Changes in cytokine production and T cell subpopulations in experimentally induced zinc-deficient humans

The Role of Zinc in Developed Countries in Pediatric Patients: A 360-Degree View

Zinc is an important trace element for growth and health at pediatric ages. Zinc is fundamental in inflammatory pathways, oxidative balance, and immune function. Zinc exhibits anti-inflammatory properties by modulating Nuclear Factor-kappa (NF-κB) activity and reducing histamine release from basophils, leukocytes, and mast cells. Furthermore, its antioxidant activity protects against oxidative damage and chronic diseases. Finally, zinc improves the ability to trigger effective immune responses against pathogens by contributing to the maturation of lymphocytes, the production of cytokines, and the regulation of apoptosis. Given these properties, zinc can be considered an adjunctive therapy in treating and preventing respiratory, nephrological, and gastrointestinal diseases, both acute and chronic. This review aims to deepen the role and metabolism of zinc, focusing on the role of supplementation in developed countries in pediatric diseases.

Understanding How Minerals Contribute to Optimal Immune Function

Sufficient mineral supply is vital not only for the innate immune system but also for the components of the adaptive immune defense, which encompass defense mechanisms against pathogens and the delicate balance of pro- and anti-inflammatory regulation in the long term. Generally, a well-balanced diet is capable of providing the necessary minerals to support the immune system. Nevertheless, specific vulnerable populations should be cautious about obtaining adequate amounts of minerals such as magnesium, zinc, copper, iron, and selenium. Inadequate levels of these minerals can temporarily impair immune competence and disrupt the long-term regulation of systemic inflammation. Therefore, comprehending the mechanisms and sources of these minerals is crucial. In exceptional circumstances, mineral deficiencies may necessitate supplementation; however, excessive intake of supplements can have adverse effects on the immune system and should be avoided. Consequently, any supplementation should be approved by medical professionals and administered in recommended doses. This review emphasizes the crucial significance of minerals in promoting optimal functioning of the immune system. It investigates the indispensable minerals required for immune system function and the regulation of inflammation. Moreover, it delves into the significance of maintaining an optimized intake of minerals from a nutritional standpoint.

Nutrient-Based Approaches for Melanoma: Prevention and Therapeutic Insights

Melanoma, a prevalent and lethal form of skin cancer, remains a formidable challenge in terms of prevention and treatment. While significant progress has been made in understanding its pathogenesis and treatment, the quest for effective prevention strategies and therapeutic approaches remains ongoing. Considering the increased advancements in understanding the dynamic interplay between nutrients and melanoma, we aim to offer a refreshed perspective on nutrient-based approaches for melanoma prevention and adjunctive therapy. In contrast to other studies, we have innovatively provided a detailed exposition of the nutrients' influences on melanoma prognosis and treatment. This review firstly examines various nutrients, including antioxidants (namely vitamins A, D, C, and E; selenium; and caffeine), polyunsaturated fatty acids, and flavonoids, for their effects and underlying mechanisms in reducing melanoma risk. Among these nutrients, caffeine shows the most promising potential, as it is supported by multiple cohort studies for its protective effect against melanoma. In contrast, there is a certain degree of inconsistency in the research of other nutrients, possibly due to inherent differences between animal studies and epidemiological research, as well as variations in the definition of nutrient intake. To comprehensively investigate the impact of nutrients on melanoma progression and therapeutic approaches, the following sections will explore how nutrients influence immune responses and other physiological processes. While there is robust support from cell and animal studies regarding the immunomodulatory attributes of vitamins D and zinc, the anti-angiogenic potential of polyphenols, and the cell growth-inhibitory effects of flavonoids, the limited availability of human-based research substantially constrains their practical relevance in clinical contexts. As for utilizing nutrients in adjuvant melanoma treatments, multiple approaches have garnered clinical research support, including the utilization of vitamin D to decrease the postoperative recurrence rates among melanoma patients and the adoption of a high-fiber diet to enhance the effectiveness of immunotherapy. In general, the effects of most nutrients on reducing the risk of melanoma are not entirely clear. However, several nutrients, including vitamin D and dietary fiber, have demonstrated their potential to improve the melanoma prognosis and enhance the treatment outcomes, making them particularly deserving of clinical attention. A personalized and interdisciplinary approach, involving dermatologists, oncologists, nutritionists, and researchers, holds the promise of optimizing melanoma treatment strategies.

Crosstalk between trace elements and T-cell immunity during early-life health in pigs

With gradual ban on the use of antibiotics, the deficiency and excessive use of trace elements in intestinal health is gaining attention. In mammals, trace elements are essential for the development of the immune system, specifically T-cell proliferation, and differentiation. However, there remain significant gaps in our understanding of the effects of certain trace elements on T-cell immune phenotypes and functions in pigs. In this review, we summarize the specificity, development, subpopulations, and responses to pathogens of porcine T cells and the effects of functional trace elements (e.g., iron, copper, zinc, and selenium) on intestinal T-cell immunity during early-life health in pigs. Furthermore, we discuss the current trends of research on the crosstalk mechanisms between trace elements and T-cell immunity. The present review expands our knowledge of the association between trace elements and T-cell immunity and provides an opportunity to utilize the metabolism of trace elements as a target to treat various diseases.

Quantitative 1HNMR Spectroscopy: Analysis of Zinc Gluconate in Utozinc® Tablets, a Mixture of Zinc Gluconate and Vitamin C

BACKGROUND

Zinc is an essential metal for humans and plays key roles in several biological events such as immunity, allergy, growth, and inflammation. The deficiency in zinc causes an increased infection rate with pathogens. Organo-zincates such as zinc gluconate are known for better absorption compared with their inorganic zinc salts. Its role in enhancing the immune system has driven a huge demand for organo-zinc supplements and in the treatment protocol of coronavirus disease, the causative agent of the COVID-19 pandemic.

OBJECTIVE

Herein, we report on a quantitative analysis of zinc gluconate in the authentic form in presence of vitamin C, and the method was applied to their dosage form (Utozinc® tablets). The method is simple, accurate, and validated according to ICH guidelines.

METHOD

Quantification of zinc gluconate formulated with vitamin C (Utozinc tablets) using Q-1HNMR. Maleic acid and deuterium oxide were used as internal standards and solvents, respectively.

RESULTS

The linearity range, the limit of detection and quantification, stability, precision, and accuracy, were validated. The validation of the method within five concentration levels (from 10 to 50 mg/0.5 mL D2O) afforded a limit of detection of 4.58 mg/mL, a quantification limit of 15.27 mg/mL, and excellent linearity.

CONCLUSIONS

The method proposed in the present study is simple, fast, nondestructive, and accurate. Zinc gluconate quantification values obtained by the Q-1HNMR method were found to show an acceptable correlation with those obtained by the thin-layer chromatographic technique.

HIGHLIGHTS

The method was successfully applied to Utozinc tablets, and the results were compared with the reported reference pharmacopeial method. The salt exchange between maleic acid (IS) and zinc gluconate was tested by noticing the change in the chemical shift of IS and zinc gluconate.

Can iron, zinc, copper and selenium status be a prognostic determinant in COVID-19 patients?

In severe COVID-19, the levels of iron (Fe), copper (Cu), zinc (Zn) and selenium (Se), do not only regulate host immune responses, but modify the viral genome, as well. While low serum Fe concentration is an independent risk factor for the increased death rate, Zn controls oxidative stress, synthesis of inflammatory cytokines and viral replication. Therefore, Zn deficiency associates with a worse prognosis. Although Cu exposure inactivates the viral genome and exhibits spike protein dispersal, increase in Cu/Zn due to high serum Cu levels, are correlated with enhanced risk of infections. Se levels are significantly higher in surviving COVID-19 patients. Meanwhile, both Zn and Se suppress the replication of SARS-CoV-2. Since the balance between the deficiency and oversupply of these metals due to a reciprocal relationship, has decisive effect on the prognosis of the SARS-CoV-2 infection, monitoring their concentrations may facilitate improved outcomes for patients suffering from COVID-19.

The Mechanisms of Zinc Action as a Potent Anti-Viral Agent: The Clinical Therapeutic Implication in COVID-19

The pandemic of COVID-19 was caused by a novel coronavirus termed as SARS-CoV2 and is still ongoing with high morbidity and mortality rates in the whole world. The pathogenesis of COVID-19 is highly linked with over-active immune and inflammatory responses, leading to activated cytokine storm, which contribute to ARDS with worsen outcome. Currently, there is no effective therapeutic drug for the treatment of COVID-19. Zinc is known to act as an immune modulator, which plays an important role in immune defense system. Recently, zinc has been widely considered as an anti-inflammatory and anti-oxidant agent. Accumulating numbers of studies have revealed that zinc plays an important role in antiviral immunity in several viral infections. Several early clinical trials clearly indicate that zinc treatment remarkably decreased the severity of the upper respiratory infection of rhinovirus in humans. Currently, zinc has been used for the therapeutic intervention of COVID-19 in many different clinical trials. Several clinical studies reveal that zinc treatment using a combination of HCQ and zinc pronouncedly reduced symptom score and the rates of hospital admission and mortality in COVID-19 patients. These data support that zinc might act as an anti-viral agent in the addition to its anti-inflammatory and anti-oxidant properties for the adjuvant therapeutic intervention of COVID-19.

Clinical importance of immunonutrition in infants: a review of the recent literature

During the last decades, the role of nutrition has been well elucidated in medicine, especially among critically ill infants and children. Many nutrients have the potential to modulate the immune system. A healthy immune system is essential for the prevention and recovery of many pediatric illnesses. Intervention using specific nutrients for the immune system is called immunonutrition. Immunonutrient supplementation has been attempted to modulate inflammatory or immune responses, leading to an improved clinical course of critically ill patients with prolonged nutritional supplementation parenterally or enterally. This review discusses immunomodulatory nutrients for infants based on the recent literature.

Serum Free Zinc Is Associated With Vaccination Response to SARS-CoV-2

Background

Zinc (Zn) is an essential trace element with high relevance for the immune system, and its deficiency is associated with elevated infection risk and severe disease course. The association of Zn status with the immune response to SARS-CoV-2 vaccination is unknown.

Methods

A cohort of adult health care workers (n=126) received two doses of BNT162B2, and provided up to four serum samples over a time course of 6 months. Total SARS-CoV-2 IgG and neutralizing antibody potency was determined, along with total as well as free Zn concentrations.

Results

The SARS-CoV-2 antibodies showed the expected rise in response to vaccination, and decreased toward the last sampling point, with highest levels measured three weeks after the second dose. Total serum Zn concentrations were relatively stable over time, and showed no significant association with SARS-CoV-2 antibodies. Baseline total serum Zn concentration and supplemental intake of Zn were both unrelated to the antibody response to SARS-CoV-2 vaccination. Time resolved analysis of free Zn indicated a similar dynamic as the humoral response. A positive correlation was observed between free Zn concentrations and both the induced antibodies and neutralizing antibody potency.

Conclusion

While the biomarkers of Zn status and supplemental Zn intake appeared unrelated to the humoral immune response to SARS-CoV-2 vaccination, the observed correlation of free Zn to the induced antibodies indicates a diagnostic value of this novel biomarker for the immune system.

Divalent Metal Uptake and the Role of ZIP8 in Host Defense Against Pathogens

Manganese (Mn) and Zinc (Zn) are essential micronutrients whose concentration and location within cells are tightly regulated at the onset of infection. Two families of Zn transporters (ZIPs and ZnTs) are largely responsible for regulation of cytosolic Zn levels and to a certain extent, Mn levels, although much less is known regarding Mn. The capacity of pathogens to persevere also depends on access to micronutrients, yet a fundamental gap in knowledge remains regarding the importance of metal exchange at the host interface, often referred to as nutritional immunity. ZIP8, one of 14 ZIPs, is a pivotal importer of both Zn and Mn, yet much remains to be known. Dietary Zn deficiency is common and commonly occurring polymorphic variants of ZIP8 that decrease cellular metal uptake (Zn and Mn), are associated with increased susceptibility to infection. Strikingly, ZIP8 is the only Zn transporter that is highly induced following bacterial exposure in key immune cells involved with host defense against leading pathogens. We postulate that mobilization of Zn and Mn into key cells orchestrates the innate immune response through regulation of fundamental defense mechanisms that include phagocytosis, signal transduction, and production of soluble host defense factors including cytokines and chemokines. New evidence also suggests that host metal uptake may have long-term consequences by influencing the adaptive immune response. Given that activation of ZIP8 expression by pathogens has been shown to influence parenchymal, myeloid, and lymphoid cells, the impact applies to all mucosal surfaces and tissue compartments that are vulnerable to infection. We also predict that perturbations in metal homeostasis, either genetic- or dietary-induced, has the potential to impact bacterial communities in the host thereby adversely impacting microbiome composition. This review will focus on Zn and Mn transport via ZIP8, and how this vital metal transporter serves as a "go to" conductor of metal uptake that bolsters host defense against pathogens. We will also leverage past studies to underscore areas for future research to better understand the Zn-, Mn- and ZIP8-dependent host response to infection to foster new micronutrient-based intervention strategies to improve our ability to prevent or treat commonly occurring infectious disease.

Zinc Essentiality, Toxicity, and Its Bacterial Bioremediation: A Comprehensive Insight

Zinc (Zn) is one of the most abundantly found heavy metals in the Earth's crust and is reported to be an essential trace metal required for the growth of living beings, with it being a cofactor of major proteins, and mediating the regulation of several immunomodulatory functions. However, its essentiality also runs parallel to its toxicity, which is induced through various anthropogenic sources, constant exposure to polluted sites, and other natural phenomena. The bioavailability of Zn is attributable to various vegetables, beef, and dairy products, which are a good source of Zn for safe consumption by humans. However, conditions of Zn toxicity can also occur through the overdosage of Zn supplements, which is increasing at an alarming rate attributing to lack of awareness. Though Zn toxicity in humans is a treatable and non-life-threatening condition, several symptoms cause distress to human activities and lifestyle, including fever, breathing difficulty, nausea, chest pain, and cough. In the environment, Zn is generally found in soil and water bodies, where it is introduced through the action of weathering, and release of industrial effluents, respectively. Excessive levels of Zn in these sources can alter soil and aquatic microbial diversity, and can thus affect the bioavailability and absorption of other metals as well. Several Gram-positive and -negative species, such as Bacillus sp., Staphylococcus sp., Streptococcus sp., and Escherichia coli, Pseudomonas sp., Klebsiella sp., and Enterobacter sp., respectively, have been reported to be promising agents of Zn bioremediation. This review intends to present an overview of Zn and its properties, uses, bioavailability, toxicity, as well as the major mechanisms involved in its bioremediation from polluted soil and wastewaters.

Immunomodulatory effects of zinc and its impact on COVID-19 severity

The COVID-19 pandemic has led to severe financial, clinical, and societal repercussions and imposed more pressure on the healthcare system of many nations. COVID-19 impacts the immune system by causing a systemic inflammatory reaction, often known as cytokine release syndrome (CRS). COVID-19 patients had elevated levels of pro-inflammatory cytokines and chemokines. In this context, many dietary interventions have been utilized to mitigate the adverse effects of COVID-19 by regulating the excessive secretion of cytokines and chemokines. Zinc, an anti-inflammatory and antioxidant mineral in food with a well-established role in immunity, is now being employed in several clinical studies against COVID-19. Zn deficiency has been correlated with the increased production of pro-inflammatory cytokines. As a result, we will summarise zinc's immunomodulatory effects in this article. We will investigate how zinc deficiency might contribute to a poor prognosis of COVID-19 disease by altering the release of particular cytokines.

The Role of Minerals in the Optimal Functioning of the Immune System

Minerals fulfil a wide variety of functions in the optimal functioning of the immune system. This review reports on the minerals that are essential for the immune system’s function and inflammation regulation. We also discuss nutritional aspects of optimized mineral supply. The supply of minerals is important for the optimal function of the innate immune system as well as for components of adaptive immune defense; this involves defense mechanisms against pathogens in addition to the long-term balance of pro- and anti-inflammatory regulation. Generally, a balanced diet is sufficient to supply the required balance of minerals to help support the immune system. Although a mineral deficiency is rare, there are nevertheless at-risk groups who should pay attention to ensure they are receiving a sufficient supply of minerals such as magnesium, zinc, copper, iron, and selenium. A deficiency in any of these minerals could temporarily reduce immune competence, or even disrupt systemic inflammation regulation in the long term. Therefore, knowledge of the mechanisms and supply of these minerals is important. In exceptional cases, a deficiency should be compensated by supplementation; however, supplement over-consumption may be negative to the immune system, and should be avoided. Accordingly, any supplementation should be medically clarified and should only be administered in prescribed concentrations.

Zinc deficiency as a possible risk factor for increased susceptibility and severe progression of Corona Virus Disease 19

The importance of Zn for human health becomes obvious during Zn deficiency. Even mild insufficiencies of Zn cause alterations in haematopoiesis and immune functions, resulting in a proinflammatory phenotype and a disturbed redox metabolism. Although immune system malfunction has the most obvious effect, the functions of several tissue cell types are disturbed if Zn supply is limiting. Adhesion molecules and tight junction proteins decrease, while cell death increases, generating barrier dysfunction and possibly organ failure. Taken together, Zn deficiency both weakens the resistance of the human body towards pathogens and at the same time increases the danger of an overactive immune response that may cause tissue damage. The case numbers of Corona Virus Disease 19 (COVID-19) are still increasing, which is causing enormous problems for health systems and economies. There is an urgent need to reduce both the number of severe cases and the resulting deaths. While therapeutic options are still under investigation, and first vaccines have been approved, cost-effective ways to reduce the likelihood of or even prevent infection, and the transition from mild symptoms to more serious detrimental disease, are highly desirable. Nutritional supplementation might be an effective option to achieve these aims. In this review, we discuss known Zn deficiency effects in the context of an infection with Severe Acute Respiratory Syndrome-Coronavirus-2 and its currently known pathogenic mechanisms and elaborate on how severe pre-existing Zn deficiency may pre-dispose patients to a severe progression of COVID-19. First published clinical data on the association of Zn homoeostasis with COVID-19 and registered studies in progress are listed.

ZIP8-Mediated Intestinal Dysbiosis Impairs Pulmonary Host Defense against Bacterial Pneumonia

Pneumococcal pneumonia is a leading cause of morbidity and mortality worldwide. An increased susceptibility is due, in part, to compromised immune function. Zinc is required for proper immune function, and an insufficient dietary intake increases the risk of pneumonia. Our group was the first to reveal that the Zn transporter, ZIP8, is required for host defense. Furthermore, the gut microbiota that is essential for lung immunity is adversely impacted by a commonly occurring defective ZIP8 allele in humans. Taken together, we hypothesized that loss of the ZIP8 function would lead to intestinal dysbiosis and impaired host defense against pneumonia. To test this, we utilized a novel myeloid-specific Zip8KO mouse model in our studies. The comparison of the cecal microbial composition of wild-type and Zip8KO mice revealed significant differences in microbial community structure. Most strikingly, upon a S. pneumoniae lung infection, mice recolonized with Zip8KO-derived microbiota exhibited an increase in weight loss, bacterial dissemination, and lung inflammation compared to mice recolonized with WT microbiota. For the first time, we reveal the critical role of myeloid-specific ZIP8 on the maintenance of the gut microbiome structure, and that loss of ZIP8 leads to intestinal dysbiosis and impaired host defense in the lung. Given the high incidence of dietary Zn deficiency and the ZIP8 variant allele in the human population, additional investigation is warranted to improve surveillance and treatment strategies.

The Role of an Anti-Inflammatory Diet in Conjunction to COVID-19

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), otherwise known as COVID-19, has challenged healthcare systems at an international level. COVID-19 suppresses the immune system by causing a systemic inflammatory response, also known as cytokine release syndrome, leaving COVID-19 patients with high levels of proinflammatory cytokines and chemokines. Nutrition's function in the respiratory and immune systems has been investigated in much research, and its significance cannot be overstated, as the nutritional status of patients has been shown to be directly connected with the severity of the disease. Key dietary components such as vitamin C, D, omega-3 fatty acids, and zinc have shown potential in their anti-inflammatory effects, as well as the famous Mediterranean diet. This review aims to discuss the use of anti-inflammatory dietary approaches to prevent Sars-CoV-2 or lessen COVID-19 effects.

Leishmaniasis and Trace Element Alterations: a Systematic Review

Leishmaniasis is a worldwide prevalent parasitic infection caused by different species of the genus Leishmania. Clinically, the disease divided into three main forms, including visceral leishmaniasis (VL), cutaneous leishmaniasis (CL), and mucocutaneous leishmaniasis (MCL). There is no vaccine for human leishmaniasis and their treatment is challenging. Trace elements (TEs) alteration, including the selenium (Se), zinc (Zn), copper (Cu), ron (Fe), and magnesium (Mg) have been detected in patients with CL and VL as well as canine leishmaniasis. Because TEs play a pivotal role in the immune system, and host immune responses have crucial roles in defense against leishmaniasis, this systematic review aimed to summarize data regarding TEs alteration in human and animal leishmaniasis as well as the role of these elements as an adjuvant for treatment of leishmaniasis. In a setting of systematic review, we found 29 eligible articles (any date until October 1, 2020) regarding TEs in human CL (N = 12), human VL (N = 4), canine leishmaniasis (N = 3), and treatment of leishmaniasis based on TEs (N = 11), which one study examined the TEs level both in CL and VL patients. Our analysis demonstrated a significantly decreased level of Fe, Zn, and Se among human CL and canine leishmaniasis, and Zn and Fe in patients with VL. In contrast, an increased level of Cu in CL patients and Cu and Mg in VL patients and canine leishmaniasis was observed. Treatment of CL based zinc supplementation revealed enhancement of wound healing and diminished scar formation in human and experimentally infected animals. The results of this systematic review indicate that the TEs have important roles in leishmaniasis, which could be assessed as a prognosis factor in this disease. It is suggested that TEs could be prescribed as an adjuvant for the treatment of CL and VL patients.

Is serum zinc status related to gestational diabetes mellitus? A meta-analysis

Gestational diabetes mellitus (GDM) is a common medical disorder that begins during pregnancy. The present work aimed to investigate the relationship of maternal or foetal circulatory zinc levels with GDM. Related studies were retrieved against the PubMed/Medline, Web of Science, Scopus databases till July 2020. The overall effects were expressed as standard mean difference (SMD). Furthermore, the random effects model was used to assess the summarised risk ratios (SRRs) to determine the relationship between zinc and the risk of GDM. A total of 15 articles involving were retrieved for meta‐analysis; in the meantime, 4955 subjects including 1549 GDM cases were enrolled for quantitative analysis. Compared with normal control, GDM cases had decreased circulating zinc level on the whole, but the difference was not statistically significant (SMD = −0.40, 95%CI: −0.80 to −0.00, P = 0.05). Interestingly, upon subgroup analysis stratified by serum zinc content but not plasma zinc concentration, there was significant difference in zinc content between GDM cases and normal controls (SMD = −0.56; 95%CI: −1.07 to −0.04, P = 0.03). Meanwhile, subgroup analysis also revealed similar tendency among the Asians and during the 2nd trimester, but not among the Caucasians or during the 1st or 3rd trimester. Data extracted from four studies that compared pregnant women with GDM in the high level of zinc and GDM in the low level of zinc yielded an SRR of 0.929 (95%CI: 0.905–0.954). According to existing evidence, the serum zinc content decreases among GDM cases compared with subjects with no abnormality in glucose tolerance, in particular among the Asians and during the second trimester. Nonetheless, more well designed prospective study should be carried out for understanding the dynamic relationship of zinc level with the incidence of GDM.

Zinc and COVID-19: Basis of Current Clinical Trials

Coronavirus disease-2019 (COVID-19) pandemic continues to threaten patients, societies, and economic and healthcare systems around the world. Like many other diseases, the host immune system determines the progress of COVID-19 and fatality. Modulation of inflammatory response and cytokine production using immunonutrition is a novel concept that has been applied to other diseases as well. Zinc, one of the anti-inflammatory and antioxidant micronutrient found in food with well-established role in immunity, is currently being used in some clinical trials against COVID-19. This review integrates the contemporary studies of role of zinc in antiviral immunity along with discussing its potential role against COVID-19, and ongoing COVID-19 clinical trials using zinc.

A comprehensive insight into the role of zinc deficiency in the renin-angiotensin and kinin-kallikrein system dysfunctions in COVID-19 patients

Hypozincemia is prevalent in severe acute respiratory syndrome coronavirus-2 (SARS-COV-2)-infected patients and has been considered as a risk factor in severe coronavirus disease-2019 (COVID-19). Whereas zinc might affect SARS-COV-2 replication and cell entry, the link between zinc deficiency and COVID-19 severity could also be attributed to the effects of COVID-19 on the body metabolism and immune response. Zinc deficiency is more prevalent in the elderly and patients with underlying chronic diseases, with established deleterious consequences such as the increased risk of respiratory infection. We reviewed the expected effects of zinc deficiency on COVID-19-related pathophysiological mechanisms focusing on both the renin-angiotensin and kinin-kallikrein systems. Mechanisms and effects were extrapolated from the available scientific literature. Zinc deficiency alters angiotensin-converting enzyme-2 (ACE2) function, leading to the accumulation of angiotensin II, des-Arg9-bradykinin and Lys-des-Arg9-bradykinin, which results in an exaggerated pro-inflammatory response, vasoconstriction and pro-thrombotic effects. Additionally, zinc deficiency blocks the activation of the plasma contact system, a protease cascade initiated by factor VII activation. Suggested mechanisms include the inhibition of Factor XII activation and limitation of high-molecular-weight kininogen, prekallikrein and Factor XII to bind to endothelial cells. The subsequent accumulation of Factor XII and deficiency in bradykinin are responsible for increased production of inflammatory mediators and marked hypercoagulability, as typically observed in COVID-19 patients. To conclude, zinc deficiency may affect both the renin-angiotensin and kinin-kallikrein systems, leading to the exaggerated inflammatory manifestations characteristic of severe COVID-19.

Potential Role of Vitamins and Zinc on Acute Respiratory Infections Including Covid-19

Background. Vitamin C, E, D, A, zinc are considered to be essential in preventing and treating of acute respiratory infections (ARI) including COVID-19. Methods. We reviewed published studies evaluating the potential roles of these vitamin and zinc for ARIs and COVID-19 using Medline database, medRxiv, and bibliographic references. Results. Vitamins C, D, and E did not reduce incidence of common cold in general, but vitamin C reduced by half in population with physical and environment stresses. Vitamins C and E shortened duration and reduced severity of common cold. A large-dose vitamin A had no effect on recovery from pneumonia. Zinc improved clinical deterioration and pneumonia duration in under five. The effect on preventing COVID-19 morbidity and related-death was lacking. Conclusions. Although the effects of vitamins and zinc on ARIs including COVID-19 were inconclusive, taking these for a short period during pandemic may be beneficial when there is risks of deficiency.

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.

Association between toenail zinc concentrations and incidence of asthma among American young adults: The CARDIA study

BACKGROUND

As an essential micronutrient, zinc plays an important role in modulating the immune system. However, data on the association between zinc concentrations and asthma incidence are sparse, especially in adults.

METHODS

We prospectively followed up 3682 individuals aged 20-32 years without history of asthma or current asthma at baseline from 1987-1988 to 2015-2016. Zinc concentrations were measured in toenail clippings collected at Exam Year 2 using inductively-coupled-plasma mass spectroscopy. Asthma was diagnosed by a physician and/or reported medication use for asthma control with verification. Cox regression was used to model the association between toenail zinc concentrations and asthma incidence.

RESULTS

Over an average of 22.5 years of follow-up, 508 incident cases of asthma were identified. After adjustment for potential confounders, no statistically significant association was found between zinc concentration and asthma incidence (HR = 0.81; 95% CI: 0.62, 1.07; Plinear trend = 0.26). The observed association was not materially modified by sex, body mass index, smoking or atopic status. When stratifying data by race, a significant inverse linear association was found among African Americans (per 1 standard deviation increment in toenail zinc concentrations: HR = 0.86; 95% CI: 0.75, 0.99; Plinear trend = 0.03), but not in Caucasians (HR = 1.07; 95% CI: 0.91, 1.25; Plinear trend = 0.42), though the test for interaction was not statistically significant (Pinteraction = 0.099).

CONCLUSIONS

Findings from this prospective cohort study do not support a significant longitudinal association between toenail zinc concentrations and incidence of asthma among American young adults. Future studies are needed to confirm our findings.

Trace Elements as Immunoregulators in SARS-CoV-2 and Other Viral Infections

Nutritional deficiency is associated with impaired immunity and increased susceptibility to infections. The complex interactions of trace elements with the macromolecules trigger the effective immune response against the viral diseases. The outcome of various viral infections along with susceptibility is affected by trace elements such as zinc, selenium, iron, copper, etc. due to their immuno-modulatory effects. Available electronic databases have been comprehensively searched for articles published with full text available and with the key words “Trace elements”, “COVID-19”, “Viral Infections” and “Immune Response” (i.e. separately Zn, Se, Fe, Cu, Mn, Mo, Cr, Li, Ni, Co) appearing in the title and abstract. On the basis of available articles we have explored the role of trace elements in viral infections with special reference to COVID-19 and their interactions with the immune system. Zinc, selenium and other trace elements are vital to triggerT_H1 cells and cytokine-mediated immune response for substantial production of proinflammatory cytokines. The antiviral activity of some trace elements is attributed to their inhibitory effect on viral entry, replication and other downstream processes. Trace elements having antioxidants activity not only regulate host immune responses, but also modify the viral genome. Adequate dietary intake of trace elements is essential for activation, development, differentiation and numerous functions.

Low Zinc Levels at Admission Associates with Poor Clinical Outcomes in SARS-CoV-2 Infection

Background: Zinc is an essential micronutrient that impacts host–pathogen interplay at infection. Zinc balances immune responses, and also has a proven direct antiviral action against some viruses. Importantly, zinc deficiency (ZD) is a common condition in elderly and individuals with chronic diseases, two groups with an increased risk for severe severe coronavirus disease 2019 (COVID-19) outcomes. We hypothesize that serum zinc content (SZC) influences COVID-19 disease progression, and thus might represent a useful biomarker. Methods: We ran an observational cohort study with 249 COVID-19 patients admitted in Hospital del Mar. We have studied COVID-19 severity and progression attending to SZC at admission. In parallel, we have studied severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) replication in the Vero E6 cell line modifying zinc concentrations. Findings: Our study demonstrates a correlation between serum zinc levels and COVID-19 outcome. Serum zinc levels lower than 50 µg/dL at admission correlated with worse clinical presentation, longer time to reach stability, and higher mortality. Our in vitro results indicate that low zinc levels favor viral expansion in SARS-CoV-2 infected cells. Interpretation: Low SZC is a risk factor that determines COVID-19 outcome. We encourage performing randomized clinical trials to study zinc supplementation as potential prophylaxis and treatment with people at risk of zinc deficiency.

Physical Activity and Natural Products and Minerals in the SARS-CoV-2 Pandemic: An Update

Coronavirus-disease 19 (COVID-19) has rapidly become a global public health issue, and there is a desperate need for strategies of prevention, reduction, and treatment to halt the epidemic. The coronavirus affects the immune system, and individuals with a compromised immune system, such as those with diabetes, hypertension, obesity, are more susceptible to this virus. Lifestyle-related variables such as physical activity and nutritional supplements can decrease inflammatory markers, increase anti-inflammatory and antioxidant status, and improve the immune system. Lifesty-lerelated variables play preventive roles against various infectious diseases including COVID-19. This review highlights the effects of physical activity and nutrients supplements on the immune system and their possible benefits in combating the harms caused by infection with the COVID-19 virus.

Zinc in the Brain: Friend or Foe?

Zinc is a trace metal ion in the central nervous system that plays important biological roles, such as in catalysis, structure, and regulation. It contributes to antioxidant function and the proper functioning of the immune system. In view of these characteristics of zinc, it plays an important role in neurophysiology, which leads to cell growth and cell proliferation. However, after brain disease, excessively released and accumulated zinc ions cause neurotoxic damage to postsynaptic neurons. On the other hand, zinc deficiency induces degeneration and cognitive decline disorders, such as increased neuronal death and decreased learning and memory. Given the importance of balance in this context, zinc is a biological component that plays an important physiological role in the central nervous system, but a pathophysiological role in major neurological disorders. In this review, we focus on the multiple roles of zinc in the brain.

Clinical Impact Potential of Supplemental Nutrients as Adjuncts of Therapy in High-Risk COVID-19 for Obese Patients

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease (COVID-19) in China at the end of 2019 caused a major global pandemic and continues to be an unresolved global health crisis. The supportive care interventions for reducing the severity of symptoms along with participation in clinical trials of investigational treatments are the mainstay of COVID-19 management because there is no effective standard therapy for COVID-19. The comorbidity of COVID-19 rises in obese patients. Micronutrients may boost the host immunity against viral infections, including COVID-19. In this review, we discuss the clinical impact potential of supplemental nutrients as adjuncts of therapy in high-risk COVID-19 for obese patients.

The Role of Micronutrients in Support of the Immune Response against Viral Infections

Viral infections are a leading cause of morbidity and mortality worldwide, and the importance of public health practices including handwashing and vaccinations in reducing their spread is well established. Furthermore, it is well known that proper nutrition can help support optimal immune function, reducing the impact of infections. Several vitamins and trace elements play an important role in supporting the cells of the immune system, thus increasing the resistance to infections. Other nutrients, such as omega-3 fatty acids, help sustain optimal function of the immune system. The main aim of this manuscript is to discuss of the potential role of micronutrients supplementation in supporting immunity, particularly against respiratory virus infections. Literature analysis showed that in vitro and observational studies, and clinical trials, highlight the important role of vitamins A, C, and D, omega-3 fatty acids, and zinc in modulating the immune response. Supplementation with vitamins, omega 3 fatty acids and zinc appears to be a safe and low-cost way to support optimal function of the immune system, with the potential to reduce the risk and consequences of infection, including viral respiratory infections. Supplementation should be in addition to a healthy diet and fall within recommended upper safety limits set by scientific expert bodies. Therefore, implementing an optimal nutrition, with micronutrients and omega-3 fatty acids supplementation, might be a cost-effective, underestimated strategy to help reduce the burden of infectious diseases worldwide, including coronavirus disease 2019 (COVID-19).

The Potential Impact of Zinc Supplementation on COVID-19 Pathogenesis

During the current corona pandemic, new therapeutic options against this viral disease are urgently desired. Due to the rapid spread and immense number of affected individuals worldwide, cost-effective, globally available, and safe options with minimal side effects and simple application are extremely warranted. This review will therefore discuss the potential of zinc as preventive and therapeutic agent alone or in combination with other strategies, as zinc meets all the above described criteria. While a variety of data on the association of the individual zinc status with viral and respiratory tract infections are available, study evidence regarding COVID-19 is so far missing but can be assumed as was indicated by others and is detailed in this perspective, focusing on re-balancing of the immune response by zinc supplementation. Especially, the role of zinc in viral-induced vascular complications has barely been discussed, so far. Interestingly, most of the risk groups described for COVID-19 are at the same time groups that were associated with zinc deficiency. As zinc is essential to preserve natural tissue barriers such as the respiratory epithelium, preventing pathogen entry, for a balanced function of the immune system and the redox system, zinc deficiency can probably be added to the factors predisposing individuals to infection and detrimental progression of COVID-19. Finally, due to its direct antiviral properties, it can be assumed that zinc administration is beneficial for most of the population, especially those with suboptimal zinc status.

Nutrition, immunity and COVID-19

The immune system protects the host from pathogenic organisms (bacteria, viruses, fungi, parasites). To deal with this array of threats, the immune system has evolved to include a myriad of specialised cell types, communicating molecules and functional responses. The immune system is always active, carrying out surveillance, but its activity is enhanced if an individual becomes infected. This heightened activity is accompanied by an increased rate of metabolism, requiring energy sources, substrates for biosynthesis and regulatory molecules, which are all ultimately derived from the diet. A number of vitamins (A, B₆, B₁₂, folate, C, D and E) and trace elements (zinc, copper, selenium, iron) have been demonstrated to have key roles in supporting the human immune system and reducing risk of infections. Other essential nutrients including other vitamins and trace elements, amino acids and fatty acids are also important. Each of the nutrients named above has roles in supporting antibacterial and antiviral defence, but zinc and selenium seem to be particularly important for the latter. It would seem prudent for individuals to consume sufficient amounts of essential nutrients to support their immune system to help them deal with pathogens should they become infected. The gut microbiota plays a role in educating and regulating the immune system. Gut dysbiosis is a feature of disease including many infectious diseases and has been described in COVID-19. Dietary approaches to achieve a healthy microbiota can also benefit the immune system. Severe infection of the respiratory epithelium can lead to acute respiratory distress syndrome (ARDS), characterised by excessive and damaging host inflammation, termed a cytokine storm. This is seen in cases of severe COVID-19. There is evidence from ARDS in other settings that the cytokine storm can be controlled by n-3 fatty acids, possibly through their metabolism to specialised pro-resolving mediators.

Role of Zinc in Mucosal Health and Disease: A Review of Physiological, Biochemical, and Molecular Processes

Zinc is an essential trace element of all highly proliferating cells in the human body. It is essential to the development and growth of all organisms. Zinc plays a critical role in modulating resistance to infectious agents and reduces the duration, severity, and risk of diarrheal disease via improved regeneration of intestinal epithelium, improved absorption of water and electrolytes, increased levels of brush border enzymes, and, possibly, an enhancement in the immune response allowing better clearance of pathogens. On the cellular level, zinc finger motifs play various roles including diverse functions that involve specific gene expression for ion channels throughout the body. It maintains the function and the structure of the membrane barrier by contributing to host defense, which is particularly crucial in the intestines due to the continuous exposure to noxious agents and pathogens. Zinc deficiency is characterized by impaired immune function, loss of appetite, and growth retardation. More severe cases cause diarrhea, delayed sexual maturation, hair loss, eye and skin lesions, impotence and hypogonadism in males, as well as weight loss, taste abnormalities, delayed healing of wounds, and mental lethargy. The objective of this study is a critical review of the molecular and genetic regulation of zinc in various cellular processes and organs, the association between zinc and diarrheal disease, the recommended dietary zinc intake, and the effects of zinc deficiency on the human body.

Lessons Learned from Experimental Human Model of Zinc Deficiency

Zinc is an essential element for humans, and its deficiency was documented in 1963. Nutritional zinc deficiency is now known to affect over two billion subjects in the developing world. Conditioned deficiency of zinc in many diseases has also been observed. In zinc-deficient dwarfs from the Middle East, we reported growth retardation, delayed sexual development, susceptibility to infections, poor appetite, and mental lethargy. We never found a zinc-deficient dwarf who survived beyond the age of 25 y. In an experimental model of human mild zinc deficiency, we reported decreased thymulin (a thymopoietic hormone) activity in Th1 cells, decreased mRNAs of IL-2 and IFN-gamma genes, and decreased activity of natural killer cells (NK) and T cytotoxic T cells. The effect of zinc deficiency on thymulin activity and IL-2 mRNA was seen within eight to twelve weeks of the institution of zinc-deficient diet in human volunteers, whereas lymphocyte zinc decreased in 20 weeks and plasma zinc decreased in 24 weeks after instituting zinc-deficient diet. We hypothesized that decreased thymulin activity, which is known to proliferate Th1 cells, decreased the proliferation differentiation of Th1 cells. This resulted in decreased generation of IL-2 and IFN-gamma. We observed no effect in Th2 cell function; thus, zinc deficiency resulted in an imbalance of Th1 to Th2 function resulting in decreased cell-mediated immunity. Zinc therapy may be very useful in many chronic diseases. Zinc supplementation improves cell-mediated immunity, decreases oxidative stress, and decreases generation of chronic inflammatory cytokines in humans. Development of sensitive immunological biomarkers may be more sensitive than an assay of zinc in plasma and peripheral blood cells for diagnosis of marginal zinc deficiency in human.

Thiamine deficiency in a patient with recurrent renal cell carcinoma who developed weight loss with normal appetite and loss of energy soon after nivolumab treatment

Background

Nivolumab has become an effective treatment option for cancer in various sites; however, this drug may cause immune-related adverse effects due to its mechanism of action. Furthermore, little has been reported on thiamine deficiency (TD) in patients receiving nivolumab treatment.

Method

From a series of cancer patients, we reported a patient with recurrent renal cell carcinoma who developed TD after the start of nivolumab treatment.

Results

A 74-year-old man with recurrent renal cell carcinoma was referred to the psycho-oncology department as he had lost about 4 kg and displayed a loss of energy after four cycles of nivolumab treatment. Psychiatric interviews revealed a decrease in energy. Neurological examination did not reveal any impairment in consciousness, ataxia, or ocular symptoms. He did not develop appetite loss. The malabsorption or overconsumption of some nutrients is thought to occur due to the rapid loss of weight; thus, a reduction in vitamin B1, which has a short storage period in the body and is often deficient in cancer patients, was suspected. The diagnosis of TD was supported by the patient's abnormally low serum thiamine level.

Significance of results

In patients treated with nivolumab, it is necessary to pay careful attention to TD when proceeding with the treatment. It is hoped that future research may reveal the link between nivolumab administration and TD.

Trace Elements Associated with Systemic Lupus Erythematosus and Insulin Resistance

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease of multifactorial origin. Studies have shown that trace elements such as zinc and copper may help maintain optimum function of the immune system and metabolism, while toxic metals such as lead may increase systemic autoimmunity. The current study aimed to assess the relationship between serum concentration of lithium (Li), vanadium (V), copper (Cu), zinc (Zn), molybdenum (Mo), cadmium (Cd), and lead (Pb) and SLE diagnosis, disease activity measured by SLE disease activity index (SLEDAI) and insulin resistance (IR). This case-control, cross-sectional study included 225 patients, 120 healthy controls, and 105 SLE patients. Serum concentration of Li, V, Cu, Zn, Mo, Cd, and Pb was measured. Serum concentrations of V (p < 0.001), Zn (p < 0.001), and Pb (p < 0.001) were lower and Mo (p < 0.001) and Li (p < 0.001) were higher in patients with SLE compared to healthy controls. SLE diagnosis was associated with higher serum Li (p < 0.001) concentration and lower V (p < 0.001), Zn (p = 0.003), and Pb (p = 0.020). Toxic metals and trace elements were not associated with disease activity. Levels of Cd were higher in patients with IR (p = 0.042). There was no significant association between IR and the other metals. The results indicate that SLE patients have different profiles of trace elements and toxic metals compared to healthy controls. While some toxic metals and trace elements were found to be associated with SLE diagnosis, they had no effect on disease activity and IR.

The Role of Micronutrients in the Infection and Subsequent Response to Hepatitis C Virus

Micronutrient deficiencies develop for a variety of reasons, whether geographic, socioeconomic, nutritional, or as a result of disease pathologies such as chronic viral infection. As micronutrients are essential for a strong immune response, deficiencies can significantly dampen both the innate and the adaptive arms of antiviral immunity. The innate immune response in particular is crucial to protect against hepatitis C virus (HCV), a hepatotropic virus that maintains chronic infection in up to 80% of individuals if left untreated. While many micronutrients are required for HCV replication, an overlapping group of micronutrients are also necessary to enact a potent immune response. As the liver is responsible for the storage and metabolism of many micronutrients, HCV persistence can influence the micronutrients’ steady state to benefit viral persistence both directly and by weakening the antiviral response. This review will focus on common micronutrients such as zinc, iron, copper, selenium, vitamin A, vitamin B12, vitamin D and vitamin E. We will explore their role in the pathogenesis of HCV infection and in the response to antiviral therapy. While chronic hepatitis C virus infection drives deficiencies in micronutrients such as zinc, selenium, vitamin A and B12, it also stimulates copper and iron excess; these micronutrients influence antioxidant, inflammatory and immune responses to HCV.

The Intracellular Free Zinc Level Is Vital for Treg Function and a Feasible Tool to Discriminate between Treg and Activated Th Cells

The intracellular free zinc level and zinc distribution are important for cellular function. Both are highly variable and are altered due to intrinsic zinc pool fluctuation via buffering and muffling reactions. Multiple autoimmune diseases are associated with pathologically changed zinc levels, which provoke altered signal transduction leading to changed immune responses, cell differentiation, and function. For instance, immunological tolerance can be impaired, causing autoimmune diseases because of a malfunction of regulatory T cells (Tregs). We investigated the intracellular free zinc concentration of resting and activated T helper (Th) cells and Tregs in an allogeneic graft versus host disease model using fluorescence-activated cell sorting (FACS) analysis and enlightened cell function under nontoxic zinc concentrations and zinc deficiency by detecting cytokine secretion via enzyme-linked immunosorbent assay (ELISA). We exhibited for the first time that Tregs could be explicitly discriminated from other Th cell subsets using significantly increased intracellular free zinc levels. Moreover, the intracellular free zinc level was essential in maintaining the Treg phenotype and function, since zinc deficiency favored the pro-inflammatory immune response. Therefore, we hypothesize that the intracellular free zinc level in Th cells is essential in guaranteeing proper cellular function and can be used to discriminate Tregs from other Th cell subsets.

Function, Structure, and Transport Aspects of ZIP and ZnT Zinc Transporters in Immune Cells

Zinc is an important trace metal in immune systems, and zinc transporters are involved in many immune responses. Recent advances have revealed the structural and biochemical bases for zinc transport across the cell membrane, with clinical implications for the regulation of zinc homeostasis in immune cells like dendritic cells, T cells, B cells, and mast cells. In this review, we discuss the function, structure, and transport aspects of two major mammalian zinc transporter types, importers and exporters. First, Zrt-/Irt-like proteins (ZIPs) mediate the zinc influx from the extracellular or luminal side into the cytoplasm. There are 14 ZIP family members in humans. They form a homo- or heterodimer with 8 transmembrane domains and extra-/intracellular domains of various lengths. Several ZIP members show specific extracellular domains composed of two subdomains, a helix-rich domain and proline-alanine-leucine (PAL) motif-containing domain. Second, ZnT (zinc transporter) was initially identified in early studies of zinc biology; it mediates zinc efflux as a counterpart of ZIPs in zinc homeostasis. Ten family members have been identified. They show a unique architecture characterized by a Y-shaped conformation and a large cytoplasmic domain. A precise, comprehensive understanding of the structures and transport mechanisms of ZIP and ZnT in combination with mice experiments would provide promising drug targets as well as a basis for identifying other transporters with therapeutic potential.

Serum Zinc Level and Eating Behaviors in Children Receiving Zinc Supplements without Physician Prescription

Background:

The aim of the study was to compare the serum zinc level and eating behaviors in 2–8-year-old children with and without arbitrarily zinc supplementation.

Materials and Methods:

This case–control study was conducted from December 2015 to December 2017 in Isfahan, Iran. The case group consisted of seventy children, aged 2–8 years, who have received zinc supplement without physician prescription; the controls were an equal number of age-matched children who did not receive any supplement. The serum zinc level was measured, and eating behaviors were identified using Children's Eating Behavior Questionnaire (CEBQ).

Results:

There was no significant difference in serum zinc level between two groups (P = 0.18). Some differences in CEBQ subscales were identified between the groups studied. In the control group, the subscale of enjoyment of food was higher than the case group (P < 0.001). In the case group, the subscales of food fussiness and satiety responsiveness were higher than controls (P < 0.001).

Conclusion:

In this study, serum zinc levels were not significantly different between the two groups, and arbitrarily zinc supplementation does not play an important role in improving anorexia subscales.

Zinc and Sepsis

Sepsis, defined as a “life-threatening organ dysfunction caused by a dysregulated host-response to infection” is a major health issue worldwide and still lacks a fully elucidated pathobiology and uniform diagnostic tests. The trace element zinc is known to be crucial to ensure an appropriate immune response. During sepsis a redistribution of zinc from serum into the liver has been observed and several studies imply a correlation between zinc and sepsis outcome. Therefore the alterations of zinc concentrations in different tissues might serve as one part of the host’s defense mechanism against pathogens during sepsis by diverse mechanisms. It has been suggested that zinc is involved in nutritional immunity, acts as a hepatoprotective agent, or a differentiation signal for innate immune cells, or supports the synthesis of acute phase proteins. Further knowledge about these events could help in the evaluation of how zinc could be optimally applied to improve treatment of septic patients. Moreover, the changes in zinc homeostasis are substantial and correlate with the severity of the disease, suggesting that zinc might also be useful as a diagnostic marker for evaluating the severity and predicting the outcome of sepsis.

Zinc Signal in Brain Diseases

The divalent cation zinc is an integral requirement for optimal cellular processes, whereby it contributes to the function of over 300 enzymes, regulates intracellular signal transduction, and contributes to efficient synaptic transmission in the central nervous system. Given the critical role of zinc in a breadth of cellular processes, its cellular distribution and local tissue level concentrations remain tightly regulated via a series of proteins, primarily including zinc transporter and zinc import proteins. A loss of function of these regulatory pathways, or dietary alterations that result in a change in zinc homeostasis in the brain, can all lead to a myriad of pathological conditions with both acute and chronic effects on function. This review aims to highlight the role of zinc signaling in the central nervous system, where it may precipitate or potentiate diverse issues such as age-related cognitive decline, depression, Alzheimer's disease or negative outcomes following brain injury.

Metallothioneins: Emerging Modulators in Immunity and Infection

Metallothioneins (MTs) are a family of metal-binding proteins virtually expressed in all organisms including prokaryotes, lower eukaryotes, invertebrates and mammals. These proteins regulate homeostasis of zinc (Zn) and copper (Cu), mitigate heavy metal poisoning, and alleviate superoxide stress. In recent years, MTs have emerged as an important, yet largely underappreciated, component of the immune system. Innate and adaptive immune cells regulate MTs in response to stress stimuli, cytokine signals and microbial challenge. Modulation of MTs in these cells in turn regulates metal ion release, transport and distribution, cellular redox status, enzyme function and cell signaling. While it is well established that the host strictly regulates availability of metal ions during microbial pathogenesis, we are only recently beginning to unravel the interplay between metal-regulatory pathways and immunological defenses. In this perspective, investigation of mechanisms that leverage the potential of MTs to orchestrate inflammatory responses and antimicrobial defenses has gained momentum. The purpose of this review, therefore, is to illumine the role of MTs in immune regulation. We discuss the mechanisms of MT induction and signaling in immune cells and explore the therapeutic potential of the MT-Zn axis in bolstering immune defenses against pathogens.

Quantifiable effects of regular exercise on zinc status in a healthy population-A systematic review

Zinc is an essential mineral of which its functions have potential implications on exercise performance and beneficial adaptations of physical activity. While the effects of aerobic exercise on zinc metabolism acutely have been well described, the effect of long-term exercise training on zinc status remains unclear. The present review aims to determine the effects of exercise training on markers of zinc status in an apparently healthy adult population. We conducted a systematic literature search on PubMed, Scopus, SPORTDiscus and Cochrane Library from inception to 28 January 2016 to identify interventional or cohort studies that investigated the effects of exercise training on indices of zinc status. Pairwise comparisons of mean differences in within-group change were calculated and summarised visually in forest plots. Six studies satisfied the inclusion criteria for the systematic review, of which 5 studies included data on changes in serum zinc concentrations and 3 studies provided changes in dietary zinc intake. Two comparisons showed significantly higher increase of serum zinc concentrations in the exercise group compared to control, while one comparison reported significantly lower change in serum zinc for the exercising group. The exercise groups consumed significantly higher dietary zinc compared to controls in two comparisons. The present review revealed an incomplete evidence base in evaluating the effect of long-term exercise training on markers of zinc status. Further well-designed investigations are required to elucidate the relationship for establishment of dietary recommendation in populations who are continuing exercise interventions.

Zinc in Infection and Inflammation

Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps (NET) formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors of differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B (NF-κB), a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli.

Parasites, nutrition, immune responses and biology of metabolic tissues

Nutritional immunology, immunometabolism and identification of novel immunotherapeutic targets are areas of active investigation in parasitology. There is a well-documented crosstalk among immune cells and cells in metabolically active tissues that is important for homeostasis. The numbers and function of these cells are altered by obesity leading to inflammation. A variety of helminths spend some part of their life cycle in the gastrointestinal tract and even entirely enteral nematode infections exert beneficial effects on glucose and lipid metabolism. The foundation of this review is the ability of enteric nematode infections to improve obesity-induced type 2 diabetes and the metabolic syndrome, which are significant health issues in developed areas. It considers the impact of nutrition and specific nutritional deficiencies, which are occur in both undeveloped and developed areas, on the host's ability mount a protective immune response against parasitic nematodes. There are a number of proposed mechanisms by which parasitic nematodes can impact metabolism including effects gastrointestinal hormones, altering epithelial function and changing the number and/or phenotype of immune cells in metabolic tissues. Nematodes can also exert their beneficial effects through Th2 cytokines that activate the transcription factor STAT6, which upregulates genes that regulate glucose and lipid metabolism.

Analysis of Blood Concentrations of Zinc, Germanium, and Lead and Relevant Environmental Factors in a Population Sample from Shandong Province, China

Trace elements, including zinc (Zn) and germanium (Ge), are essential for health; deficiency or excess levels of trace elements results is harmful. As a result of industrial and agricultural production, Pb widely exists in people’s living environment. It is absorbed mainly through the respiratory and digestive tracts, producing systemic harm. Reference values for a normal, healthy population are necessary for health assessment, prevention and treatment of related diseases, and evaluation of occupational exposures. Reference ranges for the Chinese population have not been established. From March 2009 to February 2010; we collected data and blood samples (n = 1302) from residents aged 6–60 years living in Shandong Province, China. We measured blood concentrations of Zn, Ge, and Pb using inductively coupled plasma mass spectrometry to determine reference ranges. Results were stratified by factors likely to affect the concentrations of these trace elements: sex, use of cosmetics or hair dye, age, alcohol intake, smoking habits, and consumption of fried food. The overall geometric mean (GM) concentrations (95% confidence interval) were 3.14 (3.08–3.20) mg/L for Zn, 19.9 (19.3–20.6) μg/L for Ge, and 24.1 (23.2–25.1) μg/L for Pb. Blood Zn concentrations were higher in women than in men (p < 0.001), while the opposite was found for Pb (p < 0.001) and sex did not influence Ge (p = 0.095). Alcohol use was associated with higher blood concentrations of Zn (p = 0.002), Ge (p = 0.002), and Pb (p = 0.001). The GM concentration of Zn was highest in 20–30-year-olds (p < 0.001), while Pb concentrations were highest in 12–16-year-olds (p < 0.001). Use of hair dye was associated with lower blood concentrations of Ge (p < 0.05). GM blood concentrations of Pb differed significantly between those who consumed fried foods 1–2 times/month (18.7 μg/L), 1–2 times/week (20.9 μg/L), and every day (28.5 μg/L; p < 0.001). Blood Pb concentrations were higher in subjects who used cosmetics (p < 0.05), hair dye (p < 0.05), and who smoked cigarettes (p < 0.001) than in those who did not.

Discovery of Zinc for Human Health and Biomarkers of Zinc Deficiency

Zinc deficiency in humans was recognized for the first time in 1963, and a recommended dietary allowance (RDA) for zinc was established by the US National Academy of Sciences in 1974. The present World Health Organization (WHO) estimate is that nearly 2 billion subjects living in the developing world may have zinc deficiency. This is mainly because they subsist on cereal proteins which contain high quantities of organic phosphate compounds, which combine with zinc making it unavailable for absorption. The major adverse clinical effects of zinc deficiency are growth retardation, decreased cell-mediated immunity, impairment of cognitive functions, increased oxidative stress, and upregulation of inflammatory cytokines. Our studies have shown that nearly 30% of healthy, well-to-do elderly subjects living in developed countries may also be zinc deficient due to an increased phytate to zinc molar ratio in their diet. Over 300 enzymes and 2000 transcription factors are now known to require zinc for their functions and stability of their structures, and several studies have now shown that zinc may be a molecular signal for neuronal and immune cells. Fourteen ZIP and 10 ZNT zinc transporters are known to maintain intracellular zinc homeostasis. Therapeutic impacts of zinc on human health are also being investigated. Zinc is being used for the treatment of acute diarrhea in infants and children in developing countries globally, and this has resulted in saving millions of lives. Zinc is now an approved drug for the treatment and maintenance therapy of Wilson's disease, a serious fatal genetic disorder. According to a recent Cochrane Review, zinc is the only treatment which is effective in decreasing the incidence of infections and pain crises in patients with sickle cell disease. Zinc acetate lozenges have been shown to decrease the duration of the common cold by 50%, provided the treatment is started within 24 h of the onset of symptoms, the solution chemistry of the zinc preparation is proper, and the zinc dosages are adequate. Age-related macular degeneration (AMD) accounts for a large proportion of legal blindness in elderly subjects throughout the world. The Age-Related Eye Disease Study Group (AREDS) was supported by National Eye Institute. The National Institutes of Health (NIH) has now reported the results of their 10-year zinc supplementation study in patients with AMD. Zinc was effective in decreasing the incidences of blindness and progression of AMD in elderly subjects. Most importantly, zinc-supplemented subjects showed increased longevity and this was due to a decrease in cardiovascular events. No other micronutrient has shown this dramatic effect on decreasing mortality in the elderly. Our placebo-controlled, zinc supplementation trial in the elderly has shown that zinc supplementation decreased the incidence of infections by 66% and improved cell-mediated immunity. Also, we showed that oxidative stress markers and gene expression of inflammatory cytokines were decreased in elderly subjects who received zinc supplementation. These studies suggest that zinc supplementation in the elderly may have a preventive role in atherosclerosis. Plasma zinc is widely used as a biomarker of zinc deficiency in humans. This test is, however, neither specific nor sensitive. Assays of immunological markers such as plasma active thymulin and gene expression of IL-2 in PHA-stimulated lymphocytes are very sensitive and specific for the diagnosis of human zinc deficiency. The assay of zinc in cells such as lymphocytes and granulocytes are better than plasma zinc; however, even these assays are less sensitive than immunological biomarkers.

Roles of Zinc Signaling in the Immune System

Zinc (Zn) is an essential micronutrient for basic cell activities such as cell growth, differentiation, and survival. Zn deficiency depresses both innate and adaptive immune responses. However, the precise physiological mechanisms of the Zn-mediated regulation of the immune system have been largely unclear. Zn homeostasis is tightly controlled by the coordinated activity of Zn transporters and metallothioneins, which regulate the transport, distribution, and storage of Zn. There is growing evidence that Zn behaves like a signaling molecule, facilitating the transduction of a variety of signaling cascades in response to extracellular stimuli. In this review, we highlight the emerging functional roles of Zn and Zn transporters in immunity, focusing on how crosstalk between Zn and immune-related signaling guides the normal development and function of immune cells.

Altered Levels of Serum Zinc and Cadmium in Patients with Chronic Vesiculobullous Hand and Feet Dermatitis

Micronutrients serve many important functions in our body and altered levels of heavy and trace metals are associated with cutaneous and systemic disorders. Vesicular palmoplantar eczema is an entity whose etiopathogenesis is a mystery. In this prospective case-noncase study blood levels of Zinc and Cadmium in 37 patients of chronic vesiculobullous hand dermatitis were estimated and compared with 40 noncases with similar age and gender distributions. Low serum Zinc levels were found in patients as compared to noncases. The mean difference of serum Zinc between the case and noncase groups was 27.26; the mean value of serum Zinc between the two groups was statistically significant (p < 0.0001). However, elevated Cadmium levels were detected in only 5 patients and in none of the noncases. The mean concentration of serum Cadmium was 2.32 ± 0.38 μg/dL, with a range of 1.90–2.80 μg/dL for the five cases in whom Cadmium was detected. Various toxic and trace metals can interact by influencing each other's absorption, retention, distribution, and bioavailability in the body. The clinical significance of this finding lies in the possible beneficial role of Zinc supplementation in the therapy of chronic vesiculobullous hand dermatitis.

Zinc-induced upregulation of metallothionein (MT)-2A is predicted by gene expression of zinc transporters in healthy adults

The usefulness of zinc transporter and metallothionein (MT) gene expressions to detect changes in zinc intake remains unclear. This pilot study aimed to determine the effects of zinc supplementation on zinc transporter and MT gene expressions in humans. Healthy adults (n = 39) were randomised to zinc treatment (ZT), receiving 22 mg Zn/day (n = 19), or no treatment (NT) (n = 20). Blood samples were collected on Days 0, 2, 7, 14, and 21. Plasma zinc and serum C-reactive protein concentrations were analysed. Gene expression of zinc transporters and MT in peripheral blood mononuclear cells was analysed using real-time PCR. Using repeated-measures ANOVA, MT-2A gene expression and fold change were found to be higher in the ZT group (P = 0.025 and P = 0.016, respectively) compared to the NT group, specifically at Day 2 (40 ± 18 % increase from baseline, P = 0.011), despite no significant increase in plasma zinc concentration. In a multiple regression model exploring the changes in gene expressions between Days 0 and 21, the change in MT-2A gene expression was correlated with changes in all zinc transporter expressions (r (2) = 0.54, P = 0.029); the change in ZIP1 expression emerged as a univariate predictor (P = 0.003). Dietary zinc intake was predictive of zinc transporter and MT expressions (P = 0.030). Physical activity level was positively correlated with baseline ZIP7 expression (r = 0.36, P = 0.029). The present study shows that MT-2A expression is related to changing expression of zinc transporter genes, specifically ZIP1, in response to zinc supplementation. The current report adds to our understanding of MT in the coordinated nature of cellular zinc homeostasis.