Dietary zinc supplementation inhibits bacterial plasmid conjugation in vitro by regulating plasmid replication (rep) and transfer (tra) genes.

Humans use dietary supplements for several intended effects, such as supplementing malnutrition. While these compounds have been developed for host end benefits, their ancillary impact on the gut microbiota remains unclear. The human gut has been proposed as a reservoir for the prevalent lateral transfer of antimicrobial resistance and virulence genes in bacteria through plasmid conjugation. Here, we studied the effect of dietary zinc supplements on the incidence of plasmid conjugation in vitro. Supplement effects were analyzed through standardized broth conjugation assays. The avian pathogenic Escherichia coli (APEC) strain APEC-O2-211 was a donor of the multidrug resistance plasmid pAPEC-O2-211A-ColV, and the human commensal isolate E. coli HS-4 was the plasmid-free recipient. Bacterial strains were standardized and mixed 1:1 and supplemented 1:10 with water, or zinc derived from either commercial zinc supplements or zinc gluconate reagent at varying concentrations. We observed a significant reduction in donors, recipients, and transconjugant populations in conjugations supplemented with zinc, with a dose-dependent relationship. Additionally, we observed a significant reduction (P < 0.05) in log conjugation efficiency in zinc-treated reactions. Upregulation of the mRNA for the plasmid replication initiation gene repA and the subset of transfer genes M, J, E, K, B, P, C, W, U, N, F, Q, D, I, and X was observed. Furthermore, we observed a downregulation of the conjugal propilin gene traA and the entry exclusion gene traS. This study demonstrates the effect of dietary zinc supplements on the conjugal transfer of a multidrug resistance plasmid between pathogenic and commensal bacteria during in vitro conditions.IMPORTANCEThis study identifies dietary zinc supplementation as a potential novel intervention for mitigating the emergence of multidrug resistance in bacteria, thus preventing antibiotic treatment failure and death in patients and animals. Further studies are required to determine the applicability of this approach in an in vivo model.

Minimum inhibitory and bactericidal/fungicidal concentration of commercially available products containing essential oils, zinc gluconate, or 4% chlorhexidine for Malassezia pachydermatis, Pseudomonas aeruginosa, and multi-drug resistant Staphylococcus pseudintermedius canine clinical isolates.

Skin infections are common complications in both humans and animals. Because of the increased incidence of multi-drug resistant (MDR) skin infections, essential oils have been suggested as potential alternatives to the classic antimicrobials. The goal of this study was to evaluate the minimum inhibitory and bactericidal/fungicidal concentrations (MIC and MBC/MFC) of commercially available products containing essential oils, zinc gluconate, or 4% chlorhexidine. Microbroth dilution technique was performed on clinical isolates of MDR Staphylococcus pseudintermedius (MDR-SP; n = 10), Pseudomonas aeruginosa (PA; n = 10), and Malassezia pachydermatis (MP; n = 10). For MDR-SP, essential oil-containing products showed median MICs of 1:240 and 1:320. The chlorhexidine shampoo had a MIC of 1:128,000 (0.312 µg/mL), whereas zinc gluconate products had median MICs of 1:320 and 1:160. Three essential oil-containing shampoos (MBC 1:40), the zinc gluconate (MBC 1:40), and the chlorhexidine (MBC 1:64,000 [0.625 µg/mL]) reached an MBC. For PA, essential oil-containing products showed median MICs of 1:30 and 1:80. The zinc-gluconate products had a median MIC of 1:160, whereas the chlorhexidine shampoo had a median MIC of 1:4,000 (10 µg/mL). Only the zinc-gluconate products (MBC 1:80) and the chlorhexidine shampoo (MBC 1:2,000 [20 µg/mL]) reached an MBC. For MP, essential oil-containing and zinc-gluconate products showed lower median MICs (1:4,800 and 7,200) for shampoos compared with other formulations (1:160 and 1:320), whereas the chlorhexidine shampoo had a median MIC of 1:80,000 (0.5 µg/mL). These results suggest that natural topical compounds can be an effective alternative to treat skin infections in companion animals. Further in vivo studies are needed to clinically confirm this study's results.

Protective effect of zinc gluconate on intestinal mucosal barrier injury in antibiotics and LPS-induced mice.

Objective: The aim of the study is to investigate the function and mechanism of Zinc Gluconate (ZG) on intestinal mucosal barrier damage in antibiotics and Lipopolysaccharide (LPS)-induced mice. Methods: We established a composite mouse model by inducing intestinal mucosal barrier damage using antibiotics and LPS. The animals were divided into five groups: Control (normal and model) and experimental (low, medium, and high-dose ZG treatments). We evaluated the intestinal mucosal barrier using various methods, including monitoring body weight and fecal changes, assessing pathological damage and ultrastructure of the mouse ileum, analyzing expression levels of tight junction (TJ)-related proteins and genes, confirming the TLR4/NF-κB signaling pathway, and examining the structure of the intestinal flora. Results: In mice, the dual induction of antibiotics and LPS led to weight loss, fecal abnormalities, disruption of ileocecal mucosal structure, increased intestinal barrier permeability, and disorganization of the microbiota structure. ZG restored body weight, alleviated diarrheal symptoms and pathological damage, and maintained the structural integrity of intestinal epithelial cells (IECs). Additionally, ZG reduced intestinal mucosal permeability by upregulating TJ-associated proteins (ZO-1, Occludin, Claudin-1, and JAM-A) and downregulating MLCK, thereby repairing intestinal mucosal barrier damage induced by dual induction of antibiotics and LPS. Moreover, ZG suppressed the TLR4/NF-κB signaling pathway, demonstrating anti-inflammatory properties and preserving barrier integrity. Furthermore, ZG restored gut microbiota diversity and richness, evidenced by increased Shannon and Observed features indices, and decreased Simpson's index. ZG also modulated the relative abundance of beneficial human gut bacteria (Bacteroidetes, Firmicutes, Verrucomicrobia, Parabacteroides, Lactobacillus, and Akkermansia) and harmful bacteria (Proteobacteria and Enterobacter), repairing the damage induced by dual administration of antibiotics and LPS. Conclusion: ZG attenuates the dual induction of antibiotics and LPS-induced intestinal barrier damage and also protects the intestinal barrier function in mice.

Determination of the median lethal dose of zinc gluconate in mice and safety evaluation.

BACKGROUND: Zinc Gluconate (ZG) is a safe and effective supplement for zinc. However, there is limited research on the optimal dosage for intravenous injection and the safety evaluation of animal models for ZG. This study aims to determine the safe dose range of ZG for intravenous injection in C57BL/6J mice. METHODS: A Dose titration experiment was conducted to determine the LD50 and 95% confidence interval (95%CI) of ZG in mice. Based on the LD50, four sub-lethal doses (SLD) of ZG were evaluated. Following three injections of each SLD and monitoring for seven days, serum zinc levels were measured, and pathological changes in the liver, kidney, and spleen tissues of mice were determined by histological staining. RESULTS: The dose titration experiment determined the LD50 of ZG in mice to be 39.6 mg/kg, with a 95%CI of 31.8-49.3 mg/kg. There was a statistically significant difference in the overall serum zinc levels (H = 36.912, P < 0.001) following SLD administration. Pairwise comparisons showed that the serum zinc levels of the 1/2 LD50 and 3/4 LD50 groups were significantly higher than those of the control group (P < 0.001); the serum zinc level of the 3/4 LD50 group was significantly higher than those of the 1/8 LD50 and 1/4 LD50 groups (P < 0.05). There was a positive correlation between the different SLDs of ZG and the serum zinc levels in mice (rs = 0.973, P < 0.001). H&E staining showed no significant histological abnormalities or lesions in the liver, kidney, and spleen tissues of mice in all experimental groups. CONCLUSION: The appropriate dose range of ZG for intravenous injection in C57BL/6J mice was clarified, providing a reference for future experimental research.

Safety Assessment of Zinc Salts as Used in Cosmetics.

The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of 27 inorganic and organometallic zinc salts as used in cosmetic formulations; these salts are specifically of the 2+ (II) oxidation state cation of zinc. These ingredients included in this report have various reported functions in cosmetics, including hair conditioning agents, skin conditioning agents, cosmetic astringents, cosmetic biocides, preservatives, oral care agents, buffering agents, bulking agents, chelating agents, and viscosity increasing agents. The Panel reviewed the relevant data for these ingredients, and concluded that these 27 ingredients are safe in cosmetics in the present practices of use and concentration described in this safety assessment when formulated to be non-irritating.

Hierarchically Porous Carbon Nanosheets from One-Step Carbonization of Zinc Gluconate for High-Performance Supercapacitors.

Supercapacitors, with high energy density, rapid charge-discharge capabilities, and long cycling ability, have gained favor among many researchers. However, the universality of high-performance carbon-based electrodes is often constrained by their complex fabrication methods. In this study, the common industrial materials, zinc gluconate and ammonium chloride, are uniformly mixed and subjected to a one-step carbonization strategy to prepare three-dimensional hierarchical porous carbon materials with high specific surface area and suitable nitrogen doping. The results show that a specific capacitance of 221 F g-1 is achieved at a current density of 1 A g-1. The assembled symmetrical supercapacitor achieves a high energy density of 17 Wh kg-1, and after 50,000 cycles at a current density of 50 A g-1, it retains 82% of its initial capacitance. Moreover, the operating voltage window of the symmetrical device can be easily expanded to 2.5 V when using Et4NBF4 as the electrolyte, resulting in a maximum energy density of up to 153 Wh kg-1, and retaining 85.03% of the initial specific capacitance after 10,000 cycles. This method, using common industrial materials as raw materials, provides ideas for the simple preparation of high-performance carbon materials and also provides a promising method for the large-scale production of highly porous carbons.

Evaluation of chemical castration using intra-testicular injection of zinc gluconate into the testis of the male donkey versus surgical castration: antimullerian hormone as an endpoint marker.

BACKGROUND: Chemical castration of male animals is an alternative to surgical castration for inducing azoospermia, consequent sterility. Intra-testicular injection of zinc gluconate has been used for chemical castration in several animal species. However, its application to equine species, such as donkeys, has yet to be reported. This study aimed to evaluate the use of zinc gluconate for the chemical castration of male donkeys and to compare its effectiveness relative to routine surgical castration. For this purpose, investigations of serum testosterone and anti-Müllerian hormone levels, testicular ultrasonographic echogenicity, and histopathological findings were performed. METHODS: Fourteen clinically healthy adult male donkeys were randomly and equally divided into two groups. The donkeys in group I (n = 7) underwent surgical castration. The donkeys in group II (n = 7) received intra-testicular zinc gluconate injections. The donkeys were kept under close clinical observation for 60 days. Abnormalities in donkey behavior and gross alterations in the external genitalia were recorded daily. Serum testosterone and anti-Müllerian hormone (AMH) levels were measured 15 days before the start of the treatment and 15, 30, 45, and 60 days after treatment. The testicles of group II donkeys were evaluated ultrasonographically. At the end of the study, the testes were removed and histologically examined. RESULTS: Serum testosterone levels significantly declined compared to pre-castration levels in surgically castrated donkeys (group I), but donkeys exposed to chemical castration (group II) showed a non-significant reduction in testosterone levels. Donkeys in the surgical group had considerably lower serum AMH levels. In contrast, there was a non-significant (p > 0.05) increase in AMH levels in the chemical group compared with the pre-sterilization level. In addition, ultrasonographic examination revealed that the testicular echo-density had changed, as observed by a few scattered hyperechoic regions throughout the entire testis parenchyma. The histopathological investigation confirmed the presence of necrosis of the spermatogenic epithelium, increased thickness of the basement membrane of the seminiferous tubules, marked interstitial fibrosis, and shrinkage of the seminiferous tubules. Furthermore, syncytial giant cells were present in the lumen of seminiferous tubules and were associated with Sertoli cell vacuolation. Donkeys subjected to chemical castration (group II) had orchitis, as confirmed histopathologically. CONCLUSION: Intra-testicular injection of zinc gluconate resulted in histopathological and ultrasonographic testicular changes in adult male donkeys, which may affect their reproductive potential. However, it did not significantly alter serum testosterone or AMH levels, indicating that it cannot be used as a substitute for surgical castration in male donkeys.

Preliminary Comparison of Fractional Absorption of Zinc Sulphate, Zinc Gluconate, and Zinc Aspartate after Oral Supple-Mentation in Healthy Human Volunteers.

(1) Background: Zinc is generally used as a nutritional supplement for individuals at nutritional risk, such as older adults. This preliminary study investigated the fractional Zn absorption (FZA) after the supplementation on eight healthy volunteers with three different Zn complexes acquired with milk. (2) Methods: The design was a double-blind, three-period crossover trial. The volunteers were randomly divided into three groups. Each individual consumed 200 mL of bovine milk and rotated through a simultaneous administration of a single oral dose of 70ZnSO4, 70Zn-Gluconate (70Zn-Glu), and 70Zn-Aspartate (70Zn-Asp), equivalent to 2.0 mg 70Zn, followed by 2 weeks of wash-out. An estimation of the FZA for comparative purposes was computed by the isotopic ratio between 66Zn and 70Zn in urine collected before and 48 h after administration. (3) Results: The estimated FZA was found to be significantly higher for 70Zn-Asp when compared to the other forms, while the FZA of 70Zn-Glu was found to be significantly higher than 70ZnSO4. (4) Conclusions: The results of this study suggest that complexing Zn with aspartate in milk could be a useful tool to improve FZA in individuals at risk of Zn deficiency. These results provide a rationale for conducting further studies on Zn-Asp preparations.

Analysis of risk factors for neurological symptoms in patients with purely hepatic Wilson's disease at diagnosis.

OBJECTIVE: To analyze and explore the risk factors for neurological symptoms in patients with purely hepatic Wilson's disease (WD) at diagnosis. METHODS: This retrospective study was conducted at the First Affiliated Hospital of the Guangdong Pharmaceutical University on 68 patients with purely hepatic WD aged 20.6 ± 7.2 years. The physical examinations, laboratory tests, color Doppler ultrasound of the liver and spleen, and magnetic resonance imaging (MRI) of the brain were performed. RESULTS: The elevated alanine transaminase (ALT) and aspartate transaminase (AST) levels and 24-h urinary copper level were higher in the purely hepatic WD who developed neurological symptoms (NH-WD) group than those in the purely hepatic WD (H-WD) group. Adherence to low-copper diet, and daily oral doses of penicillamine (PCA) and zinc gluconate (ZG) were lower in the NH-WD group than those in the H-WD group. Logistic regression analysis showed that insufficient doses of PCA and ZG were associated with the development of neurological symptoms in patients with purely hepatic WD at diagnosis. CONCLUSION: The development of neurological symptoms in patients with purely hepatic WD was closely associated with insufficient doses of PCA and ZG, and the inferior efficacy of copper-chelating agents. During the course of anti-copper treatment, the patient's medical status and the efficacy of copper excretion should be closely monitored.

Assessment of the Benefit of a Deep Cleansing Gel Containing Salicylic Acid 2%, Zinc Gluconate 0.2% and Lipohydroxy Acids 0.05% in Patients with Mild to Moderate Truncal Acne: Results from an Exploratory Study.

Purpose: Acne is a skin condition of the pilosebaceous unit that affects mainly the face, chest and trunk. Approximately 50% of subjects with facial acne also have acne of the trunk. This study investigated the clinical benefit of a cleansing gel containing salicylic acid 2%, zinc gluconate 0.2% and lipohydroxy acid 0.05% in truncal acne after 84 days of daily use. Materials and Methods: A single center, open label, non-randomized study with 51 subjects with mild to moderate truncal acne was conducted. Thirty-five (35) subjects completed the study; mean age was 23 years. Inflammatory and non-inflammatory lesions, Transepidermal water loss (TEWL) and local tolerance were assessed at baseline, Day 42 and Day 84 and total lesion count was calculated. Results: The total lesion count was significantly reduced (p<0.05) after 42 days (-21.5%) and 84 days (-56.3%). Non-inflammatory lesions were significantly decreased after 84 days (-64.0%) only, while inflammatory lesions were decreased at Day 42 (-29.2%), and Day 84 (-48.2%). A statistically significant skin barrier improvement was observed at Day 84 (-21.26%). No adverse events or relevant local intolerance were reported. Conclusion: The use of the cleansing gel studied was effective in improving mild to moderate truncal acne and contributed to the skin barrier improvement. The product was well tolerated. Clintrial Data Base Identifier: NCT05584150.

Attenuated effect of zinc gluconate on oxidative stress, inflammation, and angiogenic imbalance in pre-eclampsia rats.

AIMS: Pre-eclampsia (PE) is a common obstetric disease associated with oxidative stress, systemic inflammation, and angiogenic imbalance, whereas zinc (Zn) presents anti-oxidative and anti-inflammatory effects. This study is to investigate whether zinc gluconate (ZG) supplementation may ameliorate the early signs, adverse pregnancy outcomes, and pathogenic processes of PE in an animal model. MAIN METHODS: Forty pregnant Wistar rats were randomly divided into four groups: blank control (treated with normal saline, NS), Zn control (treated with ZG and followed by NS), PE model (treated with NS and followed by nitro-L-arginine methyl ester, L-NAME), and PE intervention (treated with ZG and followed by L-NAME). ZG (5 mg/kg/day) or NS was administered by gavage from day 0 to 19 of gestation, and L-NAME (80 mg/kg/day) or NS was subcutaneously injected from day 4 to 19 of gestation. The blood pressure, urinary protein, and pregnancy outcomes were recorded. Oxidative stress, inflammation, and angiogenic homeostasis were evaluated. KEY FINDINGS: PE rats exhibited oxidative stress (reduced SOD, CAT, and GSH, and increased MDA and 3-NT), inflammation (increased IL-6 and TNF-α), and angiogenic imbalance (reduced VEGF and PlGF, and increased sFlt-1). After intervention with ZG, the blood pressure and urinary protein levels were reverted, and the pregnancy outcomes were improved. The oxidative stress, inflammation, and angiogenic imbalance were effectively restored in accompany by increased Zn and MT levels. SIGNIFICANCE: ZG can ameliorate the early signs and pathological processes of PE in the animal model, indicating the value of zinc supplementation during pregnancy for PE prevention.

Inhibition of SARS-CoV-2 replication by zinc gluconate in combination with hinokitiol.

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic is currently the major challenge to global public health. Two proteases, papain-like protease (PLpro) and the 3-chymotrypsin-like protease (3CLpro or Mpro), are indispensable for SARS-CoV-2 replication, making them attractive targets for antiviral therapy development. Here we screened a panel of essential metal ions using a proteolytic assay and identified that zinc gluconate, a widely-used zinc supplement, strongly inhibited the proteolytic activities of the two proteases in vitro. Biochemical and crystallographic data reveal that zinc gluconate exhibited the inhibitory function via binding to the protease catalytic site residues. We further show that treatment of zinc gluconate in combination with a small molecule ionophore hinokitiol, could lead to elevated intracellular Zn2+ level and thereby significantly impaired the two protease activities in cellulo. Particularly, this approach could also be applied to rescue SARS-CoV-2 infected mammalian cells, indicative of potential application to combat coronavirus infections. Our studies provide the direct experimental evidence that elevated intracellular zinc concentration directly inhibits SARS-CoV-2 replication and suggest the potential benefits to use the zinc supplements for coronavirus disease 2019 (COVID-19) treatment.

Chitosan-poloxamer-based thermosensitive hydrogels containing zinc gluconate/recombinant human epidermal growth factor benefit for antibacterial and wound healing.

Chitosan/poloxamer-based thermosensitive hydrogels containing zinc gluconate/recombinant human epidermal growth factor (ZnG/rhEGF@Chit/Polo) were developed as a convenient, safe and effective dressing for skin wound treatment. Their fabrication procedure and characterization were reported, and their morphology was examined by a scanning electron microscope. Antibacterial and biofilms activities were evaluated by in vitro tests to reveal the inhibitory effects and scavenging activity on the biofilms of Staphylococcus aureus and Pseudomonas aeruginosa. ZnG/rhEGF@Chit/Polo was also investigated as a potential therapeutic agent for wound healing therapy. In vivo wound healing studies on rats for 21 days proves that ZnG/rhEGF@Chit/Polo supplements the requisite Zn2+ and rhEGF for wound healing to promote the vascular remodeling and collagen deposition, facilitate fibrogenesis, and reduce the level of interleukin 6 for wound basement repair, and thus is a good wound therapy.

A new therapeutic horizon in diaper dermatitis: Novel agents with novel action.

OBJECTIVE: This review looks at novel combinations of topical agents (i.e., zinc gluconate, zinc oxide, dexpanthenol, and taurine) that target a combination of mechanisms in diaper dermatitis. METHODS: A literature search of published studies was conducted using the search terms "diaper dermatitis", "treatment of diaper dermatitis in infants", "treatment of diaper dermatitis in adults", "nonsteroidal", "nonantibiotic", "antiinflammatory", "moisturizer", and "treatment for irritation". A total of 207 related articles were screened, and those categorized as clinical trials and reviews were studied and compared. Articles with common themes were categorized, summarized, and presented herein. RESULTS: Diaper dermatitis, also referred to as diaper rash, napkin dermatitis, and nappy rash, is the most common skin eruption in infants and toddlers. In the last several years, there have been several technologic advances in diaper design to lessen the severity of diaper dermatitis symptoms. However, due to the unique environment of the diaper area, children and adults continue to have recurring symptoms of diaper dermatitis. Both commercially available products and certain home remedies are considered effective for managing sensitive and delicate skin in the diaper area. These topical agents create a protective barrier over the skin and reduce the impact of external irritants, which cause the reddening and burning sensation often associated with diaper dermatitis. CONCLUSION: A range of therapeutic strategies for preventing and controlling diaper dermatitis are summarized in this manuscript.

Chemical sterilization with intratesticular administration of zinc gluconate in adult dogs: a preliminary report.

BACKGROUND: Chemical sterilization with zinc gluconate is being developed due to its permanent contraceptive effect in prepubertal dogs. In this study, five healthy adult dogs were selected randomly. Semen samples were collected and analyzed before the study to confirm normal testicular function. Under general anesthesia, pH neutralized zinc gluconate was injected directly into their testes. Testes diameter, ultrasonographic appearance, changes in the percentage of white blood cells, and testosterone concentration were monitored twice a week before and 1 month after the injection. At the end of the study, the dogs were castrated and their testes were removed for histopathological evaluation. RESULTS: The general health of all dogs was normal after the injection. The appearance of testicular swelling was limited within 2 days of treatment. The average diameter of left and right testes was 2.48 and 2.03 cm before the injection and reached to diameter 2.12 and 2.15 cm, respectively, at the end of the study. Serum testosterone concentration was 4.2 ng/ml at the start and 4 ng/ml at the end of the study. The percentage of white blood cells at the start and end of the study were within normal ranges reported for dogs. Histopathological analyses indicate a degeneration of germ cells in seminiferous tubules, but Leydig cells retained their structure. CONCLUSIONS: Therefore, It is inferred that the injection of pH neutralized zinc gluconate into the adult dogs' testes resulted in the loss of sperm-producing tissue without affecting the production of testosterone and the general health of adult dogs.

CONTEXTE: La stérilisation chimique par le gluconate de zinc a été développée en raison de son effet contraceptif permanent chez le chien prépubère. Dans la présente étude cinq chiens adultes en bonne santé ont été sélectionnés au hasard. Le sperme a été recueilli et analysé avant l'étude de façon à s'assurer d'une fonction testiculaire exocrine normale. Une solution de gluconate de zinc à pH neutre a été directement injectée dans les testicules sous anesthésie générale. Le diamètre des testicules et leur aspect échographique, les modifications des pourcentages de cellules blanches sanguines et la concentration sérique de testostérone ont été enregistrés deux fois une semaine avant l'injection et un mois après l'injection. Les chiens ont été castrés à la fin de l'étude et leurs testicules conservés pour analyse histopathologique. RÉSULTATS: L'état de santé général de tous les chiens fut normal après l'injection. Les testicules présentèrent un aspect gonflé qui resta limité aux deux premiers jours du traitement. Le diamètre moyen des testicules droit et gauche fut respectivement de 2,48 et 2,03 cm avant l'injection, et de 2,12 et 2,15 cm à la fin de l'étude. La concentration sérique de la testostérone fut de 4,2 ng/ml au début et de 4 ng/ml à la fin de l'étude. Le pourcentage de cellules blanches sanguines fut dans les fourchettes de la normale pour les chiens au début et à la fin de l'étude. L'analyse histopathologique a montré une dégénérescence des cellules germinales dans les tubes séminifères, mais la structure des cellules de Leydig était conservée. CONCLUSIONS: On peut par conséquent en déduire que l'injection de gluconate de zinc à pH neutre dans les testicules de chiens adultes entraine une perte du tissu à l'origine des spermatozoïdes sans affecter la production de testostérone et l'état général de santé des chiens adultes.

Zinc Gluconate-Loaded Chitosan Nanoparticles Reduce Severity of Collagen-Induced Arthritis in Wistar Rats.

Rheumatoid arthritis (RA) is the most prevalent autoimmune disease affecting about 1% world population. Zinc (Zn) is necessary for the maintenance of bone homeostasis and the level of Zn was reported to be decreased in RA patients and collagen-induced arthritic rats. Effective delivery of Zn has been reported using zinc gluconate but oral absorption of Zn from zinc gluconate (ZG) is very low in humans. Zn supplementation reduces disease severity in patients suffering from chronic, refractory RA and exerts mild and transient side effects. The aim of this study was to synthesize and characterize zinc gluconate-loaded chitosan nanoparticles (ZG-Chit NPs) and to evaluate and compare therapeutic efficacy of ZG-Chit NPs and zinc gluconate against collagen-induced RA in Wistar rats. The nanoparticles were formulated by ionic gelation method and the hydrodynamic diameter was 106.5 ± 79.55 nm as measured using DLS. The particle size, shape, and surface morphology was further confirmed by transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. These nanoparticles showed good cytocompatibility against foreskin fibroblasts (BJ) and L929 cells. Arthritic rats were treated with ZG (20 mg/kg body weight, intraperitoneally) and equivalent doses of ZG-Chit NPs. The treatment of both ZG and ZG-Chit NPs reduced the severity of arthritis as evidenced by reduced joint swelling, erythema, and edema but ZG-Chit NPs exhibited superior efficacy. Furthermore, it was found that ZG and ZG-Chit NPs attenuate biomarkers of inflammation (C-reactive protein, myeloperoxidase, nitric oxide, TNF-α, and IL-1ß) and oxidative stress (articular elastase, lipid peroxidation, catalase, glutathione, and superoxide dismutase). The results of the histopathology further confirmed that ZG-Chit NPs markedly suppressed infiltration of inflammatory cells as compared to ZG at the ankle joint tissue. Immunohistochemical analysis also revealed that treatment with ZG-Chit NPs resulted in reduced pro-inflammatory marker (TNF-α, IL-6, and iNOS) expression and enhanced SOD1 expression. Overall, this study suggests that ZG and ZG-Chit NPs suppressed the severity of arthritis plausibly mediated by attenuation of inflammation and oxidative stress and more importantly ZG-Chit NPs exhibited superior efficacy as compared to ZG.

Opinion of the Scientific Committee on Consumer safety (SCCS) - Final opinion on water-soluble zinc salts used in oral hygiene products.

The SCCS has estimated that exposure to water-soluble zinc salts via toothpaste and mouthwash at the concentrations of 1 and 0.1%, respectively, may lead to a daily intake level of 3.54 mg for adults and children aged 6-17 years. This exposure constitutes between 14 and 35% of the Upper Limit (UL) for these age groups. Therefore, the SCCS considers that the use of zinc in toothpaste and mouthwash per se is safe for adults and children aged 6-17 years. The SCCS has estimated that exposure to water-soluble zinc salts via toothpaste at the concentrations of 1% may lead to a daily intake level of 1.0-2.00 mg for children aged 0.5-5 years. This exposure constitutes between 10 and 29% of the UL for this age group. Therefore, the SCCS considers that the use of zinc in toothpaste per se is safe for children aged 0.5-5 years. Exposure to zinc may also occur from sources other than oral hygiene products. An important source of zinc in the population is the diet. This assessment has not taken into account the daily dietary intake of zinc. The dietary zinc intake (estimated by EFSA in 2014) ranges from 6.8 to 14.5 mg/day in adolescents aged 10 to < 18 years, from 5.5 to 9.3 mg/day in children aged 3 to < 10 years and from 4.6 to 6.2 mg/day in children aged 1 to <3 years. Therefore, exposure to zinc via the diet may already exceed or be close to exceeding the upper limits of 18, 13, 10 and 7 mg/day for the age groups 11-14, 7-10, 3-7 and 1-3 years, respectively. Any additional source of exposure, including cosmetics, may lead to exceeding the upper limits for children. The SCCS cannot advise which portion of the upper limit should be allocated to exposure from cosmetic products. When assessing exposure to chemicals, allocation factors that reflect a reasonable level of exposure while still being protective may be applied. For exposure via toys or drinking water, for example, allocation factors of 10% or 20% of the reference value may be considered as safe. In the case of zinc, the use of 1% in toothpaste and 0.1% in mouthwash constitutes between 10 and 35% of the upper limit depending on the age group. The SCCS is aware that upper limits may be exceeded in some cases because the default values used in this Opinion are based on conservative estimates.

Effects of intratesticular injection of zinc-based solution in rats in combination with anti-inflammatory and analgesic drugs during chemical sterilization.

AIM: Chemical sterilization is a non-surgical method of contraception based on compounds injected into the testis to induce infertility. However, these injections can cause discomfort and pain able to impair the recovery of animals after this treatment. The objective of this study was to investigate if anti-inflammatories or pain relievers inhibited the sterilizing effect of zinc gluconate-based solution on the testis. MATERIALS AND METHODS: Adult rats were treated in groups: G1 (control), G2 (dimethyl sulfoxide + dipyrone); G3 (dipyrone/zinc); G4 (dipyrone + celecoxib/zinc); G5 (dipyrone + meloxicam/zinc), and G6 (dipyrone + dexamethasone/zinc) in a single dose per day during 7 days. Animals were analyzed at 7, 15, and 30 days after treatments. RESULTS: The zinc-induced a widespread testicular degeneration and decreased testosterone levels even in combination with anti-inflammatories or pain relievers. Testis, epididymis, prostate, and seminal vesicle had a weight reduction. The anti-inflammatory effect of dexamethasone interfered in the desired action of zinc gluconate in the 1st 15 days and celecoxib up to 7 days. CONCLUSION: Meloxicam plus dipyrone did not impair the chemical sterilization based on zinc gluconate, and it can be used to reduce nociceptive effects in animals after chemical sterilization.

Combination of different antifungal agents in oil-in-water emulsions to control strawberry jam spoilage.

The combination of antifungal agents (cinnamon bark oil, zinc gluconate and trans-ferulic acid) in oil-in-water emulsions to control the fungal spoilage of strawberry jams, minimising essential oil's sensory impact, was evaluated in this work. The in vitro assays of free antifungal agents were performed against five fungal strains; meanwhile, the emulsions assays were conducted against Aspergillus niger given its strong resistance and its relevance in strawberry products. The emulsion formulated with 0.08mg/g of essential oil was able to inhibit mould growth after the incubation period. The incorporation of zinc gluconate or trans-ferulic acid, independently of the concentration used, allowed to reduce a 25% the amount of essential oil needed to inhibit the microbial growth. The combination of antifungal agents in the emulsions has demonstrated to be an effective alternative to reduce the amount of essential oil employed, maintaining the hygienic quality and sensory profile of the strawberry jam.