The effects of selenium supplementation on biomarkers of inflammation and oxidative stress in patients with diabetic nephropathy: a randomised, double-blind, placebo-controlled trial

Plasma levels and dietary intake of minerals in patients with type 2 diabetes and chronic kidney disease: A case-control study

BACKGROUND AND AIM

Diabetic kidney disease (DKD) is the primary cause of chronic kidney disease (CKD) worldwide. Altered mineral levels leading to adverse outcomes are widely reported in diabetes but limited in DKD, in the Indian scenario, hence this study was taken up to address this issue.

METHODS

A hospital-based case-control study was taken up with 54 healthy controls (C) and 140 subjects with type 2 diabetes wherein 74 subjects with diabetes and CKD formed the DKD group, and 66 subjects with diabetes but no CKD formed the diabetic no-chronic kidney disease (DNCKD) group. High-resolution inductively coupled plasma mass spectrometry was used to evaluate the blood levels of minerals (calcium (Ca), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), and selenium (Se)), and a raw food-based food frequency questionnaire for dietary intakes. Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation (mL/min/1.73 m2) and albuminuria. Spearman's rank correlation was used to evaluate the relationship between the categorical variables.

RESULTS

The median values of plasma Ca in the DKD group were significantly lower compared with the DNCKD and C groups (10.5 mg/dL vs. 11.0 mg/dL and 11.7 mg/dL, p<0.001). Furthermore, plasma Ca levels lowered with declining kidney function, as evidenced by the eGFR and albuminuria segregation. Dietary intake of minerals did not correlate with the corresponding plasma levels. However, in the DKD group, eGFR correlated positively with the plasma levels of Ca (r= 0.422, p=0.001), Cr (r= 0.351, p=0.008), Mn (r= 0.338, p=0.011), Fe (r= 0.403, p=0.002), Cu (r= 0.274, p=0.041) and negatively with Se (r= -0.486, p<0.001).

CONCLUSION

Plasma Ca levels are lower in the DKD group with a strong positive association with eGFR, indicating its role in predicting the onset and progression of kidney function decline.

Selenium, diabetes, and their intricate sex-specific relationship

Selenium (Se) is an essential trace element, which is inserted as selenocysteine (Sec) into selenoproteins during biosynthesis, orchestrating their expression and activity. Se is associated with both beneficial and detrimental health effects; deficient supply or uncontrolled supplementation raises concerns. In particular, Se was associated with an increased incidence of type 2 diabetes (T2D) in a secondary analysis of a randomized controlled trial (RCT). In this review, we discuss the intricate relationship between Se and diabetes and the limitations of the available clinical and experimental studies. Recent evidence points to sexual dimorphism and an association of Se deficiency with gestational diabetes mellitus (GDM). We highlight the emerging evidence linking high Se status with improved prognosis in patients with T2D and lower risk of macrovascular complications.

Association of Serum Selenium and Selenoprotein P with Oxidative Stress Biomarkers in Patients with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age which is characterized by various reproductive and metabolic disorders. Oxidative stress (OS) is now recognized to be involved in the pathogenesis of PCOS which could be targeted in the management of PCOS-related complications. Selenium (Se), as an antioxidant trace element, has been shown to decrease in PCOS patients. This study aimed to investigate the relationship between the Se and selenoprotein P (SELENOP) levels with OS markers in women with PCOS. In this cross-sectional study, 125 females aged 18-45 years diagnosed with PCOS were included. Demographic, clinical, and lifestyle information of participants were obtained using the relevant questionnaires. Fasting blood samples were collected to measure biochemical parameters. Serum levels of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase activities as well as anthropometric measurements were assessed across tertiles of serum concentrations of Se and SELENOP. Higher serum levels of Se were associated with higher serum TAC levels (β=0.42, P<0.001) and erythrocytes GPx activity (β=0.28, P=0.002) as well as with lower serum TBARS levels (β= -0.26, P=0.003). Similarly, higher serum levels of SELENOP were associated with higher TAC (β=0.32, P<0.001) and erythrocyte GPx activity (β=0.30, P=0.001). SELENOP also showed an inverse association with serum levels of TBARS (β= -0.40, P<0.001). Nevertheless, erythrocytes SOD and CAT activities showed no significant relationships with serum Se and SELENOP concentrations (all P>0.05). The present study found that serum Se and SELENOP levels were inversely associated with TBARS levels and positively associated with TAC levels and erythrocytes GPx activity.

Unveiling the pathogenesis and therapeutic approaches for diabetic nephropathy: insights from panvascular diseases

Diabetic nephropathy (DN) represents a significant microvascular complication in diabetes, entailing intricate molecular pathways and mechanisms associated with cardiorenal vascular diseases. Prolonged hyperglycemia induces renal endothelial dysfunction and damage via metabolic abnormalities, inflammation, and oxidative stress, thereby compromising hemodynamics. Concurrently, fibrotic and sclerotic alterations exacerbate glomerular and tubular injuries. At a macro level, reciprocal communication between the renal microvasculature and systemic circulation establishes a pernicious cycle propelling disease progression. The current management approach emphasizes rigorous control of glycemic levels and blood pressure, with renin-angiotensin system blockade conferring renoprotection. Novel antidiabetic agents exhibit renoprotective effects, potentially mediated through endothelial modulation. Nonetheless, emerging therapies present novel avenues for enhancing patient outcomes and alleviating the disease burden. A precision-based approach, coupled with a comprehensive strategy addressing global vascular risk, will be pivotal in mitigating the cardiorenal burden associated with diabetes.

Serum Selenium and Inflammation in Individuals with Human Immunodeficiency Virus Infection

HIV infection has been linked to selenium deficiency and chronic inflammation. Both selenium deficiency and inflammation have been associated with poor health outcomes among individuals with HIV. However, the role of serum selenium levels in inflammation has not been studied among individuals with HIV. We assessed the relationship of serum selenium levels to C-reactive protein (CRP), a marker of inflammation, in individuals with HIV in Kathmandu, Nepal. In this cross-sectional study, we measured the normal serum CRP and selenium levels of 233 individuals with HIV (109 women and 124 men) using the latex agglutination turbidimetric and atomic absorption methods, respectively. We used multiple linear regression analysis in examining the association of serum selenium levels with CRP adjusting for sociodemographic and clinical parameters, including antiretroviral therapy, CD4+ T cell count, chronic diseases, and body mass index. The geometric means of CRP and selenium levels were 1.43 mg/liter and 9.65 μg/dL, respectively. Overall, serum selenium levels were inversely associated with CRP levels (β for one unit change in log selenium; β = -1.01, p = .06). Mean CRP levels significantly decreased with increasing selenium across selenium tertiles (p for trend = .019). The mean serum CRP levels were 40.8% lower in the highest selenium tertile than in the lowest. Our study suggests that high serum selenium levels may reduce serum CRP levels in individuals with HIV, although a longitudinal study is warranted to establish causality.

A systematic review and dose-response meta-analysis of the effect of selenium supplementation on serum concentration of C-reactive protein

BACKGROUND

Despite conducting new studies on the potential effect of selenium in reducing inflammation; results held contradictory weights and turns into an intriguing area of research. Concerns have been raised on this matter on hand to reach conclusive/consistent results. Therefore, this study seeks to address this scientific gap by assessing randomized controlled trials (RCTs) investigating the effect of selenium intake on C-reactive protein (CRP).

METHOD AND MATERIALS

To find all the relevant English-language RCTs, databases including SCOPUS, Web of Science, Clinical Trials.gov, PubMed, and Cochrane Library were searched with no time limit (up to June 2022). Based on the mean changes for both comparison and intervention groups, the effect sizes were calculated. Further, DerSimonian and Laird random-effects model was performed to determine the summary of overall effects and their heterogeneity.

RESULTS

Fifteen studies were selected for systematic review and thirteen studies were known to be eligible for meta-analysis. Meta-analysis results indicated a significant effect in serum CRP concentrations compared to the control group (weighted mean difference (WMD)= -0.22 mg/L 95 % confidence interval (CI): - 0.39, - 0.04; p = 0.014).

CONCLUSION

In conclusion, our study confirms the downward effect of selenium on the serum concentration of CRP. On a wider level, further research is also needed to assess the selenium effect on other inflammatory mediators.

Antioxidants for adults with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a significant risk factor for cardiovascular disease (CVD) and death. Increased oxidative stress in people with CKD has been implicated as a potential causative factor. Antioxidant therapy decreases oxidative stress and may consequently reduce cardiovascular morbidity and death in people with CKD. This is an update of a Cochrane review first published in 2012.

OBJECTIVES

To examine the benefits and harms of antioxidant therapy on death and cardiovascular and kidney endpoints in adults with CKD stages 3 to 5, patients undergoing dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies until 15 November 2022 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included all randomised controlled trials investigating the use of antioxidants, compared with placebo, usual or standard care, no treatment, or other antioxidants, for adults with CKD on cardiovascular and kidney endpoints.

DATA COLLECTION AND ANALYSIS

Titles and abstracts were screened independently by two authors who also performed data extraction using standardised forms. Results were pooled using random effects models and expressed as risk ratios (RR) or mean difference (MD) with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 95 studies (10,468 randomised patients) that evaluated antioxidant therapy in adults with non-dialysis-dependent CKD (31 studies, 5342 patients), dialysis-dependent CKD (41 studies, 3444 patients) and kidney transplant recipients (21 studies, 1529 patients). Two studies enrolled dialysis and non-dialysis patients (153 patients). Twenty-one studies assessed the effects of vitamin antioxidants, and 74 assessed the effects of non-vitamin antioxidants. Overall, the quality of included studies was moderate to low or very low due to unclear or high risk of bias for randomisation, allocation concealment, blinding, and loss to follow-up. Compared with placebo, usual care, or no treatment, antioxidant therapy may have little or no effect on cardiovascular death (8 studies, 3813 patients: RR 0.94, 95% CI 0.64 to 1.40; I² = 33%; low certainty of evidence) and probably has little to no effect on death (any cause) (45 studies, 7530 patients: RR 0.95, 95% CI 0.82 to 1.11; I² = 0%; moderate certainty of evidence), CVD (16 studies, 4768 patients: RR 0.79, 95% CI 0.63 to 0.99; I² = 23%; moderate certainty of evidence), or loss of kidney transplant (graft loss) (11 studies, 1053 patients: RR 0.88, 95% CI 0.67 to 1.17; I² = 0%; moderate certainty of evidence). Compared with placebo, usual care, or no treatment, antioxidants had little to no effect on the slope of urinary albumin/creatinine ratio (change in UACR) (7 studies, 1286 patients: MD -0.04 mg/mmol, 95% CI -0.55 to 0.47; I² = 37%; very low certainty of evidence) but the evidence is very uncertain. Antioxidants probably reduced the progression to kidney failure (10 studies, 3201 patients: RR 0.65, 95% CI 0.41 to 1.02; I² = 41%; moderate certainty of evidence), may improve the slope of estimated glomerular filtration rate (change in eGFR) (28 studies, 4128 patients: MD 3.65 mL/min/1.73 m², 95% CI 2.81 to 4.50; I² = 99%; low certainty of evidence), but had uncertain effects on the slope of serum creatinine (change in SCr) (16 studies, 3180 patients: MD -13.35 µmol/L, 95% CI -23.49 to -3.23; I² = 98%; very low certainty of evidence). Possible safety concerns are an observed increase in the risk of infection (14 studies, 3697 patients: RR 1.30, 95% CI 1.14 to 1.50; I² = 3%; moderate certainty of evidence) and heart failure (6 studies, 3733 patients: RR 1.40, 95% CI 1.11 to 1.75; I² = 0; moderate certainty of evidence) among antioxidant users. Results of studies with a low risk of bias or longer follow-ups generally were comparable to the main analyses.

AUTHORS' CONCLUSIONS

We found no evidence that antioxidants reduced death or improved kidney transplant outcomes or proteinuria in patients with CKD. Antioxidants likely reduce cardiovascular events and progression to kidney failure and may improve kidney function. Possible concerns are an increased risk of infections and heart failure among antioxidant users. However, most studies were of suboptimal quality and had limited follow-up, and few included people undergoing dialysis or kidney transplant recipients. Furthermore, the large heterogeneity in interventions hampers drawing conclusions on the efficacy and safety of individual agents.

Dose-response relationship between dietary antioxidant intake and diabetic kidney disease in the US adults with diabetes

AIM

The effects of dietary antioxidants on numerous diseases have been widely studied. However, the evidence regarding composite dietary antioxidant index (CDAI) and diabetic kidney disease (DKD) in individuals with diabetes is scarce. This study aimed to investigate the associations of CDAI with DKD and mortality in adults with diabetes mellitus (DM).

METHODS

This study utilized data from 5676 adult DM participants from the National Health and Nutrition Examination Survey (NHANES) of 2007-2018. The study followed up on death outcomes by linking the data to records from the National Death Index until December 31, 2019. CDAI was evaluated using a well-established method that included six food-sourced antioxidants derived from 24-h dietary recall: selenium, zinc, vitamin A, vitamin C, vitamin E and carotenoids. The regression models were used to estimate the relationships of CDAI with DKD and mortality in diabetic individuals.

RESULTS

The weighted mean CDAI level for the 5676 participants, which represented 31.36 million noninstitutionalized residents of the US, was 0.33. Based on CDAI quartiles, participants were classified into four groups. CDAI levels were significantly associated with age, gender, race, physical activity, estimated glomerular filtration rate and the prevalence of albuminuria, DKD and hyperuricemia. DKD occurred in 36.44% of diabetic participants, and higher CDAI levels were independently associated with a lower risk of DKD (OR 0.74, 95%CI 0.59-0.94, p for trend = 0.004) in diabetic individuals after multivariate adjustment. During a median follow-up of 67 months (38-104 months), a total of 1065 (15.80%) diabetic individuals died from all causes. Diabetic individuals with higher CDAI levels (Q4) demonstrated a lower risk of all-cause mortality (HR 0.67, 95% CI: 0.52-0.86, p for trend = 0.01) after adjusting for age, gender and race.

CONCLUSIONS

Maintaining an adequate antioxidant diet, as reflected in higher CDAI levels, may lower the risk of DKD and mortality in diabetic individuals. These findings offer a promising approach to managing diabetes and highlight the potential of food-based antioxidants as a preventative measure. Further research is warranted to explore the underlying mechanism linking dietary antioxidants and DKD and mortality in diabetic individuals.

Selenium-enriched plant foods: Selenium accumulation, speciation, and health functionality

Selenium (Se) is an essential element for maintaining human health. The biological effects and toxicity of Se compounds in humans are related to their chemical forms and consumption doses. In general, organic Se species, including selenoamino acids such as selenomethionine (SeMet), selenocystine (SeCys₂), and Se-methylselenocysteine (MSC), could provide greater bioactivities with less toxicity compared to those inorganics including selenite (Se IV) and selenate (Se VI). Plants are vital sources of organic Se because they can accumulate inorganic Se or metabolites and store them as organic Se forms. Therefore, Se-enriched plants could be applied as human food to reduce deficiency problems and deliver health benefits. This review describes the recent studies on the enrichment of Se-containing plants in particular Se accumulation and speciation, their functional properties related to human health, and future perspectives for developing Se-enriched foods. Generally, Se's concentration and chemical forms in plants are determined by the accumulation ability of plant species. Brassica family and cereal grains have excessive accumulation capacity and store major organic Se compounds in their cells compared to other plants. The biological properties of Se-enriched plants, including antioxidant, anti-diabetes, and anticancer activities, have significantly presented in both in vitro cell culture models and in vivo animal assays. Comparatively, fewer human clinical trials are available. Scientific investigations on the functional health properties of Se-enriched edible plants in humans are essential to achieve in-depth information supporting the value of Se-enriched food to humans.

Biogenic Selenium Nanoparticles in Biomedical Sciences: Properties, Current Trends, Novel Opportunities and Emerging Challenges in Theranostic Nanomedicine

Selenium is an important dietary supplement and an essential trace element incorporated into selenoproteins with growth-modulating properties and cytotoxic mechanisms of action. However, different compounds of selenium usually possess a narrow nutritional or therapeutic window with a low degree of absorption and delicate safety margins, depending on the dose and the chemical form in which they are provided to the organism. Hence, selenium nanoparticles (SeNPs) are emerging as a novel therapeutic and diagnostic platform with decreased toxicity and the capacity to enhance the biological properties of Se-based compounds. Consistent with the exciting possibilities offered by nanotechnology in the diagnosis, treatment, and prevention of diseases, SeNPs are useful tools in current biomedical research with exceptional benefits as potential therapeutics, with enhanced bioavailability, improved targeting, and effectiveness against oxidative stress and inflammation-mediated disorders. In view of the need for developing eco-friendly, inexpensive, simple, and high-throughput biomedical agents that can also ally with theranostic purposes and exhibit negligible side effects, biogenic SeNPs are receiving special attention. The present manuscript aims to be a reference in its kind by providing the readership with a thorough and comprehensive review that emphasizes the current, yet expanding, possibilities offered by biogenic SeNPs in the biomedical field and the promise they hold among selenium-derived products to, eventually, elicit future developments. First, the present review recalls the physiological importance of selenium as an oligo-element and introduces the unique biological, physicochemical, optoelectronic, and catalytic properties of Se nanomaterials. Then, it addresses the significance of nanosizing on pharmacological activity (pharmacokinetics and pharmacodynamics) and cellular interactions of SeNPs. Importantly, it discusses in detail the role of biosynthesized SeNPs as innovative theranostic agents for personalized nanomedicine-based therapies. Finally, this review explores the role of biogenic SeNPs in the ongoing context of the SARS-CoV-2 pandemic and presents key prospects in translational nanomedicine.

Effects of antioxidants on diabetic kidney diseases: mechanistic interpretations and clinical assessment

Diabetic kidney disease (DKD) is more prevalent with an increase in diabetes mellitus. Oxidative stress is a major factor in the occurrence and progression of DKD. Defending against oxidative stress and restoring antioxidant defense might be key to preventing and treating DKD. The purpose of this article is to provide an explanation of how oxidative stress affects DKD, conduct a systematic review and meta-analysis on DKD, and examine the effect of antioxidants on the disease. An analysis of 19 randomized controlled trials showed that the use of antioxidants could reduce UAE (albumin excretion rate) in patients with DKD (SMD: - 0.31; 95% CI [- 0.47, - 0.14], I² = 0%), UACR (urine albumin/creatinine ratio) (SMD: - 0.60; 95% CI [- 1.15, - 0.06], I² = 89%), glycosylated hemoglobin (hbA1c) (MD: - 0.61; 95% CI [- 1.00, - 0.21], I² = 93%) and MDA (malonaldehyde) (SMD:-1.05; 95% CI [- 1.87, - 0.23], I² = 94%), suggesting that antioxidants seemed to have therapeutic effects in patients with DKD, especially in reducing proteinuria and hbA1c. The purpose of this study is to provide new targets and ideas for drug research and clinical treatment of DKD.

The Role of Nutrition on Meta-inflammation: Insights and Potential Targets in Communicable and Chronic Disease Management

PURPOSE OF REVIEW

Chronic low-grade inflammation may contribute to the onset and progression of communicable and chronic diseases. This review examined the effects and eventual mediation roles of different nutritional factors on inflammation.

RECENT FINDINGS

Potential nutritional compounds influencing inflammation processes include macro and micronutrients, bioactive molecules (polyphenols), specific food components, and culinary ingredients as well as standardized dietary patterns, eating habits, and chrononutrition features. Therefore, research in this field is still required, taking into account critical aspects of heterogeneity including type of population, minimum and maximum intakes and adverse effects, cooking methods, physiopathological status, and times of intervention. Moreover, the integrative analysis of traditional variables (age, sex, metabolic profile, clinical history, body phenotype, habitual dietary intake, physical activity levels, and lifestyle) together with individualized issues (genetic background, epigenetic signatures, microbiota composition, gene expression profiles, and metabolomic fingerprints) may contribute to the knowledge and prescription of more personalized treatments aimed to improving the precision medical management of inflammation as well as the design of anti-inflammatory diets in chronic and communicable diseases.

Calcium dobesilate efficiency in the treatment of diabetic kidney disease through suppressing MAPK and chemokine signaling pathways based on clinical evaluation and network pharmacology

Aims: To evaluate the effectiveness and potential mechanism of calcium dobesilate (CaD) in diabetic kidney disease (DKD) patients.

Methods: We searched for available randomized controlled studies on DKD patients’ treatment with CaD through open databases. Continuous variables were expressed as standardized mean difference (SMD) with a 95% confidence interval (CI). The putative targets and possible pathways of CaD on DKD were analyzed by network pharmacology. Molecular docking was employed to verify the match between CaD and the target genes.

Results: In the meta-analysis, 42 trials were included, involving 3,671 DKD patients, of which 1,839 received CaD treatment in addition to conventional treatment, while 1,832 received conventional treatment. Compared with routine therapy, the levels of serum creatinine (Scr) and blood urea nitrogen (BUN) significantly decreased in the CaD treatment (early stage of DKD, Scr: p < 0.00001; BUN: p < 0.0001; clinical stage of DKD, Scr: p < 0.00001; BUN: p < 0.00001; kidney failure stage, Scr: p = 0.001; BUN: p = 0.004). The levels of serum cystatin C (Cys-C), urine levels of molecules reflecting kidney function (urinary albumin excretion rate (UAER) and micro glycoprotein), and inflammatory factors [hypersensitive c-reactive protein (hs-CRP)] were reduced compared with control groups, while glomerular filtration rate (GFR) was increased in patients treated with CaD for 12 weeks. CaD also showed a better effect on improving endothelial function. Network pharmacology results showed that the interaction pathway between CaD and DKD was mainly enriched in MAPK and chemokine signaling pathways. AKT1, CASP3, IGF1, MAPK8, and CCL5 might be the key targets for CaD in treating DKD.

Conclusion: Combination with CaD is effective and safe in patients with DKD. Inhibition of MAPK and chemokine signaling pathways might be vital in treating CaD in DKD patients.

Antioxidant for treatment of diabetic complications: A meta-analysis and systematic review

Antioxidants may provide a complementary treatment for patients with chronic diseases. Nevertheless, studies that have measured the effects of antioxidant on diabetes complications have provided conflicting results. This study aimed to elucidate the association between antioxidant and diabetic complications and to develop robust evidence for clinical decisions by systematic reviews and meta-analysis. PubMed, Embase, The Cochrane Library, Web of Science, Scopus databases were searched to collect clinical studies related to the efficacy of antioxidants in the treatment of diabetes complications from inception to May 5, 2021. Statistical meta-analyses were performed using the RevMan 5.4 software. Stata16 software was used to detect publication bias. The data of diabetic nephropathy (DN), diabetic nonalcoholic fatty liver disease (NAFLD), and diabetic periodontitis were collected to analyze the effect of antioxidant on diabetes and the above three complications. The meta-analysis results showed that antioxidant treatment was associated with significantly changes in the fasting plasma glucose (FPG) (standardized mean difference [SMD]: - 0.21 [95% confidence interval [CI]: - 0.33, -0.10], p < 0.001), hemoglobin A1c (HbA1c) (MD: - 0.41 [95% CI: - 0.63, -0.18], p < 0.001), total antioxidant capacity (TAC) (SMD: 0.44 [95% CI: 0.24, 0.63], p < 0.001) and malondialdehyde (MDA) (SMD: - 0.82 [95% CI: - 1.24, -0.41], p < 0.001) than the control group. Antioxidant supplements have the potential to treat three complications of diabetes. In conclusion, the meta-analysis results indicate that antioxidant treatment is effective clinically for diabetes mellitus and its complications.

Association of Novel Advanced Glycation End-Product (AGE10) with Complications of Diabetes as Measured by Enzyme-Linked Immunosorbent Assay

Advanced glycation end-products (AGEs) contribute to vascular complications and organ damage in diabetes. The unique AGE epitope (AGE10) has recently been identified in human serum using synthetic melibiose-derived AGE (MAGE). We aimed at developing ELISA for AGE10 quantification, determining whether AGE10 is present in diabetic patients (n = 82), and evaluating its association with diabetic complications. In a competitive ELISA developed, the reaction of synthetic MAGE with anti-MAGE was inhibited by physiological AGE10 present in serum. In this assay, new murine IgE anti-MAGE monoclonal antibodies, which do not recognize conventional AGEs, a synthetic MAGE used to coat the plate, and LMW-MAGE (low molecular mass MAGE) necessary to plot a standard curve were used. AGE10 was significantly higher in patients with microangiopathy, in whom it depended on treatment, being lower in patients treated with aspirin. AGE10 levels were positively correlated with estimated glomerular filtration rate (eGFR) and negatively with creatinine. As a marker of stage ≥3 chronic kidney disease or microangiopathy, AGE10 displayed moderate overall accuracy (respectively, 69% and 71%) and good sensitivity (82.6% and 83.3%) but poor specificity (58.1% and 57.8%). In conclusion, newly developed immunoassay allows for AGE10 quantification. AGE10 elevation is associated with microangiopathy while its decrease accompanies stage ≥3 chronic kidney disease.

Selenium Intake and Glycemic Control in Young Adults With Normal-Weight Obesity Syndrome

Numerous endogenous functions related to antioxidant processes, reproduction, and thyroid metabolism, as well as actions related to glycemic control, have been attributed to selenium. This study aimed to evaluate whether dietary selenium consumption is associated with variables of glycemic control in a sample of young Brazilian adults with Normal-Weight Obesity (NWO) syndrome. This was a cross-sectional study that evaluated 270 individuals with adequate body weight and excess body fat, who had their body composition assessed by dual-energy X-ray absorptiometry. Socioeconomic, health, and lifestyle questionnaires and three 24-h food records were applied. Glycemic control markers were also evaluated. The prevalence of inadequate selenium intake was analyzed by the Estimated Average Requirement (EAR) cut-point method. The prevalence of disturbances in glycemic control markers according to selenium consumption was compared by either the chi-square or the Fisher's exact test, with individuals classified according to the EAR values for selenium. The associations were evaluated by multiple linear regressions, using the backward strategy. The mean ± standard deviation (SD) age was 23.7 ± 3.3 years, and the mean ± SD daily selenium intake was 59.2 ± 26.4 μg. The overall prevalence of inadequate selenium intake was 59.2%. Individuals with selenium intakes below the EAR (≤45 μg/day) showed higher concentrations of glycated hemoglobin (HbA_1c) (P = 0.002) and a higher prevalence of disturbances in HbA_1c than those with selenium intakes above the EAR (>45 μg/day) (P = 0.001). Dietary selenium intake was directly associated with female sex (β = 19.95, 95% CI 5.00 to 34.89; P = 0.001) and weight (β = 6.69, 95% CI 0.56 to 12.81; P = 0.010), and inversely associated with the percentage of total body fat (β = -0.80, 95% CI -1.56 to -0,04; P = 0.010) and HbA_1c (β = -7.41, 95% CI -13.06 to -1.75; P = 0.010). Considering the noticeable young age of the individuals evaluated and the high frequency of disturbances in HbA_1c concentrations in those with selenium consumption below the recommendation, it is suggested that adequate dietary intake or supplementation of this micronutrient should be guaranteed to prevent future possible complications associated with glycemic control disturbances.

The Role of Antioxidants Supplementation in Clinical Practice: Focus on Cardiovascular Risk Factors

Oxidative stress may be defined as an imbalance between reactive oxygen species (ROS) and the antioxidant system to counteract or detoxify these potentially damaging molecules. This phenomenon is a common feature of many human disorders, such as cardiovascular disease. Many of the risk factors, including smoking, hypertension, hypercholesterolemia, diabetes, and obesity, are associated with an increased risk of developing cardiovascular disease, involving an elevated oxidative stress burden (either due to enhanced ROS production or decreased antioxidant protection). There are many therapeutic options to treat oxidative stress-associated cardiovascular diseases. Numerous studies have focused on the utility of antioxidant supplementation. However, whether antioxidant supplementation has any preventive and/or therapeutic value in cardiovascular pathology is still a matter of debate. In this review, we provide a detailed description of oxidative stress biomarkers in several cardiovascular risk factors. We also discuss the clinical implications of the supplementation with several classes of antioxidants, and their potential role for protecting against cardiovascular risk factors.

Nutrition, Bioenergetics, and Metabolic Syndrome

According to the World Health Organization (WHO), the global nutrition report shows that whilst part of the world’s population starves, the other part suffers from obesity and associated complications. A balanced diet counterparts these extreme conditions with the proper proportion, composition, quantity, and presence of macronutrients, micronutrients, and bioactive compounds. However, little is known on the way these components exert any influence on our health. These nutrients aiming to feed our bodies, our tissues, and our cells, first need to reach mitochondria, where they are decomposed into CO₂ and H₂O to obtain energy. Mitochondria are the powerhouse of the cell and mainly responsible for nutrients metabolism, but they are also the main source of oxidative stress and cell death by apoptosis. Unappropriated nutrients may support mitochondrial to become the Trojan horse in the cell. This review aims to provide an approach to the role that some nutrients exert on mitochondria as a major contributor to high prevalent Western conditions including metabolic syndrome (MetS), a constellation of pathologic conditions which promotes type II diabetes and cardiovascular risk. Clinical and experimental data extracted from in vitro animal and cell models further demonstrated in patients, support the idea that a balanced diet, in a healthy lifestyle context, promotes proper bioenergetic and mitochondrial function, becoming the best medicine to prevent the onset and progression of MetS. Any advance in the prevention and management of these prevalent complications help to face these challenging global health problems, by ameliorating the quality of life of patients and reducing the associated sociosanitary burden.

DIBc nano metal-organic framework improves biochemical and pathological parameters of experimental chronic kidney disease

BACKGROUND

The growing morbidity and mortality rate of chronic kidney disease (CKD) has forced researchers to find more efficient strategies for controlling this disease. Studies have proven the important role of alteration in iron, zinc and selenium metabolism in CKD pathological process. Nanotechnology, through synthetizing nano metal-organic framework (NMOF) structures, can be employed as a valuable strategy for using these trace elements as the key for modification and improvement of CKD-related pathological events. After proving the anti-diabetic property of DIBc NMOF (which contains selenium and zinc) in the previous study, the impact of this NMOF on some important biochemical and pathological parameters of CKD was evaluated in the current study.

METHODS

Knowing that diabetic nephropathy (DN) is the leading cause of CKD, male wistar rats were selected and given a high fat diet for 2 weeks and then were injected with streptozotocin (35 mg/kg) to induce DN. Six weeks after streptozotocin injection, DIBc or metformin treatment started and continued for 8 weeks.

RESULTS

Eight weeks of DIBc treatment decreased plasma fasting blood glucose, blood urea nitrogen, uric acid, malondialdehyde (MDA) and HOMA-IR index compared to DN control and metformin groups. This NMOF significantly reduced urinary albumin excretion rate, MDA and 8-isoprostane, while it increased creatinine clearance in comparison to the above-mentioned groups. Renal histo-pathological images indicated that DIBc ameliorated glomerular basement membrane thickening and wrinkling, mesangial matrix expansion and hypercellularity and presence of intra-cytoplasmic hyaline droplets in proximal cortical tubules of kidney samples.

CONCLUSION

The results showed the therapeutic effect of DIBc on important biochemical and histo-pathological parameters of CKD, so this NMOF could be regarded as a promising novel anti-CKD agent.

Effect of selenium supplementation on antioxidant markers: a systematic review and meta-analysis of randomized controlled trials

AIM

The aim of this study is the systematic review and meta-analysis of controlled trial studies to assess the antioxidant effects of selenium (Se) supplementation.

METHODS

The systematic review and meta-analysis were performed according to the previously published protocol. The PubMed, Web of Sciences, and Scopus databases were meticulously searched for relevant data, without time or language restriction, up to June 1, 2017. All clinical trials which assessed the effect of Se supplementation on antioxidant markers, including oxidative stress index (OSI), antioxidant potency composite (APC) index, plasma malonaldehyde (MDA), total antioxidant capacity (TAC), antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT)), and total antioxidant plasma (TAP), were included. The effect of Se supplementation on antioxidant markers was assessed using standardized mean difference (SMD) and 95% confidence interval (CI). The random-effect meta-analysis method was used to estimate the pooled SMD.

RESULTS

In total, 13 studies which assessed the effect of Se supplementation on antioxidant markers were included. The random-effect meta-analysis method showed that Se supplementation significantly increased GPX (SMD = 0.54; 95% CI = 0.21-0.87) and TAC (SMD = 0.39, 95% CI = 0.13, 0.66) levels and decreased MDA levels (SMD = - 0.54, 95% CI = - 0.78, - 0.30). The effect of Se supplementation on other antioxidant markers was not statistically significant (P > 0.05).

CONCLUSION

The findings showed that Se supplementation might reduce oxidative stress by increasing TAC and GPX levels and decreasing serum MDA, both of which are crucial factors for reduction of oxidative stress.

Effects of Selenium Supplementation on Metabolic Status in Patients Undergoing for Coronary Artery Bypass Grafting (CABG) Surgery: a Randomized, Double-Blind, Placebo-Controlled Trial

This study was carried out to evaluate the effects of selenium supplementation on glycemic control, lipid profiles, and biomarkers of inflammation and oxidative stress in patients undergoing for coronary artery bypass grafting (CABG) surgery. This randomized, double-blind, placebo-controlled trial was performed among 33 patients undergoing for CABG surgery, aged 40-85 years old. Subjects were randomly allocated into two groups to intake either 200 μg/day selenium supplements as selenium yeast (n = 17) or placebo (n = 16) for 4 weeks. Glycemic control, lipid profiles, and biomarkers of inflammation and oxidative stress were assessed at baseline and at the end of trial. After the 4-week intervention, selenium supplementation significantly decreased fasting plasma glucose (FPG) (β, 6.76 mg/dL; 95% CI, - 13.13, - 0.40; P = 0.03), insulin (β, - 1.14 μIU/mL; 95% CI, - 2.01, - 0.28; P = 0.01); homeostasis model of assessment-estimated insulin resistance (HOMA-IR) (β - 0.35; 95% CI, - 0.62, - 0.08; P = 0.01); and total-/HDL-cholesterol ratio (β - 0.31; 95% CI, - 0.51, - 0.09; P = 0.008); and significantly increased HDL-cholesterol levels (β, 2.72 mg/dL; 95% CI, 0.89, 4.55; P = 0.005) compared with the placebo. Moreover, selenium supplementation led to a significant reduction in high-sensitivity C-reactive protein (hs-CRP) (β, - 0.68 mg/L; 95% CI, - 1.18, - 0.17; P = 0.01) and malondialdehyde (MDA) (β, - 0.27 μmol/L; 95% CI, - 0.47, - 0.07; P = 0.009), and a significant elevation in total glutathione (GSH) levels (β, 77.33 μmol/L; 95% CI, 56.11, 98.55; P < 0.001) compared with the placebo. Selenium supplementation did not affect other metabolic profiles. Overall, our study demonstrated that selenium supplementation for 4 weeks to patients undergoing for CABG surgery had beneficial effects on FPG, insulin, HOMA-IR, total-/HDL-cholesterol ratio, HDL-cholesterol, hs-CRP, GSH, and MDA levels, but did not affect other metabolic profiles. Clinical trial registration number: http://www.irct.ir : IRCT2017090533941N22.

The protective effect and mechanism of catalpol on high glucose-induced podocyte injury

BACKGROUND

Catalpol, a natural iridoid glycoside in Rehmannia glutinosa, can alleviate proteinuria associated with diabetic nephropathy (DN), however, whether catalpol has a protective effect against podocyte injury in DN remains unclear.

METHODS

In this study, we used a high glucose (HG)-induced podocyte injury model to evaluate the protective effect and mechanism of catalpol against HG-induced podocyte injury. Cell viability was determined by the 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The levels of lactate dehydrogenase (LDH), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured by commercial assay kits. Cell apoptosis and reactive oxygen species (ROS) were determined by using flow cytometry. Tumour necrosis factor α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) levels were determined by enzyme-linked immunosorbent assay (ELISA). The protein expression levels of B-cell lymphoma-2 (Bcl-2), Bcl2-associated x (Bax), cleaved caspase-3, nicotinamide adenine dinucleotide phosphate oxidase enzyme 4 (NOX4), toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88), p38 mitogen-activated protein kinase (p38 MAPK), phosphorylated p38 MAPK (p-p38 MAPK), nuclear factor kappa B inhibitor alpha (IκBα) and phosphorylated IκBα (p-IκBα) were measured by western blotting. In addition, Bcl-2, Bax, caspase-3 and nuclear factor kappa B (NF-κB) levels were determined by immunofluorescence staining.

RESULTS

Catalpol significantly increased cell viability and decreased LDH release in HG-induced podocyte injury. Catalpol significantly decreased ROS generation, apoptosis, level of MDA, levels of inflammatory cytokine TNF-α, IL-1β, and IL-6 and increased SOD activity in HG-induced podocyte injury. Moreover, catalpol significantly decreased expression of cleaved caspase-3, Bax, NOX4, TLR4, MyD88, p-p38 MAPK, p-IκBα and NF-κB nuclear translocation, as well as increased Bcl-2 expression in HG-induced podocyte injury.

CONCLUSION

Catalpol can protect against podocyte injury by ameliorating apoptosis and inflammation. These protective effects may be attributed to the inhibition of NOX4, which alleviates ROS generation and suppression of the TLR4/MyD88 and p38 MAPK signaling pathways to prevent NF-κB activation. Therefore, catalpol could be a promising drug for the prevention of DN.

Ginsenoside Rb1 prevents steroid‑induced avascular necrosis of the femoral head through the bone morphogenetic protein‑2 and vascular endothelial growth factor pathway

At present, the molecular mechanism underlying the protective effect of Ginsenoside Rb1 remains unclear. The present study was designed to investigate whether Ginsenoside Rb1 weakened the steroid-induced avascular necrosis of the femoral head (SANFH) and to explore the possible mechanisms of the above effects. As a result, it was revealed that Ginsenoside Rb1 was protective against steroid-induced avascular necrosis and inhibited serum osteocalcin in a rat model of SANFH. Ginsenoside Rb1 reduced inflammation, oxidative stress and bone cell apoptosis in a rat model of SANFH. Furthermore, Ginsenoside Rb1 attenuated trabecula parameters, total cholesterol and low density lipoprotein/high density lipoprotein in SANFH rat. Additionally, Ginsenoside Rb1 significantly reversed alkaline phosphatase and osteocalcin activities, vascular endothelial growth factor (VEGF) receptor, VEGF, Runt related transcription factor 2 (Runx2) and bone morphogenetic protein (BMP)-2 protein expression in SANFH rat. Collectively, the present study demonstrated that Ginsenoside Rb1 attenuated SANFH through the VEGF/RUNX2/BMP-2 signaling pathway.

Effectiveness and safety of selenium supplementation for type 2 diabetes mellitus in adults: a systematic review of randomised controlled trials

BACKGROUND

The role of selenium (Se) in the management of type 2 diabetes mellitus (T2DM) remains unclear. We systematically assessed the effectiveness and safety of Se supplementation in adults with T2DM.

METHODS

MEDLINE, EMBASE and the Cochrane Library were searched up to April 2018 for randomised controlled trials (RCTs) evaluating the effectiveness of Se against a comparator on DM-related outcomes.

RESULTS

Four RCTs (241 participants) were included. In individual RCTs, Se supplementation significantly reduced fasting insulin levels [mean difference (MD) = -3.6 μIU mL^-1 ; 95% confidence interval (CI) = -6.36 to -0.84; MD = -5.8 μIU mL^-1 ; 95% CI = -9.23 to -2.37], homeostasis model of assessment-estimated insulin resistance (HOMA-IR) (MD = -1; 95% CI = -1.79 to -0.21; MD = -1.6; 95% CI, -2.58 to -0.62) and homeostasis model of assessment-estimated B cell function (HOMA-B) (MD = -13.6; 95% CI = -23.4 to -3.8; MD = -22.6; 95% CI = -36.39 to -8.81). No effects of Se were noted on most of the other outcomes of interest. None of the RCTs assessed the mortality, diabetes-related complications, non-high-density lipoprotein (non-HDL), blood pressure and health-related quality of life. The impact on HDL and fasting plasma glucose (FPG) was ambiguous. Only one adverse event (nausea) was reported as a reason for discontinuing the intervention; however, among the studies, the reporting was not accurate. Furthermore, only one RCT reported increase in FPG level in the Se group (MD = 36.38 mg dL^-1 ; 95% CI = 15.39-57.37).

CONCLUSIONS

Currently, there is no evidence to support the effectiveness of Se supplementation in the T2DM population.

Plasma Selenium and Cadmium Levels in Patients with Chronic Otitis Media in a Turkish Population and Their Relation to Inflammation Markers

Chronic otitis media (COM) is a multifactorial process, for which a clear etiology has not yet been established. The aims of the present study were to evaluate selenium (Se) and cadmium (Cd) levels in patients with COM and to analyze the correlation between Se and Cd with inflammation markers. The study population consisted of 88 participants: 45 healthy controls (group 1) and 43 patients with COM (group 2). Demographic data, Se, Cd, C-reactive protein (CRP), and white blood cell count (WBC) levels were all recorded. Se and Cd measurements were performed in a graphite furnace atomic absorption spectrophotometer (Perkin Elmer Analyst 800) using Zeeman background correction. The Se and Cd levels were compared between the groups and the correlation between Se and Cd with inflammation markers was analyzed. No statistically significant difference was determined between the groups in terms of demographic data (p > 0.05). CRP and WBC levels were significantly higher in group 2 than in group 1 (p < 0.05). Se levels were significantly lower in group 2 than in group 1, at 23.40 ± 12.08 μg/L vs. 37.31 ± 22.44 μg/L (p < 0.05). Cd levels were significantly higher in group 2 than in group 1, at 1.79 ± 1.63 μg/L vs. 0.68 ± 0.45 μg/L (p < 0.05). When all the cases were evaluated together, a statistically significant negative correlation was determined between Se and CRP (r = - 0.239, p = 0.013) and a positive correlation between Cd and CRP (r = 0.266, p = 0.006), WBC (r = 0.258, p = 0.008). Our results could propose that Se deficiency and Cd excess could play a crucial and additive role in the etiopathogenesis of COM. However, further investigations with larger numbers of patients are warranted to determine the exact role of these elements.

Consumption of Brazil nuts with high selenium levels increased inflammation biomarkers in obese women: A randomized controlled trial

OBJECTIVE

Increased inflammatory response is an important factor in the pathophysiology of obesity. The mineral selenium (Se), of which one of the main food sources is the Brazil nut, has important antioxidant and anti-inflammatory functions through the action of selenoproteins. Thus, the evaluation of the influence of this micronutrient in this context is of great relevance. The aim of this study was to evaluate the effects of Brazil nut intake with high Se concentrations on inflammatory biomarkers and its relation to Se status in obese women.

METHODS

A randomized controlled clinical trial was carried out with 55 women recruited at Clinical Hospital in São Paulo, Brazil. Patients were randomly assigned to either the Brazil nut group (BN) or the control group (CO) and followed up for 2 mo. The BN group consumed 1 unit/d of Brazil nuts (∼ 1261 μg/Se); the CO group did not receive any intervention. At baseline and after 2 mo, analysis of biochemical parameters related to Se status, oxidative stress, and inflammatory biomarkers were performed.

RESULTS

At baseline, both groups did not present Se deficiency. In the BN group, a significant increase (P < 0.05) in all Se biomarkers and in gene expression of several proinflammatory parameters (interleukin-6, tumor necrosis factor-α, and Toll-like receptors 2 and 4) were observed after the intervention period. No changes were observed for the CO group.

CONCLUSION

Although there were no changes in plasma inflammatory biomarkers levels, a significant increase in gene expression may be an indication of a proinflammatory stimulus in obesity, induced by the consumption of Brazil nuts with high Se levels.

Selenium-layered nanoparticles serving for oral delivery of phytomedicines with hypoglycemic activity to synergistically potentiate the antidiabetic effect

Diabetes mellitus (DM) remains a great challenge in treatment due to pathological complexity. It has been proven that phytomedicines and natural medicines have prominent antidiabetic effects. This work aimed to develop selenium-layered nanoparticles (SeNPs) for oral delivery of mulberry leaf and Pueraria Lobata extracts (MPE), a group of phytomedicines with significant hypoglycemic activities, to achieve a synergic antidiabetic effect. MPE-loaded SeNPs (MPE-SeNPs) were prepared through a solvent diffusion/in situ reduction technique and characterized by particle size, ζ potential, morphology, entrapment efficiency (EE) and drug loading (DL). The resulting MPE-SeNPs were 120 nm around in particle size with EE of 89.38% for rutin and 90.59% for puerarin, two marker components in MPE. MPE-SeNPs exhibited a slow drug release and good physiological stability in the simulated digestive fluid. After oral administration, MPE-SeNPs produced significant hypoglycemic effects both in the normal and diabetic rats. Ex vivo intestinal imaging and cellular examinations demonstrated that MPE-SeNPs were provided with outstanding intestinal permeability and transepithelial transport aptness. It was also revealed that MPE-SeNPs could alleviate the oxidative stress, improve the pancreatic function, and promote the glucose utilization by adipocytes. Our study provides new insight into the use of integrative nanomedicine containing phytomedicines and selenium for DM treatment.

Selenium-Rich Yeast Protects Against Aluminum-Induced Renal Inflammation and Ionic Disturbances

The aim of this study was to evaluate the protective effects of SeY (selenium-rich yeast) against Al (aluminum)-induced inflammation and ionic imbalances. Male Kunming mice were treated with Al (10 mg/kg) and/or SeY (0.1 mg/kg) by oral gavage for 28 days. The degree of inflammation was assessed by mRNA expression of inflammatory biomarkers. Ionic disorders were assessed by determining the Na⁺, K⁺, and Ca²⁺ content, as well as the alteration in ATP-modifying enzymes (ATPases), including Na⁺K⁺-ATPase, Ca²⁺-ATPase, Mg²⁺-ATPase, Ca²⁺Mg²⁺-ATPase, and the mRNA levels of ATPase's subunits in kidney. It was observed here that SeY exhibited a significant protective effect on the kidney against the Al-induced upregulation of pro-inflammatory and downregulation of anti-inflammatory cytokines. Furthermore, a significant effect of Al on the Na⁺, K⁺, Ca²⁺, and Mg²⁺ levels in kidney was observed, and Al was observed to decrease the activities of Na⁺K⁺-ATPase, Mg²⁺-ATPase, and Ca²⁺Mg²⁺-ATPase. The mRNA expression of the Na⁺K⁺-ATPase subunits and Ca²⁺-ATPase subunits was regulated significantly by Al. Notably, SeY modulated the Al-induced alterations of ion concentrations, ATPase activity, and mRNA expression of their subunits. These results suggest that SeY prevents renal toxicity caused by Al via regulation of inflammatory responses, ATPase activities, and transcription of their subunits.

Recent novel approaches to limit oxidative stress and inflammation in diabetic complications

Diabetes is considered a major burden on the healthcare system of Western and non‐Western societies with the disease reaching epidemic proportions globally. Diabetic patients are highly susceptible to developing micro‐ and macrovascular complications, which contribute significantly to morbidity and mortality rates. Over the past decade, a plethora of research has demonstrated that oxidative stress and inflammation are intricately linked and significant drivers of these diabetic complications. Thus, the focus now has been towards specific mechanism‐based strategies that can target both oxidative stress and inflammatory pathways to improve the outcome of disease burden. This review will focus on the mechanisms that drive these diabetic complications and the feasibility of emerging new therapies to combat oxidative stress and inflammation in the diabetic milieu.

Effects of Selenium Supplementation on Gene Expression Levels of Inflammatory Cytokines and Vascular Endothelial Growth Factor in Patients with Gestational Diabetes

Selenium is known to exert multiple beneficial effects including anti-inflammatory actions. The aim of the study was to evaluate the effects of selenium supplementation on gene expression levels of inflammatory cytokines and vascular endothelial growth factor (VEGF) in women with gestational diabetes (GDM). This randomized double-blind, placebo-controlled trial was carried out among 40 subjects diagnosed with GDM aged 18-40 years old. Subjects were randomly allocated into two groups to receive either 200 μg/day selenium supplements (n = 20) or placebo (n = 20) for 6 weeks. Gene expression of inflammatory cytokines and VEGF were assessed in lymphocytes of GDM women with RT-PCR method. Results of RT-PCR indicated that after the 6-week intervention, compared with the placebo, selenium supplementation downregulated gene expression of tumor necrosis factor alpha (TNF-α) (P = 0.02) and transforming growth factor beta (TGF-β) (P = 0.01), and upregulated gene expression of VEGF (P = 0.03) in lymphocytes of patients with GDM. There was no statistically significant change following supplementation with selenium on gene expression of interleukin (IL)-1β and IL-8 in lymphocytes of subjects with GDM. Selenium supplementation for 6 weeks in women with GDM significantly decreased gene expression of TNF-α and TGF-β, and significantly increased gene expression of VEGF, but did not affect gene expression of IL-1β and IL-8. Clinical trial registration number http://www.irct.ir : IRCT201612045623N95.

Selenium, Vanadium, and Chromium as Micronutrients to Improve Metabolic Syndrome

Trace metals play an important role in the proper functioning of carbohydrate and lipid metabolism. Some of the trace metals are thus essential for maintaining homeostasis, while deficiency of these trace metals can cause disorders with metabolic and physiological imbalances. This article concentrates on three trace metals (selenium, vanadium, and chromium) that may play crucial roles in controlling blood glucose concentrations possibly through their insulin-mimetic effects. For these trace metals, the level of evidence available for their health effects as supplements is weak. Thus, their potential is not fully exploited for the target of metabolic syndrome, a constellation that increases the risk for cardiovascular disease and type 2 diabetes. Given that the prevalence of metabolic syndrome is increasing throughout the world, a simpler option of interventions with food supplemented with well-studied trace metals could serve as an answer to this problem. The oxidation state and coordination chemistry play crucial roles in defining the responses to these trace metals, so further research is warranted to understand fully their metabolic and cardiovascular effects in human metabolic syndrome.

Clinical and Metabolic Response to Selenium Supplementation in Pregnant Women at Risk for Intrauterine Growth Restriction: Randomized, Double-Blind, Placebo-Controlled Trial

Data on the effects of selenium supplementation on clinical signs and metabolic profiles in women at risk for intrauterine growth restriction (IUGR) are scarce. This study was designed to assess the effects of selenium supplementation on clinical signs and metabolic status in pregnant women at risk for IUGR. This randomized double-blind placebo-controlled clinical trial was performed among 60 women at risk for IUGR according to abnormal uterine artery Doppler waveform. Participants were randomly assigned to intake either 100 μg selenium supplements as tablet (n = 30) or placebo (n = 30) for 10 weeks between 17 and 27 weeks of gestation. After 10 weeks of selenium administration, a higher percentage of women in the selenium group had pulsatility index (PI) of <1.45) (P = 0.002) than of those in the placebo group. In addition, changes in plasma levels of total antioxidant capacity (TAC) (P < 0.001), glutathione (GSH) (P = 0.008), and high-sensitivity C-reactive protein (hs-CRP) (P = 0.004) in the selenium group were significant compared with the placebo group. Additionally, selenium supplementation significantly decreased serum insulin (P = 0.02), homeostasis model of assessment-estimated insulin resistance (HOMA-IR) (P = 0.02), and homeostatic model assessment for B-cell function (HOMA-B) (P = 0.02) and significantly increased quantitative insulin sensitivity check index (QUICKI) (P = 0.04) and HDL-C levels (P = 0.02) compared with the placebo. We did not find any significant effect of selenium administration on malondialdehyde (MDA), nitric oxide (NO), fasting plasma glucose (FPG), and other lipid profiles. Overall, selenium supplementation in pregnant women at risk for IUGR resulted in improved PI, TAC, GSH, hs-CRP, and markers of insulin metabolism and HDL-C levels, but it did not affect MDA, NO, FPG, and other lipid profiles.Clinical trial registration number http://www.irct.ir : IRCT201601045623N64.

Role of Nuclear Factor Erythroid 2-Related Factor 2 in Diabetic Nephropathy

Diabetic nephropathy (DN) is manifested as increased urinary protein level, decreased glomerular filtration rate, and final renal dysfunction. DN is the leading cause of end-stage renal disease worldwide and causes a huge societal healthcare burden. Since satisfied treatments are still limited, exploring new strategies for the treatment of this disease is urgently needed. Oxidative stress takes part in the initiation and development of DN. In addition, nuclear factor erythroid 2-related factor 2 (Nrf2) plays a key role in the cellular response to oxidative stress. Thus, activation of Nrf2 seems to be a new choice for the treatment of DN. In current review, we discussed and summarized the therapeutic effects of Nrf2 activation on DN from both basic and clinical studies.