Zinc in human health: effect of zinc on immune cells

Zinc Deficiency in Critically Ill Patients: Impact on Clinical Outcome

Background Zinc is a trace element essential for the normal functioning of many vital enzymes and organ systems. Studies examining the rates and degrees of zinc deficiency and its consequences in patients with critical illnesses remain scarce. Materials and methods This is a prospective observational study assessing zinc deficiency in critically ill adult patients admitted to a tertiary care intensive care unit (ICU) and its impact on clinical outcomes. Patients were divided into those with normal (≥ 71 µg/dl) and low (≤ 70 µg/dl) zinc levels. Zinc-deficient patients were further divided into mild, moderate, and severe zinc deficiency groups based on zinc levels of 61-70 µg/dl, 51-60 µg/dl, and below 51 µg/dl, respectively. The primary outcome assessed was ICU mortality, and the secondary outcomes were ICU length of stay (LOS), duration of invasive mechanical ventilation (IMV), acute kidney injury (AKI) at admission, need for non-invasive ventilation (NIV), renal replacement therapy (RRT), or vasopressors during the course of the ICU. Other parameters compared included APACHE (Acute Physiology and Chronic Health Evaluation) II, SOFA (Sequential Organ Failure Assessment) score on day 1, and levels of lactate, procalcitonin, calcium, magnesium, phosphate, and serum albumin. The study also compared the mean zinc levels in patients with low and high SOFA scores (scores up to 7 vs. 8 and above) and low and high APACHE II values (scores up to 15 vs. 16 and above). Results A total of 50 patients were included, of whom 43 (86%) were zinc deficient. Mortality in zinc-deficient and normal zinc-level patients was 33% and 43%, respectively (p = 0.602). Patients with zinc deficiency were also older (mean age 69 vs. 49 years, p = 0.02). There was no difference in secondary outcome parameters, except for more zinc-deficient patients needing RRT. Twenty-six of the zinc-deficient patients had severe zinc deficiency, ten moderate, and seven mild (p = 0.663). ICU mortality was approximately 42%, 10%, and 29% in the severe, moderate, and mild deficiency groups, respectively (p = 0.092). Zinc levels were similar between those with low and high APACHE II scores (mean 47.9 vs. 45.5 µg/dl, p = 0.606) as well as between low and high SOFA scores (mean 47.8 vs. 45.7 µg/dl, p = 0.054). Conclusion The present study suggests that zinc deficiency is very common in critically ill patients but does not correlate with their severity of illness, nor does it lead to a poorer outcome in these patients. However, further studies with a larger cohort of patients would be required to make definitive conclusions.

The nutritional roles of zinc for immune system and COVID-19 patients

Zinc (Zn) is a vital micronutrient that strengthens the immune system, aids cellular activities, and treats infectious diseases. A deficiency in Zn can lead to an imbalance in the immune system. This imbalance is particularly evident in severe deficiency cases, where there is a high susceptibility to various viral infections, including COVID-19 caused by SARS-CoV-2. This review article examines the nutritional roles of Zn in human health, the maintenance of Zn concentration, and Zn uptake. As Zn is an essential trace element that plays a critical role in the immune system and is necessary for immune cell function and cell signaling, the roles of Zn in the human immune system, immune cells, interleukins, and its role in SARS-CoV-2 infection are further discussed. In summary, this review paper encapsulates the nutritional role of Zn in the human immune system, with the hope of providing specific insights into Zn research.

Zinc-nanoparticles alleviate the ovarian damage induced by bacterial lipopolysaccharide (LPS) in pregnant rats and their fetuses

Lipopolysaccharide (LPS) is an endotoxin derived from the cell wall of Gram-negative bacteria. LPS exposure during early gestation is associated with adverse effects on the placenta as well as on developmental outcomes, including embryonic resorption, fetal death, congenital teratogenesis, and fetal growth retardation. This work aimed to explore the adverse effects of LPS injected at an early stage of gestation on the gonads of pregnant rats and the ovaries of their pups and the role of zinc nanoparticles (Zn-NPs) against these adverse effects. Twenty-four pregnant rats were used in this study. They were divided at gestation day 4 into four groups (n = 6): control, Zn-NPs (20 mg/kg orally from gestation day E14 till the end of weaning), LPS (50 µg/kg at gestation days E7 and E9), and LPS + Zn-NPs group. The body weight and placenta weight were recorded at gestational day 16. At postnatal day 21 (weaning), the mothers rats and their offspring were sacrificed and immediately dissected to remove the ovaries and uteri from the mothers and the ovaries from their offspring for subsequent biochemical, histological, and immunohistochemical investigations. The obtained results revealed that LPS exposure during early gestation caused severe histopathological alterations in the placenta, uterus, and ovaries of mothers, as well as in the ovaries of their pups. Also, the uterine and ovarian sections displayed a positive reaction for caspase-3 antibody and a negative reaction for Bcl-2 antibody, which reflects the apoptotic effect of LPS. Additionally, remarkable reductions in the levels of antioxidants (superoxide dismutase and catalase) and significant increases in malondialdehyde (MDA) levels were recorded in the serum of LPS-treated mothers and in the ovarian tissues of their offspring. Further biochemical analysis of the ovarian tissues from LPS-maternally treated offspring showed a significant increase in the levels of caspase-3, TNF-α, and TGF-β1, but a significant decrease in the level of IGF-1. On the other hand, treatment of mothers with Zn-NPs from day 14 of gestation until the weaning day (21st day postnatal) successfully ameliorated most of the deleterious histopathological, immunohistochemical, and biochemical changes induced by LPS.

Zinc status in public health: exploring emerging research trends through bibliometric analysis of the historical context from 1978 to 2022

The current study aims to provide a roadmap for future research by analyzing the research structures and trends in scholarly publications related to the status of zinc in public health. Only journal articles published between 1978 and 2022 are included in the refined bibliographical outputs retrieved from the Web of Science (WoS) database. The first section announces findings based on WoS categories, such as discipline heterogeneity, times cited and publications over time, and citation reports. The second section then employs VoSViewer software for bibliometric analysis, which includes a thorough examination of co-authorship among researchers, organizations, and countries and a count of all bibliographic databases among documents. The final section discusses the research's weaknesses and strengths in zinc status, public health, and potential future directions; 7158 authors contributed to 1730 papers (including 339 with publications, more than three times). "Keen, C.L." is a researcher with the most publications and a better understanding of zinc status in public health. Meanwhile, the USA has been the epicenter of research on the status of zinc in public health due to the highest percentage of publications with the most citations and collaboration with the rest of the world, with the top institution being the University of California, Davis. Future research can be organized collaboratively based on hot topics from co-occurrence network mapping and bibliographic couplings to improve zinc status and protect public health.

The relationship between nutrition and the immune system

Nutrition plays an essential role in the regulation of optimal immunological response, by providing adequate nutrients in sufficient concentrations to immune cells. There are a large number of micronutrients, such as minerals, and vitamins, as well as some macronutrients such as some amino acids, cholesterol and fatty acids demonstrated to exert a very important and specific impact on appropriate immune activity. This review aims to summarize at some extent the large amount of data accrued to date related to the modulation of immune function by certain micro and macronutrients and to emphasize their importance in maintaining human health. Thus, among many, some relevant case in point examples are brought and discussed: (1) The role of vitamin A/all-trans-retinoic-acids (ATRA) in acute promyelocytic leukemia, being this vitamin utilized as a very efficient therapeutic agent via effective modulation of the immune function (2) The involvement of vitamin C in the fight against tumor cells via the increase of the number of active NK cells. (3) The stimulation of apoptosis, the suppression of cancer cell proliferation, and delayed tumor development mediated by calcitriol/vitamin D by means of immunity regulation (4) The use of selenium as a cofactor to reach more effective immune response to COVID vaccination (5). The crucial role of cholesterol to regulate the immune function, which is demonstrated to be very sensitive to the variations of this macronutrient concentration. Other important examples are reviewed as well.

A Review on Measures to Rejuvenate Immune System: Natural Mode of Protection Against Coronavirus Infection

SARS-CoV-2, a novel Corona virus strain, was first detected in Wuhan, China, in December 2019. As of December 16, 2021, almost 4,822,472 people had died and over 236,132,082 were infected with this lethal viral infection. It is believed that the human immune system is thought to play a critical role in the initial phase of infection when the viruses invade the host cells. Although some effective vaccines have already been on the market, researchers and many bio-pharmaceuticals are still working hard to develop a fully functional vaccine or more effective therapeutic agent against the COVID-19. Other efforts, in addition to functional vaccines, can help strengthen the immune system to defeat the corona virus infection. Herein, we have reviewed some of those proven measures, following which a more efficient immune system can be better prepared to fight viral infection. Among these, dietary supplements like- fresh vegetables and fruits offer a plentiful of vitamins and antioxidants, enabling to build of a healthy immune system. While the pharmacologically active components of medicinal plants directly aid in fighting against viral infection, supplementary supplements combined with a healthy diet will assist to regulate the immune system and will prevent viral infection. In addition, some personal habits, like- regular physical exercise, intermittent fasting, and adequate sleep, had also been proven to aid the immune system in becoming an efficient one. Maintaining each of these will strengthen the immune system, allowing innate immunity to become a more defensive and active antagonistic mechanism against corona-virus infection. However, because dietary treatments take longer to produce beneficial effects in adaptive maturation, personalized nutrition cannot be expected to have an immediate impact on the global outbreak.

Attenuating the Effects of Novel COVID-19 (SARS-CoV-2) Infection-Induced Cytokine Storm and the Implications

The COVID-19 pandemic constitutes an arduous global health challenge, and the increasing number of fatalities calls for the speedy pursuit of a remedy. This review emphasizes the changing aspects of the COVID-19 disease, featuring the cytokine storm's pathological processes. Furthermore, we briefly reviewed potential therapeutic agents that may modulate and alleviate cytokine storms. The literature exploration was made using PubMed, Embase, MEDLINE, Google scholar, and China National Knowledge Infrastructure databases to retrieve the most recent literature on the etiology, diagnostic markers, and the possible prophylactic and therapeutic options for the management of cytokine storm in patients hospitalized with COVID-19 disease. The causative agent, severe acute respiratory coronavirus-2 (SARS-CoV-2), continually threatens the efficiency of the immune system of the infected individuals. As the first responder, the innate immune system provides primary protection against COVID-19, affecting the disease's progression, clinical outcome, and prognosis. Evidence suggests that the fatalities associated with COVID-19 are primarily due to hyper-inflammation and an aberrant immune function. Accordingly, the magnitude of the release of pro-inflammatory cytokines such as interleukin (IL)-1, (IL-6), and tumor necrosis alpha (TNF-α) significantly differentiate between mild and severe cases of COVID-19. The early prediction of a cytokine storm is made possible by several serum chemistry and hematological markers. The prompt use of these markers for diagnosis and the aggressive prevention and management of a cytokine release syndrome is critical in determining the level of morbidity and fatality associated with COVID-19. The prophylaxis and the rapid treatment of cytokine storm by clinicians will significantly enhance the fight against the dreaded COVID-19 disease.

Intensely clustered outbreak of visceral leishmaniasis (kala-azar) in a setting of seasonal migration in a village of Bihar, India

Background

A visceral leishmaniasis outbreak was reported from a village in a low-endemic district of Bihar, India.

Methods

Outbreak investigation with house-to-house search and rapid test of kala-azar suspects and contacts was carried out. Sandfly collection and cone bio-assay was done as part of entomological study.

Results

A spatially and temporally clustered kala-azar outbreak was found at Kosra village in Sheikhpura district with 70 cases reported till December 2018. Delay of more than a year was found between diagnosis and treatment of the index case. The southern hamlet with socio-economically disadvantaged migrant population was several times more affected than rest of the village (attack rate of 19.0% vs 0.5% respectively, OR_MH = 39.2, 95% CI 18.2–84.4). The median durations between onset of fever to first contact with any health services, onset to kala-azar diagnosis, diagnosis to treatment were 10 days (IQR 4–18), 30 days (IQR 17–73) and 1 day (IQR 0.5 to 3), respectively, for 50 kala-azar cases assessed till June 2017. Three-fourths of these kala-azar cases had out-of-pocket medical expenditure for their condition. Known risk factors for kala-azar such as illiteracy, poverty, belonging to socially disadvantaged community, migration, residing in kutcha houses, sleeping in rooms with unplastered walls and non-use of mosquito nets were present in majority of these cases. Only half the dwellings of the kala-azar cases were fully sprayed. Fully gravid female P. argentipes collected post indoor residual spraying (IRS) and low sandfly mortality on cone-bioassay indicated poor effectiveness of vector control.

Conclusions

There is need to focus on low-endemic areas of kala-azar. The elimination programme should implement a routine framework for kala-azar outbreak response. Complete case-finding, use of quality-compliant insecticide and coverage of all sprayable surfaces in IRS could help interrupt transmission during outbreaks.

Effect of the Zn Supplementation on Immuno-Modulatory Activities of Bovine Lactoferrin in the Murine Splenocytes and RAW264.7 Macrophages

Lactoferrin (LF) has important bio-functions including immuno-modulation, while essential trace metals may interact with LF and thereby induce property especially bio-activity changes. Bovine LF was thus supplemented with Zn²⁺ at 0.16, 0.32, and 0.64 mg/g LF to yield 10%, 20%, and 40% Zn-saturation, respectively. Afterwards, bovine LF and the Zn-supplemented LF products at 10-40-μg/mL doses were compared for their immuno-modulatory activities in two immune cells (murine splenocytes and RAW264.7 macrophages), using the stimulation index of the splenocytes, T lymphocyte subpopulations, macrophage phagocytosis, and cytokine production as evaluation reflectors. The results showed that bovine LF and the Zn-supplemented LF products had suppressive effect on the splenocytes and concanavalin A (ConA)- and lipopolysaccharide-stimulated splenocytes, but lower Zn-saturation and lower dose could alleviate and even counteract this suppressive effect (P < 0.05). More importantly, the Zn-supplemented LF product with lower Zn-saturation at lower dose exerted slightly higher macrophage stimulation, increased CD4⁺/CD8⁺ ratio of T lymphocyte subpopulations, and were capable of enhancing the interleukin-2 (IL-2), IL-4, and interferon-γ production in the splenocytes or the IL-1β, IL-6, and tumor necrosis factor-α production in the macrophages significantly (P < 0.05). Contrary to its counterpart at lower dose, the Zn-supplemented LF product with higher Zn-saturation at higher dose mostly showed opposite effects in the two cell models. It is concluded that Zn supplementation has an impact on the immuno-modulation of bovine LF, while Zn-saturation is a key factor to modulate these assessed immune activities.

Immunosenescence and Its Hallmarks: How to Oppose Aging Strategically? A Review of Potential Options for Therapeutic Intervention

Aging is accompanied by remodeling of the immune system. With time, this leads to a decline in immune efficacy, resulting in increased vulnerability to infectious diseases, diminished responses to vaccination, and a susceptibility to age-related inflammatory diseases. An age-associated immune alteration, extensively reported in previous studies, is the reduction in the number of peripheral blood naïve cells, with a relative increase in the frequency of memory cells. These two alterations, together with inflamm-aging, are considered the hallmarks of immunosenescence. Because aging is a plastic process, it is influenced by both nutritional and pharmacological interventions. Therefore, the role of nutrition and of immunomodulation in immunosenescence is discussed, due to the multifactorial influence on these hallmarks. The close connection between nutrition, intake of bioactive nutrients and supplements, immune function, and inflammation demonstrate the key role of dietary strategies as regulators of immune response and inflammatory status, hence as possible modulators of the rate of immunosenescence. In addition, potential options for therapeutic intervention are clarified. In particular, the use of interleukin-7 as growth factor for naïve T cells, the function of checkpoint inhibitors in improving T cell responses during aging and, the potential of drugs that inhibit mitogen-activated protein kinases and their interaction with nutrient signaling pathways are discussed. Finally, it is suggested that the inclusion of appropriate combinations of toll-like receptor agonists may enhance the efficacy of vaccination in older adults.

The Effect of Zinc Supplementation on Sleep Quality of ICU Nurses: A Double Blinded Randomized Controlled Trial

This study examined the effect of zinc supplementation on the sleep quality (SQ) of intensive care unit (ICU) nurses. In a double-blind, randomized controlled trial, 54 ICU nurses were randomly assigned to the intervention group ( n = 27) that received 220 mg zinc sulfate capsules every 72 hours for 1 month and the control group ( n = 26) that received placebo. Sleep quality of ICU nurses was measured by calculating the total quality sleep score using the Pittsburgh Sleep Quality Index (PSQI). The serum zinc level was a secondary outcome. All measurements were calculated at both baseline and 1 month after intervention. The total PSQI, subjective SQ, and sleep latency scores for the intervention group were significantly lower than the control group, which means that the SQ of ICU nurses in the intervention group improved from baseline. The serum zinc level of the intervention group at the end of the study was significantly higher than the control group, which means that zinc supplementation improved participants’ serum zinc level. Based on these findings, the researcher suggested that zinc supplementation could be associated with better SQ, subjective SQ, and sleep latency in this group of workers.

Antioxidant role of zinc in diabetes mellitus

Chronic hyperglycemia statue noticed in diabetes mellitus favors the manifestation of oxidative stress by increasing the production of reactive oxygen species and/or by reducing the antioxidant defense system activity. Zinc plays an important role in antioxidant defense in type 2 diabetic patients by notably acting as a cofactor of the superoxide dismutase enzyme, by modulating the glutathione metabolism and metallothionein expression, by competing with iron and copper in the cell membrane and by inhibiting nicotinamide adenine dinucleotide phosphate-oxidase enzyme. Zinc also improves the oxidative stress in these patients by reducing chronic hyperglycemia. It indeed promotes phosphorylation of insulin receptors by enhancing transport of glucose into cells. However, several studies reveal changes in zinc metabolism in individuals with type 2 diabetes mellitus and controversies remain regarding the effect of zinc supplementation in the improvement of oxidative stress in these patients. Faced with the serious challenge of the metabolic disorders related to oxidative stress in diabetes along with the importance of antioxidant nutrients in the control of this disease, new studies may contribute to improve our understanding of the role played by zinc against oxidative stress and its connection with type 2 diabetes mellitus prognosis. This could serve as a prelude to the development of prevention strategies and treatment of disorders associated with this chronic disease.