Zinc asparaginate supplementation induces redistribution of toxic trace elements in rat tissues and organs

Associations Between Serum Multiple Metals Exposures and Metabolic Syndrome: a Longitudinal Cohort Study

Although many studies have confirmed metabolic syndrome (MetS) is correlated with metal exposures, few studies have elucidated the associations of multiple metals with MetS risk. We aim to explore the relationship between serum 22 metals and MetS. We determined serum 22 metals using ICP-MS and used LASSO regression to select metals independently related with MetS to construct multiple-metals model. We further explored the dose-response relationship between positive metals and MetS by the restricted cubic spline regression. After screening by LASSO regression, serum 11 metals were selected to construct multiple-metals model in cross-sectional analysis, while 5 metals in longitudinal analysis. In the 11-metal model, only tin and zinc were associated with MetS in cross-sectional analysis (OR_tin = 2.22, 95% CI:1.43, 3.45; OR_zinc = 2.17, 95% CI: 1.42, 3.32; both P_trend < 0.05). Besides, the same results were found in the 5-metal model in longitudinal analysis (HR_tin = 1.66, 95% CI: 0.87, 3.17; HR_zinc = 1.83, 95% CI: 1.07, 3.14; both P_trend < 0.05). Moreover, there were positive linear relationships between serum tin and zinc concentrations and the increasing risk of MetS (both P_overall < 0.05, P_{non-linearity} > 0.05). Furthermore, the interaction between high tin and high zinc was also associated with increasing MetS risk (P_interaction < 0.05). We found that serum tin and zinc were independently and interactively associated with MetS in the southern Chinese men. Our results suggested that high tin and zinc may be the risk factors of MetS.

Zinc Protects against MDMA-Induced Apoptosis of Sertoli Cells in Mouse via Attenuation of Caspase-3

Background

3,4-Methylenedioxymethamphetamine (MDMA) disrupts function of the endocrine system and different organs such as heart, blood vessels, kidney, liver and nervous systems. This revision was conducted to evaluate impact of MDMA on apoptosis and Zinc in the MDMA-induced apoptosis of cultured Sertoli cells by measuring Caspase-3 gene expression.

Materials and Methods

In this experimental study, Sertoli cells were incubated with MDMA (0, 0.5, 1, 3 and 5 mM), Zinc (0, 8, 16, 32, 64 μM) and Zinc (8 μM) prior to adding MDMA (5 mM) for 24 and 48 hours. MTT assay was used for evaluating impacts of these conditions on the viability of Sertoli cells. Caspase-3 gene expression level was detected using quantitative reverse transcription PCR (qRT-PCR) in all of the tested groups.

Results

Finding showed that cellular viability was decreased and level of Caspase-3 mRNA was increased in MDMA treated cells. Additionally, pre-treatment with Zinc (8 μM) attenuated MDMA-induced apoptosis and down-regulated caspase-3. The mean of caspase-3 mRNA level (fold change ± SE) was 3.98 ± 1.18, 0.31 ± 0.28, and 1.72 ± 0.28 in respectively MDMA (5 mM), Zinc (8 μM), and Zinc+MDMA groups vs. control group. The mean of Caspase-3 mRNA (fold change) was not statistically different in the tested groups (P>0.05), unless MDMA (5 mM) group (P=0.008).

Conclusion

We suggest that MDMA toxicity could be involved in apoptosis of Sertoli cells. In addition, Zinc could reduce MDMA-induced apoptosis by down-regulation of Caspase-3 mRNA levels.

Effect of Zn Supplementation on Trace Element Status in Rats with Diet-Induced Non-alcoholic Fatty Liver Disease

The present study aimed to assess the effect of Zn supplementation on trace element levels in the liver, serum, and hair of rats with dietary-induced non-alcoholic fatty liver disease (NAFLD). A total of 26 3-month-old female Wistar rats were divided into four groups: control, NAFLD, Zn-supplemented (227 mg/L zinc as Zn sulfate Zn(SO)₄ dissolved in a drinking water), and NAFLD-Zn-supplemented. NAFLD was verified by histological assessment of liver samples. The serum was examined for routine biochemical parameters. Trace elements content was assessed using inductively coupled plasma mass spectrometry (ICP-MS). Zn treatment resulted in an improvement in liver weight and morphology. Dietary supplementation with Zn prevented NAFLD-induced decrease liver Co. The tendency to increase liver Fe in the Zn-treated group was observed. Zn treatment decreased hepatic Al and serum V levels. However, Zn administration did not affect NAFLD-induced I, Mn, and Se depletion in the liver. Hair Zn levels raised in Zn-supplemented groups. Conclusively, the results of the study indicate that Zn supplementation could have a beneficial effect in modulation of the altered trace element status and liver morphology. HIGHLIGHTS: •Zn treatment improved liver weight and morphology in rats with NAFLD. •Zn supplementation decreased liver Al in NAFLD. •Treatment by Zn prevented depletion of liver Co. •Zn decreased serum V and increased hair Zn levels. •No effect of Zn on NAFLD-induced hepatic I, Mn and Se depletion was observed.

Determination of heavy metals in cancerous and healthy colon tissues using laser induced breakdown spectroscopy and its cross-validation with ICP-AES method

Certain types of cancer deaths are widespread due to the diagnostic complexities at the early stages. Recent studies revealed that the bio-accumulated heavy metals (act as pro-carcinogens) in the human colon cause strong interactions with the nuclear proteins, leading to the DNA damages and repair processes inhibition, resulting in the cancers. Most of the conventional detection techniques suffer from the insensitiveness, cost-intensiveness, imprecision, slowness, cumbersomeness of sample preparation, and conflicting outcomes. To surmount these shortcomings an accurate, reliable, and rapid detection technique is essential for the early diagnostic and prevention of heavy metals accumulation induced colon cancers. This will enable not only to classify the malignant and non-malignant cells but can differentiate the proteins from abnormal cellular morphology. Using the indigenously developed fast and accurate (calibration-free) laser-induced breakdown spectroscopy (LIBS), we analyzed several cancerous and normal colon tissues collected from the colon cancer infected patients aged 40-60 years. The results showed the presence of carcinogenic heavy metals including lead (Pb), chromium (Cr), and mercury (Hg) in the malignant colon tissues, while the healthy tissues were devoid of these elements. The concentrations of Pb, Cr and Hg in the cancerous samples were discerned to be 3.1, 13.4 and 7.1 μg/L, respectively. Furthermore, the performance accuracy of the LIBS technique was validated by comparing the results obtained from the standard inductively coupled plasma atomic emission spectroscopy (ICP-OES). It was established that the LIBS analysis is useful for the speedy, precise and early detection of the heavy metals amassed malignant colon tissues, thereby saving millions of lives by promoting the chances for cancer cure.

Selenium and zinc protections against metal-(loids)-induced toxicity and disease manifestations: A review

Metals are ubiquitous in the environment due to huge industrial applications in the form of different chemicals and from extensive mining activities. The frequent exposures to metals and metalloids are crucial for the human health. Trace metals are beneficial for health whereas non-essential metals are dangerous for the health and some are proven etiological factors for diseases including cancers and neurological disorders. The interactions of essential trace metals such as selenium (Se) and zinc (Zn) with non-essential metals viz. lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) in biological system are very critical and complex. A huge number of studies report the protective role of Se and Zn against metal toxicity, both in animal and cellular levels, and also explain the numerous mechanisms involved. However, it has been considered that a tiny dyshomeostasis in the metals/trace metals status in biological system could induce severe deleterious effects that can manifest to numerous diseases. Thus, in this particular review, we have demonstrated the critical protection mechanism/s of Se and Zn against Cd, Pb, As and Hg toxicity in a one by one manner to clarify the up-to-date findings and perspectives. Furthermore, biomolecular consequences are comprehensively presented in light of particular cellular/biomolecular events which are somehow linked to a subsequent disease. The analyzed reports support significant protection potential of Se and Zn, either alone or in combination with other agents, against each of the abovementioned non-essential metals. However, Se and Zn are still not being used as detoxifying agents due to some unexplained reasons. We hypothesized that Se could be a potential candidate for detoxifying As and Hg regardless of their chemical speciations, but requires intensive clinical trials. However, particularly Zn-Hg interaction warrants more investigations both in animal and cellular level.

Zinc, copper, cadmium, and lead levels in cattle tissues in relation to different metal levels in ground water and soil

The objective of the present study was to investigate the interaction between environmental (water and soil) levels of zinc, copper, cadmium, and lead levels, as well as their content in Hereford beef cattle tissues in five districts (D₁-western area, D₂ and D₃-central area, D₄ and D₅-eastern area) of the Orenburg region. Soil metal levels were assessed using atomic emission spectrometry, whereas water and tissue (liver, kidney, muscle, heart) metal content was studied using inductively coupled plasma-mass spectrometry. The obtained data demonstrate that the highest levels Zn in soil and water (p < 0.001), as well as cattle muscle, liver, and kidney (p < 0.05) were observed in D₄ and D₅ (eastern area), exceeding the maximum permissible concentration levels (MPCL) for drinking water and muscle for all regions. Similar associations were found for Cu levels. The highest soil and water Cd and Pb content were observed in D₂ (central area) and D₅ (eastern area), respectively. At the same time, cattle tissue Cd and Pb content did not correspond to the respective environmental levels. Correlation analysis demonstrated that water and soil Zn and Cu content directly correlated with muscle, liver, and kidney, but not heart metal content. At the same time, water Cd levels were negatively interrelated with muscle cadmium content but correlated directly with hepatic metal content. Both water and soil Pb levels positively correlated with renal metal levels in cattle. In turn, soil lead content was inversely associated with muscle metal levels. Regression analysis also demonstrated a significant association between environmental and tissue levels of Zn and Cu. The models adjusted for all studied elements demonstrated a significant effect of metal interaction on tissue metal levels. Hypothetically, excessive environmental Zn, and possibly Cu, levels may affect the uptake of heavy metals including Cd and Pb from the environment.

Dynamical features in fetal and postnatal zinc-copper metabolic cycles predict the emergence of autism spectrum disorder

Metals are critical to neurodevelopment, and dysregulation in early life has been documented in autism spectrum disorder (ASD). However, underlying mechanisms and biochemical assays to distinguish ASD cases from controls remain elusive. In a nationwide study of twins in Sweden, we tested whether zinc-copper cycles, which regulate metal metabolism, are disrupted in ASD. Using novel tooth-matrix biomarkers that provide direct measures of fetal elemental uptake, we developed a predictive model to distinguish participants who would be diagnosed with ASD in childhood from those who did not develop the disorder. We replicated our findings in three independent studies in the United States and the UK. We show that three quantifiable characteristics of fetal and postnatal zinc-copper rhythmicity are altered in ASD: the average duration of zinc-copper cycles, regularity with which the cycles recur, and the number of complex features within a cycle. In all independent study sets and in the pooled analysis, zinc-copper rhythmicity was disrupted in ASD cases. In contrast to controls, in ASD cases, the cycle duration was shorter (F = 52.25, P < 0.001), regularity was reduced (F = 47.99, P < 0.001), and complexity diminished (F = 57.30, P < 0.001). With two distinct classification models that used metal rhythmicity data, we achieved 90% accuracy in classifying cases and controls, with sensitivity to ASD diagnosis ranging from 85 to 100% and specificity ranging from 90 to 100%. These findings suggest that altered zinc-copper rhythmicity precedes the emergence of ASD, and quantitative biochemical measures of metal rhythmicity distinguish ASD cases from controls.

Apocynin Alleviates Renal Ischemia/Reperfusion Injury Through Regulating the Level of Zinc and Metallothionen

The purpose of this research was to evaluate the protective effects of apocynin on renal ischemia/reperfusion (I/R) injury (RI/RI) in rats. Rats preconditioned with apocynin were subjected to renal I/R. Zinc levels in serum and renal tissues, blood urea nitrogen (BUN), and serum creatinine (Scr) were detected. We further measured the activity of superoxide dismutase (SOD); the content of malondialdehyde (MDA), IL-4, IL-6, IL-10, and TNF-α; and the expression of metallothionein (MT) in the renal tissues. Results indicated that the levels of MDA, IL-4, IL-6, IL-10, TNF-α, and MT in the kidney tissue and serum BUN and Scr levels in RI/RI group were significantly higher than those in sham-operated group, while the levels of serum Zn and kidney Zn and SOD were reduced in RI/RI group. Apocynin treatment further decreased the levels of MDA, IL-6, TNF-α, and serum BUN and Scr, whereas it significantly increased the levels of Zn, SOD, IL-4, IL-10, and MT in the kidney tissue and serum Zn. These findings suggest that apocynin might play a protective role against RI/RI in rats through regulating zinc level and MT expression involving in oxidative stress.