Zn is an essential trace element for all organisms. In human subjects body growth and development is strictly dependent on Zn. The nervous, reproductive and immune systems are particularly influenced by Zn deficiency, as well as by increased levels of Zn. The relationship between Zn and the immune system is complex, since there are four different types of influence associated with Zn. (1) The dietary intake and the resorption of Zn depends on the composition of the diet and also on age and disease status. (2) Zn is a cofactor in more than 300 enzymes influencing various organ functions having a secondary effect on the immune system. (3) Direct effects of Zn on the production, maturation and function of leucocytes. (4) Zn influences the function of immunostimulants used in the experimental systems. Here we summarize all four types of influence on the immune function. Nutritional aspects of Zn, the physiology of Zn, the influence of Zn on enzymes and cellular functions, direct effects of Zn on leucocytes at the cellular and molecular level, Zn-altered function of immunostimulants and the therapeutic use of Zn will be discussed in detail.

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Zinc and the immune system

Zinc and immune system.

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

/pdf/the-potential-impact-of-zinc-supplementation-on-covid-19-2b6zn48prd.pdf

The Potential Impact of Zinc Supplementation on COVID-19 Pathogenesis.

https://josorge.com/publications/Citations/IJL/009.pdf

Zinc supplementation for the treatment or prevention of disease: Current status and future perspectives

According to new hypothesis, depression is characterized by decreased neurogenesis and enhanced neurodegeneration which, in part, may be caused by inflammatory processes. There is much evidence indicating that depression, age-related changes often associated with impaired brain function and cognitive performances or neurodegenerative processes could be related to dysfunctions affecting the zinc ion availability. Clinical studies revealed that depression is accompanied by serum hypozincemia, which can be normalized by successful antidepressant treatment. In patients with major depression, a low zinc serum level was correlated with an increase in the activation of markers of the immune system, suggesting that this effect may result in part from a depression-related alteration in the immune-inflammatory system. Moreover, a preliminary clinical study demonstrated the benefit of zinc supplementation in antidepressant therapy in both treatment non-resistant and resistant patients. In the preclinical study, the antidepressant activity of zinc was observed in the majority of rodent tests and models of depression and revealed a causative role for zinc deficiency in the induction of depressive-like symptoms, the reduction of neurogenesis and neuronal survival or impaired learning and memory ability. This paper provides an overview of the clinical and experimental evidence that implicates the role of zinc in the pathophysiology and therapy of depression within the context of the inflammatory and neurodegenerative hypothesis of this disease.

The role of zinc in neurodegenerative inflammatory pathways in depression.

The tube assay employing Escherichia coli 113‐3 with the medium of Davis and Mingioli gave low estimates of potency for vitamin B12 in aqueous extracts of multi‐vitamin preparations when compared with the U. S. P. method. The presence of thiamine in the multivitamin samples was found to be responsible for these low values which were most evident in the shaken assays. When samples were extracted with sodium meta‐bisulfite to destroy the thiamine, the potency estimates agreed well with those obtained with the U. S. P. procedure. This extraction eliminated the need for cyanide treatment. In view of its stability of response and greater simplicity as compared with the U. S. P. assay, the E. coli method seems particularly applicable to the estimation of vitamin B12 activity in the absence of interfering materials, e. g., pseudo‐forms of vitamin B12 or methionine.

The influence of thiamine on the microbiological assay for vitamin B12 with Escherichia coli 113‐3

Available evidence has shown that most common foods are deficient in lysine, methionine, or in methionine and cystine. Based on the determination of these amino acids, a simplified chemical score w...

Evaluation of protein in foods: iv. a simplified chemical score

Bacteriological methods for the determination of protein quality were evaluated by comparison with protein efficiency ratio (P.E.R.) values determined by a standardized rat growth assay. Enzyme or acid hydrolyzates of foods were used as the source of amino acids with hydrolyzed whole egg powder as the reference standard. With Streptococcus faecalis A.T.C.C. 9790 autolysis occurred in media containing hydrolyzates of proteins deficient in lysine, and was largely responsible for results which did not agree with P.E.R. values. In methods employing Leuconostoc mesenteroides P-60 A.T.C.C. 8042, growth was influenced only by the most limiting amino acid relative to the requirements of the test organism.Results with enzyme hydrolyzates correlated poorly with P.E.R. values, whereas, with acid hydrolyzates, a good correlation was obtained for cereal proteins. A difference in amino acid requirements was largely responsible for the lack of agreement between the P.E.R. assay and methods employing L. mesenteroides, pa...

Evaluation of protein in foods. III. A study of bacteriological methods.

The isotope dilution assay for vitamin B12 depends on the extraction and removal of vitamin B12-like factors prior to the spectrophotometric measurement of vitamin B12. Since it is not suitable for low potency materials, modifications have been made in the method of extraction and purification. Vitamin B12 is measured with Lactobacillus leichmannii 313. The purification procedure was effective in removing pseudovitamin B12 and factor A, but was ineffective in the removal of vitamin B12III. A correction factor was used in place of Co60-labelled vitamin B12 to adjust for loss during purification. Statistical analysis showed this correction factor to be valid and reproducible. Purification did not affect the estimates of vitamin B12 activity of milk, blood plasma, chick mash, or fish meal. True vitamin B12 activity was apparently responsible for 50% of the total vitamin B12 activity of dried cattle faeces and for less than 10% of the total activity of yeast extract. The coefficient of variation of the modifi...

C. G. Rogers

Papers

The influence of thiamine on the microbiological assay for vitamin B12 with Escherichia coli 113‐3

Evaluation of protein in foods: iv. a simplified chemical score

Evaluation of protein in foods. III. A study of bacteriological methods.

A modified procedure for the estimation of vitamin B12 in natural materials of low potency.