Change of zinc, copper, and metallothionein concentrations and the copper-zinc superoxide dismutase activity in patients with pancreatitis

Zinc and Diabetes: A Connection between Micronutrient and Metabolism

Diabetes mellitus is a global health problem and a major contributor to mortality and morbidity. The management of this condition typically involves using oral antidiabetic medication, insulin, and appropriate dietary modifications, with a focus on macronutrient intake. However, several human studies have indicated that a deficiency in micronutrients, such as zinc, can be associated with insulin resistance as well as greater glucose intolerance. Zinc serves as a chemical messenger, acts as a cofactor to increase enzyme activity, and is involved in insulin formation, release, and storage. These diverse functions make zinc an important trace element for the regulation of blood glucose levels. Adequate zinc levels have also been shown to reduce the risk of developing diabetic complications. This review article explains the role of zinc in glucose metabolism and the effects of its inadequacy on the development, progression, and complications of diabetes mellitus. Furthermore, it describes the impact of zinc supplementation on preventing diabetes mellitus. The available information suggests that zinc has beneficial effects on the management of diabetic patients. Although additional large-scale randomized clinical trials are needed to establish zinc's clinical utility further, efforts should be made to increase awareness of its potential benefits on human health and disease.

New insights into the antimicrobial action and protective therapeutic effect of tirapazamine towards Escherichia coli-infected mice

OBJECTIVES

Escherichia coli is an important pathogen responsible for numerous cases of diarrhoea worldwide. The bioreductive agent tirapazamine (TPZ), which was clinically used to treat various types of cancers, has obvious antibacterial activity against E. coli strains. In the present study, we aimed to evaluate the protective therapeutic effects of TPZ in E. coli-infected mice and provide insights into its antimicrobial action mechanism.

METHODS

The MIC and MBC tests, drug sensitivity test, crystal violet assay and proteomic analysis were used to detect the in vitro antibacterial activity of TPZ. The clinical symptoms of infected mice, tissue bacteria load, histopathological features and gut microbiota changes were regarded as indicators to evaluation the efficacy of TPZ in vivo.

RESULTS

Interestingly, TPZ-induced the reversal of drug resistance in E. coli by regulating the expression of resistance-related genes, which may have an auxiliary role in the clinical treatment of drug-resistant bacterial infections. More importantly, the proteomics analysis showed that TPZ upregulated 53 proteins and downregulated 47 proteins in E. coli. Among these, the bacterial defence response-related proteins colicin M and colicin B, SOS response-related proteins RecA, UvrABC system protein A, and Holliday junction ATP-dependent DNA helicase RuvB were all significantly upregulated. The quorum sensing-related protein glutamate decarboxylase, ABC transporter-related protein glycerol-3-phosphate transporter polar-binding protein, and ABC transporter polar-binding protein YtfQ were significantly downregulated. The oxidoreductase activity-related proteins pyridine nucleotide-disulfide oxidoreductase, glutaredoxin 2 (Grx2), NAD(+)-dependent aldehyde reductase, and acetaldehyde dehydrogenase, which participate in the elimination of harmful oxygen free radicals in the oxidation-reduction process pathway, were also significantly downregulated. Moreover, TPZ improved the survival rate of infected mice; significantly reduced the bacteria load in the liver, spleen, and colon; and alleviated E. coli-associated pathological damages. The gut microbiota also changed in TPZ-treated mice, and these genera were considerably differentiated: Candidatus Arthromitus, Eubacterium coprostanoligenes group, Prevotellaceae UCG-001, Actinospica, and Bifidobacterium.

CONCLUSIONS

TPZ may represent an effective and promising lead molecule for the development of antimicrobial agents for the treatment of E. coli infections.

Metallothioneins, a Part of the Retinal Endogenous Protective System in Various Ocular Diseases

Metallothioneins are the metal-rich proteins that play important roles in metal homeostasis and detoxification. Moreover, these proteins protect cells against oxidative stress, inhibit proapoptotic mechanisms and enhance cell differentiation and survival. Furthermore, MTs, mainly MT-1/2 and MT-3, play a vital role in protecting the neuronal retinal cells in the eye. Expression disorders of these proteins may be responsible for the development of various age-related eye diseases, including glaucoma, age-related macular degeneration, diabetic retinopathy and retinitis pigmentosa. In this review, we focused on the literature reports suggesting that these proteins may be a key component of the endogenous protection system of the retinal neurons, and, when the expression of MTs is disrupted, this system becomes inefficient. Moreover, we described the location of different MT isoforms in ocular tissues. Then we discussed the changes in MT subtypes' expression in the context of the common eye diseases. Finally, we highlighted the possibility of the use of MTs as biomarkers for cancer diagnosis.

The effect of zinc deficiency and iron overload on endocrine and exocrine pancreatic function in children with transfusion-dependent thalassemia: a cross-sectional study

BACKGROUND

Children with transfusion-dependent thalassemia (TDT) suffer from secondary hemosiderosis and the delirious effects this iron overload has on their different body organs, including the pancreas. They are also more prone to develop zinc deficiency than the general pediatric population. This study aimed to determine the effect of zinc deficiency and iron overload on the endocrine and exocrine pancreas in TDT children.

METHODS

Eighty children, already diagnosed with TDT, were included in this study. We assessed the following in the participant children: serum ferritin, serum zinc, endocrine pancreatic function (oral glucose tolerance test (OGTT), fasting insulin level and from them, HOMA-IR was calculated), and exocrine pancreatic function (serum lipase and serum amylase).

RESULTS

Forty-four TDT children had a subnormal zinc level, while 36 of them had a normal serum zinc level. TDT children with low serum zinc had significantly more impaired endocrine pancreatic function and an abnormally high serum lipase than children with normal serum zinc, p < 0.05 in all. Serum zinc was significantly lower in TDT children with serum ferritin above the ferritin threshold (≥2500 ng/ml) than those below (59.1 ± 20.2 vs. 77.5 ± 28.13), p = 0.02. TDT children, having a serum ferritin ≥2500 ng/ml, had significantly more frequently impaired endocrine pancreatic function and abnormally high serum lipase than TDT children below the ferritin threshold, p < 0.05 in all.

CONCLUSION

In children with transfusion-dependent thalassemia, zinc deficiency aggravates iron-induced pancreatic exocrine and endocrine dysfunction.

The effect of Crocin on TFAM and PGC-1α expression and Catalase and Superoxide dismutase activities following cholestasis-induced neuroinflammation in the striatum of male Wistar rats

Bile secretion is a physiological function that is disrupted following Bile Duct Ligation (BDL) and induces cholestasis. Cholestasis is a bile flow reduction that induces apoptosis, oxidative stress, and inflammation, and alters the expression of genes. Evidence shows the relationship between cholestasis and neuroinflammation. Cholestasis via attenuating mitochondrial biogenesis and anti-oxidant activity can induce neuroinflammation and apoptosis. Mitochondrial transcriptional factor A (TFAM) and Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) are involved in mitochondrial biogenesis, and TFAM, PGC-1α, Catalase (CAT), and Superoxide dismutase (SOD) have a role in upregulating antioxidant pathways. On the other hand, many studies have shown the neuroprotective effects of Crocin, the water-soluble carotenoid of Saffron (Crocus sativus L.). In this study, we aimed to investigate the effect of Crocin on the level of TFAM, PGC-1α, CAT, and SOD following cholestasis-induced neuroinflammation in the rat's striatum. Cholestasis was induced by BDL surgery and administration of Crocin was intraperitoneal, at the dose of 30 mg/kg every day, 24 h after BDL surgery up to thirty days. The results showed that TFAM, PGC-1α, and SOD were decreased following cholestasis; while, CAT was increased. In addition, Crocin restored the effects of cholestasis on the level of TFAM, PGC-1α, and SOD. In conclusion, Crocin may have improvement effects on cholestasis-induced neuroinflammation in the rat's striatum.

Importance of Genetic Polymorphisms in MT1 and MT2 Genes in Metals Homeostasis and Their Relationship with the Risk of Acute Pancreatitis Occurrence in Smokers-Preliminary Findings

This study was aimed at evaluating the changes in metallothionein (MT) concentration in the blood of patients with acute pancreatitis (AP) and healthy subjects, taking into account the extracellular (plasma) and intracellular (erythrocyte lysate) compartments. The impact of single-nucleotide polymorphisms (SNPs) in the MT1A (rs11640851), MT1B (rs964372) and MT2A (rs10636) genes on MT concentration and their association with the concentration of metals (Cu, Zn, Cd) and ceruloplasmin as Cu-related proteins were analyzed. The concentration of a high-sensitivity C-reactive protein (hs-CRP) and IL-6 as markers of inflammation, and malonyldialdehyde (MDA), superoxide dismutase (SODs) activity and the value of total antioxidant capacity (TAC) as parameters describing the pro/antioxidative balance were also assessed. In the AP patient groups, an increased MT concentration in erythrocyte lysate compared to healthy subjects was shown, especially in individuals with the GG genotype for rs964372 in the MT1B gene. A Zn concentration was especially decreased in the blood of smoking AP patients with the AA genotype for SNP rs11640851 in the MT1A gene and the GC genotype for SNP rs10636 in MT2A, compared to non-smokers with AP, which was accompanied by an increase in the value of the Cu/Zn ratio. The exposure to tobacco smoke xenobiotics increased the risk of AP occurrence in subjects with the CC genotype for SNP rs11640851 in the MT1A gene by more than fourfold. The investigated polymorphisms, rs11640851 in the MT1A gene, rs964372 in the MT1B gene and rs10636 in the MT2A gene, seem to be an important factor in maintaining homeostasis in an organism under oxidative stress conditions.

Altered intestinal microflora and barrier injury in severe acute pancreatitis can be changed by zinc

To investigate the effect of zinc (Zn) supplementation on intestinal microflora changes and bacterial translocation in rats with severe acute pancreatitis (SAP), the rats were divided into the sham surgery (SS), SAP, SS + Zn, and SAP + Zn groups. Saline (0.1 mL/100g) and 5% sodium taurocholate were injected into the pancreaticobiliary duct of the rats in the SS and SAP + Zn groups, respectively. Intraperitoneal injection of 5 mg/kg Zn was performed immediately after injecting saline or 5% sodium taurocholate into the rats in both groups. Serum amylase and Zn levels, plasma endogenous endotoxin, intestinal permeability, and the positive rate of intestinal bacterial translocation were detected, haematoxylin and eosin (H&E) staining was performed, and the pancreatic tissue scores were calculated for each group. In addition, immunohistochemical (IHC) staining was performed to evaluate the expression of IL-1β and TNF-α. Real-time fluorescence quantitative PCR was used to quantify the gene copy numbers of Escherichia, Bifidobacterium, and Lactobacillus in the cecum. The levels of amylase and plasma endotoxin in the SAP group were significantly higher than those in the SS and SS + Zn groups. Intestinal mucosal permeability and intestinal bacterial translocation in the liver, pancreas, and mesenteric lymph nodes were increased in the SAP group. However, the levels of amylase and plasma endotoxin were decreased as a result of zinc supplementation in the SAP group. The expression of IL-1β and TNF-α was also reduced to a greater degree in the SAP + Zn group than in the SAP group. Moreover, alleviated intestinal mucosal permeability and intestinal bacterial translocation in the liver, pancreas, and mesenteric lymph nodes were found in the SAP + Zn group. The results of real-time quantitative PCR showed that the gene copy number of Escherichia increased with time, and the gene copy numbers of Lactobacillus and Bifidobacterium decreased over time. Zn supplementation prevented the release of TNF-α and IL-1β, alleviated intestinal permeability and endotoxemia, reduced bacterial translocation, and inhibited changes in pathogenic intestinal flora in rats with SAP.

Zinc: Roles in pancreatic physiology and disease

Zinc is an essential trace element. Deficiencies are frequently seen with gastrointestinal diseases, including chronic pancreatitis, nutritional deficiency, and reduced intestinal absorption. Additionally, reduced zinc levels have been linked to cellular changes associated with acute pancreatitis such as enhanced inflammation with increased macrophage activation and production of inflammatory cytokines such as IL-1β, impaired autophagy, and modulation of calcium homeostasis. Preliminary data suggest that zinc deficiency may lead to pancreatic injury in animal models. The purpose of this review is to explore the biologic effects of zinc deficiency that could impact pancreatic disease. MESH KEYWORDS: Malnutrition, inflammation, trace element.

Changes in the Activity and Concentration of Superoxide Dismutase Isoenzymes (Cu/Zn SOD, MnSOD) in the Blood of Healthy Subjects and Patients with Acute Pancreatitis

This study was aimed at evaluating the changes in the concentration and activity of all superoxide dismutase isoenzymes (SOD1, SOD2, SOD3) in the blood of patients with acute pancreatitis (AP) and healthy subjects, taking into account the extracellular (plasma) and intracellular (erythrocyte lysate) compartment. The relationships between the activity/concentration of SODs, metal concentration and the markers of inflammation were evaluated. To assess the pro/antioxidative imbalance, the malonyldialdehyde (MDA) concentration and the value of total antioxidant capacity (TAC) were measured. The impact of single-nucleotide polymorphism (SNP) in the SOD1 gene (rs2070424) on the activity/concentration of SOD1 as the main isoenzyme of the SOD family was also analyzed in this study. The SOD2 activity in erythrocytes was increased compared to plasma: 10-fold in the AP patient group and 5-fold in healthy subjects. The plasma of AP patients showed an increased SOD1 concentration and decreased SOD2 and SOD3 concentrations compared to healthy subjects. The Cu/Zn SOD (SOD1 + SOD3) concentration in plasma of AP patients was elevated compared to healthy subjects, but changes in plasma Cu/Zn SOD (SOD1 + SOD3) activity in the examined groups were not observed. An influence of SNP rs2070424 in the SOD1 gene on the total activity of SOD in AP patients (with AG genotype), accompanied by an increased IL-6 concentration, was observed. In oxidative stress conditions induced by inflammation, the participation of individual forms of plasma SOD isoenzymes in total antioxidative activity of SOD changed. A significant increase in the intracellular SOD1 concentration in plasma of AP patients proves the important role of this isoenzyme in the neutralization of oxidative stress induced by impaired Cu and Zn homeostasis. The presence of increased concentration of SOD2 in erythrocytes of healthy subjects and AP patients confirms the important function of this isoenzyme in the antioxidative defense.

By reducing oxidative stress, naringenin mitigates hyperglycaemia-induced upregulation of hepatic nuclear factor erythroid 2-related factor 2 protein

OBJECTIVES

Antioxidant and anti-inflammatory properties of naringenin could confer hepatoprotective effects.

METHODS

Chang cells in culture media were maintained at 37°C and treated with increased concentrations of glucose (5.5-50 mm) and/or naringenin (25-100 µm), respectively, for 24 h. The cells were harvested and carbonyl proteins, antioxidant enzymes and proteins measured in cell lysates. Sprague Dawley rats were divided into 5 groups (n = 7) and orally treated daily for 56 days with 3.0 ml/kg per body weight (BW) distilled water (group 1), 60 mg/kg BW of naringenin (groups 2 and 4), respectively. Groups 3, 4 and 5 were given single 60 mg/kg per BW intraperitoneal injections of streptozotocin or insulin (2.0 IU/kg BW bid), (group 5 only).

KEY FINDINGS

Cell viability was significantly decreased in response to increased hyperglycaemia but naringenin dose-dependently, significantly reversed this compared to controls, respectively. However, antioxidant enzyme activities were reduced due to increased and reduced oxidative stress, respectively. Naringenin further significantly reduced hepatic oxidative stress and nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression and liver : body weight ratios in diabetic compared to controls rats.

CONCLUSIONS

Naringenin confers hepatoprotective antioxidant effects by initially preventing upregulation of Nrf2 protein expression and its downstream antioxidant enzymes.

Increased risk of acute pancreatitis occurrence in smokers with rs5751901 polymorphisms in GGT1 gene

Objectives: The study was aimed to assess γ‑glutamyltransferase (GGT) activity and concentration as a marker of oxidative stress induced by exposure to tobacco smoke in acute pancreatitis (AP) course. Examination of the relationship between GGT activity/concentration and single-nucleotide polymorphism (SNP rs5751901 and rs2236626) in GGT1 gene was performed. Subjects and methods: We examined SNPs in 38 AP patients and 51 healthy subjects by PCR-RFLP methods. GGT concentration in blood was measured with the use of the ELISA method; GGT activity and GSH concentration were measured by the Szasz and Patterson methods, respectively. Results: In the non-AP smokers group with TC genotype for SNPrs5751901 an increased blood GGT activity compared to smokers with CC genotypes was shown. In the course of AP was observed an elevated GGT activity and the value of GGT activity/GGT concentration ratio in smokers compared to non-smokers, in AP patients with TC genotypes and CC genotypes, respectively, for both SNP: rs5751901 and rs2236626. In the group of smoking AP patients with the CC and TC genotypes in rs5751901 locus and CC and TT genotypes in rs2236626 locus a decreases in GSH concentration during hospitalization were noted. Conclusions: SNP rs5751901 and rs2236626 cause changes in GGT activity. Smoking in the AP course contributes to increased GGT activity and excessive GSH use up in patients with TC and CC genotypes for both SNPs. Exposure to smoke xenobiotics enhances (3-fold) the risk of AP occurrence in individuals with TC genotypes for SNP rs5751901.

Role of Zinc in Immune System and Anti-Cancer Defense Mechanisms

The human body cannot store zinc reserves, so a deficiency can arise relatively quickly, e.g., through an improper diet. Severe zinc deficiency is rare, but mild deficiencies are common around the world. Many epidemiological studies have shown a relationship between the zinc content in the diet and the risk of cancer. The anti-cancer effect of zinc is most often associated with its antioxidant properties. However, this is just one of many possibilities, including the influence of zinc on the immune system, transcription factors, cell differentiation and proliferation, DNA and RNA synthesis and repair, enzyme activation or inhibition, the regulation of cellular signaling, and the stabilization of the cell structure and membranes. This study presents selected issues regarding the current knowledge of anti-cancer mechanisms involving this element.

Metallothionein and Superoxide Dismutase-Antioxidative Protein Status in Fullerene-Doxorubicin Delivery to MCF-7 Human Breast Cancer Cells

Doxorubicin (DOX) is one of the most frequently used anticancer drugs in breast cancer treatment. However, clinical applications of DOX are restricted, largely due to the fact that its action disturbs the pro/antioxidant balance in both cancerous and non-cancerous cells. The aim of this study was to investigate the influence of fullerene (C₆₀) in cell treatment by DOX on the proliferation of human breast cancer cells (MCF-7), concentration of metallothionein (MT) and superoxide dismutase (SOD), and SOD activity in these cells. The use of C₆₀ in complexes with DOX causes a change in the level of cell proliferation of about 5% more than when caused by DOX alone (from 60–65% to 70%). The use of C₆₀ as a DOX nanotransporter reduced the MT level increase induced by DOX. C₆₀ alone caused an increase of SOD1 concentration. On the other hand, it led to a decrease of SOD activity. C₆₀ in complex with DOX caused a decrease of the DOX-induced SOD activity level. Exposure of MCF-7 cells to DOX-C₆₀ complexes results in a decrease in viable cells and may become a new therapeutic approach to breast cancer. The effects of C₆₀ in complexes with DOX on MCF-7 cells included a decreased enzymatic (SOD activity) and nonenzymatic (MT) antioxidant status, thus indicating their prooxidant role in MCF-7 cells.

Improving nutritional status assessment in patients with chronic pancreatitis

INTRODUCTION

Chronic pancreatitis (CP) is a progressive inflammatory disorder causing irreversible destruction of pancreatic tissue, leading to malnutrition. A previous study has found that currently used screening methods (periodic recording of body weight and faecal and serological markers) fall short in identifying and curbing malnutrition. Moreover, data is lacking regarding change in nutritional status over time. The aim of our study is to investigate changes in nutritional status in CP patients over time and to determine whether a more extensive set of measurements would be beneficial for nutritional screening of these patients.

METHODS

CP patients who had undergone a nutritional assessment in 2012 were recruited to undergo a second assessment. The assessment consisted of anthropometric measurements, bioelectrical impedance analysis (BIA), handgrip strength (HGS), the Mini Nutritional Assessment (MNA), determination of faecal and serological markers and the Short Form Health (SF-36) questionnaire. These two assessments were compared and correlations between the various measures were calculated.

RESULTS

Twenty-eight patients underwent a second assessment. An increase in fat mass and a decrease in both fat free mass (FFM) and HGS were observed. The number of patients scoring under the 10th percentile for FFM (43%-54%) and HGS in their dominant side (38%-46%) increased. FFM and HGS were positively correlated (R = 0.57).

CONCLUSION

Even though current guidelines for CP follow-up were adhered to, there was a general deterioration in nutritional status. HGS correlated with FFM. HGS might be useful as a screening instrument for malnutrition in CP patients.

Nutritional Considerations in Pediatric Pancreatitis: A Position Paper from the NASPGHAN Pancreas Committee and ESPGHAN Cystic Fibrosis/Pancreas Working Group

OBJECTIVES

Wide variations exist in how physicians manage the nutritional aspects of children affected by acute pancreatitis (AP), acute recurrent pancreatitis (ARP), and chronic (CP) pancreatitis. Better consensus for optimal management is needed.

METHODS

This consensus statement on nutrition in pediatric pancreatic diseases was developed through a joint ESPGHAN-NASPGHAN working group that performed an evidence-based search of the literature on nutrition in AP, ARP, and CP with a focus on pediatrics. The literature was summarized, quality of evidence reviewed, and expert recommendations developed. The authorship met to discuss the evidence and statements. Voting on recommendations occurred over 2 rounds based on feedback. A consensus of at least 75% was required to approve a recommendation. Areas requiring further research were identified.

RESULTS AND DISCUSSION

The literature on nutrition in pediatric pancreatitis is limited. Children with mild AP benefit from starting an early nutritional regimen in the course of the attack. Early nutrition should be attempted in severe AP when possible; enteral nutrition is preferred over parenteral nutrition. Children with ARP are likely to tolerate and benefit from a regular diet. Children with CP need ongoing assessment for growth and nutritional deficiencies, exocrine and endocrine insufficiencies.

CONCLUSIONS

This document presents the first authoritative recommendations on nutritional considerations in pediatric pancreatitis. Future research should address the gaps in knowledge particularly relating to optimal nutrition for AP in children, role of diet or dietary supplements on recurrent attacks of pancreatitis and pain episodes, monitoring practices to detect early growth and nutritional deficiencies in CP and identifying risk factors that predispose children to these deficiencies.

Inhibition of copper-zinc superoxide dismutase activity by selected environmental xenobiotics

The function of Cu,Zn-SOD is to dismutate superoxide into hydrogen peroxide and oxygen. This task is fulfilled due to structural nuances of the enzyme. Many environmental xenobiotics have been proved to inhibit Cu,Zn-SOD. Those compounds could be found not only in industrial sewage, cigarettes and various chemical agents - some of them are used as drugs, drug production substrates or are the product of drug biotransformation. Cu,Zn-SOD exposition to these compounds leads to inhibition due to: copper ion chelation, unfolding the structure of the enzyme, affecting residues vital for activity maintenance. This review covers a selection of Cu,Zn-SOD inhibitors, referring to in vivo and in vitro study.

The neuronal protection of a zinc-binding protein isolated from oyster

Mitochondrial function is applied as oxidative stress and neuronal damage index. In this study, d-galactose was used to induce free radicals production and neuronal damage in HN-h cells, and the effect of novel 43 kDa protein isolated from oyster on anti-mitochondrial dysfunction and zinc-binding ability were evaluated. Crystal violet stain results indicated zinc-binding protein of oyster (ZPO) attenuated neuronal cell death induced by 100 mM of d-galactose on HN-h cells in a dose-dependent manner. ZPO alleviated mitochondrial inactivation, mitochondrial membrane potential decreasing, oxidative stress, and fusion/fission state in non-cytotoxic concentration of d-galactose (50 mM)-treated HN-h cells. ZPO treatment recovered metallathionein-3 (MT-3) decrease and inhibited β- and γ-secretase as well as amyloid beta (Aβ) accumulation in HN-h cells caused by d-galactose induction. These results suggest ZPO could avoid oxidative stress and is a functional protein for zinc concentration maintainability, which has potential for development of functional foods for neuronal protection.

Effect of zinc gluconate, sage oil on inflammatory patterns and hyperglycemia in zinc deficient diabetic rats

BACKGROUND

The relationship between zinc homeostasis and pancreatic function had been established. In this study we aimed firstly to configure the inflammatory pattern and hyperglycemia in zinc deficient diabetic rats. Secondly to illustrate the effect of two selected agents namely Zinc gluconate and sage oil (Salvia Officinalis, family Lamiaceae).

METHODS

Rats were fed on Zinc deficient diet, deionized water for 28days along with Zinc level check up at intervals to achieve zinc deficient state then rats were rendered diabetic through receiving one dose of alloxan monohydrate (120mg/kg) body weight, classified later into 5 subgroups.

RESULTS

Treatment with sage oil (0.042mg/kg IP) and Zinc gluconate orally (150mg/kg) body weight daily for 8 weeks significantly reduced serum glucose, C-reactive protein (CRP), Tumor necrosis factor alpha (TNF- α), interleukins-6 1 β, inflammatory8 (IFN ȣ), pancreatic 1L1-β along with an increase in serum Zinc and pancreatic Zinc transporter 8 (ZNT8). Histopathological results of pancreatic tissues showed a good correlation with the biochemical findings.

CONCLUSIONS

Both sage oil and zinc gluconate induced an improvement in the glycemic and inflammatory states. This may be of value like the therapeutic agent for diabetes.

细胞内锌稳态调控及其在胰腺癌发生发展过程中的作用

锌参与300种以上的细胞生理过程, 包括DNA及蛋白合成、酶的活化以及细胞内信号转导过程. 同时锌也是许多酶类, 如碳酸酐酶、基质金属蛋白酶的关键组分, 而这些酶类与缺氧、血管生成、细胞增殖及肿瘤转移密切相关, 因此, 锌的获取对于恶性肿瘤的生长和进展非常重要. 细胞内锌离子的浓度变化受到ZnT1、ZIP4、金属硫蛋白及金属转录因子1等的调控, 细胞内锌稳态是多种调控机制参与下锌内流、锌外流和保留之间动态平衡的结果. 已有大量研究证实锌稳态调控失衡与胰腺癌的发生和转移有关, 因此, 锌及锌稳态的调控异常在胰腺癌的发生发展中具有重要作用.

The effect of ozone on the expression of metallothionein in tissues of rats chronically exposed to cadmium

Our aims were to evaluate the expression of metallothionein (MT) in an experimental rat model which experienced chronic exposure to cadmium (Cd) and to measure its expression after ozone therapy (OT) or oxygen (Ox) in the same model, as compared to the control group, which was exposed to neither cadmium nor ozone. Forty male Wistar rats were divided into 5 groups: control, Cd, Cd and Ox, Cd and Oz, and Oz. During our research, Cd concentration (ASA) and MT concentration (ELISA) were determined in supernatants of the kidneys, liver and pancreas. SDS-PAGE analyses and immunohistochemical localization were used to evaluate the level of MT expression in the tissue. In rats intoxicated with Cd, the highest concentration of both Cd and MT was observed in the kidneys and liver, with a significantly lower concentration measured in the pancreas. Ozone therapy reduces the accumulation of cadmium in the liver and kidneys, resulting in a reduced expression of metallothionein in those tissues.

Zinc directly stimulates cholecystokinin secretion from enteroendocrine cells and reduces gastric emptying in rats

Zinc, an essential mineral element, regulates various physiological functions such as immune responses and hormone secretion. Cholecystokinin (CCK), a gut hormone, has a role in protective immunity through the regulation of gastrointestinal motility, appetite, and inflammatory response. Here, we examined the effect of zinc on CCK secretion in STC-1 cells, an enteroendocrine cell line derived from murine duodenum, and in rats. Extracellular zinc triggered CCK secretion accompanied with increased intracellular Ca(2+) and Zn(2+) mobilization in STC-1 cells. Zinc-induced CCK secretion was abolished in the absence of intracellular Zn(2+) or extracellular calcium. Upon inhibition of transient receptor potential ankyrin 1 (TRPA1), extracellular zinc failed to increase intracellular Ca(2+) and subsequent CCK secretion. In rats, oral zinc administration decreased gastric emptying through the activation of CCK signaling. These results suggest that zinc is a novel stimulant for CCK secretion through the activation of TRPA1 related to intracellular Zn(2+) and Ca(2+) mobilization.

Tempol, a Membrane-Permeable Radical Scavenger, Exhibits Anti-Inflammatory and Cardioprotective Effects in the Cerulein-Induced Pancreatitis Rat Model

To date, it remains unclear whether mild form of acute pancreatitis (AP) may cause myocardial damage which may be asymptomatic for a long time. Pathogenesis of AP-related cardiac injury may be attributed in part to ROS/RNS overproduction. The aim of the present study was to evaluate the oxidative stress changes in both the pancreas and the heart and to estimate the protective effects of 1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine (tempol) at the early phase of AP. Cerulein-induced AP led to the development of acute edematous pancreatitis with a significant decrease in the level of sulfhydryl (–SH) groups (oxidation marker) both in heart and in pancreatic tissues as well as a substantial increase in plasma creatine kinase isoenzyme (CK-MB) activity (marker of the heart muscle lesion) which confirmed the role of oxidative stress in the pathogenesis of cardiac damage. The tempol treatment significantly reduced the intensity of inflammation and oxidative damage and decreased the morphological evidence of pancreas injury at early AP stages. Moreover, it markedly attenuated AP-induced cardiac damage revealed by normalization of the –SH group levels and CK-MB activity. On the basis of these studies, it is possible to conclude that tempol has a profound protective effect against cardiac and pancreatic damage induced by AP.

The antioxidant profiles, lysosomal and membrane enzymes activity in patients with acute pancreatitis

Oxidative stress and inflammatory mediators, such as IL-6, play an important role in the pathophysiology of acute pancreatitis. The study was aimed to assess the degree of the pro/antioxidative imbalance and estimate which antioxidant plays a role in the maintenance of pro/antioxidative balance during acute pancreatitis. The study was investigated in the blood of 32 patients with acute pancreatitis and 37 healthy subjects. IL-6 concentration as early marker of inflammation was determinated. The intensity of oxidative stress was assessed by TBARS concentration. To investigate antioxidative status, the GPx and Cu/Zn SOD activities and the levels of GSH, MT, SH groups, and TRAP were measured. The concentrations of Cu and Zn as ions participating in the maintenance of antioxidant enzymes stability and playing a role in the course of disease were determinated. The activities of GGT, AAP, NAG, and β-GD as markers of tissue damage were also measured. An increase in IL-6 concentration, which correlated with Ranson criteria, and an increase in GPx activity, levels of MT, TBARS, or GGT, and NAG activities in patients group compared to healthy subjects were demonstrated. A decrease in GSH level in patients group compared to control group was noted. The studies suggest that GPx/GSH and MT play the role of the first line of defence against oxidative stress and pro/antioxidant imbalance in the course of acute pancreatitis.

Participation of metallothionein and superoxide dismutase in the blood of smoking smelters

OBJECTIVES

Metallothionein (MT) and two forms of superoxide dismutase (SOD), which are dependent on zinc and copper ions, are involved in defense against the same superoxide anion radicals and are present in extra- and intracellular compartments. The aim of our study was to investigate MT concentration and Cu/Zn SOD activity in the plasma and erythrocyte lysate of the non-smoking and smoking smelters.

MATERIAL AND METHODS

The investigations were performed in the blood of 300 male smelters and 100 non-exposed male subjects. We have measured zinc, copper, malondialdehyde (MDA) and MT concentrations as well as SOD activity.

RESULTS

We have observed an increase of Cu/Zn coefficient and decrease of Zn/Cu coefficient in the serum of smelters in comparison with the non-smoking control group. Concentration of MDA in the plasma of smelters was higher in comparison with its concentration in the non-smoking control group. The plasma and the erythrocyte lysate MT concentration increased significantly in the whole group of smelters as compared to the non-smoking control group. The mean value of MT concentration in plasma of the smoking smelters was above 2-fold higher than in the non-smoking control group. The activity of Cu/Zn SOD in plasma of the smoking and non-smoking smelters was decreased in comparison with the smoking and non-smoking control groups, respectively. The lowest activity of Cu/Zn SOD, about 2-3-fold decreased in comparison with the smoking and non-smoking control groups, was detected in plasma of the smelters. An inverse relationship was observed in the erythrocyte lysate. The highest activity of Cu/Zn SOD was reported in the erythrocyte lysate of the smoking smelters and it was about 2-fold higher than in the non-smoking control group.

CONCLUSIONS

In extracellular environment MT plays a crucial role in comparison with the SOD, while in the intracellular compartment Cu/Zn SOD and MT cooperate with each other.

Reappraisal of xenobiotic-induced, oxidative stress-mediated cellular injury in chronic pancreatitis: A systematic review

AIM: To reappraise the hypothesis of xenobiotic induced, cytochrome P450-mediated, micronutrient-deficient oxidative injury in chronic pancreatitis.

METHODS: Individual searches of the Medline and Embase databases were conducted for each component of the theory of oxidative-stress mediated cellular injury for the period from 1^st January 1990 to 31^st December 2012 using appropriate medical subject headings. Boolean operators were used. The individual components were drawn from a recent update on theory of oxidative stress-mediated cellular injury in chronic pancreatitis.

RESULTS: In relation to the association between exposure to volatile hydrocarbons and chronic pancreatitis the studies fail to adequately control for alcohol intake. Cytochrome P450 (CYP) induction occurs as a diffuse hepatic and extra-hepatic response to xenobiotic exposure rather than an acinar cell-specific process. GSH depletion is not consistently confirmed. There is good evidence of superoxide dismutase depletion in acute phases of injury but less to support a chronic intra-acinar depletion. Although the liver is the principal site of CYP induction there is no evidence to suggest that oxidative by-products are carried in bile and reflux into the pancreatic duct to cause injury.

CONCLUSION: Pancreatic acinar cell injury due to short-lived oxygen free radicals (generated by injury mediated by prematurely activated intra-acinar trypsin) is an important mechanism of cell damage in chronic pancreatitis. However, in contemporary paradigms of chronic pancreatitis this should be seen as one of a series of cell-injury mechanisms rather than a sole mediator.

The effect of smoking on expression of IL-6 and antioxidants in pancreatic fluids and tissues in patients with chronic pancreatitis

OBJECTIVES

The present study was conducted to ascertain whether cigarette smoke induces oxidative stress in the human pancreas concurrently with inflammation.

MATERIALS AND METHODS

The influence of tobacco smoking on the serum level of interleukin-6 (IL-6), on the activities of glutathione peroxidase (GPx) and copper-zinc superoxide dismutase (Cu/Zn SOD) as well as on the metallothionein (MT) level in the pancreatic pseudocyst fluid and its immunohistochemical localization in tissues of non-smoking (n = 9) and smoking (n = 12) patients with diagnosed chronic pancreatitis (CP) was measured. The concentration of interleukin-6 and metallothionein was determined by means of ELISA and the radioisotopic method, respectively. The enzyme activities in the fluid were assayed by the colorimetric method. Samples of tissues of normal pancreas (n = 4) and CP (non-smoking n = 7; smoking n = 12) were verified histopathologically and then IL-6, MT and enzymes were localized by immunohistochemical staining using the monoclonal anti-human antibody.

RESULTS

The concentrations of metallothionein and interleukin-6 were significantly higher in smoking patients with CP (as compared with the non-smoking population (p < 0.01; p < 0.001). Interestingly, the ratio of MT/IL-6 in smoking patients with CP was reduced in comparison to non-smoking patients (respectively: 1.1; 5.6). In smoking patients, a significant elevation of the Cu/Zn SOD and GPx activities was revealed as compared with the non-smokers (p < 0.04; p < 0.0007). These studies clearly demonstrate a moderate and strong expression of IL-6 and enzymes in acinar, islet and duct cells of smoking patients.

CONCLUSIONS

These observations favor the role of the oxidative stress in the induction of pancreatitis associated with chronic cigarette smoke inhalation.

Effects of chronic chromium(vi) exposure on blood element homeostasis: an epidemiological study

One hundred chromate production workers chronically exposed to low-level of hexavalent chromium [Cr(vi)] and eighty healthy individuals free from Cr exposure were recruited to the study. Personal sampling of airborne Cr was conducted and Cr content was quantified by Flame Atomic Absorption Spectrometry (FAAS). At the end of the sampling shift, blood samples were collected and element concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS) for Cr, Cd, Cu, Mo and Se and inductively coupled plasma atomic emission spectrometry (ICP-AES) for Ca, Fe, Mg and Zn. According to our results, 90% of the chromate production workers were exposed to airborne Cr in a concentration lower than 50 μg m(-3), which is the threshold limit value recommended by the American Conference of Governmental Industrial Hygienists and Chinese Ministry of Health. After Cr(vi) exposure, a significant increase in blood Cr, Cd, Fe, Mg, Mo, Se and Zn concentrations was observed, as well as a significant decrease in Ca concentration. A decrease in blood Cu was only observed among female workers. Blood Cr concentrations of the exposed workers (median = 15.68 ng mL(-1)) was four times higher than that of the controls (median = 3.03 ng mL(-1)), and significantly correlated with airborne Cr (r = 0.568, P<0.001). In addition, the inter-element correlations exhibited significant differences between the two groups. Our findings of the related health effects suggested that the underlying mechanisms of chronic Cr(vi) exposure on blood element homeostasis might be partly explained by oxidative stress in the body, dysfunction of Fe metabolism and renal injury.

Influence of copper, iron, zinc and fe (3) (+) haemoglobin levels on the etiopathogenesis of chronic calcific pancreatitis--a study in patients with pancreatitis

Chronic pancreatitis is a serious condition associated with severe abdominal pain, and a significant percentage of patients progresses to irreversible calcification in pancreas. The present study evaluates the degree to which the levels of trace elements, copper, iron, selenium, zinc and haemoglobin-Fe(3+), in blood, serum and pancreas have any role to play in the calcification process associated with fibrosis in pancreas. Twenty-seven calcific (CCP) and 23 non-calcific chronic pancreatitis (CP) patients and equal number of age- and sex-matched normal volunteers (50) were enrolled in the study. Surgically removed pancreatic tissue and blood samples were analysed for copper, iron, selenium, zinc, protein, collagen and lipid peroxidation products in terms of malondialdehyde, protein carbonyls, glutathione, methemoglobin, methemoglobin reductase and ceruloplasmin activity levels. We could find that the pancreatic tissue levels of copper, iron, protein and collagen contents were significantly elevated in CCP patients when compared to CP patients. Serum levels of copper, free ionic copper and iron were also elevated in CCP patients. The serum and the pancreatic tissue level of zinc and selenium showed a significant decrease in CCP patients. The level of methemoglobin was elevated more significantly with the concomitant decline in the activity of methemoglobin reductase. There was a positive correlation between the pancreatic level of copper and iron with the collagen and protein levels. The results of the present study revealed that the levels of copper and iron, the pro-oxidants and zinc and selenium may influence calcification process in CCP patients. Hypoxia-related tissue injury due to the formation of oxidised haemoglobin may also contribute to the pathogenesis of calcification in pancreas.

Zinc in specialized secretory tissues: roles in the pancreas, prostate, and mammary gland

Zinc (Zn) is an essential micronutrient required for over 300 different cellular processes, including DNA and protein synthesis, enzyme activity, and intracellular signaling. Cellular Zn homeostasis necessitates the compartmentalization of Zn into intracellular organelles, which is tightly regulated through the integration of Zn transporting mechanisms. The pancreas, prostate, and mammary gland are secretory tissues that have unusual Zn requirements and thus must tightly regulate Zn metabolism through integrating Zn import, sequestration, and export mechanisms. Recent findings indicate that these tissues utilize Zn for basic cellular processes but also require Zn for unique cellular needs. In addition, abundant Zn is transported into the secretory pathway and a large amount is subsequently secreted in a tightly regulated manner for unique biological processes. Expression of numerous members of the SLC30A (ZnT) and SLC39A (Zip) gene families has been documented in these tissues, yet there is limited understanding of their precise functional role in Zn metabolism or their regulation. Impairments in Zn secretion from the pancreas, prostate, and mammary gland are associated with disorders such as diabetes, infertility, and cancer, respectively. In this review, we will provide a brief summary of the specific role of Zn in each tissue and describe our current knowledge regarding how Zn metabolism is regulated. Finally, in each instance, we will reflect upon how this information shapes our current understanding of the role of Zn in these secretory tissues with respect to human health and disease.

Therapeutic implications of oxidative stress in acute and chronic pancreatitis

PURPOSE OF REVIEW

This review presents new evidence on the role of oxidative stress and antioxidant status in acute and chronic pancreatitis published in the last year.

RECENT FINDINGS

In-vitro studies showed that protein phosphatases may play an important role in the interaction between reactive oxygen species and proinflammatory cytokines in acute pancreatitis. In-vivo studies found that several natural compounds ameliorate oxidative stress and, therefore, have therapeutic potential. In the domain of clinical studies, the major development is the first double-blind placebo-controlled randomized trial that showed effectiveness of oral antioxidant supplementation (organic selenium, ascorbic acid, alpha-tocopherol, beta-carotene, and methionine) in relieving pain in patients with chronic pancreatitis. The developments in clinical studies on acute pancreatitis are less spectacular and mainly limited to evaluation of different markers of oxidative stress and antioxidant status in the course of disease.

SUMMARY

A significant advance has been made in the arena of research in chronic, but not acute, pancreatitis. There is now solid evidence to justify the use of oral antioxidants in the treatment of patients with chronic pancreatitis. The progress in clinical research on antioxidants in acute pancreatitis is hampered by several factors, including suboptimal classification of acute pancreatitis and route of administration used in previous studies.

Role of metallothionein in cadmium traffic and toxicity in kidneys and other mammalian organs

Metallothioneins are cysteine-rich, small metal-binding proteins present in various mammalian tissues. Of the four common metallothioneins, MT-1 and MT-2 (MTs) are expressed in most tissues, MT-3 is predominantly present in brain, whereas MT-4 is restricted to the squamous epithelia. The expression of MT-1 and MT-2 in some organs exhibits sex, age, and strain differences, and inducibility with a variety of stimuli. In adult mammals, MTs have been localized largely in the cell cytoplasm, but also in lysosomes, mitochondria and nuclei. The major physiological functions of MTs include homeostasis of essential metals Zn and Cu, protection against cytotoxicity of Cd and other toxic metals, and scavenging free radicals generated in oxidative stress. The role of MTs in Cd-induced acute and chronic toxicity, particularly in liver and kidneys, is reviewed in more details. In acute toxicity, liver is the primary target, whereas in chronic toxicity, kidneys are major targets of Cd. The intracellular MTs bind Cd ions and form CdMT. In chronic intoxication, Cd stimulates de novo synthesis of MTs; it is assumed that toxicity in the cells starts when loading with Cd ions exceeds the buffering capacity of intracellular MTs. CdMT, released from the Cd-injured organs, or when applied parenterally for experimental purposes, reaches the kidneys via circulation, where it is filtered, endocytosed in the proximal tubule cells, and degraded in lysosomes. Liberated Cd can immediately affect the cell structures and functions. The resulting proteinuria and CdMT in the urine can be used as biomarkers of tubular injury.