Effect of oral zinc supplementation on metallothionein and superoxide dismutase concentrations in patients with inflammatory bowel disease

Abstract Oxygen-derived free radicals may contribute to intestinal tissue damage in inflammatory bowel disease. The concentrations of metallothionein and superoxide dismutase, two copper and zinc containing proteins involved in the scavenging of free radicals, were previously found to be decreased in the intestinal mucosa of patients with this disorder. The plasma zinc concentration is often decreased also in these patients. Since zinc is reported to be an efficient inducer of metallothionein synthesis, and probably of superoxide dismutase, we evaluated the effect of oral zinc supplementation on metallothionein and superoxide dismutase levels in patients with inflammatory bowel disease. Fourteen patients with inactive to moderately active inflammatory bowel disease received oral zinc supplementation (300 mg zinc aspartate, equal to 60 mg elemental zinc per day) for 4 weeks in a placebo-controlled double-blind cross-over trial. The plasma zinc concentration of these patients was low at the start of the study (12.2 ± 1.7 μmol/L, P <0.05), when compared to that of 22 healthy controls (13.6 ± 2.3 μmol/L), but increased (P <0.05) towards the levels of controls during the supplementation period (13.3 ± 2.5 μmol/L). The concentrations of metallothionein and superoxide dismutase in plasma and in erythrocytes did not change in relation to the supplementation. The metallothionein concentration in both inflamed and non-inflamed intestinal mucosa was slightly higher after zinc supplementation but the superoxide dismutase concentration in the tissue was not altered. The histological inflammation score of intestinal biopsies, plasma albumin levels, and the disease activity index of the patients did not change during the study. Thus, although zinc supplementation therapy increased plasma zinc concentrations, there was no effect on the plasma, erythrocyte and mucosal metalloprotein levels in inactive to moderately active patients with inflammatory bowel disease.     

金属硫蛋白3对快速老化痴呆模型小鼠海马锌和铜含量的影响

目的研究快速老化痴呆模型小鼠(SAMP8)海马锌和铜含量的变化及外源性金属硫蛋白3(MT3)对SAMP8海马锌和铜含量变化的影响,并与MT1进行比较。方法将SAMP8 60只随机分为痴呆组、低浓度MT3组、中浓度MT3组、高浓度MT3组、MT1对照组和空白对照组;每组10只,SAMP1 10只为正常对照组。连续腹腔注射不同浓度MT3等4周后处死小鼠,应用原子吸收分光光度计检测各组小鼠海马锌和铜的含量,并观察其与低、中、高3种浓度MT3的量效关系。结果与正常对照组比较,痴呆组小鼠海马锌含量明显下降(P<0.05);与低浓度MT3组和高浓度MT3组比较,中浓度MT3组小鼠海马锌含量明显升高(P<0.05);与空白对照组比较,中浓度MT3组小鼠海马锌含量明显升高(P<0.05);MT1对照组与低、中、高浓度MT3组比较,小鼠海马锌含量差异无统计学意义。各组小鼠海马铜含量差异无统计学意义。结论 SAMP8海马锌含量降低。MT3可以增加SAMP8海马锌含量,但锌含量不随MT3浓度增加而增加。而对铜含量影响不大。     

Efficacy of zinc supplementation in preventing acute hepatitis in Long-Evans Cinnamon rats.

OBJECTIVES: Long-Evans Cinnamon (LEC) rats are characterized by an abnormal hepatic deposition of copper (Cu) due to a lack of the Cu-transporter P-type adenosine triphosphatase: accordingly, the strain is a good animal model of Wilson's disease. The effect of oral zinc (Zn) acetate treatment on the development of acute hepatitis and the biochemical parameters of Cu-induced liver damage was studied in 5-week-old LEC rats (n=52). METHODS: Rats receiving 50 or 80 mg/ml/day Zn acetate by gavage and control rats receiving a daily dose of glucose solution 0.02 g/ml by gastric intubation were killed at 1, 2 or 8 weeks after the start of treatment. RESULTS: Treatment with Zn acetate resulted in the prevention of acute hepatitis: 10 of the 13 untreated rats developed signs and symptoms compatible with acute hepatitis between the 6th and 7th week of treatment. Tissue metallothionein (MT) significantly increased in the treated rats and positively correlated with Zn concentrations within the liver. Control rats had a significantly higher iron concentration in the liver and kidneys compared with supplemented rats, after both short- and long-term experiments. 8-hydroxy-2'-deoxyguanosine amounts were significantly lower in untreated rats. CONCLUSIONS: Zn acetate prevents acute hepatitis, by increasing tissue MT concentrations, reducing Cu absorption and interfering with Fe metabolism.     

Effect of sucralfate on experimental colitis in the rat

The therapeutic effect of sucralfate on ulcerated gastric and duodenal mucosa is well known. There is, however, almost no information about its activity in colitis. Experimental colitis was produced in rats by rectal instillation of 1 ml of 10 percent acetic acid, and 1.5 ml of a 20 percent suspension of sucralfate was then administered every 12 hours for various lengths of time. Study animals and appropriate controls were killed after 3, 7, 10, or 14 days. The distal colons were studied macroscopically and histologically. Colonic prostaglandin E₂ levels were measured in animals killed after 3, 7, 10, or 14 days. The macroscopic score was significantly improved 10 and 14 days after induction of colitis, although the histologic appearence was unchanged. Acetic acid administration increased and sucralfate treatment reduced prosta-glandin E₂ levels in colitic animals on days 3 and 7, but not later. The present study supports a role for sucralfate in the treatment of colitis, but further studies on the mechanism of its effect and on its clinical activity are indicated. Supported by ABIC Pharmaceutical Company, Netanya, Israel.     

Mechanisms of increased intestinal [51Cr]EDTA absorption during experimental colitis in the rat

Experimental colitis was induced in the rat, by ethanol-oxazolone injections into the distal colon, resulting in diarrhea together with edema, ulcers, and cell infiltration in the exposed colon. Colitic rats showed an elevated urinary recovery of the permeability marker [⁵¹Cr]EDTA after intragastric feeding, 19±10%, compared to 2.9±0.7% for control rats (P<0.001). An increased retention of [⁵¹Cr]EDTA in the intestines and a decreased discharge in feces suggested an increased intestinal transit time in colitic rats. Thein vitro permeability to [⁵¹Cr]EDTA and ovalbumin was not elevated in the severely inflamed distal colon, but was in the proximal, unaffected colon to ovalbumin (P<0.05) and in the distal small intestine, to both [⁵¹Cr]EDTA (P<0.01) and ovalbumin (P<0.05), indicating that an inflammation in one part of the intestine could have permeability effects in other remote parts. In conclusion, the increased [⁵¹Cr]EDTA absorptionin vivo during colitis was probably due to both an increased permeability and an increased intestinal transit time.This study was supported by grants from The Swedish Natural Sciences Research Council and Astra Draco AB.     

Butyrate from bacterial fermentation of germinated barley foodstuff preserves intestinal barrier function in experimental colitis in the rat model

BACKGROUND AND AIMS: The consumption of germinated barley foodstuff (GBF) prevents inflammation and diarrhoea in a colitis model. In this study we investigated the mechanism of the preventative effect of GBF on experimental colitis in rats, in view of production of bacterial butyrate and preservation of intestinal barrier function. METHODS: Sprague-Dawley rats administered with diets supplemented with 3.5% dextran sodium sulphate were used as an experimental colitis model. Butyrate was given to rats orally or intracaecally. Intestinal barrier function was estimated by light microscopic observation of the mucosa, intestinal permeability and bacterial translocation. RESULTS: Mucosal damage was reduced by intracaecal administration of butyrate, but not by oral administration. Bacterial butyrate production and reduction of mucosal damage depended on the dose of GBF in diets. The action of endogenous bacterial butyrate, including the reduction of intestinal permeability and bacterial translocation, was inhibited by administration of an inhibitor of beta-oxidation of short-chain fatty acids. CONCLUSIONS: The feeding of GBF promotes bacterial butyrate production and improves intestinal barrier function in rats, resulting in mitigation of experimental colitis.     

Effect of copper and zinc supplementation on peripheral leukocytes in neutropenia due to copper deficiency

Background: Recent quantitative and qualitative studies in animals suggest that copper deficiency causes immunological impairment and a decrease in leukocytes. We investigated the effect of copper supplementation in remedying these effects of its deficiency and whether zinc, a trace element that is significant to the immune status modifies such effects. Methods: In the present investigation, the effects of copper supplementation on circulating lymphocyte levels of 18 patients (aged 61–98 years, mean 85 years) with severe copper deficiency, elicited by a long‐term low copper diet, were examined in comparison with six age and sex‐matched healthy elderly subjects. Every day for 28 days, 2 mg of copper sulfate was added to the diets of 12 of the copper‐deficient subjects. The remaining copper‐deficient subjects received 2 mg of copper sulfate daily in their diets and were also given 17.3 mg of zinc sulfate every day by intravenous infusion, both supplements were also given for 28 days. Two‐color flow‐cytometry was conducted and the blastogenesis of circulating lymphocytes was examined. Results: Copper supplementation increased the number of circulating CD2⁺, CD4⁺, CD20⁺ cells without affecting numbers of NK‐type CD8⁺ T cells (CD11b⁺ and CD57⁺ lymphocytes). The percentage of monocytes to total leukocytes decreased after copper supplementation. Zinc supplementation, however, did not augment these effects and did not increase the total number of CD57⁺ cells. The ratio of pokeweed mitogen reactivity to concanavalin‐A reactivity was diminished by copper supplementation but not additional zinc. There was no change in the immunological colloid reaction in the zinc sulfate turbidity test. Conclusion: Our results suggest that copper depletion has a deleterious effect on the immune system, with a decrease in circulating lymphocytes numbers. Monocytes seemed to be more resistant to copper deficiency than neutrophils, and to play a significant role in lymphocyte activation. Despite this, however, it seems unlikely that there is any synergy between copper supplementation and zinc supplementation.     

地塞米松对大鼠心肌缺血再灌注后细胞凋亡及金属硫蛋白表达的影响

目的观察地塞米松预处理对大鼠心肌缺血再灌注损伤的影响并探讨其作用机制。方法32只SD大鼠随机分成地塞米松组(16只)和对照组(16只),分别给予地塞米松(0.8mg/kg)和蒸馏水腹腔注射。预处理24h后,构建体外心脏缺血再灌注动物模型,动态观测缺血前期及再灌注期左心室发展压(LVDP)、左心室压力最大上升和下降速率(±dp/dtmax)、冠状动脉流出量(CF);测定冠状动脉流出液肌酸激酶同工酶(CK-MB)的漏出率;TUNEL法检测心肌细胞凋亡;Westernblot法检测金属硫蛋白(MT)、Bcl-2及Bcl-xl蛋白的表达;免疫组织化学法测定半胱天冬酶-3(caspase-3)的水平。结果与对照组比较,地塞米松组大鼠再灌注期LVDP、±dp/dtmax及CF得到改善(P<0.05);CK-MB的漏出率明显降低[(8.69±4.16)U/gvs(18.15±5.59)U/g,P<0.01];心肌细胞凋亡指数(10.18±1.99)%vs(14.66±2.97)%和caspase-3水平明显减少[(18.66±5.15)%vs(27.93±6.23)%,P<0.01],Bcl-xl(4.74±0.66)vs(1.69±0.73)和MT的表达明显增加[(3.09±1.07)vs(1.03±0.02),P<0.05],Bcl-2无明显变化(P>0.05)。结论地塞米松预处理对大鼠缺血再灌注的心肌具有保护作用,上调MT表达及抑制细胞凋亡可能是其机制之一。     

The antiviral role of zinc and metallothioneins in hepatitis C infection

Metallothioneins (MTs) are small, cysteine‐rich proteins characterized by a high affinity for monovalent and divalent cations, such as copper and zinc. Of the four known MT isoforms, only, members of the MT 1 and 2 subfamilies are widely expressed, acting as metal chaperones whose primary role is to mediate intracellular zinc homoeostasis. Metallothioneins are potently induced by heavy metals and other sources of oxidative stress where they facilitate metal binding and detoxification as well as free radical scavenging. Metallothionein expression is well documented in the context of viral infection; however, it remains uncertain whether MTs possess specific antiviral roles or whether induction is merely a consequence of cellular stress. To better understand the role of MTs following hepatitis C virus (HCV) infection, we examined MT expression and localization in vitro and in vivo and used a siRNA knockdown approach to ascertain their antiviral efficacy. We confirmed HCV‐driven MT induction in vitro and demonstrated MT accumulation in the nucleus of HCV‐infected hepatocytes by immunofluorescence. Using a pan‐MT siRNA to knock down all members of the MT1 and MT2 subfamilies, we demonstrate that they are mildly antiviral against the JFH1 strain of HCV in vitro (~1.4 fold increase in viral RNA, P < .05). Furthermore, the antiviral effect of zinc treatment against HCV in vitro was mediated through MT induction (P < .05). Our data suggest a potential benefit of using zinc as a low‐cost adjunct to current HCV antiviral therapies and suggest that zinc may facilitate the antiviral role of MTs against other viruses.     

Effect of zinc supplementation on respiratory tract infections in children with cystic fibrosis

Zinc (Zn) has significant anti-oxidant and anti-inflammatory activity. Zn deficiency can occur in subsets of patients with cystic fibrosis (CF) especially those with malabsorption and impaired growth. Although supplemental Zn has significantly reduced infections in various disorders, its efficacy has not been thoroughly investigated in CF. We performed a double blind placebo controlled pilot study to investigate the effect of daily 30 mg elemental Zn for 1 year on the rate of respiratory tract infections (RTIs), use of antibiotics and plasma cytokines in 26 children with CF (ages 7-18 years). Plasma Zn, Cu, inflammatory cytokines and ex vivo generation of IL-2 were measured at baseline and at the end of the study. The number of days of oral antibiotics was lower in Zn treated patients compared to placebo (P = 0.05). However, compared to placebo, the effect of Zn was greater in patients who exhibited low plasma Zn at baseline (P = 0.02) than those who had plasma Zn levels identical to normal subjects (P = 0.55). Zn supplementation was marginally effective in reducing percentage increase in plasma IL-6 and IL-8 while increasing the percentage change in ex vivo generation of IL-2 in isolated mononuclear cell. In conclusion, oral intake of 30 mg/day of Zn reduced the number of days of oral antibiotics used to treat RTIs in children with CF. A higher daily Zn dose may be needed to decrease RTIs and modify immune responses.     

Dietary zinc and metallothionein on small intestinal disaccharidases activity in mice

AIM: To examine the effect of increasing dietary zinc (Zn) intake and the lack of metallothionein (MT) expression on activity of small intestinal disaccharidases. METHODS: MT-Ⅰ and Ⅱ knockout (MT-/-) and wild-type (MT+/+) female mice at 3.5 wk of age were randomly fed with a diet containing 2 (2 Zn), 15 (15 Zn) or 50 (50 Zn) mg Zn/kg (n = 8/group/genotype) for 5 wk. Small intestinal segments (duodenum, jejunum and ileum) were collected and either fixed in 10% formalin for histological analysis or snap froze...     

Effect of zinc supplementation on serum testosterone level in adult male sickle cell anemia subjects

Previously, we have documented primary testicular failure in adult male subjects with sickle cell anemia. We have also reported the occurrence of zinc deficiency and suggested that androgen deficiency may be related to zinc deficiency in such patients. In this study, we present data with respect to the efferent of oral zinc supplementation on serum testosterone levels in adult male patients with sickle cell anemia. An increase in serum testosterone, neutrophil zinc, and neutrophil alkaline phosphatase activity ws observed in the zinc-supplemented group in comparison with the group on placebo. Additionally, body weight increased and serum lactic dehydrogenase activity decrease in response to zinc supplementation. We conclude that androgen deficiency in adult male subjects with sickle cell anemia is correctable with zinc supplementation and that the determination of neutrophil zinc and alkaline phosphatase activity in the neutrophils may be utilized as good indicators of body zinc status in such subjects.     

补锌联合消旋卡多曲颗粒治疗对轮状病毒性肠炎患儿血锌及免疫功能的影响

目的 观察补锌联合消旋卡多曲颗粒治疗对轮状病毒性肠炎(RVE)患儿血锌及免疫功能的影响.方法 选择2016年8月至2019年7月我院收治的RVE患儿106例,采用随机数字法分为两组,每组53例.对照组患儿接受常规治疗,观察组患儿在常规治疗的基础上加用葡萄糖酸锌糖浆、消旋卡多曲颗粒治疗,治疗7 d为1疗程,共治疗2个疗程...     

Analysis of zinc and other elements in rat pancreas,with studies in acute pancreatitis

Determination of the concentration of certain elements makes it possible to investigate the physiology of the pancreas: We used X-ray fluorescence to determine the concentrations of zinc and other elements in the pancreas of normal (control) rats and those with cerulein-induced pancreatitis. Ten elements (Zn, Ni, Fe, P, Ca, Cl, S, K, Ti, and Mn) were detected in controls. In the early stage of acute pancreatitis, the pancreatic concentrations of Zn, Ni, Fe, and P were significantly decreased (P<0.05) and=" those=" of=" ca=" and=" cl=" were=" significantly=" increased=">P<0.05), compared=" with=" control=" levels.=" however,=" levels=" of=" s,=" k,=" and=" ti=" did=" not=" differ=" significantly=" from=" the=" control=" values.=" mn=" was=" detected=" in=" only=" some=" samples.=" the=" serum=" levels=" of=" zn=" and=" fe=" were=" significantly=" elevated=">P<0.05) in=" acute=" pancreatitis.=" these=" observations=" indicate=" that=" zn=" and=" these=" other=" nine=" elements=" could=" play=" an=" important=" role=" in=" acute=">     

Effect of cyclosporine in a murine model of experimental colitis

The use of immunosuppressive therapy may be associated with significant toxicity. The aim of this study was to investigate the effect of cyclosporine A (CsA) in murine model of experimental colitis. Experimental colitis was induced in NMRI mice using an enema of 0.2% solution of dinitrofluorobenzene, combined with skin sensitization. After inducing colitis, experimental groups of animals were treated with CsA (1, 3, 5, 10, 25, 50 mg/kg/day) intraperitoneally (i.p.) or intracolonically (i.c.), and control groups were treated with phosphate-buffered saline intraperitoneally or intracolonically, respectively. Colonic inflammatory changes were assessed using a histopathologic score of 0–30, and pooled whole blood samples were processed with monoclonal antibodies for cyclosporine concentration. In addition, two groups of animals with experimental colitis were treated intraperitoneally or intracolonically with 3 mg/kg/day of CsA, and the colons were also taken for immunohistochemistry for CD25. CsA diminished the extent of colitis in groups treated with 3, 5, 10, or 25 mg/kg intraperitoneally or intracolonically, and in groups treated with 1 and 50 mg/kg intracolonically (P < 0.05). The effect of intracolonic application of CsA was not related to whole blood cyclosporine concentrations. In addition, the effect of CsA at 3 mg/kg, applied intraperitoneally or intracolonically was, in part, expressed in decreasing the numbers of CD25+ cells within colonic mucosa/submucosa (P < 0.05). In conclusions, the results of this study indicate the possibility of intracolonic application of cyclosporine in order to widen the therapeutic window for effective, but possibly toxic drug, such as cyclosporine.     

Zinc sulphate induces metallothionein in pancreatic islets of mice and protects against diabetes induced by multiple low doses of streptozotocin

Aims/hypothesis. Diabetes is induced by multiple low doses of streptozotocin (MLD-STZ) in male mice of susceptible strains. In this model beta-cell injury and T-cell-mediated inflammatory reactions are induced. Probably, reactive oxygen species (ROS) participate in the destruction of beta cells. The effects of ROS can be counterbalanced by several antioxidant systems. One of these is metallothionein (MT), cytosolic proteins that are induced by zinc ions (Zn²⁺) and scavenge hydroxyl radicals (^·OH). The effect of Zn²⁺ on MLD-STZ-diabetes was studied. Methods. We gave C57BL/6 and (C57BL/6 × SJL)F₁ hybrid mice either MLD-STZ or in addition Zn²⁺-enriched drinking water. We analysed metallothionein ex vivo in pancreatic islets for protein and mRNA concentration for the isoforms 1 and 2. Pancreatic sections were examined by immunohistochemistry for metallothionein and histologically for insulitis. Results. In both strains, Zn²⁺-enriched drinking water significantly up-regulated metallothionein and prevented MLD-STZ-diabetes and loss of beta-cell function. In the F₁ hybrid mice a variant of MLD-STZ-diabetes was observed. These mice developed hyperglycaemia 10 weeks after the first injection of STZ (in contrast to 2 weeks observed in other mouse strains) and pronounced insulitis. The mRNA of the metallothionein isoforms 1 and 2 were constitutively expressed and slightly up-regulated by Zn²⁺-enriched drinking water. All islets cells stained for metallothionein. Conclusions/interpretations. Drinking water enriched with Zn²⁺ significantly up-regulated metallothionein production in pancreatic islets of mice and prevented diabetes induced with MLD-STZ. [Diabetologia (2000) 43: 1020–1030] Received: 22 February 2000 and in revised form: 10 April 2000     

Sputum zinc concentration and clinical outcome in older asthmatics

Background and objective: Mouse models of asthma show that zinc deficiency is associated with airway inflammation (AI), which is attenuated by zinc supplements. Whether zinc has a similar role in the human airway remains controversial, with studies demonstrating both high and low plasma zinc concentrations [Zn] in asthmatic patients compared with control subjects. This variability may reflect the inability of plasma measurements to accurately assess airway zinc levels. Examination of induced sputum is an established technique for measuring AI and mediators of inflammation. Recent advances allow measurement of the rapidly exchangeable (labile) and total zinc pools in sputum. The aims of this study were to measure labile and total [Zn] in sputum and plasma of subjects with or without asthma, and second to correlate [Zn] with symptoms, asthma severity, lung function (FEV₁) and airway hyper‐responsiveness. Methods: A total of 163 subjects (114 with asthma) completed a single visit for sputum induction and a blood test. Labile and total [Zn] were measured by Zinquin fluorescence and atomic absorption spectrophotometry. Results: The mean (SD) age of subjects with and without asthma was 55 (14) and 57 (14) years, respectively. Baseline FEV₁ was significantly lower in subjects with asthma (94.2 (16)%) than in those without asthma (103 (16.6)%). Sputum total and labile [Zn] were lower in subjects with asthma compared with control subjects, with median (interquartile range) values of 31.8 (117) versus 50 (188.5), P = 0.02 and 0 (48) versus 26 (84.5) µg/L, P = 0.05, respectively. Increased frequency of wheeze, as well as asthma severity and reduced FEV₁, was associated with significantly lower labile sputum [Zn]. Conclusions: These findings suggest that sputum [Zn] reflect clinical outcomes and underlying AI, suggesting a potential role for zinc as a biomarker in asthma.     

Effect of marginal zinc nutriture on protein and lipid metabolism in rat pancreas in vitro

To determine the effect of marginal zinc nutriture on the pancreas, rats were divided into three groups and fed Rodent Blox ad libitum, 4-ppm-zinc-supplemented liquid diet ad libitum, and 50-ppm-zinc-supplemented liquid diet in amounts isocaloric to the 4-ppm-zinc supplemented diet, for a period of 15 wk. Compared to Rodent Blox-fed animals, animals fed diet supplemented with 4 ppm zinc and with 50 ppm zinc had lower body weights and higher pancreas weights in relation to body weight. DNA synthesis and total content and specific activity of amylase were decreased, whereas trypsinogen, chymotrypsinogen, and lipase were not affected in animals fed diet supplemented with 4 ppm zinc (compared with animals fed 50-ppm-zinc-supplemented diet). Lipid studies revealed increased free and esterified cholesterol and a decreased level of triglyceride. Incorporation of¹⁴C-1 -acetate in triglyceride was increased. Electron microscopy showed no change in number, size, and volume fraction of zymogen granules/unit. These studies indicate that marginal zinc nutriture alters the function of the pancreatic acinar cell, independent of the caloric intake in the diet. Although marginal zinc nutriture was expected to impair DNA synthesis, isolated decrease of amylase seems to be mediated through altered insulin and/or glucose homeostasis. Changes observed in lipid metabolism may underlie the membrane pathology associated with zinc deficiency.