently subjected to western blot analysis in order to determine the levels of disulfide dimers indicating oxidation. For reasons of comparison, the results were correlated with those from a previous study, in which the same samples were analyzed using different oxidative stress markers. The results revealed a good correlation between albumin dimers and protein carbonyls at all time points, while there was also a significant correlation with static oxidation reduction potential at 24 h, and a negative correlation with capacity oxidation reduction potential at 24 and 48 h. In addition, an individual analysis of albumin dimers exhibited great inter-individual differences, indicating the variation of HSA oxidation between different athletes. Namely, in some athletes, HSA seemed to be the main oxidation target of serum proteins, while in other athletes, there was even a reduction of HSA. This inter-individual variability in the oxidation of HSA may suggest that different interventions (e.g., through diet) may be required in order to confront the effects on athletes following strenuous exercise. On the whole, this study suggests the importance of the assessment of albumin dimers as a predictive marker for exercise-induced oxidative stress. © 2017, Spandidos Publications. All rights reserved

Assessment of Oxidative Stress in Septic and Obese Patients Using Markers of Oxidation-reduction Potential

Background/ Aim: The novel static (sORP) and capacity (cORP) oxidation-reduction potential markers were examined for assessing oxidative stress in plasma of patients with sepsis. Moreover, the possible effect of obesity-induced oxidative stress on patients with sepsis was investigated. Materials and Methods: sORP and cORP markers, as well as the conventional oxidative stress biomarkers total antioxidant capacity (TAC), thiobarbituric acid-reactive substances (TBARS) and protein carbonyls (CARB), were assessed in plasma. Results: sORP marker was increased significantly in the sepsis group, while cORP was significantly lower compared to the control group, indicating oxidative stress. Furthermore, in patients with sepsis, TAC was significantly lower compared to control group. However, obesity had no effect on sORP, cORP and TAC in patients with sepsis, although it increased levels of CARB and TBARS. Conclusion: The present results suggest, for the first time, that ORP markers could be used for assessing oxidative stress in patients with sepsis

Variations in oxidative stress markers in elite basketball players at the beginning and end of a season

The aim of the present study was to examine the changes occuring in the redox status in male basketball players at the beginning and end of a highly competitive season. For this purpose, the redox status of 14 professional athletes of a European basketball club was examined at 2 different time points, at the beginning (phase 1) and at the end of the season (phase 2). The redox status was assessed in blood using conventional oxidative stress markers, such as thiobarbituric acid reactive substances (TBARS), protein carbonyls (CARB) and the total antioxidant capacity (TAC) in plasma, as well as glutathione (GSH) levels and catalase (CAT) activity in erythrocytes. Moreover, a new static oxidation‑reduction potential marker (sORP) was assessed in plasma. Our results revealed that sORP was significantly increased by 9.6% and GSH levels were significantly decreased by 35.0% at phase 2 compared to phase 1, indicating the induction of oxidative stress due to excessive exercise. Moreover, TAC was significantly increased by 12.9% at phase 2 compared to phase 1, indicating the activation of adaptive responses for counteracting oxidative stress. The CARB and TBARS levels were not significantly altered between the 2 phases, although there was a significant correlation (r=0.798) between the sORP and CARB levels. Furthermore, the variations in these markers between athletes were examined. We found that 3 markers exhibited a similar response between athletes, that is, sORP was increased in all 14 athletes, TAC was increased in 13 and the GSH levels were decreased in 14. However, the other 3 markers (i.e., TBARS, CARB and CAT) exhibited marked variations between the athletes, suggesting that the optimal approach with which to counteract (e.g., antioxidant supplementation) the observed increase in oxidative stress is the individualized examination of the redox status of athletes using a series of markers. This would allow the identification of athletes affected by severe oxidative stress and inflammation, and would thus indicate when necessary intervention measures are required to improve their health and performance. © 2016, Spandidos Publications. All rights reserved