The Correlation between Selenium-Dependent Glutathione Peroxidase Activity and Oxidant/Antioxidant Balance in Sera of Diabetic Patients with Nephropathy

Pro-Oxidant/ Antioxidant Balance Correlates with Red Blood Cell Indices and Anemia Severity in the Anemic Patients

Background

The oxidant/ antioxidant balance is disrupted in anemia. Antioxidant capacity depends on antioxidant enzyme activity and some trace elements. This study aimed to evaluate oxidant/ antioxidant status and its correlation with red blood cell indices and anemia severity in anemic patients.

Methods

Blood samples were taken from 90 anemic patients and 95 healthy people. Circulatory miR-122 was assayed by real-time PCR. Malondialdehyde (MDA), pro-oxidant/ antioxidant balance (PAB), supper oxide demitasse (SOD), glutathione peroxidase (GPxs) activity, total antioxidant capacity (TAC), and zinc were measured by colorimetric method. Selenium was also determined using atomic absorption.

Results

Selenium and zinc decreased significantly in the case group (**P=0.004 and ***P=0.000). The amount of miR-122 up-regulated in the anemia (**P=0.003). MDA was significantly raised in the case vs control (***P=0.0002). PAB was higher in the case group (**P=0.005). SOD and GPxs activity was decreased along with TAC in anemic patients (*P=0.02, **P=0.008, *P=0.038). Zinc and PAB levels correlated with some red blood cell indices. PAB was associated with anemia severity.

Conclusions

Increased PAB and decreased zinc/selenium increased oxidant levels in anemic patients. RBC indices and anemia severity were correlated with oxidant/ antioxidant somewhere.

Pathomechanisms of Diabetic Kidney Disease

The worldwide occurrence of diabetic kidney disease (DKD) is swiftly rising, primarily attributed to the growing population of individuals affected by type 2 diabetes. This surge has been transformed into a substantial global concern, placing additional strain on healthcare systems already grappling with significant demands. The pathogenesis of DKD is intricate, originating with hyperglycemia, which triggers various mechanisms and pathways: metabolic, hemodynamic, inflammatory, and fibrotic which ultimately lead to renal damage. Within each pathway, several mediators contribute to the development of renal structural and functional changes. Some of these mediators, such as inflammatory cytokines, reactive oxygen species, and transforming growth factor β are shared among the different pathways, leading to significant overlap and interaction between them. While current treatment options for DKD have shown advancement over previous strategies, their effectiveness remains somewhat constrained as patients still experience residual risk of disease progression. Therefore, a comprehensive grasp of the molecular mechanisms underlying the onset and progression of DKD is imperative for the continued creation of novel and groundbreaking therapies for this condition. In this review, we discuss the current achievements in fundamental research, with a particular emphasis on individual factors and recent developments in DKD treatment.

Vitamin E Treatment Improves the Antioxidant Capacity of Patients Receiving Dialysis: A Systematic Review and Meta-Analysis

SCOPE

To summarize the effect of vitamin E-coated dialyzer membranes (VEMs) treatment or oral vitamin E intake on antioxidant molecules, such as superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), and total antioxidant level in patients receiving dialysis.

METHODS AND RESULTS

A literature search of PubMed, Embase, CNKI, and the Cochrane Library databases is performed from inception to July 1, 2023, with no language nor country restrictions. Twenty-four experimental studies involving 512 patients undergoing dialysis are selected for meta-analysis. The levels of antioxidant markers in the blood of patients receiving hemodialysis (HD) improve with long-term VEMs treatment (p = 0.016). According to the findings of each antioxidant index, there is a significant increase in the levels of erythrocyte-derived SOD (p = 0.047), CAT (p = 0.029), and plasma-derived total antioxidant level (p < 0.001). The antioxidant marker levels in patients receiving HD are significantly increased by oral vitamin E intake (p < 0.001). Erythrocyte-derived SOD (p = 0.003), GPX (p < 0.001), and CAT (p = 0.001) substantially improves after 2-6 months of intervention with oral vitamin E preparation. The antioxidant index of patients receiving peritoneal dialysis (PD) is unaffected by oral vitamin E treatment (p = 0.945).

CONCLUSION

Vitamin E therapy has a favorable effect on the retention of antioxidant compounds in patients undergoing dialysis.

Selenoneine-inspired selenohydantoins with glutathione peroxidase-like activity

Chronic diseases such as cystic fibrosis, inflammatory bowel diseases, rheumatoid arthritis, and cardiovascular illness have been linked to a decrease in selenium levels and an increase in oxidative stress. Selenium is an essential trace element that exhibits antioxidant properties, with selenocysteine enzymes like glutathione peroxidase being particularly effective at reducing peroxides. In this study, a series of synthetic organoselenium compounds were synthesized and evaluated for their potential antioxidant activities. The new selenohydantoin molecules were inspired by selenoneine and synthesized using straightforward methods. Their antioxidant potential was evaluated and proven using classical radical scavenging and metal-reducing methods. The selenohydantoin derivatives exhibited glutathione peroxidase-like activity, reducing hydroperoxides. Theoretical calculations using Density Functional Theory (DFT) revealed the selenone isomer to be the only one occurring in solution, with selenolate as a possible tautomeric form in the presence of a basic species. Cytocompatibility assays indicated that the selenohydantoin derivatives were non-toxic to primary human aortic smooth muscle cells, paving the way for further biological evaluations of their antioxidant activity. The results suggest that selenohydantoin derivatives with trifluoro-methyl (-CF3) and chlorine (-Cl) substituents have significant activities and could be potential candidates for further biological trials. These compounds may contribute to the development of effective therapies for chronic diseases such cardiovascular diseases.

Diabetic Nephropathy: Significance of Determining Oxidative Stress and Opportunities for Antioxidant Therapies

Diabetes mellitus (DM) belongs to the category of socially significant diseases with epidemic rates of increases in prevalence. Diabetic nephropathy (DN) is a specific kind of kidney damage that occurs in 40% of patients with DM and is considered a serious complication of DM. Most modern methods for treatments aimed at slowing down the progression of DN have side effects and do not produce unambiguous positive results in the long term. This fact has encouraged researchers to search for additional or alternative treatment methods. Hyperglycemia has a negative effect on renal structures due to a number of factors, including the activation of the polyol and hexosamine glucose metabolism pathways, the activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, the accumulation of advanced glycation end products and increases in the insulin resistance and endothelial dysfunction of tissues. The above mechanisms cause the development of oxidative stress (OS) reactions and mitochondrial dysfunction, which in turn contribute to the development and progression of DN. Modern antioxidant therapies for DN involve various phytochemicals (food antioxidants, resveratrol, curcumin, alpha-lipoic acid preparations, etc.), which are widely used not only for the treatment of diabetes but also other systemic diseases. It has also been suggested that therapeutic approaches that target the source of reactive oxygen species in DN may have certain advantages in terms of nephroprotection from OS. This review describes the significance of studies on OS biomarkers in the pathogenesis of DN and analyzes various approaches to reducing the intensity of OS in the prevention and treatment of DN.

The GPx-1 Gene Variants (rs1050450) in Obesity: Association with the Risk of Obesity and the GPx Activity in Females

Background

This study aimed to investigate the GPx-1 gene polymorphism (rs1050450), the level of oxidative stress and antioxidant parameters, and the lipid profile in an obese Kurdish population in Sulaimani, Iraq.

Methods

In a case-control study,134 obese subjects and 131 normal BMI healthy individuals participated. The GPx-1 gene polymorphism was assessed by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method. The levels of biochemical and oxidative parameters were determined using photometric methods.

Results

The results showed that the fasting blood sugar (FBS), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) levels were significantly higher in obese subjects compared to the control group. Obese individuals had significantly lower levels of high-density lipoprotein cholesterol (HDL-C) than the controls. The GPx-1 activity and total antioxidant capacity (TAC) levels were significantly elevated in the obese group compared to the control group (P=0.006, and P<0.001, respectively). No significant difference was detected in genotype and allele frequencies of GPx-1 (rs1050450) between obese and normal BMI groups. However, the presence of the GPx-1 TT genotype enhanced the risk of obesity in females by 1.93-fold (95% CI 1.04-3.58, P=0.036). In the total population, the GPx activity increased in the presence of TT compared to CC+CT and CT genotypes.

Conclusion

The study indicated that obesity is linked to significantly higher levels of FBS, TG, LDL-C, TAC, and GPx activity and lower level of HDL-C. Also, we found the GPx-1 gene polymorphism was associated with the risk of obesity in females and increased the GPx activity.

Visnagin Attenuates Gestational Diabetes Mellitus in Streptozotocin-induced Diabetic Pregnant Rats via Regulating Dyslipidemia, Oxidative Stress, and Inflammatory Response

Background:

Gestational diabetes mellitus (GDM) is a condition of glucose intolerance and insulin resistance only diagnosed during pregnancy. GDM has exhibited several adverse effects on both mother and offspring. The current research focuses on discovering visnagin’s beneficial properties against the streptozotocin (STZ)-induced GDM in rats via alleviating the inflammation and oxidative stress.

Materials and Methods:

GDM was caused in the pregnant rats by the administration of 25 mg/kg of STZ by the intraperitoneal route and then treated with 20 mg/kg of visnagin for 20 consecutive days. The rats’ body weight was measured, and fasting blood glucose (FBG) status was determined using a standard glucometer. The contents of total cholesterol (TCh), triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were assessed using kits. The MDA level, total antioxidant capacity (TAC) status, and activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST) were determined using assay kits. Kits also assessed the contents of TNF-α and IL-1β. The contents of TNF-α and IL-1β effectively improved the body weight and decreased the FBG status in the GDM rats. The visnagin also decreased the TCh, TG, and LDL, and elevated the HDL content. The content of MDA was decreased and the visnagin treatment increased SOD, CAT, GST, and GPx, and the visnagin treatment increased SOD, CAT, GST, and GPx activities SOD, CAT, GST, and GPx activities. The visnagin effectively decreased the STZ-induced histopathological alterations in the pancreas.

Conclusion:

Altogether, our investigation results suggest a beneficial role visnagin against STZ-induced GDM in rats via inhibiting the inflammatory responses. Hence, it can be a talented therapeutic candidate for the successful management of GDM.

The Effects of Momordica charantia on Type 2 Diabetes Mellitus and Alzheimer's Disease

T2DM is a complex metabolic disorder characterized by hyperglycemia and glucose intolerance. It is recognized as one of the most common metabolic disorders and its prevalence continues to raise major concerns in healthcare globally. Alzheimer's disease (AD) is a gradual neurodegenerative brain disorder characterized by the chronic loss of cognitive and behavioral function. Recent research suggests a link between the two diseases. Considering the shared characteristics of both diseases, common therapeutic and preventive agents are effective. Certain bioactive compounds such as polyphenols, vitamins, and minerals found in vegetables and fruits can have antioxidant and anti-inflammatory effects that allow for preventative or potential treatment options for T2DM and AD. Recently, it has been estimated that up to one-third of patients with diabetes use some form of complementary and alternative medicine. Increasing evidence from cell or animal models suggests that bioactive compounds may have a direct effect on reducing hyperglycemia, amplifying insulin secretion, and blocking the formation of amyloid plaques. One plant that has received substantial recognition for its numerous bioactive properties is Momordica charantia (M. charantia), otherwise known as bitter melon, bitter gourd, karela, and balsam pear. M. charantia is utilized for its glucose-lowering effects and is often used as a treatment for diabetes and related metabolic conditions amongst the indigenous populations of Asia, South America, India, and East Africa. Several pre-clinical studies have documented the beneficial effects of M. charantia through various postulated mechanisms. Throughout this review, the underlying molecular mechanisms of the bioactive components of M. charantia will be highlighted. More studies will be necessary to establish the clinical efficacy of the bioactive compounds within M. charantia to effectively determine its pertinence in the treatment of metabolic disorders and neurodegenerative diseases, such as T2DM and AD.

Effects of short-distance transportation on physiological indexes, intestinal morphology, microbial community, and the transcriptome of the jejunum in weaned piglets

Transportation of livestock is unavoidable in animal production. A total of 72 piglets were randomly divided into the CON group and the TSG group, and the piglets in CON group were transported for two hours. The purpose of this study was to determine the effects of short-distance road transportation lasting 2 h on the jejunum of weaned piglets. Our results showed that compared with the control group, there was no impact on the growth performance of piglets in the transport group (P > 0.05). The concentrations of cortisol, heat shock protein (HSP)70, HSP90, C-reactive protein, interleukin (IL)-6, IL-8, IL-12, and interferon-γ and the activity of reactive oxygen species were increased in the jejunum of piglets in the transport group (P < 0.05 compared with the control group). The concentrations of glutathione peroxidase, claudin-1, occludin, and zonula occludens-1 showed no between-group differences (P > 0.05). Regarding intestinal morphology, the transport group showed infiltration of a small amount of lymphocytes into the jejunum mucosa epithelium that was accompanied by edema of the lamina propria, whereas the control group showed no obvious abnormalities. At the genus level, in the transport group, the 16S rRNA sequencing revealed a downward trend in the relative abundance of Lactobacillus and an upward trend in the relative abundance of Muribaculaceae_unclassified. There was also increased mRNA expression of genes associated with inflammation in the transport group, but the genes and pathways related to apoptosis were not activated. In summary, weaned piglets undergoing 2 h of short-distance road transportation showed stress and inflammatory reactions of the jejunum but did not exhibit oxidative damage or activation of the apoptosis pathway of the jejunum. Furthermore, the growth performance of the piglets was not affected by the trip.

Receiver Operator Characteristic (ROC) Analysis of Lipids, Proteins, DNA Oxidative Damage, and Antioxidant Defense in Plasma and Erythrocytes of Young Reproductive-Age Men with Early Stages of Type 1 Diabetes Mellitus (T1DM) Nephropathy in the Irkutsk Region, Russia

Oxidative stress plays a leading role in the pathogenesis of diabetic nephropathy. However, many aspects of oxidative stress reactions in the initial stages of this disease are not fully understood. The men cohort is of particular interest because of the severe effects of diabetes on their urogenital system. The aim of this study is to assess the intensity of lipids, proteins, DNA oxidative damage, blood antioxidant defense enzymatic, and activity of non-enzymatic components in men with type 1 diabetes mellitus (T1DM) in the early stages of diabetic nephropathy using receiver operator characteristic (ROC) analysis. This study included eighty-nine reproductive-age men in the initial stages of diabetic nephropathy (DN) and thirty-nine age- and sex-matched individuals not suffering from glycemic disorders. The DN patients were divided into two subgroups: stage 1 patients (urinary albumin < 30 mg/day and albumin/creatinine ratio < 3 mg/mmol (n = 45)) and stage 2 patients (urinary albumin 30−300 mg/day and albumin/creatinine ratio 3−30 mg/mmol (n = 44)). Levels of oxidative damage products (conjugated dienes (CDs), thiobarbituric acid reactants (TBARs), methylglyoxal (MGO), and 8-hydroxy-2’-deoxyguanosine (8-OHdG)) and antioxidants (glutathione peroxidase (GPx), glutathione S-transferases π (GSTp), glutathione reductase (GR), copper and zinc-containing superoxide dismutase 1 (SOD-1), total antioxidant status (TAS), α-tocopherol, retinol, reduced glutathione (GSH), and oxidative glutathione (GSSG)) were estimated in plasma and erythrocytes. Oxidative damage to cellular structures (higher values of median CDs (1.68 µmol/L; p = 0.003), MGO (3.38 mg/L; p < 0.001) in the stage 1 group and CDs (2.28 µmol/L; p < 0.0001), MGO (3.52 mg/L; p < 0.001), 8-OHdG (19.44 ng/mL; p = 0.010) in the stage 2 group) and changes in the antioxidant defense system (lower values of TAS (1.14 units; p = 0.011), α-tocopherol (12.17 µmol/L; p = 0.009), GPx (1099 units; p = 0.0003) and elevated levels of retinol (1.35 µmol/L; p < 0.001) in the group with stage 1; lower values of α-tocopherol (12.65 µmol/L; p = 0.033), GPx (1029.7 units; p = 0.0001) and increased levels of GR (292.75 units; p < 0.001), GSH (2.54 mmol/L; p = 0.010), GSSG (2.31 mmol/L; p < 0.0001), and retinol (0.81 µmol/L; p = 0.005) in the stage 2 group) were identified. The ROC analysis established that the following indicators have the highest diagnostic significance for stage 1 diabetic nephropathy: CDs (AUC 0.755; p < 0.0001), TBARs (AUC 0.748; p = 0.0001), MGO (AUC 0.720; p = 0.0033), retinol (AUC 0.932; p < 0.0001), GPx (AUC 0.741; p = 0.0004), α-tocopherol (AUC 0.683; p = 0.0071), and TAS (AUC 0.686; p = 0.0052) and the following for stage 2 diabetic nephropathy: CDs (AUC 0.714; p = 0.001), TBARs (AUC 0.708; p = 0.001), 8-OHdG (AUC 0.658; p = 0.0232), GSSG (AUC 0.714; p = 0.001), and GSH (AUC 0.667; p = 0.0108). We conclude that changes in indicators of damage to lipids, proteins, DNA, and the insufficiency of antioxidant defense factors already manifest in the first stage of diabetic nephropathy in men with T1DM. The ROC established which parameters have the greatest diagnostic significance for stages 1 and 2 of diabetic nephropathy, which may be utilized as additional criteria for defining men with T1DM as being in the risk group for the development of initial manifestations of the disease and thus allow for substantiating appropriate approaches to optimize preventive measures.

Importance of Microminerals for Maintaining Antioxidant Function After COVID-19-induced Oxidative Stress

Background

COVID-19 is caused by the Severe Acute Respiratory Distress Syndrome Coronavirus 2. Since the antioxidant mechanisms such as glutathione peroxidase or superoxide dismutase are downregulated during infection by the virus, there is an imbalance in the oxidant-antioxidant system. In this study we aimed to identify the effect of COVID-19 on the antioxidant defense mechanism by comparing the concentrations of antioxidants and microminerals in COVID-19 patients and healthy controls.

Methods

This cross-sectional analytical study involved 200 patients at Kasturba Hospital, Manipal University. The serum concentrations of antioxidants and minerals were determined to establish the impact of COVID-19 on antioxidants mechanism and nutrient status in COVID-19 patients.

Results

The serum concentrations of GPX (10.36 ± 2.70 ≥ 5.82 ± 1.64 mKAT/L, p < 0.0001) and copper (2192.5 ± 449.8 ≥ 782.15 ± 106.5 µg/dL, p < 0.0001) were significantly greater, and zinc (34.78 ± 4.5 ≤ 81.07 ± 10.13 µg/dL, p < 0.0001) was significantly less, in the study group than in controls. The Pearson correlation between serum SOD and zinc was significant (r = 0.491, p < 0.0001) indicating the importance of zinc in maintaining and improving SOD activity. No significant correlations were observed between copper and SOD (r = -0.089) or iron and CAT (r = -0.027).

Conclusion

Our study demonstrated the expected increase in oxidant-radical production during COVID-19 by estimating the altered concentrations of antioxidants and the minerals required to neutralize the elevated ROS. This finding is not novel but adds to the existing literature, which recommends nutritional supplementation of microminerals and antioxidants.

Comparative Study of New Biomarkers in Iraqi DM2 with and without Complications

Background

Recent research indicates that persistent inflammatory responses may contribute to the rise of diabetic nephropathy (DN) and diabetic cardiovascular disease (DCVD) in type 2 diabetes mellitus patients (DM2). Numerous molecules associated with inflammation and angiogenesis have been implicated in the development and progression of DN and DCVD, respectively.

Methods

The subjects were separated into five groups: healthy controls (n= 25), type 2 diabetes mellitus patients (n= 30), type 2 diabetes mellitus patients with nephropathy DN (n= 30), and type 2 diabetes mellitus patients with cardiovascular disease DCVD (n= 30). The blood levels of irisin, IL-8, HbA1C, urea, and creatinine were determined.

Results

In current study there was high significant increased irisin levels (p< 0.001) in DN patients than other groups and a high significant decreased IL-8 level in DCVD.

Discussion

Serum IL-8 and irisin levels may serve as early indicators of DM2 problems (DN, DCVD).

Role of c-miR-21, c-miR-126, Redox Status, and Inflammatory Conditions as Potential Predictors of Vascular Damage in T2DM Patients

The development of type 2 diabetes mellitus (T2DM) vascular complications (VCs) is associated with oxidative stress and chronic inflammation and can result in endothelial dysfunctions. Circulating microRNAs play an important role in epigenetic regulation of the etiology of T2DM. We studied 30 healthy volunteers, 26 T2DM patients with no complications, and 26 T2DM patients with VCs, to look for new biomarkers indicating a risk of developing VCs in T2DM patients. Peripheral blood samples were used to determine redox state, by measuring the endogenous antioxidant defense system (superoxide dismutase, SOD; catalase, CAT; glutathione reductase, GRd; glutathione peroxidase, GPx; and glucose-6-phosphate dehydrogenase, G6DP) and markers of oxidative damage (advanced oxidation protein products, AOPP; lipid peroxidation, LPO). Additionally, inflammatory marker levels (IL-1, IL-6, IL-18, and TNF-α), c-miR-21, and c-miR-126 expression were analyzed. T2DM patients showed the highest oxidative damage with increased GSSG/GSH ratios, LPO, and AOPP levels. In both diabetic groups, we found that diminished SOD activity was accompanied by increased CAT and decreased GRd and G6PD activities. Diabetic patients presented with increased relative expression of c-miR-21 and decreased relative expression of c-miR-126. Overall, c-miR-21, SOD, CAT, and IL-6 had high predictive values for diabetes diagnoses. Finally, our data demonstrated that IL-6 exhibited predictive value for VC development in the studied population. Moreover, c-miR-21 and c-miR-126, along with GPx and AOPP levels, should be considered possible markers for VC development in future studies.

Association of exposure to polycyclic aromatic hydrocarbons with inflammation, oxidative DNA damage and renal-pulmonary dysfunctions in barbecue makers in Southern Nigeria

BACKGROUND

Multiple organ dysfunctions have been linked to exposure to polycyclic aromatic hydrocarbons (PAH) and oxidative stress (OS), oxidative DNA damage, and inflammatory response to PAH have been implicated. The biomarkers of OS (malondialdehyde (MDA), total plasma peroxide (TPP), total antioxidant capacity (TAC), glutathione (GSH), nitric oxide (NO), oxidative stress index (OSI)); 8-hydroxy-2-deoxyguanosine (8-OHdG)); tumor necrosis factor-alpha (TNF-α)); 1-hydroxy pyrene (1-HOP)), serum and urine creatinine, uric acid (UA), estimated glomerular filtration rate (eGFR) and peak expiratory flow rate (PEFR) were assessed in barbecue makers.

METHODS

One hundred barbecue makers and 50 controls were enrolled into the study. Serum and urine creatinine, UA, TAC, MDA, GSH, NO and TPP were estimated by colorimetry, 8-OHdG and TNF-α by ELISA, PEFR using peak flow meter, 1-HOP by HPLC, eGFR and OSI by calculation.

RESULTS

Barbecue makers had lower TAC, PEFR, and higher TNF-α and OS compared to controls (p<0.05). Higher TNF-α, lipid peroxidation, and lower antioxidants were observed in barbecue makers who had worked for >5years compared to <5years (p <0.05). Increasing number of working hours was associated with higher NO, lipid peroxidation, OS and lower antioxidants in barbecue makers (p <0.05). Positive associations were observed between 1-HOP and TPP (r=0.570, p=0.000), OSI (r=0.299, p=0.035) and negative association between TAC and TNF-α (r=-0.209, p=0.037), MDA (r=-0.265, p=0.008) in barbecue makers.

CONCLUSION

Increased lipid peroxidation, OS, inflammation and depressed antioxidants and lung function observed in barbecue makers suggest increased risk of chronic lung conditions which may be associated with exposure to PAH in barbecue fumes.