The antioxidant properties of zinc

Zinc Administration and Improved Serum Markers of Hepatic Fibrosis in Patients with Autoimmune Hepatitis

AIM

The aim of the present study is to investigate the effect of long-term zinc supplementation, which is important for the activation of various enzymes that contribute to antioxidant and antifibrotic activities, on the improvement of serum fibrotic markers in patients with autoimmune hepatitis (AIH).

METHODS

A total of 38 patients with AIH under regular treatment at our hospital who provided their consent for being treated with polaprezinc (75 mg twice daily) were included and classified into 2 groups: the patients with zinc elevation (n = 27) and the patients without zinc elevation (n = 11). Serum biomarker of fibrosis, protein expression levels of matrix metalloproteinases (MMPs), and their inhibitors (TIMPs) were evaluated.

RESULTS

A significant difference was found between the variability of serum procollagen type Ⅲ and collagen type Ⅳ-7S between the 2 groups before and after zinc administration for more than 24 months (p = 0.043 and p = 0.049). In the patients with zinc elevation, no significant changes were found in collagenase (MMP-1 and MMP-13) before and after zinc administration, whereas a significant increase in the expression of gelatinase (MMP-2 and MMP-9) was found after administration (p = 0.021 and p = 0.005). As for the relative ratio of MMPs to TIMPs, only MMP-9 to TIMP-1 showed a significant increase (p = 0.004).

CONCLUSIONS

Long-term treatment with polaprezinc has been demonstrated to safely improve serum fibrosis indices through increases in MMP-2/-9 and MMP-9/TIMP-1 and is expected to be well combined with direct antifibrotic therapies such as molecularly targeted agents.

The role of nutritional interventions in prostate cancer: A review

The high prevalence rate in conjunction with the long latency period made prostate cancer (PCa) an attractive and reasonable candidate for preventive measures. So far, several dietary and nutritional interventions have been implemented and studied with the aim of preventing the development or delaying the progression of PCa. Calorie restriction accompanied by weight loss has been shown to be associated with decreased likelihood of aggressive PCa. Supplements have played a major role in nutritional interventions. While genistein and lycopene seemed promising as preventive agents, minerals such as zinc and selenium were shown to be devoid of protective effects. The role of vitamins has been widely studied, with special emphasis on vitamins with antioxidant properties. Data related to Vitamin A and Vitamin C were rather controversial and positive effects were of insignificant magnitude. Vitamin E was associated with a decreased risk of PCa in high-risk groups like smokers. However, when it comes to Vitamin D, the serum levels might affect the risk of PCa. While deficiency of this vitamin was associated with increased risk, high serum levels imposed the risk of aggressive disease. Despite the seemingly promising effects of dietary measures on PCa, no firm recommendation could be made due to the limitations of the studies and evidence. However, the majority of these advices could be followed by the patients with the intent of living a healthy lifestyle.

Intestinal digestibility of selected minerals, growth performance and meat quality in turkeys fed diets supplemented with different sources and levels of zinc

The aim of this study was to determine whether dietary supplementation with zinc oxide nanoparticales (NP-ZnO) as a substitute for the conventional ZnO affects the intestinal digestibility of selected minerals, growth performance and meat quality in turkeys. The replacement of ZnO with NP-ZnO had no effect on the intestinal digestibility of Zn, Cu, Fe and Ca, whereas the lowest dose of supplemental Zn reduced Zn digestibility. The applied inclusion levels and sources of Zn had no effect on the growth performance (except the feed intake) of turkeys, including liveability. No differences in the relative weights of the heart, spleen and bursa of Fabricius (except the liver), or the weights of the femur and tibia were found between the dietary treatments. Neither the dose nor the source of supplemental Zn influenced carcass dressing percentage or the share of breast, thigh and drumstick muscles in the carcass. In comparison with the highest and moderate doses of Zn, the lowest inclusion level of Zn contributed to increased yellowness of breast meat (P=0.005). The analyzed doses and sources of supplemental Zn exerted varied effects on the redox status of fresh and frozen breast meat. In conclusion, the growth performance of turkeys, carcass yield and composition as well as the redox status of fresh and frozen breast meat were generally similar, regardless of the dietary source and level of Zn. The beneficial effect of Zn addition at 100 mg/kg was improved Zn and Ca digestibility, and increased redness of breast meat.

Nutritional Support for Bariatric Surgery Patients: The Skin beyond the Fat

Body contouring surgery after the massive weight loss due to bariatric surgery deals with different kinds of complications. The aim of this review is to analyze the role that some nutrients may play in tissue healing after surgery, thus helping plastic surgeons to improve the aesthetic and health outcomes in massive weight loss patients under a multidisciplinary approach. As a matter of fact, preoperative nutritional deficiencies have been shown for vitamins and minerals in a large percentage of post-bariatric patients. Preoperative deficiencies mainly concern iron, zinc, selenium, and vitamins (both fat-soluble and water-soluble), but also total protein. During the postoperative period, these problems may increase because of the patients' very low intake of vitamins and minerals after bariatric surgery (below 50% of the recommended dietary allowance) and the patients' low compliance with the suggested multivitamin supplementation (approximately 60%). In the postoperative period, more attention should be given to nutritional aspects in regard to the length of absorptive area and the percentage of weight loss.

Zinc limitation triggers anticipatory adaptations in Mycobacterium tuberculosis

Mycobacterium tuberculosis (Mtb) has complex and dynamic interactions with the human host, and subpopulations of Mtb that emerge during infection can influence disease outcomes. This study implicates zinc ion (Zn2+) availability as a likely driver of bacterial phenotypic heterogeneity in vivo. Zn2+ sequestration is part of "nutritional immunity", where the immune system limits micronutrients to control pathogen growth, but this defense mechanism seems to be ineffective in controlling Mtb infection. Nonetheless, Zn2+-limitation is an environmental cue sensed by Mtb, as calprotectin triggers the zinc uptake regulator (Zur) regulon response in vitro and co-localizes with Zn2+-limited Mtb in vivo. Prolonged Zn2+ limitation leads to numerous physiological changes in vitro, including differential expression of certain antigens, alterations in lipid metabolism and distinct cell surface morphology. Furthermore, Mtb enduring limited Zn2+ employ defensive measures to fight oxidative stress, by increasing expression of proteins involved in DNA repair and antioxidant activity, including well described virulence factors KatG and AhpC, along with altered utilization of redox cofactors. Here, we propose a model in which prolonged Zn2+ limitation defines a population of Mtb with anticipatory adaptations against impending immune attack, based on the evidence that Zn2+-limited Mtb are more resistant to oxidative stress and exhibit increased survival and induce more severe pulmonary granulomas in mice. Considering that extracellular Mtb may transit through the Zn2+-limited caseum before infecting naïve immune cells or upon host-to-host transmission, the resulting phenotypic heterogeneity driven by varied Zn2+ availability likely plays a key role during early interactions with host cells.

The lack of association between dietary antioxidant quality score with handgrip strength and handgrip endurance amongst Tehranian adults: A cross-sectional study from a Middle East country

OBJECTIVE

The association between dietary antioxidant quality score (DAQS) and handgrip strength (HS) and handgrip endurance (HE) is still unclear. We aimed to investigate whether adherence to dietary antioxidant quality score (DAQS) is associated with handgrip strength (HS) and handgrip endurance (HE) amongst adults in Tehran.

METHODS

This cross-sectional study was conducted on 270 (43.7% males, mean age 37 years and 56.3% females, mean age 35 years) apparently healthy adult subjects (53.2% were married) selected from different parts of Tehran, Iran. Dietary intake was assessed using a 168-item validated food frequency questionnaire. DAQS was calculated using antioxidant-nutrient intake. Body composition was measured using a body composition analyser. Handgrip strength and endurance were measured by a digital handgrip dynamometer. Relative muscle strength was expressed as the ratio of handgrip strength by body mass index (BMI).

RESULTS

The results showed that DAQs had no significant association with HS (P = .67, adjusted R²  = .60) and HE (P = .19, adjusted R²  = .08) after adjusting for potential confounders. However, a significant positive association was found between selenium intake and HE even after adjusting for potential confounders (P = .01, adjusted R²  = .10). After controlling for potential confounders no differences in the mean of HS (P = .29) and also HE (P = .61) amongst tertiles of DAQS was found. Positive linear association was found between vitamin C (P = .02, adjusted R²  = .53) and vitamin E (P = .03, adjusted R²  = .55) intake with relative muscle strength.

CONCLUSION

Our results revealed that no significant association between DAQS and HE and HS. It was found that more intake of selenium was positively linked to HE. Dietary intake of vitamin C and vitamin E are associated with higher relative muscle strength. It is evident that more prospective studies are needed to confirm the veracity of our results.

Supplementation of Lipoic Acid, Zinc and Clopidogrel Reduces Mortality Rate and Incidence of Ventricular Arrhythmia in Experimental Myocardial Infarction

Despite the significant advances in management of coronary heart diseases, myocardial infarction (MI) is still associated with a high mortality rate. The present study was planned to investigate the possible protective effects of the anti-oxidants lipoic acid and zinc sulfate as well as the anti-platelet clopidogrel on cardiac dysfunction in experimental isoproterenol (ISO)-induced MI, aiming at achieving useful means for protection and therapy against MI. Wistar rats of both sexes were allocated into five groups: control, untreated MI and MI pre-treated with lipoic acid, zinc, or clopidogrel. All rats were subjected to ECG recording and measurement of plasma levels of troponin I, creatine kinase-MB (CK-MB) unit, triglycerides and total cholesterol. The hearts were isolated and studied on Langendorff preparation for assessment of intrinsic cardiac activities. The results revealed that the percent mortality was markedly reduced upon pre-treatment and the total arrhythmia was also decreased except for the zinc pre-treated rats. The ST-segment elevation was significantly reduced and the plasma levels of CK-MB were only decreased in lipoic acid and clopidogrel pre-treated rats with variable hypolipidemic effect. Hearts of clopidogrel pre-treated rats showed augmented inotropic activity both basal and in response to β-adrenergic stimulation. While zinc pre-treated hearts revealed improved rate of contraction and increased myocardial flow rate. Overall, these results indicate that lipoic acid, zinc and clopidogrel were variably effective in modifying the ISO-induced MI insults and offered partial protection against experimental myocardial damage.

The effect of iron and/or zinc diet supplementation and termination of this practice on the antioxidant status of the reproductive tissues and sperm viability in rats

AIMS

The aim of this study was to investigate the effect of iron or/and zinc supplementation and termination of this treatment on the antioxidant defence of the male reproductive system and sperm viability in rats.

METHODS

The study consisted of 3 stages: I) 4-week adaptation to the diets (C-control or D-iron deficient); II) 4-week iron and/or zinc supplementation (10-times more than in the C diet of iron: CSFe, DSFe; zinc: CSZn, DSZn; or iron and zinc: CSFeZn, DSFeZn; and III) 2-week post-supplementation period (the same diets as during stage I). Parameters of antioxidant status (total antioxidant capacity and SOD, GPx, and CAT activiy), oxidative damage (lipid and protein peroxidation), and sperm viability were measured.

RESULTS

Simultaneous iron and zinc supplementation compared to iron supplementation (CSFeZn vs CSFe) increased SOD activity in the testes and decreased the level of malondialdehyde in the epididymis after stage II, and increased the percentage of live sperm after stage III. After discontinuation of the iron and zinc supplementation and a return to the control diet, the following was observed a decrease of SOD activity in the testes and GPx activity in the epididymis, and a increase malondialdehyde concentration in prostates. After stage III, in DSFeZn vs DSFe rats, an increase of SOD and CAT activity in the epididymis was found.

CONCLUSION

Zinc supplementation simultaneous with iron may protect the male reproductive system against oxidative damage induced by high doses of iron and may have a beneficial effect on sperm viability. The effect of this supplementation was observed even two weeks after the termination of the intervention.

Towards Zero Zinc Oxide: Feeding Strategies to Manage Post-Weaning Diarrhea in Piglets

Simple Summary

Zinc oxide (ZnO) supplementation at pharmacological doses in post-weaning piglets is a consolidated practice that allows efficient control of post-weaning diarrhea (PWD), a condition exacerbated by Escherichia coli F4 (K88) infections. Far from being completely elucidated, the multifactorial ZnO mechanism of action is in all likelihood exerted at the gastrointestinal level. However, increasing environmental concerns are arising from prolonged ZnO use. This article reviews the utilization of ZnO in piglets, the biological rationale behind its powerful activity, and the emerging threats that are leading towards a significant reduction in its use. Finally, a wide analysis of the strengths and weaknesses of innovative alternative strategies to manage PWD at the nutritional level is given.

Abstract

Zinc oxide (ZnO) at pharmacological doses is extensively employed in the pig industry as an effective tool to manage post-weaning diarrhea (PWD), a condition that causes huge economic losses because of its impact on the most pivotal phase of a piglet’s production cycle. In a multifactorial way, ZnO exerts a variety of positive effects along the entire gastrointestinal tract by targeting intestinal architecture, digestive secretions, antioxidant systems, and immune cells. ZnO also has a moderate antibacterial effect against Escherichia coli F4 (K88), the main causative agent of PWD. However, the environmental impact of ZnO and new emerging threats are posing serious questions to the sustainability of its extensive utilization. To work towards a future free from pharmacological ZnO, novel nutritional approaches are necessary, and many strategies have been investigated. This review article provides a comprehensive framework for ZnO utilization and its broad mode of action. Moreover, all the risks related to pharmacological ZnO levels are presented; we focus on European institutions’ decisions subsequently. The identification of a novel, complete solution against PWD should be accompanied by the adoption of holistic strategies, thereby combining good management practices to feeding approaches capable of mitigating Escherichia coli F4 (K88) infections and/or lowering ZnO utilization. Promising results can be obtained by adjusting diet composition or employing organic acids, natural identical compounds, polyphenol-rich extracts, prebiotics, and probiotics.

Fighting Bisphenol A-Induced Male Infertility: The Power of Antioxidants

Bisphenol A (BPA), a well-known endocrine disruptor present in epoxy resins and polycarbonate plastics, negatively disturbs the male reproductive system affecting male fertility. In vivo studies showed that BPA exposure has deleterious effects on spermatogenesis by disturbing the hypothalamic–pituitary–gonadal axis and inducing oxidative stress in testis. This compound seems to disrupt hormone signalling even at low concentrations, modifying the levels of inhibin B, oestradiol, and testosterone. The adverse effects on seminal parameters are mainly supported by studies based on urinary BPA concentration, showing a negative association between BPA levels and sperm concentration, motility, and sperm DNA damage. Recent studies explored potential approaches to treat or prevent BPA-induced testicular toxicity and male infertility. Since the effect of BPA on testicular cells and spermatozoa is associated with an increased production of reactive oxygen species, most of the pharmacological approaches are based on the use of natural or synthetic antioxidants. In this review, we briefly describe the effects of BPA on male reproductive health and discuss the use of antioxidants to prevent or revert the BPA-induced toxicity and infertility in men.

The testicular protective effects of standardised hydroalcoholic extract of Ziziphus jujuba Mill against adriamycin-induced toxicity

In this study, because of the anti-inflammatory and antioxidant effect of the Ziziphus jujuba (ZJ), we assessed the protective properties of the ZJ extract against testis toxicity caused by Adriamycin in the rat. Twenty rats were grouped into (a) control, (b) Adriamycin, (c) ZJ group and (d) treatment group in which Adriamycin was administrated and the ZJ hydroalcoholic extract was used for three weeks. On the 21st day, two testes were removed to determine the oxidation markers and pathological evaluation. The levels of sex hormones were determined. Epididymis also was crushed, and its spermatozoa were evaluated as concentration, motility and normality. Adriamycin increased oxidative stress markers as well as Luteinising hormone, and follicle-stimulating hormone and decreased testosterone levels compared to control. In the treated group, the levels of the above markers improved. The decreased number and motility of spermatozoa in treatment group increased, and the increased rate of abnormal spermatozoa in this group decreased. Pathological evaluations also show the healing process of damaged testicular tissue in the group receiving the ZJ extract. The ZJ extract relatively improves oxidative stress, sperm characteristics, hormonal alternation and pathological changes. These findings reveal the probable role of ZJ effective compounds in repairing tissue damage.

Microstructural and chemical properties of gari and eba: Food products from cassava (Manihot esculenta Cranz)

The microstructure, elemental distribution and rheological behavior of two varieties of gari and their doughs (eba) were investigated. SEM analysis revealed a concave structure with fibre-strands, which were altered after processing to eba. Gari nanostructures which were analyzed with TEM were not affected when processed to eba. SEM-EDX microanalysis revealed the presence of magnesium, potassium, calcium, manganese, iron, and cobalt for both varieties, which were altered after processing. Rheological analysis revealed increases in storage modulus, with concomitant loss factor for both varieties. Their viscosity decreased with increasing shear rate. GC-MS analysis revealed the presence of sugar, fatty acids, and steroids in both varieties, which were also affected after processing. Both varieties showed significant free radical scavenging activity which was not affected after processing. These results indicate that the conclave microstructure, elements and phytochemicals of both gari varieties are altered after processing to eba, with their nanostructure and antioxidant activity unaltered.

Arsenite induce neurotoxicity of common carp: Involvement of blood brain barrier, apoptosis and autophagy, and subsequently relieved by zinc (Ⅱ) supplementation

Arsenic pollution is a common threat to aquatic ecosystems. The effects of chronic exposure to arsenite on the brains of aquatic organisms are unknown. This study was designed to evaluate arsenic-induced brain damage in common carp (Cyprinus carpio) and the ameliorating effects of divalent zinc ion (Zn2+) supplementation from the aspects of oxidative stress (OxS), tight junction (TJ), apoptosis and autophagy. After arsenite exposure (2.83 mg/L) for 30 days, oxidative damage to the brain was determined, as indicated by inhibited antioxidants system (catalase-superoxide dismutase system, and glutathione system) and elevated levels of biomacromolecule peroxidation (malondialdehyde and 8-hydroxydeoxyguanosine). Moreover, we also found functional damage to the brain as suggested by injuries to the blood-brain barrier (decreases in tight junction) and nerve conduction (depletion of AChE). Mechanisticly, apoptotic and autophagic cell death were indicated by typical morphologies including karyopyknosis and autophagosome, accompanying by key bio-indicators (Bcl-2, caspase and autophagy related gene family proteins). In contrast, the coadministration of Zn2+ (1 mg/L) with arsenite effectively alleviated this damage as suggested by the recovery of the aforementioned bioindicators. This study provides new insight into the brain toxicity caused by arsenite and suggests the application of zinc preparations in the aquatic pollution of arsenic.

Altered intestinal microflora and barrier injury in severe acute pancreatitis can be changed by zinc

To investigate the effect of zinc (Zn) supplementation on intestinal microflora changes and bacterial translocation in rats with severe acute pancreatitis (SAP), the rats were divided into the sham surgery (SS), SAP, SS + Zn, and SAP + Zn groups. Saline (0.1 mL/100g) and 5% sodium taurocholate were injected into the pancreaticobiliary duct of the rats in the SS and SAP + Zn groups, respectively. Intraperitoneal injection of 5 mg/kg Zn was performed immediately after injecting saline or 5% sodium taurocholate into the rats in both groups. Serum amylase and Zn levels, plasma endogenous endotoxin, intestinal permeability, and the positive rate of intestinal bacterial translocation were detected, haematoxylin and eosin (H&E) staining was performed, and the pancreatic tissue scores were calculated for each group. In addition, immunohistochemical (IHC) staining was performed to evaluate the expression of IL-1β and TNF-α. Real-time fluorescence quantitative PCR was used to quantify the gene copy numbers of Escherichia, Bifidobacterium, and Lactobacillus in the cecum. The levels of amylase and plasma endotoxin in the SAP group were significantly higher than those in the SS and SS + Zn groups. Intestinal mucosal permeability and intestinal bacterial translocation in the liver, pancreas, and mesenteric lymph nodes were increased in the SAP group. However, the levels of amylase and plasma endotoxin were decreased as a result of zinc supplementation in the SAP group. The expression of IL-1β and TNF-α was also reduced to a greater degree in the SAP + Zn group than in the SAP group. Moreover, alleviated intestinal mucosal permeability and intestinal bacterial translocation in the liver, pancreas, and mesenteric lymph nodes were found in the SAP + Zn group. The results of real-time quantitative PCR showed that the gene copy number of Escherichia increased with time, and the gene copy numbers of Lactobacillus and Bifidobacterium decreased over time. Zn supplementation prevented the release of TNF-α and IL-1β, alleviated intestinal permeability and endotoxemia, reduced bacterial translocation, and inhibited changes in pathogenic intestinal flora in rats with SAP.

Zinc Gluconate Induces Potentially Cancer Chemopreventive Activity in Barrett's Esophagus: A Phase 1 Pilot Study

BACKGROUND

Chemopreventive effects of zinc for esophageal cancer have been well documented in animal models. This prospective study explores if a similar, potentially chemopreventive action can be seen in Barrett's esophagus (BE) in humans.

AIMS

To determine if molecular evidence can be obtained potentially indicating zinc's chemopreventive action in Barrett's metaplasia.

METHODS

Patients with a prior BE diagnosis were placed on oral zinc gluconate (14 days of 26.4 mg zinc BID) or a sodium gluconate placebo, prior to their surveillance endoscopy procedure. Biopsies of Barrett's mucosa were then obtained for miRNA and mRNA microarrays, or protein analyses.

RESULTS

Zinc-induced mRNA changes were observed for a large number of transcripts. These included downregulation of transcripts encoding proinflammatory proteins (IL32, IL1β, IL15, IL7R, IL2R, IL15R, IL3R), upregulation of anti-inflammatory mediators (IL1RA), downregulation of transcripts mediating epithelial-to-mesenchymal transition (EMT) (LIF, MYB, LYN, MTA1, SRC, SNAIL1, and TWIST1), and upregulation of transcripts that oppose EMT (BMP7, MTSS1, TRIB3, GRHL1). miRNA arrays showed significant upregulation of seven miRs with tumor suppressor activity (-125b-5P, -132-3P, -548z, -551a, -504, -518, and -34a-5P). Of proteins analyzed by Western blot, increased expression of the pro-apoptotic protein, BAX, and the tight junctional protein, CLAUDIN-7, along with decreased expression of BCL-2 and VEGF-R2 were noteworthy.

CONCLUSIONS

When these mRNA, miRNA, and protein molecular data are considered collectively, a cancer chemopreventive action by zinc in Barrett's metaplasia may be possible for this precancerous esophageal tissue. These results and the extensive prior animal model studies argue for a future prospective clinical trial for this safe, easily-administered, and inexpensive micronutrient, that could determine if a chemopreventive action truly exists.

Zinc Supplementation Prevented Type 2 Diabetes-Induced Liver Injury Mediated by the Nrf2-MT Antioxidative Pathway

Zinc is an essential trace element that is often reduced under the type 1 diabetic condition. Previous studies demonstrated that zinc deficiency enhanced type 1 diabetes-induced liver injury and that zinc supplementation significantly helped to prevent this. Due to the differences in pathogenesis between type 1 and type 2 diabetes, it is unknown whether zinc supplementation can induce a beneficial effect on type 2 diabetes-induced liver injury. This possible protective mechanism was investigated in the present study. A high-fat diet, along with a one-time dose of streptozotocin, was applied to metallothionein (MT) knockout mice, nuclear factor-erythroid 2-related factor (Nrf) 2 knockout mice, and age-matched wild-type (WT) control mice, in order to induce type 2 diabetes. This was followed by zinc treatment at 5 mg/kg body weight given every other day for 3 months. Global metabolic disorders of both glucose and lipids were unaffected by zinc supplementation. This induced preventive effects on conditions caused by type 2 diabetes like oxidative stress, apoptosis, the subsequent hepatic inflammatory response, fibrosis, hypertrophy, and hepatic dysfunction. Additionally, we also observed that type 2 diabetes reduced hepatic MT expression, while zinc supplementation induced hepatic MT expression. This is a crucial antioxidant. A mechanistic study showed that MT deficiency blocked zinc supplementation-induced hepatic protection under the condition of type 2 diabetes. This suggested that endogenous MT is involved in the hepatic protection of zinc supplementation in type 2 diabetic mice. Furthermore, zinc supplementation-induced hepatic MT increase was unobserved once Nrf2 was deficient, indicating that Nrf2 mediated the upregulation of hepatic MT in response to zinc supplementation. Results of this study indicated that zinc supplementation prevented type 2 diabetes-induced liver injury through the activation of the Nrf2-MT-mediated antioxidative pathway.

Varicocoele and oxidative stress: New perspectives from animal and human studies

BACKGROUND

Varicocoele (VCL), one of the main causes of male subfertility, negatively affects testicular function. Due to limited access to human testicular tissue, animal model studies have been used to evaluate molecular and, recently, epigenetic changes attributed to pathophysiology induced by VCL.

OBJECTIVES

This review aims to provide an update on the latest findings regarding the link between VCL-induced biochemical stress and molecular changes in germ cells and spermatozoa. Endocrine and antioxidant status, testicular chaperone-specific hemostasis failure, altered testicular ion balance, metabolic disorders, and altered carbon cycling during spermatogenesis are among the many features that will be presented.

DISCUSSION

Literature review coupled with our own findings suggests that ionic imbalance, hypoxia, hyperthermia, and altered blood flow could lead to severe chronic oxidative and nitrosative stress in patients with VCL leading to defective spermatogenesis and impairment of the integrity of all sperm cell components and compartments down to the epigenetic information they carry.

CONCLUSION

Since oxidative stress is an important feature of the reproductive pathology of VCL, therapeutic strategies such as the administration of appropriate antioxidants could be undertaken as a complementary non-invasive treatment line.

Does underweight amplify the relationship between short-term particulate matter exposure and blood pressure in children and adolescents: a large cross-sectional study in a metropolis of China

Overweight/obesity modified the effects of ambient particulate matter (PM) exposure on blood pressure (BP). This study aims to assess whether interaction of underweight and short-term PM exposure on BP exists in Chinese children. A cross-sectional analysis including 144,513 children aged 6 to 17 years in 2016 Health Promotion Program for Children and Adolescents of Suzhou, China, was performed. Daily concentrations of inhalable PM (PM₁₀) and fine PM (PM_2.5) were extracted from air monitoring stations close to students' schools. We applied generalized linear mixed-effects models to estimate the interactions. Estimated changes (95% confidence intervals (CIs)) of systolic BP (SBP), diastolic BP (DBP), and odds ratios (ORs) (95% CIs) for prevalence of HBP were calculated. Significant interactions between PM and underweight on BP and prevalence of high BP (HBP) were observed. For example, at lag 6, the ORs (95% CIs) for HBP by each 10 μg/m³ changes of PM_2.5 were 1.066 (1.039, 1.093) and 1.036 (1.028, 1.043) among underweight and normal weight subjects, respectively; these values for PM₁₀ were 1.048 (1.031, 1.065) and 1.025 (1.021, 1.030). At lag 5, the increases of SBP for PM_2.5 were 0.32 (95% CI 0.22, 0.43) mmHg and 0.23 (95% CI 0.29, 0.26) mmHg, while changes of DBP were 0.27 (95% CI 0.18, 0.35) mmHg and 0.19 (95% CI 0.16, 0.21) mmHg among underweight and normal weight subjects, respectively. Stratified analyses demonstrated that these interactions were only obtained in males. Effects of short-term PM exposure on BP and prevalence of HBP are enhanced in underweight children and adolescents.

High dietary copper induces oxidative stress and leads to decreased egg quality and reproductive performance of Chinese Yellow broiler breeder hens

The objective of this study was to investigate the effects of dietary copper (Cu) on production, egg quality, and hatchability of Chinese Yellow broiler breeder hens and growth performance of their offspring. A total of 576 30-week-old hens were randomly allotted into 6 groups, each with 6 replicates (8 cages for each replicate with 2 birds per cage). The basal diet contained 3.50 mg/kg Cu, and the other 5 treatment diets contained 8.5, 13.5, 23.5 43.5, and 83.5 mg/kg Cu, respectively, additionally supplemented with Cu on the basal diet. The trial lasted for 15 wk. Qualified egg rate of birds fed 23.5 or 83.5 mg/kg Cu was significantly decreased (P < 0.05) compared with those given 3.5, 8.5, or 13.5 mg/kg Cu. Plasma malondialdehyde concentration showed quadratic effect (P = 0.002) which that decreased first then increased with dietary Cu increased. Highest values of Cu content and hepatic activity of Cu-ATPase occurred in hens fed 83.5 mg/kg dietary Cu with linear (P = 0.001) and quadratic (P = 0.001) effects. Shell strength and proportion on 18th day of live embryos of hens fed 13.5 mg/kg Cu were the greatest compared with other groups respectively (P < 0.05); rate of qualified eggs for hatch and hatchability of fertilized eggs of hens fed 83.5 mg/kg Cu were the least (P < 0.05). In conclusion, both inadequate (3.5 mg/kg diet) and excess (83.5 mg/kg) of dietary Cu can induce oxidative stress in hens and lead to decreased egg quality. Hatchability and growth performance of offspring were decreased when breeder hens were fed excess Cu in spite of greater hatching weight. The appropriate dietary Cu level for Chinese Yellow broiler breeder hens during the egg-laying period is 15.7 to 21.2 mg/kg (1.81-2.44 mg Cu fed per day) when based on Cu level and Cu-ATPase activity in the liver. This dietary Cu requirement is approximately doubled (∼40 mg/kg, ∼4.60 mg Cu per bird per day) for maximal response of eggshell thickness.

Endogenous zinc nanoparticles in the rat olfactory epithelium are functionally significant

The role of zinc in neurobiology is rapidly expanding. Zinc is especially essential in olfactory neurobiology. Naturally occurring zinc nanoparticles were detected in olfactory and nasal respiratory epithelia and cilia in animals. The addition of these nanoparticles to a mixture of odorants, including ethyl butyrate, eugenol, and carvone, considerably increased the electrical responses of the olfactory sensory receptors. Studies of these nanoparticles by ransmission electron microscopy (TEM) and selected area electron diffraction revealed metal elemental crystalline zinc nanoparticles 2–4 nm in diameter. These particles did not contain oxidized zinc. The enhancement of the odorant responses induced by the endogenous zinc nanoparticles appears to be similar to the amplification produced by engineered zinc nanoparticles. Zinc nanoparticles produce no odor response but increase odor response if mixed with an odorant. These effects are dose-dependent and reversible. Some other metal nanoparticles, such as copper, silver, gold, and platinum, do not have the effects observed in the case of zinc nanoparticles. The olfactory enhancement was observed in young and mature mouse olfactory epithelium cultures, in the dissected olfactory epithelium of rodents, and in live conscious dogs. The physiological significance of the detected endogenous metal nanoparticles in an animal tissue has been demonstrated for the first time. Overall, our results may advance the understanding of the initial events in olfaction.

Dietary supplements in the management of varicocele-induced infertility: A review of potential mechanisms

Varicocele is a main cause of lower production of spermatozoon and infertility with multiple pathophysiological mechanisms. In the past decades, the use of dietary supplements has significantly increased due to both the modern lifestyle and the food shortages of the industrialised countries. The purpose of this review paper is to collect scientific evidences from basic and clinical studies which support the use of dietary supplements to define the clinical framework for patients with varicocele. In the present review, we used keywords such as dietary supplements, varicocele, male infertility, oxidative stress, DNA fragmentation, sperm parameters to find the proper articles. The standard search biomedical engines were used for seeking the papers. The use of dietary supplements such as minerals, vitamins and antioxidants has an essential role in the prevention and treatment of varicocele by increasing the levels of antioxidant enzymes (e.g. peroxidase, superoxide dismutase and catalase) and decreasing the levels of inflammatory markers (e.g. tumour necrosis factor-α, interleukin-6 and interleukin-1) in testis. According to the results, the dietary supplements may alleviate the spermatogenesis in varicocele patients through different mechanisms such as suppression of stress oxidative and inflammation in testicular tissue.

Subcellular localised small molecule fluorescent probes to image mobile Zn2

Zn2+, as the second most abundant d-block metal in the human body, plays an important role in a wide range of biological processes, and the dysfunction of its homeostasis is related to many diseases, including Type 2 diabetes, Alzheimer's disease and prostate and breast cancers. Small molecule fluorescent probes, as effective tools for real-time imaging, have been widely used to study Zn2+ related processes. However, the failure to control their localisation in cells has limited their utility somewhat, as they are generally incapable of studying individual processes in a specific cellular location. This perspective presents an overview of the recent developments in specific organelle localised small molecule fluorescent Zn2+ probes and their application in biological milieu, which could help to extend our understanding of the mechanisms that cells use to respond to dysfunction of zinc homeostasis and its roles in disease initiation and development.

Impact of dietary zinc oxide nanoparticles on selected serum biomarkers, lipid peroxidation and tissue gene expression of antioxidant enzymes and cytokines in Japanese quail

Background

The use of zinc oxide in the form of nanoparticles (ZnO-NPs) is of great benefit due to its potent effectiveness and higher bioavailability compared to zinc oxide. This study aimed to investigate the impact of dietary inclusion of different doses of ZnO-NPs on selected serum biomarkers, lipid peroxidation and tissue gene expression of antioxidant enzymes and cytokines in Japanese quail. Eighty Japanese quails (Coturnix japonica) (45 days old) were randomly divided into four groups (20 birds for each) with 4 replicates (5 birds each). Birds in the first group were fed a basal diet alone and served as a control (C). Birds in groups 2–4 were fed the basal diet supplemented with ZnO-NPs at doses of 15 mg/kg, 30 mg/kg and 60 mg/kg for a period of 60 days. At the end of the experiment, all birds were sacrificed to collect blood in a plain vacutainer, whereas liver and brain tissues were stored frozen at -80 °C. The obtained sera were used for the analysis of selected biochemical parameters, whereas tissue homogenates were used for the estimation of zinc, oxidative stress biomarkers and gene expression of selected antioxidant enzymes and cytokines.

Results

ZnO-NPs (30 and 60 mg/kg) induced a significant decrease in serum triacylglycerol (TAG) compared to the control. ZnO-NPs did not affect the activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein, albumin, globulin and tissue zinc concentrations but reduced the malondialdehyde (MDA) levels compared to the control. The liver retained a higher zinc concentration than that of brain tissue. In a dose-dependent manner, ZnO-NPs upregulated the mRNA levels of antioxidant enzymes (superoxide dismutase: SOD1; catalase: CAT; glutathione peroxidase-1: GPX 1) and pro-inflammatory cytokines (interferon α: IFN-α; interleukin 6: IL-6) in liver and brain tissues.

Conclusion

The current study suggests the inclusion of ZnO-NPs, particularly 60 mg/kg, in the diet of Japanese quails to improve antioxidant and immune status.

The role of reactive oxygen species in the pathogenesis and treatment of retinal diseases

Reactive oxygen species (ROS) normally play an important physiological role in health regulating cellular processes and signal transduction. The amount of ROS is usually kept in fine balance with the generation of ROS largely being offset by the body's antioxidants. A tipping of this balance has increasingly been recognised as a contributor to human disease. The retina, as a result of its cellular anatomy and physical location, is a potent generator of ROS that has been linked to several major retinal diseases. This review will provide a summary of the role of oxidative stress in the pathogenesis of diabetic retinopathy, age-related macular degeneration, myopia, retinal vein occlusion, retinitis pigmentosa and retinopathy of prematurity. Therapies aimed at controlling oxidative stress in these diseases are also examined.

Inflammation in Obesity-Related Complications in Children: The Protective Effect of Diet and Its Potential Role as a Therapeutic Agent

Obesity is a growing health problem in both children and adults, impairing physical and mental state and impacting health care system costs in both developed and developing countries. It is well-known that individuals with excessive weight gain frequently develop obesity-related complications, which are mainly known as Non-Communicable Diseases (NCDs), including cardiovascular disease, type 2 diabetes mellitus, metabolic syndrome, non-alcoholic fatty liver disease, hypertension, hyperlipidemia and many other risk factors proven to be associated with chronic inflammation, causing disability and reduced life expectancy. This review aims to present and discuss complications related to inflammation in pediatric obesity, the critical role of nutrition and diet in obesity-comorbidity prevention and treatment, and the impact of lifestyle. Appropriate early dietary intervention for the management of pediatric overweight and obesity is recommended for overall healthy growth and prevention of comorbidities in adulthood.

COVID‐19 and obesity in childhood and adolescence: a clinical review

Objetivo

Identificar fatores que contribuem para o aumento da suscetibilidade e gravidade da COVID‐19 em crianças e adolescentes obesos e suas consequências para a saúde.

Fontes de dados

Estudos publicados entre 2000 e 2020 nas bases de dados PubMed, Medline, Scopus, SciELO e Cochrane.

Síntese dos dados

A obesidade é uma comorbidade altamente prevalente em casos graves de COVID‐19 em crianças e adolescentes e o isolamento social pode levar ao aumento do acúmulo de gordura. Tecido adiposo excessivo, déficit de massa magra, resistência à insulina, dislipidemia, hipertensão, altos níveis de citocinas pró‐inflamatórias e baixa ingestão de nutrientes essenciais são fatores que comprometem o funcionamento dos órgãos e sistemas no indivíduo obeso. Esses fatores estão associados a danos nos sistemas imunológico, cardiovascular, respiratório e urinário, juntamente com a modificação da microbiota intestinal (disbiose). Na infecção por SARS‐CoV‐2, essas alterações orgânicas causadas pela obesidade podem aumentar a necessidade de assistência ventilatória, risco de tromboembolismo, taxa de filtração glomerular reduzida, alterações na resposta imune inata e adaptativa e perpetuação da resposta inflamatória crônica.

Conclusões

A necessidade de isolamento social pode ter o efeito de causar ou agravar a obesidade e suas comorbidades e pediatras precisam estar cientes desse problema. Diante de crianças com suspeita ou confirmação de COVID‐19, os profissionais de saúde devem 1) diagnosticar o excesso de peso; 2) aconselhar sobre cuidados de saúde em tempos de isolamento; 3) fazer a triagem de comorbidades, garantindo que o tratamento não seja interrompido; 4) medir os níveis de imunonutrientes; 5) orientar a família respeitando as especificidades da situação; e 6) encaminhamento a unidades qualificadas para cuidar de crianças e adolescentes obesos, quando necessário.

COVID-19 and obesity in childhood and adolescence: a clinical review

OBJECTIVE

To identify factors that contribute to the increased susceptibility and severity of COVID-19 in obese children and adolescents, and its health consequences.

SOURCES

Studies published between 2000 and 2020 in the PubMed, MEDLINE, Scopus, SciELO, and Cochrane databases.

SUMMARY OF FINDINGS

Obesity is a highly prevalent comorbidity in severe cases of COVID-19 in children and adolescents; social isolation may lead to increase fat accumulation. Excessive adipose tissue, deficit in lean mass, insulin resistance, dyslipidemia, hypertension, high levels of proinflammatory cytokines, and low intake of essential nutrients are factors that compromise the functioning of organs and systems in obese individuals. These factors are associated with damage to immune, cardiovascular, respiratory, and urinary systems, along with modification of the intestinal microbiota (dysbiosis). In severe acute respiratory syndrome coronavirus 2 infection, these organic changes from obesity may increase the need for ventilatory assistance, risk of thromboembolism, reduced glomerular filtration rate, changes in the innate and adaptive immune response, and perpetuation of the chronic inflammatory response.

CONCLUSIONS

The need for social isolation can have the effect of causing or worsening obesity and its comorbidities, and pediatricians need to be aware of this issue. Facing children with suspected or confirmed COVID-19, health professionals should 1) diagnose excess weight; 2) advise on health care in times of isolation; 3) screen for comorbidities, ensuring that treatment is not interrupted; 4) measure levels of immunonutrients; 5) guide the family in understanding the specifics of the situation; and 6) refer to units qualified to care for obese children and adolescents when necessary.

Combined effects of dietary zinc at 3 years of age and obesity at 7 years of age on the serum uric acid levels of Korean children

BACKGROUND/OBJECTIVES

To assess the longitudinal associations of the antioxidant capacity of zinc and body mass index (BMI) with serum uric acid (SUA) in South Korean children.

SUBJECTS/METHODS

Using follow-up data from the Ewha Birth and Growth Cohort, we included subjects who were seen at 3 and 7 years of age (n = 183; 90 boys, 93 girls). Daily zinc intake and BMI were assessed at 3 and 7 years of age. SUA measured at 7 years was used as the outcome variable. Using a general linear model, the effects of dietary zinc intake and BMI on SUA were assessed. We also assessed the combined effect of early dietary zinc intake and BMI on SUA in children.

RESULTS

The dietary zinc intake at 3 years of age was negatively correlated (ρ = −0.18, P = 0.04), whereas the BMI at 7 years of age was positively correlated (r = 0.18, P = 0.01), with the SUA level at 7 years of age. The dietary zinc intake level at 3 years of age and the BMI level at 7 years of age were, together, significantly related to SUA in children at 7 years of age. SUA was lower in group 1 (normal-weight, high-zinc group) than in the other two groups (group 2: normal-weight, low-zinc and overweight, high-zinc group; and group 3: overweight, low-zinc group). Our results demonstrate the combined effect of zinc intake and BMI on SUA. The combined association remained significant in both the crude and adjusted models (P < 0.01).

CONCLUSIONS

SUA was related to combined BMI and dietary zinc intake, and increased zinc intake and normal body weight had a beneficial effect on reducing SUA in children.

Effect of zinc supplementation on chronic hepatorenal toxicity following oral exposure to glyphosate-based herbicide (Bushfire®) in rats

OBJECTIVES

To assess the effects of zinc pretreatment on hepatorenal toxicity following chronic exposure to glyphosate-based herbicides in male rats.

METHODS

Following zinc pretreatment (50 mg/kg and 100 mg/kg), 14.4 to 750 mg/kg of oral glyphosate (Bushfire® herbicide) was administered daily for 36 weeks. Thereafter, serum samples were obtained following jugular venipuncture. Liver and kidney samples were processed for histopathological examination.

RESULTS

Serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activity as well as levels of bicarbonate, calcium, creatinine were significantly increased following chronic exposure to Bushfire®. Serum levels of sodium, potassium, chloride, total protein, albumin, globulin and urea were unchanged. Moderate to severe coagulative necrosis of hepatocytes as well as glomerular and renal tubular necrosis were observed in herbicide-treated rats. Zinc pretreatment reduced the elevation of serum enzymes associated with hepatobiliary lesions, abrogated hypercalcemia and metabolic alkalosis, and mitigated serum accumulation of creatinine following Bushfire® exposure, but was ineffective in completely preventing histological lesions.

CONCLUSION

Chronic Bushfire® exposure in rats caused hepatorenal toxicity. The effects of exposure on serum parameters were ameliorated by zinc pretreatment, but the histopathological changes associated with toxicity persisted in milder forms in zinc-pretreated animals.

Proteomics reveals the alleviation of zinc towards aflatoxin B1-induced cytotoxicity in human hepatocyes (HepG2 cells)

Aflatoxin B1 (AFB1) is a known carcinogen found in contaminated food and designated by the World Health Organization as a class I carcinogenic substance. AFB1 presents with carcinogenicity, teratogenicity, and mutagenicity, and the liver is the human organ most susceptible to AFB1. Zinc (Zn), which is one of the essential nutrient elements that could protect the cells from biological toxins, heavy metals, hydrogen peroxide, metal chelators and radiation, is assessed in this study for its potential to alleviate AFB1-induced cytotoxicity. Samples were divided into three groups, namely CK, AFB1, and AFB1+Zn. Protein expressions were analyzed by two-way electrophoresis combined with flight mass spectrometry, with 41 differentially expressed proteins identified in the results, mainly related to oxidative stress, cell apoptosis, DNA damage, and energy metabolism. Zn was found to regulate the expression of peroxidases (peroxiredoxin-1, peroxiredoxin-5, peroxiredoxin-6) to relieve AFB1-induced oxidative stress. Moreover, Zn could decrease the expression of pro-apoptotic genes (cleaved-caspase-3, caspase-9, and Bax) and increase the expression of anti-apoptotic genes (Bcl-2 and Bcl-xl) to alleviate the cell apoptosis induced by AFB1. In addition, AFB1 reduced intracellular ATP levels, whereas Zn supplementation boosted ATP levels and maintained homeostasis and a steady state of cellular energy metabolism by modulating AMPK-ACC phosphorylation levels, while many zinc finger proteins changed after AFB1 treatment. These results, therefore, indicate that Zn could alleviate AFB1-induced cytotoxicity by changing the expressions of zinc finger proteins in liver hepatocellular carcinoma (HepG2 cells).

Role of Zinc Supplementation on Ischemia/Reperfusion Injury in Various Organs

Ischemia-reperfusion (I/R) injury is a serious condition which is associated with myocardial infarction, stroke, acute kidney injury, trauma, circulatory arrest, sickle cell disease, and sleep apnea and can lead to high morbidity and mortality. Salts of zinc (Zn) are commonly used by humans and have protective effects against gastric, renal, hepatic, muscle, myocardial, or neuronal ischemic injury. The present review evaluates molecular mechanisms underlying the protective effects of Zn supplement against I/R injury. Data of this review have been collected from the scientific articles published in databases such as Science Direct, Scopus, PubMed, and Scientific Information Database from 1991 to 2019. Zn supplementation increased the decreased parameters including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH), metallothionein (MT), protein sulfhydryl (P-SH), and nuclear factor-erythroid 2-related factor-2 (Nrf2) expression and decreased the increased elements such as endoplasmic reticulum (ER) stress, mitochondrial permeability transition pore (mPTP) opening, malondialdehyde (MDA), serum level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and microRNAs-(122 and 34a), apoptotic factors, and histopathological changes. Zn also increases phosphatidylinositol 3-kinase (PI3K)/Akt and glycogen synthase kinase-3β (GSK-3β) phosphorylation and preserves protein kinase C isoforms. It is suggested that Zn can be administered before elective surgeries for prevention of side effects of I/R injury.

Role of antioxidants and a nutrient rich diet in Alzheimer's disease

The joint attack on the body by metabolic acidosis and oxidative stress suggests that treatment in degenerative diseases, including Alzheimer's disease (AD), may require a normalizing of extracellular and intracellular pH with simultaneous supplementation of an antioxidant combination cocktail at a sufficiently high dose. Evidence is also accumulating that combinations of antioxidants may be more effective, taking advantage of synergistic effects of appropriate antioxidants as well as a nutrient-rich diet to prevent and reverse AD. This review focuses on nutritional, nutraceutical and antioxidant treatments of AD, although they can also be used in other chronic degenerative and neurodegenerative diseases.

Determining a critical threshold for G6PD activity below which red blood cell response to oxidative stress is poor

Background

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme disorder in the world. Its main function is to generate NADPH that is required for anti-oxidative pathway in the cells especially in red blood cells (RBC). G6PD deficiency is X-linked and thus subject to random X-chromosome inactivation in women giving them mosaic expression of G6PD activities in their individual cells. This phenomenon makes it difficult for diagnosis with the currently available G6PD qualitative diagnostic tests. With the rolling out of newly marketed anti-malarial drug tafenoquine, which has a long half-life, screening for G6PD deficiency becomes a necessity where those with < 70% G6PD activity cannot receive this drug. Thus, evidence for a quantitative cut-off for G6PD activity is needed to ensure safe drug administration.

Methods

RBC models were developed to analyse the effect of oxidant on RBC oxidative markers namely total glutathione (GSH)and malondialdehyde (MDA). G6PD activity was measured using quantitative assay from Trinity Biotech and was correlated with cytofluorometric assay. RBC from two G6PD heterozygous women with different G6PD activities were also analysed for comparison.

Results

There was a negative correlation between G6PD activity and CuCl concentration and a strong association between G6PD activities and proportion of G6PD normal RBC in CuCl-treated models and in ex vivo RBC. However, in terms of oxidative stress markers analyses, unlike the hypothesis where the lower G6PD activity, the higher MDA and the lower GSH level, the CuCl RBC model showed that in low G6PD activities (10–30%) cells, the MDA level is lower compared to the rest of the models (p < 0.05). The ex vivo models however were in line with the hypothesis, although the result was not significant (p = 0.5). There was a significant difference between RBC with < 60% and those with > 80% G6PD activities in CuCl RBC model, but not in ex vivo RBC (p = 0.5). Genotyping heterozygous subjects showed G6PDViangchan variant with 2.97 U/gHb (33% activity) and 6.58 U/gHb (74% activity).

Conclusions

The GSH analysis has pointed to the 60% G6PD activity cut-off and this data is supportive of the old World Health Organization threshold for intermediate upper limit of 60% G6PD activity. However, there are significant limitations in using MDA assay with CuCl RBC model because the RBC was already stressed due to the copper treatment and thus present a different result when compared to the ex vivo model.

Total antioxidant capacity-Relevance, methods and clinical implications

Oxidative stress is pre-empted by an adequate level of antioxidants, which scavenge oxidants when they are produced in excess by different sources, including leukocytes and immature spermatozoa. Enzymatic antioxidants, such as superoxide dismutase, catalase and glutathione peroxidase, and several non-enzymatic antioxidants (proteins, vitamins and minerals), working as oxidant scavengers and cofactors of enzymatic antioxidants have been identified in seminal plasma. The total antioxidant capacity (TAC) is a diagnostic test that can be utilised in the male infertility workup. TAC measures the amount of total antioxidants in seminal plasma. Therefore, it provides an assessment of the reductive potential in seminal plasma. Several studies have investigated the diagnostic application of TAC in various andrology conditions. There is substantial evidence in the literature to show that infertile patients have lower seminal TAC in comparison with fertile men. Moreover, there is a positive correlation between TAC and seminal parameters, such as sperm concentration, motility and morphology. Evaluation of TAC together with reactive oxygen species (ROS) and sperm DNA fragmentation index (DFI) may be beneficial in the diagnosis of male infertility.

Evaluation of treatment with zinc acetate hydrate in patients with liver cirrhosis complicated by zinc deficiency

AIM

In Japan, no zinc preparation had been approved for therapeutic purposes before March 2017. Zinc acetate hydrate was recently approved for the treatment of hypozincemia. We evaluated the efficacy and safety of treatment with zinc acetate hydrate.

METHODS

A total of 97 patients with cirrhosis complicated by hypozincemia were treated with zinc acetate hydrate, and their serum zinc normalization rates; factors contributing to normalization; changes in blood ammonia levels; branched-chain amino acids-to-tyrosine ratios; levels of albumin, hemoglobin, alkaline phosphatase, serum copper, and iron; incidence of adverse events; improvement in subjective symptoms; and serum zinc levels taken at 3 months post-treatment were determined.

RESULTS

The cumulative serum zinc normalization rates, when normalization was defined as achievement of a serum zinc level ≥80 μg/dL, after 2, 4, and 6 months of treatment were 64.9%, 80.3%, and 82.5%, respectively. Multivariate analysis identified an albumin level of ≥3.3 g/dL and branched-chain amino acids to tyrosine ratio of ≥3.46 as factors contributing to zinc normalization within 3 months of treatment. Treatment resulted in a significant decrease in blood ammonia and serum copper levels, and significant increases in branched-chain amino acids-to-tyrosine ratios and alkaline phosphatase levels. Seven (7.2%) patients prematurely discontinued treatment due to hypocupremia. By the end of treatment, subjective symptoms had resolved in 46.2% of patients. By 3 months post-treatment, serum zinc levels had reverted to levels close to those at baseline.

CONCLUSIONS

Treatment with zinc acetate hydrate resulted in normalization of serum zinc levels at a high rate. The main reasons for discontinuation of treatment included hypocupremia.

Copper and cadmium administration induce toxicity and oxidative stress in the marine flatworm Macrostomum lignano

The contamination of coastal regions with different toxicants, including heavy metal ions such as copper and cadmium jeopardize health and survival of organisms exposed to this habitat. To study the effects of high copper and cadmium concentrations in these marine environments, we used the flatworm Macrostomum lignano as a model. This platyhelminth lives in shallow coastal water and is exposed to high concentrations of all toxicants that accumulate in these sea floors. We could show that both, cadmium and copper show toxicity at higher concentrations, with copper being more toxic than cadmium. At concentrations below acute toxicity, a reduced long-term survival was observed for both metal ions. The effects of sublethal doses comprise reduced physical activities, an increase in ROS levels within the worms, and alterations of the mitochondrial biology. Moreover, cell death events were substantially increased in response to sublethal concentrations of both metal ions and stem cell activity was reduced following exposure to higher cadmium concentrations. Finally, the expression of several genes involved in xenobiotic metabolism was substantially altered by this intervention. Taken together, M. lignano has been identified as a suitable model for marine toxicological studies as it allows to quantify several relevant life-history traits as well as of physiological and behavioral read-outs.

What diet should I recommend my patient with Hepatic Encephalopathy?

Purpose of Review

The burden of malnutrition is high in patients with cirrhosis, especially in those with hepatic encephalopathy (HE). This has a bearing on increased morbidity and mortality. Heightened attention needs to be paid to screen the patients at high nutritional risk both in the outpatient and hospitalized settings. This review summarizes the current evidence for nutritional support in HE patients and compares the recommendations about nutritional requirement as laid out by various organizations.

Recent Findings

On survey of the literature, there is a consensus on avoiding protein restriction of the diets in HE patients along with uniform recommendations on caloric requirements. An exciting field of manipulating the gut microbiome in nutritional sciences may hold promise as well as there may be a future role for branched chain amino acids in nutritional management of HE patients.

Summary

Even though the data suggest that nutritional improvement lead to better outcomes including lower readmission rates in cirrhosis, operationalizing these into practice remains a challenge. To achieve this, a multi-disciplinary approach with nutritional education of the frontline care providers, earlier nutritional risk screening of patients, involvement of the nutrition professionals as part of the team and repeated dietary counseling for the patient and caregiver/s is required. Ultimately, this may need more focus, resource allocation and uniform guidelines across all countries to make this a success.

Zinc alleviates maneb-induced kidney injury in adult mice through modulation of oxidative stress, genotoxicity, and histopathological changes

Zinc is one of the important essential trace minerals to human health due to its antioxidant properties. The present study was conducted to elucidate its potential protective role against maneb-induced nephrotoxicity. For this purpose, animals were randomly divided into four groups of six each. Mice of group I (negative controls) have received daily 0.5 ml of distilled water, a solvent of maneb. Mice of group II (MB) have received 30 mg/kg bw of maneb daily by intraperitoneal way. Mice of group III (MB + Zn) have received the same dose of maneb as group II, along with ZnSO4 (30 mg/kg bw) daily. Mice of group IV (Zn), considered as positive controls, have received the same dose of ZnSO4 as group III daily. Our results revealed that ZnSO4 co-administration to maneb-treated mice decreased kidney levels of malondialdehyde, hydrogen peroxide, protein carbonyls, and advanced oxidation protein products; the levels of non-enzymatic antioxidants like vitamin C, glutathione, and metallothionein. It recovered the alteration of antioxidant enzyme activities (catalase, superoxide dismutase, and glutathione peroxidase) and attenuated DNA fragmentation. Furthermore, this essential trace element was also able to alleviate kidney biomarkers' alterations by lowering plasma levels of creatinine, urea, uric acid, and lactate dehydrogenase. In addition, the histopathological changes induced by maneb were improved following zinc administration. Our results indicated that zinc might be beneficial against maneb-induced renal oxidative damage in mice.

Effect of Zinc Supplementation on Physical and Psychological Symptoms, Biomarkers of Inflammation, Oxidative Stress, and Brain-Derived Neurotrophic Factor in Young Women with Premenstrual Syndrome: a Randomized, Double-Blind, Placebo-Controlled Trial

Zinc is known to have multiple beneficial effects including anti-inflammatory and antioxidant and anti-depressant actions. Data on the effects of zinc supplementation on biomarkers of inflammation, oxidative stress, and antidepressant-like effect among young women with premenstrual syndrome (PMS) are scarce. This study was a randomized, double-blind, placebo-controlled trial. Sixty women (18-30 years) with premenstrual syndrome diagnosed according to 30-item questionnaire were randomly assigned to receive either 30-mg zinc gluconate (group 1; n = 30) and/or placebo (group 2; n = 30) for 12 weeks. Premenstrual syndrome symptoms, total antioxidant capacity, high sensitivity reactive protein, and brain-derived neurotrophic factor were measured at study baseline and after 12-week intervention. After 12 weeks of intervention, PMS physical symptoms (P = 0.03) and psychological symptoms (P = 0.006) significantly decreased in zinc group compared to placebo group. We observed a significant increase in brain-derived neurotrophic factor (P = 0.01) and total antioxidant capacity (P ˂ 0.001) after 12 weeks of intervention with zinc compared to placebo. We failed to find any significant effect of zinc supplementation on high sensitivity reactive protein. Overall, zinc supplementation for 12 weeks among women with premenstrual syndrome had beneficial effects on physical and psychological symptoms of premenstrual syndrome, total antioxidant capacity, and brain-derived neurotrophic factor.

Nanotechnology Approaches to Modulate Immune Responses to Cell-based Therapies for Type 1 Diabetes

Islet transplantation is a promising curative treatment option for type 1 diabetes (T1D) as it can provide physiological blood glucose control. The widespread utilization of islet transplantation is limited due to systemic immunosuppression requirements, persisting graft immunodestruction, and poor islet engraftment. Traditional macro- and micropolymeric encapsulation strategies can alleviate the need for antirejection immunosuppression, yet the increased graft volume and diffusional distances imparted by these coatings can be detrimental to graft viability and glucose control. Additionally, systemic administration of pro-engraftment and antirejection therapeutics leaves patients vulnerable to adverse off-target side effects. Nanoscale engineering techniques can be used to immunocamouflage islets, modulate the transplant microenvironment, and provide localized pro-engraftment cues. In this review, we discuss the applications of nanotechnology to advance the clinical potential of islet transplantation, with a focus on cell surface engineering, bioactive functionalization, and use of nanoparticles in T1D cell-based treatments.

The Associations of Dietary Iron, Zinc and Magnesium with Metabolic Syndrome in China's Mega Cities

Background: Iron, zinc and magnesium perform differently in body metabolism but exist in similar food. This study was to evaluate the associations of dietary iron, zinc and magnesium with metabolic syndrome (MetS). Methods: A sample of a total of 5323 participants from four of China’s mega cities was included in the current study. Both a 3-day 24-h dietary recall and household condiment weighing were applied to assess dietary intake, respectively. Hierarchical logistic regression models were used to evaluate the associations of dietary iron, zinc and magnesium with MetS. Results: After adjusting for age, sex, region, years of education, physical activity level, intended physical exercises, smoking status, alcohol use, daily energy intake and mutual adjustment for dietary iron, zinc and magnesium, significant positive trends were found across quartiles of total dietary iron and the risk of MetS, as well as for magnesium and MetS (p value for trends = 0.01 and 0.02, respectively); dietary zinc was inversely associated with MetS risk (p value for trend < 0.01). Magnesium from grains and potato was positively associated with MetS (p value for trend < 0.01). Conclusions: Dietary iron and magnesium were positively associated with the risk of MetS, while zinc was inversely associated with the risk of MetS, in China’s mega cities. The positive association of magnesium with MetS could be a result confounding by other factors correlated with magnesium in grains and potato, which warrants further study.

Identification of the Genetic Requirements for Zinc Tolerance and Toxicity in Saccharomyces cerevisiae

Zinc is essential for almost all living organisms, since it serves as a crucial cofactor for transcription factors and enzymes. However, it is toxic to cell growth when present in excess. The present work aims to investigate the toxicity mechanisms induced by zinc stress in yeast cells. To this end, 108 yeast single-gene deletion mutants were identified sensitive to 6 mM ZnCl₂ through a genome-wide screen. These genes were predominantly related to the biological processes of vacuolar acidification and transport, polyphosphate metabolic process, cytosolic transport, the process utilizing autophagic mechanism. A result from the measurement of intracellular zinc content showed that 64 mutants accumulated higher intracellular zinc under zinc stress than the wild-type cells. We further measured the intracellular ROS (reactive oxygen species) levels of 108 zinc-sensitive mutants treated with 3 mM ZnCl₂. We showed that the intracellular ROS levels in 51 mutants were increased by high zinc stress, suggesting their possible involvement in regulating ROS homeostasis in response to high zinc. The results also revealed that excess zinc could generate oxidative damage and then activate the expression of several antioxidant defenses genes. Taken together, the data obtained indicated that excess zinc toxicity might be mainly due to the high intracellular zinc levels and ROS levels induced by zinc stress in yeast cells. Our current findings would provide a basis to understand the molecular mechanisms of zinc toxicity in yeast cells.

Effect of zinc on growth performance and cellular metabolic stress of fish exposed to multiple stresses

Global warming due to increasing temperature and contamination in aquatic environment has been found to be inducing cellular metabolic stress in fish. The present study focused on temperature and contamination in aquatic ecosystems and its alleviation/mitigation. Hence, this study was conducted to evaluate the role of zinc to improve growth performance, cellular metabolic stress, and digestive enzymes of the Pangasianodon hypophthalmus reared under lead (Pb) and high temperature. Two hundred and seventy-three fishes were distributed randomly into seven treatments, each with three replicates. Three isocaloric and isonitrogenous diets with graded levels of zinc at 0 mg/kg, 10 mg/kg, and 20 mg/kg were prepared. The Pb in treated water was maintained at the level of 1/21th of LC₅₀ (4 ppm) and maintained at a temperature of 34 °C in exposure groups. The growth performance in terms of weight gain (%), protein efficiency ratio (PER), and specific growth rate (SGR) was found to be inhibited, and the feed conversion ratio (FCR) was enhanced in the Pb and high temperature-exposed group, whereas zinc supplementation has improved weight gain (%), FCR, PER, and SGR. The liver, gill, muscle, and kidney tissues of carbohydrate metabolic enzymes (LDH and MDH), protein metabolic enzymes (ALT and AST), and liver, gill, and muscle G6PDH and ATPase as well as intestinal digestives enzymes (proteases, amylase, and lipase) and intestinal ALP were significantly affected (p < 0.01) by Pb and high temperature exposure to P. hypophthalmus. We herein report the role of zinc in mitigating cellular metabolic stress in fish exposed to Pb and high temperature.

The Effects of Dietary Inclusion of Bilberry and Walnut Leaves in Laying Hens' Diets on the Antioxidant Properties of Eggs

Simple Summary

Eggs are considered common dietary sources of n-3 polyunsaturated fatty acids (PUFA), but they are susceptible to quality deterioration. In order to reduce oxidation, the best strategy is the addition of antioxidants to hens’ diets. Walnut and bilberry co-products, rich in phenolic compounds, are produced in agricultural industries, and are a valuable source of antioxidants for animal nutrition. The dietary inclusion of bilberry and walnut leaves as natural sources of antioxidants in poultry diets led to the accumulation of nutrients with antioxidant activity in the egg yolk, and the susceptibility of the yolk to lipid peroxidation during storage improved. The results of the present study showed that including bilberry and walnut leaves in laying hens’ diets enhanced the oxidative stability of the egg yolk and retarded the lipid peroxidation process during storage.

Abstract

The purpose of this study was to examine the effects of dietary inclusion of walnut and bilberry leaves (WL and BL), as sources of natural antioxidants in poultry diets, on the enrichment of antioxidant nutrients in the egg yolk and on the susceptibility of the yolk to lipid peroxidation during storage. The experiment was conducted on 32-week-old TETRA SL LL laying hens, which were assigned to three dietary treatments with 30 birds each. Each treatment was replicated 10 times with three chicks per replicate pen. Experimental dietary treatments differed from control diet (C) by addition of 0.5% BL supplement or 1% WL supplement. The phytoadditives were not significant contributors to the productive parameters. The addition of BL and WL in laying hens’ diets significantly increased the total polyphenol content, and the zinc, lutein and zeaxanthin concentrations in the egg yolks. In regards to the oxidative stability parameters, a significant decrease in the concentrations of primary oxidation products formed in the egg yolk of experimental groups was seen, proving an efficient inhibition effect of the phytoadditives on peroxyl radical formation. A significant correlation was observed between primary oxidation products and total polyphenol content of the egg yolks, where zinc, lutein and zeaxanthin are the bioactive compounds that inhibit the formation of secondary oxidation products.

Zinc oxide nanoparticles for therapeutic purposes in cancer medicine

Zinc oxide nanoparticles are characterized by a good biocompatibility while providing a versatile potential as innovative therapeutic agents in cancer medicine.

Sensing of zinc ions and sulfide using a highly practical and water-soluble fluorescent sensor: applications in test kits and zebrafish

A practical fluorescent sensor was synthesized for recognition of Zn²⁺ and S²⁻ and applied in various applications such as in live zebrafish.