Zinc Supplementation Stimulates Red Blood Cell Formation in Rats

Continuous blood exchange in rats as a novel approach for experimental investigation

Blood exchange therapy, specifically Whole blood exchange (WBE), is increasingly being utilized in clinical settings to effectively treat a range of diseases. Consequently, there is an urgent requirement to establish convenient and clinically applicable animal models that can facilitate the exploration of blood exchange therapy mechanisms. Our study conducted continuous WBE in rats through femoral and tail vein catheterization using dual-directional syringe pumps. To demonstrate the applicability of continuous WBE, drug-induced hemolytic anemia (DIHA) was induced through phenylhydrazine hydrochloride (PHZ) injection. Notability, the rats of DIHA + WBE group all survived and recovered within the subsequent period. After the implementation of continuous WBE therapy day (Day 1), the DIHA + WBE group exhibited a statistically significant increase in red blood cells (RBC) (P = 0.0343) and hemoglobin (HGB) levels (P = 0.0090) compared to DIHA group. The rats in the DIHA + WBE group exhibited a faster recovery rate compared to the DIHA group, indicating the successful establishment of a continuous blood exchange protocol. This experimental approach demonstrates not just promising efficacy in the treatment of DIHA and offers a valuable tool for investigating the underlying mechanisms of blood exchange. Furthermore, it has a great potential to the advancement of biomedical research such as drug delivery exploration.

CUTANEOUS MYIASIS AND ITS RELATIONSHIP TO WELLNESS IN EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA) IN CAPE COD, MASSACHUSETTS

Eastern box turtles (Terrapene carolina carolina) face a variety of anthropogenic, infectious, and environmental threats and have been affected by high morbidity and mortality disease events. Wellness parameters in free-ranging eastern box turtles with a high prevalence of myiasis on Cape Cod, MA, were documented to identify epidemiologic trends or associations with several health parameters. There were 109 samples collected from 59 individual box turtles over the course of 4 mon. Six turtles died over the course of this study. Fly larvae infestations varied in severity and were observed in the cutaneous and subcutaneous tissue (n = 18; 30.5%). Animals with myiasis had fewer plastron abnormalities than those without (P = 0.034), and all turtles found in bogs had evidence of fly larvae infections (P < 0.0001). Individuals with myiasis also had lower body condition index (P = 0.014), lower total white blood cells (P = 0.031), lower PCV (P < 0.0001), lower total solids (P < 0.0001), higher erythrocyte sedimentation rate (P < 0.0001), lower calcium (P = 0.018), and lower phosphorus (P = 0.017). Three turtles tested positive for terrapene herpesvirus 1, but presence was not associated with myiasis. Heavy metal analysis revealed no significant differences between turtles with and without myiasis. This study examined the health of a population of eastern box turtles, and continued health assessments will be beneficial in determining the impact of myiasis on future conservation plans.

Hematopoietic effect of echinochrome on phenylhydrazine-induced hemolytic anemia in rats

Background

Hemolytic anemia (HA) is a serious health condition resulting from reduced erythrocytes' average life span. Echinochrome (Ech) is a dark-red pigment found in shells and spines of sea urchins.

Aim

Studying the potential therapeutic effect of Ech on phenylhydrazine (PHZ)-induced HA in rats.

Methods

Eighteen rats were divided into three groups (n = 6): the control group, the phenylhydrazine-induced HA group and the Ech group, injected intraperitoneally with PHZ and supplemented with oral Ech daily for 6 days.

Results

Ech resulted in a considerable increase in RBCs, WBCs, and platelets counts, hemoglobin, reduced glutathione, catalase, and glutathione-S-transferase levels, and a significant decrease in aspartate & alanine aminotransferases, alkaline phosphatase, gamma-glutamyl transferase, bilirubin, creatinine, urea, urate, malondialdehyde & nitric oxide levels in anemic rats. Histopathological examination of liver and kidney tissue samples showed marked improvement.

Conclusion

Ech ameliorated phenylhydrazine-induced HA with a hepatorenal protective effect owing to its anti-inflammatory and antioxidant properties.

Effect of royal jelly on acrylamide-induced neurotoxicity in rats

Royal Jelly (RJ) is a natural product made by nurse bees known for its multiple therapeutic properties. The research aims to discover the ability of RJ to improve the hematological alterations and neurotoxicity caused by acrylamide (AA). The study rats were separated equally into four groups (6 in each group), the control group, the AA (38.27 mg/kg bw) group, the RJ (150 mg/kg bw) + AA group, and the RJ (300 mg/kg bw) + AA group. Blood and brain samples were collected after 10 days to evaluate haematological and biochemical parameters and to examine histopathological and immunohistochemistry. The administration of AA increased the level of malondialdehyde (MDA), decreases levels of haematological parameters, superoxide dismutase (SOD), reduced glutathione (GSH), brain-derived neurotrophic factor (BDNF), neurotransmitters (serotonin, dopamine, and acetylcholine), and cleaved caspase-3, as well as increase the damage to the brain tissues. Meanwhile, RJ improved levels of haematological parameters, oxidative stress parameters (MDA, SOD, and GSH), BDNF, neurotransmitters, cleaved caspase-3, and brain tissue damage induced by AA. The study demonstrated the protective impact of RJ against the haematological alterations and neurotoxicity caused by AA.

Oral Zinc-Rich Oyster Supplementation Corrects Anemia in Rats

This study investigates the impact of various zinc supplementation methods on anemia in rats induced by phenylhydrazine (PHZ) and in 5/6-nephrectomized anemic rats. We compare oral zinc sulfate (ZnSO4) supplementation, oyster Crassostrea gigas supplementation, and hard clam Meretrix lusoria supplementation on red blood cell (RBC) levels. Oral zinc-rich oyster supplementation (2.70 mg Zn (30 g oyster)/day/rat) effectively corrects anemia in both experimental groups. Rats orally fed oysters for four days exhibit similar effectiveness as those receiving a single ZnSO4 injection (0.95 mg Zn (4.18 mg ZnSO4⋅7H2O)/rat). In contrast, oral ZnSO4 supplementation (2.70 mg Zn (11.88 mg ZnSO4⋅7H2O)/day/rat) does not significantly increase RBC levels, suggesting better zinc absorption from oysters. A placebo group of anemic rats supplemented with hard clams, similar in composition to oysters but much lower in zinc, did not change RBC counts. This supports oysters' high zinc content as the key to correcting anemia. Oysters also contain high iron levels, offering a potential solution for iron-deficiency anemia while supporting bone marrow erythropoiesis. In summary, oral oyster supplementation emerges as an effective strategy to correct anemia in rats with added zinc and iron support for erythropoiesis.

Zinc and aging: a narrative review of the effects on hematopoiesis and its link with diseases

There has been a global increase in the older population in recent decades and, as age advances, complex metabolic and epigenetic changes occur in the organism, and these may trigger some health complications commonly found among this population. Additionally, several changes occur in older people that can reduce the dietary intake or the process of nutrient absorption. In this way, tissues with high nutrient requirements are more affected. Hematopoiesis is the process of formation, development, and maturation of blood cells and is a process with a high turnover. This high demand makes the integrity of the hematopoietic process susceptible to various factors that impair physiological function, such as aging and micronutrient bioavailability. Among these micronutrients, Zinc is considered an important micronutrient, playing diverse roles across various tissues and cell types. Some of the alterations in hematopoiesis that appear as a consequence of aging and due to insufficient micronutrient intake are well described in the literature; however, not much is known about how zinc deficiency contributes towards the development of diseases seen in aging. Considering the importance of zinc to act on several biological processes, this narrative review discusses several studies related to the physiological requirements, deficiency, or excess of zinc, including studies in experimental models and humans, and aimed to shed light on the relationship between zinc and the regulation of hematopoietic tissue, exploring possible links between this mineral with common disorders that appear during aging.

Effects of Zinc on the Right Cardiovascular Circuit in Long-Term Hypobaric Hypoxia in Wistar Rats

Hypobaric hypoxia under chromic conditions triggers hypoxic pulmonary vasoconstriction (HPV) and right ventricular hypertrophy (RVH). The role of zinc (Zn) under hypoxia is controversial and remains unclear. We evaluated the effect of Zn supplementation in prolonged hypobaric hypoxia on HIF2α/MTF-1/MT/ZIP12/PKCε pathway in the lung and RVH. Wistar rats were exposed to hypobaric hypoxia for 30 days and randomly allocated into three groups: chronic hypoxia (CH); intermittent hypoxia (2 days hypoxia/2 days normoxia; CIH); and normoxia (sea level control; NX). Each group was subdivided (n = 8) to receive either 1% Zn sulfate solution (z) or saline (s) intraperitoneally. Body weight, hemoglobin, and RVH were measured. Zn levels were evaluated in plasma and lung tissue. Additionally, the lipid peroxidation levels, HIF2α/MTF-1/MT/ZIP12/PKCε protein expression and pulmonary artery remodeling were measured in the lung. The CIH and CH groups showed decreased plasma Zn and body weight and increased hemoglobin, RVH, and vascular remodeling; the CH group also showed increased lipid peroxidation. Zn administration under hypobaric hypoxia upregulated the HIF2α/MTF-1/MT/ZIP12/PKCε pathway and increased RVH in the intermittent zinc group. Under intermittent hypobaric hypoxia, Zn dysregulation could participate in RVH development through alterations in the pulmonary HIF2α/MTF1/MT/ZIP12/PKCε pathway.

Study on the Zinc Nutritional Status and Risk Factors of Chinese 6–18-Year-Old Children

Zinc is an essential micronutrient that is involved in several metabolic processes, especially children’s growth and development. Although many previous studies have evaluated the zinc nutritional status of children, there are very few reports on children aged 6–18 years old. Furthermore, there are few reports on children’s zinc nutrition status based on the Chinese population. According to WHO data, the prevalence of zinc deficiency in Asian countries is rather high and has resulted in high child mortality. In this study, we aimed to comprehensively assess zinc nutritional status and the prevalence of zinc deficiency among children aged 6–18 years in China based on nationally representative cross-sectional data. Subgroup comparisons were made under possible influencing factors. The potential risk factors of zinc deficiency were also discussed. A total of 64,850 children, equally male and female, were recruited from 150 monitoring sites in 31 provinces through stratified random sampling from China National Nutrition and Health Survey of Children and Lactating Mothers (CNNHS 2016–2017). Median and interquartile intervals were used to represent the overall zinc concentration levels and different subgroups. A Chi-square test was used to compare serum zinc levels and the prevalence of zinc deficiency in children under different group variables. In order to study the influencing factors of zinc deficiency, multiple logistic regression was utilized. It was found that the median concentration of serum Zn was 88.39 μg/dL and the prevalence of Zn deficiency was 9.62%. The possible influence factors for Zn deficiency were sex, anemia, nutritional status, city type and income. By conducting a subgroup analysis of the factors, it was found that males; those with anemia, stunting and low income; and children living in rural areas have a higher risk of Zn deficiency. This study offers a comprehensive analysis of Zn nutritional status among Chinese children, which provides reliable data for policy formulation to improve the zinc nutrition status of children.

Iron as a therapeutic target in chronic liver disease

It was clearly realized more than 50 years ago that iron deposition in the liver may be a critical factor in the development and progression of liver disease. The recent clarification of ferroptosis as a specific form of regulated hepatocyte death different from apoptosis and the description of ferritinophagy as a specific variation of autophagy prompted detailed investigations on the association of iron and the liver. In this review, we will present a brief discussion of iron absorption and handling by the liver with emphasis on the role of liver macrophages and the significance of the iron regulators hepcidin, transferrin, and ferritin in iron homeostasis. The regulation of ferroptosis by endogenous and exogenous mod-ulators will be examined. Furthermore, the involvement of iron and ferroptosis in various liver diseases including alcoholic and non-alcoholic liver disease, chronic hepatitis B and C, liver fibrosis, and hepatocellular carcinoma (HCC) will be analyzed. Finally, experimental and clinical results following interventions to reduce iron deposition and the promising manipulation of ferroptosis will be presented. Most liver diseases will be benefited by ferroptosis inhibition using exogenous inhibitors with the notable exception of HCC, where induction of ferroptosis is the desired effect. Current evidence mostly stems from in vitro and in vivo experimental studies and the need for well-designed future clinical trials is warranted.

Benefits and risks of essential trace elements in chronic kidney disease: a narrative review

Background and Objective

Chronic kidney disease (CKD) is an important public health concern. With the decline of renal function, CKD patients gradually progress to end-stage kidney disease and need to undergo dialysis or kidney transplantation to maintain life, bringing a heavy economic burden to the family and society. Therefore, it is necessary to effectively prevent and delay the progression of CKD. Essential trace elements play an indispensable role in CKD, and the objective of this study is to systematically review their benefits in the disease and summarize the risks of their excess.

Methods

The keywords "trace elements", "chronic kidney disease", "dialysis", "inflammation", and "fibrosis" and their combinations were used to search for relevant literature published in the PubMed database and Web of Science. We then summarized the role of trace element abnormalities in CKD patients in anemia, oxidative stress, inflammation, and chronic fibrosis, and the risk of their excess.

Key Content and Findings

Imbalance of essential trace elements is a common complication of CKD and a risk factor for CKD progression, cardiovascular events, and death. This article reviews the effects of essential trace elements (iron, zinc, selenium, copper, iodine, and manganese) on CKD. We analyze literature and discuss the advantages and disadvantages of various essential trace elements.

Conclusions

Research shows CKD patients have an imbalance of essential trace elements, and treatment based on these is an important direction for future exploration. A knowledge of the homeostasis of trace elements is important to improving the prognosis of CKD patients and delaying the progression of the disease.

Association of Zinc with Anemia

Zinc is an essential trace element, and anemia is the most common blood disorder. The association of zinc with anemia may be divided into three major forms: (1) zinc deficiency contributing to anemia, (2) excess intake of zinc leading to anemia, and (3) anemia leading to abnormal blood-zinc levels in the body. In most cases, zinc deficiency coexists with iron deficiency, especially in pregnant women and preschool-age children. To a lesser extent, zinc deficiency may cooperate with other factors to lead to anemia. It seems that zinc deficiency alone does not result in anemia and that it may need to cooperate with other factors to lead to anemia. Excess intake of zinc is rare. However, excess intake of zinc interferes with the uptake of copper and results in copper deficiency that leads to anemia. Animal model studies indicate that in anemia, zinc is redistributed from plasma and bones to the bone marrow to produce new red blood cells. Inadequate zinc status (zinc deficiency or excess) could have effects on anemia; at the same time, anemia could render abnormal zinc status in the body. In handling anemia, zinc status needs to be observed carefully, and supplementation with zinc may have preventive and curative effects.

Sex differences and associations between zinc deficiency and anemia among hospitalized adolescents and young adults with eating disorders

PURPOSE

To determine sex differences in and associations between zinc deficiency and anemia among adolescents and young adults hospitalized for medical complications of eating disorders.

METHODS

We retrospectively reviewed electronic medical records of 601 patients aged 9-25 years admitted to the University of California, San Francisco Eating Disorders Program for medical instability, between May 2012 and August 2020. Descriptive statistics, crude, and adjusted logistic regression models were used to assess the association between zinc deficiency (< 55 mcg/dL) and anemia (< 13.6 g/dL in males [M] and < 11.8 g/dL in females [F]).

RESULTS

A total of 87 males and 450 females met eligibility criteria (age 15.98 ± 2.81, 59.4% anorexia nervosa; admission body mass index 17.49 ± 2.82). In unadjusted comparisons, plasma zinc in males and females were not statistically different (M 64.88 ± 14.89 mcg/dL vs F 63.81 ± 13.96 mcg/dL, p = 0.517); moreover, there were no differences in the percentage of males and females with zinc deficiency (M 24.14% vs F 24.89%). However, a greater percentage of males than females were anemic (M 50.00% vs F 17.61%, p < 0.001), with similar findings in the subgroup with anorexia nervosa. In logistic regression models stratified by sex and eating disorder diagnosis, zinc deficiency was significantly associated with anemia in males (AOR 3.43, 95% CI 1.16, 10.13), but not females (AOR 1.47, 95% CI 0.86, 2.54).

CONCLUSIONS

For the first time, we demonstrate that zinc deficiency is equally severe in males compared to females hospitalized with medical complications from eating disorders, with nearly a quarter of inpatients experiencing zinc deficiency. Anemia is more common in males than females hospitalized with eating disorders.

LEVEL OF EVIDENCE

Level V: descriptive cross-sectional study.

Iron-Induced Hepatocarcinogenesis—Preventive Effects of Nutrients

The liver is a primary organ that stores body iron, and plays a central role in the regulation of iron homeostasis. Hepatic iron overload (HIO) is a prevalent feature among patients with chronic liver diseases (CLDs), including alcoholic/nonalcoholic liver diseases and hepatitis C. HIO is suggested to promote the progression toward hepatocellular carcinoma because of the pro-oxidant nature of iron. Iron metabolism is tightly regulated by various factors, such as hepcidin and ferroportin, in healthy individuals to protect the liver from such deteriorative effects. However, their intrinsic expressions or functions are frequently compromised in patients with HIO. Thus, various nutrients have been reported to regulate hepatic iron metabolism and protect the liver from iron-induced damage. These nutrients are beneficial in HIO-associated CLD treatment and eventually prevent iron-mediated hepatocarcinogenesis. This mini-review aimed to discuss the mechanisms and hepatocarcinogenic risk of HIO in patients with CLDs. Moreover, nutrients that hold the potential to prevent iron-induced hepatocarcinogenesis are summarized.

Exploration of the relationship between anemia and iron and zinc deficiencies in children under 5 years of age living in the malaria endemic area of South Kivu/Democratic Republic of Congo

The aim of this study was to explore the relationship of iron and zinc deficiencies and anemia in children aged under 5 years living in malaria endemic area of South Kivu/DRC. We conducted a cross-sectional study in the health zone of Miti Murhesa in South Kivu/DRC. A total of 1088 children in good general health were included in this study. Almost 40% of children were anemic. The prevalence of iron deficiency (ID) was found in 34.9% and 49.1% children based on ferritin or free erythrocyte protoporphyrin (FEP), respectively. If anemia is present, we found iron deficiency anemia (IDA) according to the WHO-criteria (ferritin) in 31%, and according to FEP in 66% of children. The overall prevalence of zinc deficiency was 17.6%. If anemia is present, zinc deficiency was found in 24.4% of children. Inflammation/infection, based upon CRP, was present in 39.7% children. The independent factors associated with anemia were recent illness, middle upper arm circumference, weight-for-height, ID according to FEP, zinc deficiency, and submicroscopic Plasmodium infection. A high prevalence of ID was observed in children in South Kivu according to FEP. Ferritin as acute phase protein was less suited in this population due to a high frequency of infection/inflammation. Iron and zinc deficiencies were found to be significantly associated with anemia in this population.

New Insights into Potential Beneficial Effects of Bioactive Compounds of Bee Products in Boosting Immunity to Fight COVID-19 Pandemic: Focus on Zinc and Polyphenols

The coronavirus disease 2019 (COVID-19) is an epidemic caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Populations at risk as well as those who can develop serious complications are people with chronic diseases such as diabetes, hypertension, and the elderly. Severe symptoms of SARS-CoV-2 infection are associated with immune failure and dysfunction. The approach of strengthening immunity may be the right choice in order to save lives. This review aimed to provide an overview of current information revealing the importance of bee products in strengthening the immune system against COVID-19. We highlighted the immunomodulatory and the antiviral effects of zinc and polyphenols, which may actively contribute to improving symptoms and preventing complications caused by COVID-19 and can counteract viral infections. Thus, this review will pave the way for conducting advanced experimental research to evaluate zinc and polyphenols-rich bee products to prevent and reduce the severity of COVID-19 symptoms.

Effect of zinc depletion/repletion on intestinal iron absorption and iron status in rats

Iron and zinc deficiencies likely coexist in general population. We have previously demonstrated that zinc treatment induces while zinc deficiency inhibits iron absorption in intestinal cell culture models, but this needs to be tested in vivo. In the present study we assessed intestinal iron absorption, iron status (haemoglobin), red blood cell number, plasma ferritin, transferrin receptor, hepcidin) and tissue iron levels in zinc depleted, replete and pair fed control rats. Zinc depletion led to reduction in body weight, tissue zinc levels, intestinal iron absorption, protein and mRNA expression of iron transporters, the divalent metal ion transporter-1, hephaestin and ferroportin, but elevated the intestinal and liver tissue iron levels compared with the pair fed control rats. Zinc repletion led to a significant weight gain compared to zinc deficient rats and normalized the iron absorption, iron transporter expression, tissue iron levels to that of pair fed control rats. Surprisingly, haemoglobin levels and red blood cell number reduced significantly in zinc repleted rats, which could be due to rapid weight gain. Together, these results indicate that whole body zinc status has profound influence on growth, intestinal absorption and systemic utilization of iron, mediated via modulation of iron transporter expression.

Human iPSC-derived neural crest stem cells can produce EPO and induce erythropoiesis in anemic mice

Inadequate production of erythropoietin (EPO) leads to anemia. Although erythropoiesis-stimulating agents can be used to treat anemia, these approaches are limited by high costs, adverse effects, and the need for frequent injections. Developing methods for the generation and transplantation of EPO-producing cells would allow for the design of personalized and complication-free therapeutic solutions. In mice, the first EPO source are neural crest cells (NCCs), which ultimately migrate to the fetal kidney to differentiate into EPO-producing fibroblasts. In humans however, it remains unknown whether NCCs can produce EPO in response to hypoxia. Here, we developed a new protocol to differentiate human induced pluripotent stem cells (hiPSCs) into NCCs and showed that cthese cells can produce functional EPO that can induce human CD34⁺ hematopoietic progenitor differentiation into erythroblasts in vitro. Moreover, we showed that hiPSC-derived NCCs can be embedded in clinical-grade atelocollagen scaffolds and subcutaneously transplanted into anemic mice to produce human EPO, accelerate hematocrit recovery, and induce erythropoiesis in the spleen. Our findings provide unprecedented evidence of the ability of human NCCs to produce functional EPO in response to hypoxia, and proof-of-concept for the potential clinical use of NCC-containing scaffolds as cell therapy for renal and non-renal anemia.

Associations between Zinc and Hemoglobin Concentrations in Preschool Children and Women of Reproductive Age: An Analysis of Representative Survey Data from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) Project

BACKGROUND

Anemia is a worldwide concern. Nutritional deficiencies and inflammation are considered main contributors, but zinc deficiency has only recently been associated with anemia.

OBJECTIVES

In this study we assessed associations between zinc status and hemoglobin (Hb) concentrations and anemia in preschool children 6-59 mo old (PSC) and nonpregnant women of reproductive age 15-49 y old (WRA) in population-based nutrition surveys.

METHODS

Cross-sectional data from 13 (PSC) and 12 (WRA) countries within the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project were used. Multivariable linear models were constructed that included zinc status (plasma/serum zinc concentrations), Hb concentrations and anemia, iron status, age, sex, and inflammation (C-reactive protein and α-1-acid glycoprotein). Zinc was adjusted for inflammation in PSC according to the BRINDA algorithm.

RESULTS

Data were available for 18,658 PSC and 22,633 WRA. Prevalence of anemia ranged from 7.5% to 73.7% and from 11.5% to 94.7% in PSC and WRA, respectively. Prevalence of zinc deficiency ranged from 9.2% to 78.4% in PSC and from 9.8% to 84.7% in WRA, with prevalence of zinc deficiency >20% in all countries except Azerbaijan (PSC), Ecuador (PSC), and the United Kingdom (WRA). Multivariable linear regression models showed that zinc concentrations were independently and positively associated with Hb concentrations in 7 of 13 countries for PSC and 5 of 12 countries for WRA. In the same models, ferritin concentration was also significantly associated with Hb among PSC and WRA in 9 and 10 countries, respectively. Zinc deficiency was significantly associated with anemia in PSC and WRA in 5 and 4 countries respectively.

CONCLUSIONS

Zinc deficiency was prevalent in most countries and associations between zinc and Hb in roughly half of the countries examined suggesting that strategies to combat zinc deficiency may help reduce anemia prevalence. More research on mechanisms by which zinc deficiency is associated with anemia and the reasons for the heterogeneity among countries is warranted.

Influence of Zinc on the Acute Changes in Erythropoietin and Proinflammatory Cytokines with Hypoxia

Baranauskas, Marissa N., Joseph Powell, Alyce D. Fly, Bruce J. Martin, Timothy D. Mickleborough, Hunter L. Paris, and Robert F. Chapman. Influence of zinc on the acute changes in erythropoietin and proinflammatory cytokines with hypoxia. High Alt Med Biol. 22: 148-156, 2021. Background: Considerable, unexplained, interindividual variability characterizes the erythropoietin (EPO) response to hypoxia, which can impact hematological acclimatization for individuals sojourning to altitude. Zinc supplementation has the potential to alter EPO by attenuating increases in inflammation and oxidative stress. Yet, the application of such an intervention has not been evaluated in humans. In this proof-of-concept study, we aimed to evaluate the EPO and inflammatory responses to acute hypoxia in human participants following chronic zinc supplementation. Methods: Nine physically active participants (men n = 5, women n = 4, age 28 ± 4 years, height 176 ± 11 cm, mass 77 ± 21 kg) were exposed to 12 hours of normobaric hypoxia simulating an altitude of 3,000 m (F_iO₂ = 0.14) before and after 8 weeks of supplementation with 40 mg/day of elemental zinc from picolinate. Blood samples for subsequent analysis of serum zinc, EPO, superoxide dismutase (extracellular superoxide dismutase [EC-SOD]), C-reactive protein (CRP), and proinflammatory cytokines were obtained pre- and postsupplementation and exposure to hypoxia. Results: After zinc supplementation, EPO increased by 64.9 ± 36.0% (mean ± standard deviation) following 12 hours of hypoxia, but this response was not different from presupplementation (70.8 ± 46.1%). Considerable interindividual (range: -1% to +208%) variability was apparent in the acute EPO response. While most markers of inflammation did not change with hypoxia, interleukin-6 concentrations increased from 1.17 ± 0.05 to 1.97 ± 0.32 pg/ml during the final 6 hours. The acute EPO response at 12 hours was not related to changes in serum zinc, EC-SOD, CRP, or proinflammatory cytokines. Conclusions: Zinc supplementation does not influence the acute EPO or inflammatory response with short-term exposure to moderate levels of normobaric hypoxia (3,000 m) in apparently healthy young adults.

Crotalaria verrucosa Leaf Extract Mediated Synthesis of Zinc Oxide Nanoparticles: Assessment of Antimicrobial and Anticancer Activity

In this work, we present an ecofriendly, non-hazardous, green synthesis of zinc oxide nanoparticles (ZnO NPs) by leaf extract of Crotalaria verrucosa (C. verrucosa). Total phenolic content, total flavonoid and total protein contents of C. verrucosa were determined. Further, synthesized ZnO NPs was characterized by UV-visible spectroscopy (UV-vis), X-ray diffractometer (XRD), Fourier transform infra-red (FTIR) Spectra, transmission electron microscope (TEM), and Dynamic light scattering (DLS) analysis. UV-vis shows peak at 375 nm which is unique to ZnO NPs. XRD analysis demonstrates the hexagonal phase structures of ZnO NPs. FTIR spectra demonstrates the molecules and bondings associated with the synthesized ZnO NPs and assures the role of phytochemical compounds of C. verrucosa in reduction and capping of ZnO NPs. TEM image exhibits that the prepared ZnO NPs is hexagonal shaped and in size ranged between 16 to 38 nm which is confirmed by DLS. Thermo-gravimetric analysis (TGA) was performed to determine the thermal stability of biosynthesized nanoparticles during calcination. The prepared ZnO NPs showed significant antibacterial potentiality against Gram-positive (S. aureus) and Gram-negative (Proteus vulgaris, Klebsiella pneumoniae, and Escherichia coli) pathogenic bacteria and SEM image shows the generalized mechanism of action in bacterial cell after NPs internalization. In addition, NPs are also found to be effective against the studied cancer cell lines for which cytotoxicity was assessed using MTT assay and results demonstrate highest growth of inhibition at the concentration of 100 µg/mL with IC50 value at 7.07 µg/mL for HeLa and 6.30 µg/mL for DU145 cell lines, in contrast to positive control (C. verrucosa leaf extract) with IC50 of 22.30 µg/mL on HeLa cells and 15.72 µg/mL on DU145 cells. Also, DAPI staining was performed in order to determine the effect on nuclear material due to ZnO NPs treatment in the studied cell lines taking leaf extract as positive control and untreated negative control for comparison. Cell migration assay was evaluated to determine the direct influence of NPs on metastasis that is potential suppression capacity of NPs to tumor cell migration. Outcome of the synthesized ZnO NPs using C. verrucosa shows antimicrobial activity against studied microbes, also cytotoxicity, apoptotic mediated DNA damage and antiproliferative potentiality in the studied carcinoma cells and hence, can be further used in biomedical, pharmaceutical and food processing industries as an effective antimicrobial and anti-cancerous agent.

Vitamin and mineral supplementation for β-thalassemia during COVID-19 pandemic

AIM

Low levels of immune-related micronutrients have been identified in β-thalassemia samples. Moreover, the excess amount of iron, contributing to oxidative stress in the pathogenesis of the disease, alters the immune system in β-thalassemia, which is important during the COVID-19 pandemic.

MATERIALS & METHODS

Searches of PUBMED and EMBASE were conducted to identify the level and supplementation of micronutrients in β-thalassemia, published from 2001-May 2020.

RESULTS

The review found six observational and five interventional studies supporting the importance of supplementing vitamins and minerals among patients with β-thalassemia.

CONCLUSION

Supplementation of immune-related vitamins and minerals might bring benefits to the immune system, especially in reducing oxidative stress in β-thalassemia.

In anemia zinc is recruited from bone and plasma to produce new red blood cells

Anemia is highly prevalent in people with chronic kidney disease (CKD), and CKD patients always have lower plasma but higher erythrocyte Zn levels than healthy people. To date, no satisfactory mechanism has explained these Zn metabolism abnormalities. We collected blood samples from patients on hemodialysis, 5/6 nephrectomized rats and phenylhydrazine (PHZ)-induced anemic mice and rats and compared them with their normal counterparts. We found that all the anemic animals had significantly decreased plasma Zn levels but elevated erythrocyte Zn levels. We also found that in anemic mice, new red blood cells (reticulocytes) had a ~7-fold higher Zn concentration than mature erythrocytes. When excess Zn was supplied to the rats, there was a ~1.2-fold increase in the Zn level in the rat bones. When Zn was depleted in the rats, the bones lost the greatest amount of Zn in the body (a 45% decrease). We prepared Zn-depleted rats and rendered these rats anemic by treating them with PHZ, and we compared them with normal rats. We found that in PHZ-induced anemia, rats released ~16% of Zn from their bones. Rat bones not only act as a 'reservoir' to adjust the excess or deficient Zn levels but also release Zn in anemia, and the released Zn stimulates erythropoiesis in the bone marrow. In anemia, Zn is redistributed from the plasma (causing the plasma Zn level to decreases) and bones to the bone marrow to produce reticulocytes (causing erythrocyte Zn level elevation).

Effect of Zinc Supplementation on Renal Anemia in 5/6-Nephrectomized Rats and a Comparison with Treatment with Recombinant Human Erythropoietin

Anemia is a severe complication in patients with chronic kidney disease (CKD). Treatment with exogenous erythropoietin (EPO) can correct anemia in many with CKD. We produced 5/6-nephrectomized rats that became uremic and anemic at 25 days post surgery. Injection of the anemic 5/6-nephrectomized rats with 2.8 mg zinc/kg body weight raised their red blood cell (RBC) levels from approximately 85% of the control to 95% in one day and continued for 4 days. We compared the effect of ZnSO4 and recombinant human erythropoietin (rHuEPO) injections on relieving anemia in 5/6-nephrectomized rats. After three consecutive injections, both the ZnSO4 and rHuEPO groups had significantly higher RBC levels (98 ± 6% and 102 ± 6% of the control) than the saline group (90 ± 3% of the control). In vivo, zinc relieved anemia in 5/6-nephrectomized rats similar to rHuEPO. In vitro, we cultured rat bone marrow cells supplemented with ZnCl2, rHuEPO, or saline. In a 4-day suspension culture, we found that zinc induced erythropoiesis similar to rHuEPO. When rat bone marrow cells were supplement-cultured with zinc, we found that zinc stimulated the production of EPO in the culture medium and that the level of EPO produced was dependent on the concentration of zinc supplemented. The production of EPO via zinc supplementation was involved in the process of erythropoiesis.