Erythrocyte superoxide dismutase, glutathione peroxidase, and catalase activities and risk of coronary heart disease in generally healthy women: a prospective study

Modulation of the Human Erythrocyte Antioxidant System by the 5- and 6-Membered Heterocycle-Based Nitroxides

Nitroxides are stable radicals consisting of a nitroxyl group, >N-O•, which carries an unpaired electron. This group is responsible for the paramagnetic and antioxidant properties of these compounds. A recent study evaluated the effects of pyrrolidine and pyrroline derivatives of nitroxides on the antioxidant system of human red blood cells (RBCs). It showed that nitroxides caused an increase in the activity of superoxide dismutase (SOD) and the level of methemoglobin (MetHb) in cells (in pyrroline derivatives) but had no effect on the activity of catalase and lactate dehydrogenase. Nitroxides also reduced the concentration of ascorbic acid (AA) in cells but did not cause any oxidation of proteins or lipids. Interestingly, nitroxides initiated an increase in thiols in the plasma membranes and hemolysate. However, the study also revealed that nitroxides may have pro-oxidant properties. The drop in the AA concentration and the increase in the MetHb level and in SOD activity may indicate the pro-oxidant properties of nitroxides in red blood cells.

The analyse of the antioxidant effect of natural peloidotherapy in aging process

Medical research has developed remarkably in recent years, including the involvement of the glutathione peroxidase (GPx) family of enzymes in the course of human aging, with numerous clinical studies published in the literature reporting this particular fact. Thus, mud therapy and its effect on biological aging have been represented in papers that have been published to date. Papers published in the literature analyzing GPx vari-ation during sapropelic mud therapy suggest the beneficial effect of this family of en-zymes in diseases with an important inflammatory component, mainly monitored in patients with osteoarthritis. This study investigated the effects of sapropelic mud treat-ment on GPx values in patients receiving treatment with sapropelic mud at the Balneal and Rehabilitation Sanatorium of Techirghiol, Romania. We included 52 patients, split into two groups, who received treatment with cold mud baths and warm mud baths. Values close to statistical significance were found in patients who received treatment with cold mud baths in terms of mean GPx values at the four-time points studied. Fur-ther studies evaluating GPx in patients receiving sapropelic mud treatment are needed.

New insights into geraniol's antihemolytic, anti-inflammatory, antioxidant, and anticoagulant potentials using a combined biological and in silico screening strategy

The study aims to assess the antihemolytic and antioxidant activities of geraniol versus 2, 2'-azobis, 2-amidinopropane dihydro-chloride- (AAPH-) induced oxidative damage and hemolysis to erythrocytes and its anti-inflammatory potential against lipopolysaccharide- (LPS-) induced inflammation in white blood cells (WBCs) with a focus on its integrated computational strategies against different targeted receptors participating in inflammation and coagulation. The rats' erythrocyte suspension was incubated with different geraniol concentrations. Molecular docking and simulation were used to explore the possible interaction patterns of geraniol against the potential targeted proteins for therapeutic screening. The results displayed that geraniol had a prolonged noteworthy effect on activated partial thromboplastin time and thromboplastin time. Geraniol displayed strong antioxidant effects via reduced malondialdehyde (MDA) formation and increased GSH level and SOD activity. We observed dose-dependent prevention of K⁺ ion leakage along with a remarkable decline of hemolysis in erythrocytes pretreated with geraniol. Geraniol 100 µg/mL and diclofenac 100 µM were nontoxic to WBCs. Geraniol significantly reduces the expression and release of cellular pro-inflammatory factors TNF-α, IL-1β, IL-8, and nitric oxide, accompanied by a significant upregulation of gene expression of anti-inflammatory cytokine IL-10 in LPS-induced WBCs compared to nontreated cells. It demonstrates a much stronger inhibition potential than diclofenac in terms of inflammation inhibition. When comparing molecular docking and simulation data, current work showed that geraniol has a good affinity toward apoptosis signal-regulating kinase 1 (ASK1) and human P2Y12 receptors and could be developed as an antioxidant, anti-inflammatory, and anticoagulant medication in the future. Consequently, geraniol is recommended to have a defensive influence against oxidative stress, and hemolysis also could be developed as a promising anti-inflammatory, antioxidant, and anticoagulant medication.

Common and Novel Markers for Measuring Inflammation and Oxidative Stress Ex Vivo in Research and Clinical Practice-Which to Use Regarding Disease Outcomes?

Many chronic conditions such as cancer, chronic obstructive pulmonary disease, type-2 diabetes, obesity, peripheral/coronary artery disease and auto-immune diseases are associated with low-grade inflammation. Closely related to inflammation is oxidative stress (OS), which can be either causal or secondary to inflammation. While a low level of OS is physiological, chronically increased OS is deleterious. Therefore, valid biomarkers of these signalling pathways may enable detection and following progression of OS/inflammation as well as to evaluate treatment efficacy. Such biomarkers should be stable and obtainable through non-invasive methods and their determination should be affordable and easy. The most frequently used inflammatory markers include acute-phase proteins, essentially CRP, serum amyloid A, fibrinogen and procalcitonin, and cytokines, predominantly TNFα, interleukins 1β, 6, 8, 10 and 12 and their receptors and IFNγ. Some cytokines appear to be disease-specific. Conversely, OS-being ubiquitous-and its biomarkers appear less disease or tissue-specific. These include lipid peroxidation products, e.g., F2-isoprostanes and malondialdehyde, DNA breakdown products (e.g., 8-OH-dG), protein adducts (e.g., carbonylated proteins), or antioxidant status. More novel markers include also -omics related ones, as well as non-invasive, questionnaire-based measures, such as the dietary inflammatory-index (DII), but their link to biological responses may be variable. Nevertheless, many of these markers have been clearly related to a number of diseases. However, their use in clinical practice is often limited, due to lacking analytical or clinical validation, or technical challenges. In this review, we strive to highlight frequently employed and useful markers of inflammation-related OS, including novel promising markers.

Chronic Kidney Disease as Oxidative Stress- and Inflammatory-Mediated Cardiovascular Disease

Generating reactive oxygen species (ROS) is necessary for both physiology and pathology. An imbalance between endogenous oxidants and antioxidants causes oxidative stress, contributing to vascular dysfunction. The ROS-induced activation of transcription factors and proinflammatory genes increases inflammation. This phenomenon is of crucial importance in patients with chronic kidney disease (CKD), because atherosclerosis is one of the critical factors of their cardiovascular disease (CVD) and increased mortality. The effect of ROS disrupts the excretory function of each section of the nephron. It prevents the maintenance of intra-systemic homeostasis and leads to the accumulation of metabolic products. Renal regulatory mechanisms, such as tubular glomerular feedback, myogenic reflex in the supplying arteriole, and the renin-angiotensin-aldosterone system, are also affected. It makes it impossible for the kidney to compensate for water-electrolyte and acid-base disturbances, which progress further in the mechanism of positive feedback, leading to a further intensification of oxidative stress. As a result, the progression of CKD is observed, with a spectrum of complications such as malnutrition, calcium phosphate abnormalities, atherosclerosis, and anemia. This review aimed to show the role of oxidative stress and inflammation in renal impairment, with a particular emphasis on its influence on the most common disturbances that accompany CKD.

Peroxiredoxin I deficiency increases LPS‑induced lethal shock in mice

Peroxiredoxin I (Prx I) plays a role in regulating macrophage proinflammatory cytokine production and gene expression and participates in immune regulation. However, the possible protective role of Prx I in endotoxin‑induced lethal shock is poorly understood. In the present study, western blot analysis, ELISA and haematoxylin and eosin staining were performed to examine the protein expression of cytoines and analyses the levels of cytokines in the serum and tissue to evaluate the tissue damage. The present study revealed that lipopolysaccharide (LPS)‑induced lethality in Prx I‑/‑ mice was is accelerated via the observed decreased serum IL‑10 levels. Results also demonstrated rapid immune cell infiltration and oxidative stress in the Prx I‑/‑mice liver after LPS injections. These phenomena increased liver apoptosis through increasing cleaved caspase‑3 protein expression in Prx I‑/‑ mice after LPS injections, resulting in high lethality after LPS challenges. These findings provide a new insight for understanding the function of Prx I against endotoxin‑induced injury.

Selenium in the prevention of atherosclerosis and its underlying mechanisms

Atherosclerosis and related cardiovascular diseases (CVDs) represent the greatest threats to human health worldwide. Selenium, an essential trace element, is incorporated into selenoproteins that play a crucial role in human health and disease. Although findings from a limited number of randomized trials have been inconsistent and cannot support a protective role of Se supplementation in CVDs, prospective observational studies have generally shown a significant inverse association between selenium or selenoprotein status and CVD risk. Furthermore, a benefit of selenium supplementation in the prevention of CVDs has been seen in population with low baseline selenium status. Evidence from animal studies shows consistent results that selenium and selenoproteins might prevent experimental atherosclerosis, which can be explained by the molecular and cellular effects of selenium observed both in animal models and cell cultures. Selenoproteins of particular relevance to atherosclerosis are glutathione peroxidases, thioredoxin reductase 1, selenoprotein P, selenoprotein S. The present review is focusing on the existing evidence that supports the concept that optimal selenium intake can prevent atherosclerosis. Its underlying mechanisms include inhibiting oxidative stress, modulating inflammation, suppressing endothelial dysfunction, and protecting vascular cells against apoptosis and calcification. However, the benefit of selenium supplementation in the prevention of atherosclerosis remains insufficiently documented so far. Future studies with regard to the effects of selenium supplementation on atherosclerosis should consider many factors, especially the baseline selenium status, the dose and forms of selenium supplementation, and the selenoprotein genotype. Additionally, much more studies are needed to confirm the roles of selenoproteins in atherosclerosis prevention and clarify the underlying mechanisms.

Antihemolytic and antioxidant properties of pearl powder against 2,2′-azobis(2-amidinopropane) dihydrochloride-induced hemolysis and oxidative damage to erythrocyte membrane lipids and proteins

Pearl powder, a well-known traditional mineral medicine, is reported to be used for well-being and to treat several diseases from centuries in Taiwan and China. We investigated the in vitro antihemolytic and antioxidant properties of pearl powder that could protect erythrocytes against 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative damage to membrane proteins/lipids. Human erythrocytes were incubated with different concentrations of pearl powder (50–200 μg/mL) for 30 minutes and then exposed to AAPH for 2–6 hours. We found that AAPH alone time dependently increased the oxidative hemolysis of erythrocytes, while pearl powder pretreatment substantially inhibited the hemolysis in a concentration-/time-dependent manner. AAPH-induced oxidative damage to erythrocyte membrane lipids was evidenced by the elevated malondialdehyde (MDA) levels. However, pearl powder remarkably inhibited the malondialdehyde formation, and the 200 μg/mL concentration showed almost similar malondialdehyde values to the control. Furthermore, pearl powder suppressed the AAPH-induced high-molecular-weight protein formation and concomitantly increased the low-molecular-weight proteins in erythrocytes. Antioxidant potential that was measured as superoxide dismutase activity and glutathione content was significantly dropped by AAPH incubation, which suggests the vulnerability of erythrocytes to AAPH-induced oxidative stress. Noteworthy, erythrocytes pretreated with pearl powder showed restored superoxide dismutase activity and glutathione levels against AAPH-induced loss. Our findings conclude that pearl powder attenuate free radical-induced hemolysis and oxidative damage to erythrocyte membrane lipids/proteins. The potent antioxidant property of pearl powder may offer protection from free radical-related diseases.

Topiramate Improves Neuroblast Differentiation of Hippocampal Dentate Gyrus in the D-Galactose-Induced Aging Mice via Its Antioxidant Effects

Some anticonvulsant drugs are associated with cognitive ability in patients; Topiramate (TPM) is well known as an effective anticonvulsant agent applied in clinical settings. However, the effect of TPM on the cognitive function is rarely studied. In this study, we aimed to observe the effects of TPM on cell proliferation and neuronal differentiation in the dentate gyrus (DG) of the D-galactose-induced aging mice by Ki-67 and doublecortin (DCX) immunohistochemistry. The study is divided into four groups including control, D-galactose-treated group, 25 and 50 mg/kg TPM-treated plus D-galactose-treated groups. We found, 50 mg/kg (not 25 mg/kg) TPM treatment significantly increased the numbers of Ki-67⁺ cells and DCX immunoreactivity, and improved neuroblast injury induced by D-galactose treatment. In addition, we also found that decreased immunoreactivities and protein levels of antioxidants including superoxide dismutase and catalase induced by D-galactose treatment were significantly recovered by 50 mg/kg TPM treatment in the mice hippocampal DG (P < 0.05). In conclusion, our present results indicate that TPM can ameliorate neuroblast damage and promote cell proliferation and neuroblast differentiation in the hippocampal DG via increasing SODs and catalase levels in the D-galactose mice.

Effects of estrogen on glutathione and catalase levels in human erythrocyte during menstrual cycle

The present study evaluated the effects of physiological serum estrogen during the menstrual cycle on glutathione (GSH) and catalase activities. The sample included 43 healthy females between the ages of 22 and 51 years. The subjects were divided into two groups according to the stage of the menstrual cycle. Group A consisted of 16 samples extracted between days 10 and 20 from the first day of menstruation when estrogen levels were considered to be at their highest. Group B consisted of 27 samples extracted during other times of the estimated 30 days of menstruation. Data showed that the estrogen level in group A (184±106 pg/ml) was higher than that in group B (105±56 pg/ml) (P<0.01). The GSH and catalase levels in group A (4.4±2.3 µg/mg and 210±72 IU/mg, respectively) were also significantly higher compared to the levels in group B (3.2±1.8 µg/mg and 168±62 IU/mg, respectively) (P <0.05). Spearman's rank correlation showed that the expression of catalase in red blood cells significantly correlated with serum estrogen level but not with GSH. However, the changes in estrogen plasma levels, erythrocyte GSH level and catalase activity suggested that the consumption of GSH and catalase in erythrocyte during the menstrual cycle may be associated with the level of estrogen present in the bloodstream.