Is Cataract in Patients under 60 Years Associated with Oxidative Stress?

Oxidative stress is considered as a possible factor in the genesis of cataract. The study aimed to determine the systemic antioxidant status in cataract patients under 60 years. We studied 28 consecutive cataract patients, mean of 53 years (SD = 9.2), a range of 22-60 and 37 controls. In erythrocytes, activity of antioxidant enzymes was determined: superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), in contrast with plasma concentrations of vitamin A and E. Conjugated dienes (CD) level and protein carbonyls (PC) concentration were also determined in plasma. Malondialdehyde (MDA) concentrations in erythrocytes and plasma were also measured. SOD and GPx activity and vitamin A and E concentrations were lower in cataract patients (p = 0.000511, 0.02, 0.022, and 0.000006, respectively). MDA plasma and erythrocytes concentrations were higher in cataract patients (p = 0.000001 and 0.0000001, respectively). PC concentration was higher in cataract patients than in controls (p = 0.00000013). There were statistically significant correlations between oxidative stress markers both in the cataract patients group as well as in the control group. Cataract incidence in patients under 60 years seems to be accompanied by enhanced lipid peroxidation and protein oxidation, as well as antioxidant defense depletion. Thus, supplementation with antioxidants could be beneficial in this group of patients.

The Role of Selected Trace Elements in Oxidoreductive Homeostasis in Patients with Thyroid Diseases.

Impaired levels of selenium (Se), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn) and iodine (I) in the organism may adversely affect the thyroid endocrine system. These trace elements play a role in the fight against oxidative stress as components of enzymes. Oxidative-antioxidant imbalance is considered a possible factor in many pathological conditions, including various thyroid diseases. In the available literature, there are few scientific studies showing a direct correlation of the effect of supplementation of trace elements on slowing down or preventing the occurrence of thyroid diseases in combination with the improvement of the antioxidant profile, or through the action of these elements as antioxidants. Among the available studies, it has been shown that an increase in lipid peroxidation levels and a decrease in the overall antioxidant defense status occur during such thyroid diseases as thyroid cancer, Hashimoto's thyroiditis and dysthyroidism. In studies in which trace elements were supplemented, the following were observed: a decrease in the level of malondialdehyde after supplementation with Zn during hypothyroidism and reduction in the malondialdehyde level after Se supplementation with a simultaneous increase in the total activity status and activity of antioxidant defense enzymes in the course of autoimmune thyroiditis. This systematic review aimed to present the current state of knowledge about the relationship between trace elements and thyroid diseases in terms of oxidoreductive homeostasis.

Links between Vitamin K, Ferroptosis and SARS-CoV-2 Infection.

Ferroptosis is a recently discovered form of programmed cell death. It is characterized by the accumulation of iron and lipid hydroperoxides in cells. Vitamin K is known to have antioxidant properties and plays a role in reducing oxidative stress, particularly in lipid cell membranes. Vitamin K reduces the level of reactive oxygen species by modulating the expression of antioxidant enzymes. Additionally, vitamin K decreases inflammation and potentially prevents ferroptosis. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leading to coronavirus disease 2019 (COVID-19) is associated with oxidant-antioxidant imbalance. Studies have shown that intensified ferroptosis occurs in various tissues and cells affected by COVID-19. Vitamin K supplementation during SARS-CoV-2 infection may have a positive effect on reducing the severity of the disease. Preliminary research suggests that vitamin K may reduce lipid peroxidation and inhibit ferroptosis, potentially contributing to its therapeutic effects in COVID-19 patients. The links between ferroptosis, vitamin K, and SARS-CoV-2 infection require further investigation, particularly in the context of developing potential treatment strategies for COVID-19.

Increased Oxidative Stress Markers in Acute Ischemic Stroke Patients Treated with Thrombolytics.

One of the most common neurological disorders involving oxidative stress is stroke. During a stroke, the balance of redox potential in the cell is disturbed, and, consequently, protein oxidation or other intracellular damage occurs, ultimately leading to apoptosis. The pineal gland hormone, melatonin, is one of the non-enzymatic antioxidants. It not only modulates the perianal rhythm but also has anti-inflammatory properties and protects against stress-induced changes. The focus of this research was to evaluate the concentration of the carbonyl groups and melatonin metabolite in time in patients with acute ischemic stroke that were treated with intravenous thrombolysis. This included a comparison of the functional status of patients assessed according to neurological scales with the control sample comprising healthy people. The studies showed that the serum concentrations of carbonyl groups, which were elevated in patients with ischemic stroke (AIS) in comparison to the control samples, had an impact on the patients' outcome. A urine concentration of the melatonin metabolite, which was lower in patients than controls, was related to functional status after 24 h from cerebral thrombolysis. It shows that determination of carbonyl groups at different time intervals may be an important potential marker of protein damage in patients with AIS treated with cerebral thrombolysis, and that impaired melatonin metabolism induces a low antioxidant protection. Thus, due to the neuroprotective effects of melatonin, attention should also be paid to the design and conduct of clinical trials and hormone supplementation in AIS patients to understand the interactions between exogenous melatonin and its endogenous rhythm, as well as how these relationships may affect patient outcomes.

Association between Vitamin D Supplements, Oxidative Stress Biomarkers, and Hyperbaric Therapy in Patients with Sudden Sensorineural Hearing Loss.

The effect of vitamin D supplementation to patients with sudden sensorineural hearing loss (SSNHL), treated with hyperbaric oxygen (HBO) therapy, on the markers of the oxidant-antioxidant equilibrium was investigated. Patients were divided into two groups: those who did and did not receive vitamin D (cholecalciferol at 4000 IU/24 h). Concentrations of the following compounds, thiobarbituric acid reactive substances (TBARS), malondialdehyde (MDA), conjugated dienes (CD) in plasma and erythrocytes and activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in erythrocytes, were determined. Haemoglobin (HGB) and haematocrit (HCT) were measured. Blood for analyses was collected from the basilic vein at three time points: before the first HBO procedure, up to 5 min after the first procedure, and after 14 procedures. No statistically significant differences in parameters tested were found between patients who did and did not receive vitamin D. In patients without supplementation, an increase of 53.2% (P ≤ 0.05) in erythrocyte TBARS was observed after the first HBO treatment. In patients receiving vitamin D, a reduction of 27.6% (P ≤ 0.05) was observed in erythrocyte MDA after 14 HBO treatments vs. that after the first treatment. In both groups, a decrease of 33.3% in plasma CD was observed after 14 treatments vs. that after the first treatment (P ≤ 0.05 and P ≤ 0.01, respectively). No statistically significant changes were observed in the erythrocyte SOD, GPx, and CAT activities and in HCT. A reduction of HGB concentration of 10.9% (P ≤ 0.05) was demonstrated in nonsupplemented patients after 14 treatments compared with baseline. The results confirm that the effect of HBO therapy on oxidative stress markers is inconclusive and complex. Repeated HBO procedures can induce adaptive changes which protect against disruption of the oxidant-antioxidant equilibrium. It is possible that vitamin D supplementation inhibits the process of lipid peroxidation in erythrocytes.

Ionizing Radiation as a Source of Oxidative Stress-The Protective Role of Melatonin and Vitamin D.

Ionizing radiation (IR) has found widespread application in modern medicine, including medical imaging and radiotherapy. As a result, both patients and healthcare professionals are exposed to various IR doses. To minimize the negative side effects of radiation associated with oxidative imbalance, antioxidant therapy has been considered. In this review, studies on the effects of melatonin and vitamin D on radiation-induced oxidative stress are discussed. According to the research data, both substances meet the conditions for use as agents that protect humans against IR-induced tissue damage. Numerous studies have confirmed that melatonin, a hydro- and lipophilic hormone with strong antioxidant properties, can potentially be used as a radioprotectant in humans. Less is known about the radioprotective effects of vitamin D, but the results to date have been promising. Deficiencies in melatonin and vitamin D are common in modern societies and may contribute to the severity of adverse side effects of medical IR exposure. Hence, supporting supplementation with both substances seems to be of first importance. Interestingly, both melatonin and vitamin D have been found to selectively radiosensitise cancer cells, which makes them promising adjuvants in radiotherapy. More research is needed in this area, especially in humans.

Evaluation of Oxidative Stress in Patients with Difficult-to-Heal Skin Wounds Treated with Hyperbaric Oxygen.

OBJECTIVE: To determine the concentration of thiobarbituric acid reactive substances (TBARS) in erythrocytes and blood plasma, and the activities of selected antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in erythrocytes in patients receiving hyperbaric oxygen (HBO) treatment due to difficult-to-heal "skin wounds". Material and Methods. Indices of oxidative stress were assessed in venous blood taken from 23 patients three times: immediately before HBO procedure, approx. 5 minutes after leaving the hyperbaric chamber, and after 25 HBO procedures. Moreover, selected blood counts were measured in the collected material two times: prior to treatment and after 25 HBO procedures. RESULTS: A statistically significant positive correlation between the CAT activity and the TBARS concentration in the erythrocytes of patients was found before treatment in the hyperbaric chamber (r = 0.394; P ≤ 0.05). No statistically significant changes in the TBARS concentration in erythrocytes and blood plasma were observed both after the first HBO procedure and after 25 procedures. No statistically significant changes in the activities of CAT, SOD, and GPx were noted. Platelet count decreased by 18.7% (P ≤ 0.05) after 25 HBO procedures. Granulocyte count decreased by approx. 21% (P ≤ 0.05), and granulocyte percentage by 11.8% (P ≤ 0.01). In turn, the percentage of lymphocytes and monocytes increased after the treatment by 16.6% (P < 0.05) and 16.4% (P < 0.05), respectively. CONCLUSIONS: Exposure to HBO due to difficult-to-heal skin wounds does not significantly affect the levels of oxidative stress in the peripheral blood of patients and, from the point of view of oxidation-reduction processes, appears to be a safe therapeutic method for the treatment of chronic wounds.

Application of ELISA Technique and Human Microsomes in the Search for 11ß-Hydroxysteroid Dehydrogenase Inhibitors.

The metabolic syndrome is defined by impaired carbohydrate metabolism and lipid disorders and often accompanied by hypertension, all of which will lead to obesity and insulin resistance. Glucocorticoids play a regulatory role in the metabolism of proteins, lipids, and carbohydrates. There is growing evidence for a role of glucocorticoids in the development of the metabolic syndrome. The most important factor that regulates the access of endogenous glucocorticoids to receptors after release of glucocorticoids and their diffusion into the cytoplasm of target cells is the steroid metabolism involving a microsomal enzyme, 11ß-hydroxysteroid dehydrogenase (11ß-HSD). The changes in intracellular glucocorticoid metabolism in the pathogenesis of obesity indicate the participation of modulation by 11ß-HSD1, which may represent a new therapeutic target for the treatment of diseases such as type 2 diabetes, visceral obesity, or atherosclerosis. The aim of our study was to determine the fast and effective method to assess inhibition activity of compounds in relation with 11ß-hydroxysteroid dehydrogenase. The material for this study was human liver and kidney microsomes. In this study we used ELISA technique using 96-well microplates coated with antibodies which were specific for analyzed enzymes. The method can quickly and efficiently measure the inhibition of both 11ß-HSD1 and 11ß-HSD2. This method can be used to search for and determine inhibitors of this enzyme. Cortisone and cortisol were used as the substrates for corresponding enzyme assays. Furthermore, 3-N-allyl-2-thiouracil derivatives were used by us for comparison purposes in developing the method, although, due to their structure, those derivatives have not previously been considered as potential inhibitors of 11ß-HSD1. 3-N-Allyl-2-thiouracil derivatives are a group worth considering, because by modifying their structure (e.g., by introducing other substituents into the pyrimidine ring) it will be possible to obtain an increase in the activity of compounds in this regard. In conclusion, this study shows an efficient and fast method of determining inhibition activity of compounds in relation with 11ß-hydroxysteroid dehydrogenase.

Markers of Oxidant-Antioxidant Equilibrium in Patients with Sudden Sensorineural Hearing Loss Treated with Hyperbaric Oxygen Therapy.

The concentration of thiobarbituric acid reactive substances (TBARSs) in plasma and erythrocytes, the activity of selected antioxidant enzymes in erythrocytes: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), and the levels of hemoglobin (HGB) and haematocrit (HCT) were determined in 40 patients with sudden sensorineural hearing loss (SSNHL) subjected to 14 treatment sessions in a Haux Starmed 2200 hyperbaric chamber. Hyperbaric oxygen (HBO) therapy involved breathing 100% oxygen at 0.25 MPa. Blood for analysis was collected from the basilic vein at three time points: before the first HBO session, approximately 5 min after the first session, and after the 14th session. The control group included 20 healthy individuals never before treated with HBO therapy. Compared to the pre-HBO values, a 10% increase (P < 0.05) in the TBARS concentration in erythrocytes, a 28% increase in the GPx activity (P < 0.05), and a 7% decrease in the SOD activity (P < 0.05) were observed after 14 HBO sessions. The CAT activity decreased by 6% (P < 0.05) after the first session. The TBARS concentration in plasma was 13% higher (P < 0.01), while that in erythrocytes was 24% lower (P < 0.001) in the SSNHL patients before the first HBO session compared to the control group. The CAT activity in the SSNHL patients before HBO therapy was 26% higher (P < 0.001) than that in the control group. A statistically significant reduction in HGB and HCT after 14 HBO sessions (P < 0.01) compared to the pre-HBO values was demonstrated. SSNHL is accompanied by disturbance in the oxidant-antioxidant equilibrium. Repeated stimulation with hyperbaric oxygen modulates the activity of antioxidant enzymes. It seems that the increased generation of hydrogen peroxide is responsible for the changes in the activity of antioxidant barrier enzymes observed after HBO sessions.

Melatonin supplementation improves oxidative and inflammatory state in the blood of professional athletes during the preparatory period for competitions.

Melatonin supplementation has been proved to have antioxidant and anti-inflammatory effects in humans. The aim of the study was to estimate the influence of a 30-day melatonin supplementation on oxidative and inflammatory state in the blood of intense training professional athletes. The study was conducted in 47 football players, 19 rowers, and 15 adults who did not practice sports (control group). Blood samples were taken once from the control group and twice from the athletes: before and after 30-day melatonin administration (5 mg daily before sleep). Serum levels of melatonin, isoprostanes, antiox-LDL antibodies, interleukin-6, and C-reactive protein were measured. In erythrocytes, the concentrations of reduced glutathione (GSH) and malondialdehyde (MDA), and the activities of glutathione peroxidase (GSH-Px), cytoplasmic superoxide dismutase (SOD-1), and glutathione reductase (GR) were determined. Melatonin supplementation caused a significant decrease in markers of oxidative stress and a significant increase in melatonin concentration and the activities of SOD-1 and GSH-Px in athletes. The obtained data showed increased oxidative stress and inflammatory processes in professional athletes during intense training and indicated that supplementation of melatonin in their daily diet may have a beneficial effect on the protection of tissues against the adverse action of RONS and inflammatory processes.

Melatonin Supplementation Lowers Oxidative Stress and Regulates Adipokines in Obese Patients on a Calorie-Restricted Diet.

Obesity is one of the major global health problems. Melatonin deficiency has been demonstrated to correlate with obesity. The aim of the study was to estimate the effect of melatonin on oxidative stress and adipokine levels in obese patients on a calorie-restricted diet. Thirty obese patients were supplemented with a daily dose of 10 mg of melatonin (n = 15) or placebo (n = 15) for 30 days with a calorie-restricted diet. Serum levels of melatonin, 4-hydroxynonenal (HNE), adiponectin, omentin-1, leptin, and resistin, as well as erythrocytic malondialdehyde (MDA) concentration and Zn/Cu-superoxide dismutase, catalase, and glutathione peroxidase (GPx) activities, were measured at baseline and after supplementation. Significant body weight reduction was observed only in the melatonin group. After melatonin supplementation, the adiponectin and omentin-1 levels and GPx activities statistically increased, whereas the MDA concentrations were reduced. In the placebo group, a significant rise in the HNE and a drop in the melatonin concentrations were found. The results show evidence of increased oxidative stress accompanying calorie restriction. Melatonin supplementation facilitated body weight reduction, improved the antioxidant defense, and regulated adipokine secretion. The findings strongly suggest that melatonin should be considered in obesity management. This trial is registered with CTRI/2017/07/009093.

Deferoxamine prevents cerebral glutathione and vitamin E depletions in asphyxiated neonatal rats: role of body temperature.

Hypoxic-ischaemic brain injury involves increased oxidative stress. In asphyxiated newborns iron deposited in the brain catalyses formation of reactive oxygen species. Glutathione (GSH) and vitamin E are key factors protecting cells against such agents. Our previous investigation has demonstrated that newborn rats, showing physiological low body temperature as well as their hyperthermic counterparts injected with deferoxamine (DF) are protected against iron-mediated, delayed neurotoxicity of perinatal asphyxia. Therefore, we decided to study the effects of body temperature and DF on the antioxidant status of the brain in rats exposed neonatally to critical anoxia. Two-day-old newborn rats were exposed to anoxia in 100% nitrogen atmosphere for 10 min. Rectal temperature was kept at 33 °C (physiological to rat neonates), or elevated to the level typical of healthy adult rats (37 °C), or of febrile adult rats (39 °C). Half of the rats exposed to anoxia under extremely hyperthermic conditions (39 °C) were injected with DF. Cerebral concentrations of malondialdehyde (MDA, lipid peroxidation marker) and the levels of GSH and vitamin E were determined post-mortem, (1) immediately after anoxia, (2) 3 days, (3) 7 days, and (4) 2 weeks after anoxia. There were no post-anoxic changes in MDA, GSH and vitamin E concentrations in newborn rats kept at body temperature of 33 °C. In contrast, perinatal anoxia at elevated body temperatures intensified oxidative stress and depleted the antioxidant pool in a temperature-dependent manner. Both the depletion of antioxidants and lipid peroxidation were prevented by post-anoxic DF injection. The data support the idea that hyperthermia may extend perinatal anoxia-induced brain lesions.

Inter-relationships of the chronobiotic, melatonin, with leptin and adiponectin: implications for obesity.

Obesity and its medical complications represent a significant problem throughout the world. In recent decades, mechanisms underlying the progression of obesity have been intensively examined. The involvement of both the behavioral aspects, such as calorie-rich diet, low physical activity and sleep deprivation, and the intrinsic factors, including adipose tissue deregulation, chronic inflammation, oxidative stress, and chronodisruption, has been identified. The circadian disturbances of the adipose tissue endocrine function have been correlated with obesity. Leptin and adiponectin are adipokines strongly associated with glucose and lipid metabolism and with energy balance. Their synthesis and secretion display circadian rhythms that are disturbed in the obese state. Hyperleptinemia resulting in leptin resistance, and hypo-adiponectinemia have been linked to the pathophysiology of the obesity-related disorders. A deficiency of melatonin, one of the consequences of sleep deprivation, has also been demonstrated to correlate with obesity. Melatonin is a pineal secretory product involved in numerous actions, such as regulation of internal biological clocks and energy metabolism, and it functions as an antioxidant and as an anti-inflammatory agent. There exists a substantial amount of evidence supporting the beneficial effects of melatonin supplementation on obesity and its complications. In the current review, the results of studies related to the interactions between melatonin, and both leptin and adiponectin are discussed. Despite the existence of some inconsistencies, melatonin has been found to normalize the expression and secretion patterns of both adipokines. These results support the concept of melatonin as a potential therapeutic agent for obesity and related disorders.

Single whole-body cryostimulation procedure versus single dry sauna bath: comparison of oxidative impact on healthy male volunteers.

Exposure to extreme heat and cold is one of the environmental factors whose action is precisely based on the mechanisms involving free radicals. Fluctuations in ambient temperature are among the agents that toughen the human organism. The goal of the study was to evaluate the impact of extremely high (dry sauna, DS) and low (whole-body cryostimulation, WBC) environmental temperatures on the oxidant-antioxidant equilibrium in the blood of healthy male subjects. The subjects performed a single DS bath (n = 10; 26.2 ± 4.6 years) and a single WBC procedure (n = 15; 27.5 ± 3.1 years). In the subjects' blood taken immediately before and 20 min after the interventions, the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and the concentration of thiobarbituric acid reactive substances in erythrocytes (TBARSer) and blood plasma (TBARSpl) were determined. Single WBC and DS procedures induced an increase in the activity of SOD and GPx, as well as SOD and CAT, respectively. The SOD activity was higher after WBC than after DS. Extremely high and low temperatures probably induce the formation of reactive oxygen species in the organisms of healthy men and, therefore, disturb the oxidant-antioxidant balance.

The effect of a single Finnish sauna bath after aerobic exercise on the oxidative status in healthy men.

BACKGROUND: The aim of this study was to determine the effect of Finnish sauna as a regeneration method post-exercise on the oxidant-antioxidant balance in healthy men. MATERIAL: 43 men aged 24.0 ± 4.3 years performed a 30-min aerobic exercise on a cycle ergometer and rested for 39 min at a room temperature (Day 1; 20°C) or in a sauna for post-workout recovery (Day 2; 90°C, air humidity 10%). Blood was taken 3 times during both study days: Before the exercise (baseline), 20 and 40 min after the recovery. Methods. The activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) was determined in the subjects' erythrocytes. The concentration of thiobarbituric acid reactive substances (TBARS) was measured both in plasma (TBARSpl) and in the erythrocytes (TBARSer). RESULTS: A 12.7% increase in the TBARSpl concentration versus the baseline was observed 40 min after the Finnish sauna (p < 0.01). The CAT activity observed 20 and 40 min after the sauna was also found higher by 8.1% and 8.9%, respectively, in comparison with the baseline (p < 0.05). In turn, the TBARSer concentration was lower by 17.5% 40 min after the recovery in the sauna, as compared with the TBARSer concentration 40 min after the recovery at the room temperature (p < 0.05). CONCLUSIONS: A single Finnish sauna bath as a source of free radicals per se is able to reduce oxidative stress induced by a 30-min aerobic exercise in healthy men.

Ozone therapy and the activity of selected lysosomal enzymes in blood serum of patients with lower limb ischaemia associated with obliterative atheromatosis.

BACKGROUND: The paper compares the effects of ozone therapy and conventional balneological methods on health condition of patients with obliterative atheromatosis and on serum activity of three lysosomal enzymes. MATERIAL/METHODS: Sixty-four patients with lower limb ischaemia in the course of obliterative atheromatosis (without diabetes) were enrolled in the study. Thirty-two patients were treated with ozone administered by intravenous infusions and 30-minute aerosol oxygen-ozone baths. A comparative group was formed of 32 patients treated with traditional balneology. There was also a control group made up of 30 healthy subjects. Ozone therapy as well as traditional balneology were administered daily for the period of 10 days, excluding Saturdays and Sundays. Blood for biochemical analysis was collected from elbow vein in the following time intervals: 24 hours before ozone therapy or classical balneology, one hour after therapy and on the 10th day of treatment. The activity of cathepsin D, acid phosphatase and arylsulphatase as well as the levels of a-1-antitrypsin (protease inhibitor) were determined in blood serum of patients with obliterative atheromatosis. RESULTS: In patients who received ozone therapy the activity of analysed lysosomal hydrolases returned to the values typical for healthy subjects. Patients' general condition also improved. The use of traditional balneological methods did not result in any significant change either in the activity of lysosomal hydrolases, the level of a-1-antitrypsin or general condition of patients. CONCLUSIONS: Ozone therapy administered by intravenous infusions and aerosol oxygen-ozone baths of lower extremities yields much better therapeutic results in comparison with classical balneology.