Effect of Antioxidants on Heavy Metals Induced Conformational Altera-tion of Cytochrome C And Myoglobin

2020 ◽  
Vol 27 ◽  
Author(s):  
Anwar Ahmed ◽  
Khadega Khamis Moh Alazoumi ◽  
Salman Freeh Alamery ◽  
Anas Shamsi ◽  
Basir Ahmad ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Cytochrome C ◽  
Peroxidase Activity ◽  
Heme Proteins ◽  
Deleterious Effect ◽  
Tertiary Structure ◽  
Animal Origin ◽  
Metal Exposure ◽  
Secondary And Tertiary Structure

Background: The exposure to heavy metals due to unrestrained industrialization, pollution and non-degradability imposes a significant risk to human health. Proteins are prime targets of heavy metal stress, however, the underlying mechanisms and its impact on heme proteins is still not entirely clear. Objective: To analyze the deleterious effect of heavy metals such as cadmium, chromium and mercury on conformation of two proteins namely, cytochrome c and myoglobin. The protective effect of glycine and ascorbic acid (animal origin), gallic acid and sesamol (plant origin) on heavy metal exposure was studied. Methods: Far- and near-UV circular dichroism (CD) measurements monitored the changes in secondary and tertiary structure. Absorption Soret spectroscopy study revealed changes in heme-protein interaction. Peroxidase activity has been assayed to measure the absorption of tetraguaiacol. The interaction of heme proteins with different heavy metals was done using docking study. Result: Far- and near–UV CD measurements reveal that heavy metals disrupt the secondary and tertiary structure of heme proteins. Antioxidants counteract the deleterious effect of heavy metals. Absorption spectroscopy revealed changes in the Soret region of these heme proteins. Changes in peroxidase activity was observed on addition of heavy metals and antioxidants. Molecular docking validated interaction of the heavy metals with proteins with a significant binding affinity (-2.3 kcal/mol). Conclusion: Heavy metals interfered and disrupted both the heme proteins and mercury showed the maximum deleterious effect, further, chromium showed detrimental effect at very small concentration. The antioxidants from animal origin exhibited better protective response than those from plant source.

scholarly journals Relationship between heavy metal exposure and type 2 diabetes: a large-scale retrospective cohort study using occupational health examinations

BMJ Open ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. e039541
Author(s):  
Jun Ho Ji ◽  
Mi Hyeon Jin ◽  
Jung-Hun Kang ◽  
Soon Il Lee ◽  
Suee Lee ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Type 2 Diabetes ◽  
Heavy Metal ◽  
Cohort Study ◽  
Retrospective Cohort ◽  
Metal Exposure ◽  
Heavy Metal Exposure ◽  
Lead And Cadmium

ObjectivesTo investigate the associations between heavy metal exposure and serum ferritin levels, physical measurements and type 2 diabetes mellitus (DM).DesignA retrospective cohort study.SettingChangwon, the location of this study, is a Korean representative industrial city. Data were obtained from medical check-ups between 2002 and 2018.ParticipantsA total of 34 814 male subjects were included. Of them, 1035 subjects with lead exposure, 200 subjects with cadmium exposure and the 33 579 remaining were assigned to cohort A, cohort B and the control cohort, respectively. Data including personal history of alcohol and smoking, age, height, weight, the follow-up duration, haemoglobin A1c (HbA1c), fasting blood sugar (FBS), ferritin levels, and lead and cadmium levels within 1 year after exposure were collected.Primary outcome measureIn subjects without diabetes, changes in FBS and HbA1c were analysed through repeated tests at intervals of 1 year or longer after the occupational exposure to heavy metals.ResultsIn Cohort A, DM was diagnosed in 33 subjects. There was a significant difference in lead concentrations between the subjects diagnosed with DM and those without DM during the follow-up period (3.94±2.92 mg/dL vs 2.81±2.03 mg/dL, p=0.002). Simple exposure to heavy metals (lead and cadmium) was not associated with DM in Cox regression models (lead exposure (HR) 1.01, 95% CI: 0.58 to 1.77, p 0.971; cadmium exposure HR 1.48, 95% CI: 0.61 to 3.55, p=0.385). Annual changes in FBS according to lead concentration at the beginning of exposure showed a positive correlation (r=0.072, p=0.032).ConclusionOur findings demonstrated that simple occupational exposure to heavy metals lead and cadmium was not associated with the incidence of DM. However, lead concentrations at the beginning of the exposure might be an indicator of DM and glucose elevations.

scholarly journals TINGKAT BIOKONSENTRASI LOGAM BERAT DAN GAMBARAN HISTOPATOLOGI IKAN MUJAIR (Oreochromis Mossambicus) YANG HIDUP DI PERAIRAN TUKAD BADUNG KOTA DENPASAR

2015 ◽  
Vol 9 (1) ◽  
pp. 25
Author(s):  
Made Rahayu Kusumadewi ◽  
I Wayan Budiarsa Suyasa ◽  
I Ketut Berata
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Hexavalent Chromium ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Quality Standards ◽  
Oreochromis Mossambicus ◽  
Metal Exposure ◽  
Histopathological Changes ◽  
Food Ingredient

Tukad Badung River is one of the potential contamination of heavy metal sare very highin the city of Denpasar. Tilapia (Oreochromis mossambicus) isa commonspecies of fish found in the river and became the object of fishing by the public. The fish is usually consume das a food ingredient forever yangler. Fish can be used as bio-indicators of chemical contamination in the aquatic environment. Determination of heavy metal bioconcentration and analysis of liver histopathology gills organs and muscles is performed to determine the content of heavy metals Pb, Cd, and Cr+6, and the influence of heavy metal exposure to changes in organ histopathology Tilapia that live in Tukad Badung. In this observational study examined the levels of heavy metal contamination include Pb, Cd and Cr+6 in Tilapia meat with AAS method (Atomic Absorption Spectrofotometric), and observe the histopathological changes in organ preparations gills, liver, and muscle were stained with HE staining (hematoxylin eosin). Low Pb content of the fish that live in Tukad Badung 0.8385 mg/kg and high of 20.2600 mg/kg. The content of heavy metals Pb is above the quality standards specified in ISO 7378 : 2009 in the amount of 0.3 mg / kg. The content of Cr+6 low of 1.1402 mg / kg and the highest Cr+6 is 6.2214 mg / kg. The content of Cr+6 is above the quality standards established in the FAO Fish Circular 764 is equal to 1.0 mg / kg. In fish with Pb bioconcentration of 0.8385 mg / kg and Cr+6 of 1.1402 mg / kg was found that histopathological changes gill hyperplasia and fusion, the liver was found degeneration, necrosis, and fibrosis, and in muscle atrophy found. Histopathologicalchangessuch asedema and necrosis ofthe liveris foundin fishwith Pb bioconcentration of 4.5225mg/kg and Cr+6 amounted to2.5163mg/kg. Bio concentration of heavy metal contamination of lead (Pb) and hexavalent chromium (Cr+6) on Tilapia ( Oreochromis mossambicus ) who lives in Tukad Badung river waters exceed the applicable standard. Histopathological changes occur in organs gills, liver, and muscle as a result of exposure to heavy metals lead and hexavalent chromium. Advised the people not to eat Tilapia that live in Tukad Badung

scholarly journals Heavy Metal Sorption by Sludge-Derived Biochar with Focus on Pb2+ Sorption Capacity at μg/L Concentrations

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1559
Author(s):  
Ida Sylwan ◽  
Hanna Runtti ◽  
Lena Johansson Westholm ◽  
Henrik Romar ◽  
Eva Thorin
Keyword(s):  
Experimental Data ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Sorption Capacity ◽  
Municipal Wastewater ◽  
Metal Removal ◽  
Metal Exposure ◽  
Isotherm Models ◽  
Metal Sorption ◽  
Heavy Metal Sorption

Municipal wastewater management causes metal exposure to humans and the environment. Targeted metal removal is suggested to reduce metal loads during sludge reuse and release of effluent to receiving waters. Biochar is considered a low-cost sorbent with high sorption capacity for heavy metals. In this study, heavy metal sorption to sludge-derived biochar (SDBC) was investigated through batch experiments and modeling and compared to that of wood-derived biochar (WDBC) and activated carbon (AC). The aim was to investigate the sorption efficiency at metal concentrations comparable to those in municipal wastewater (<1 mg/L), for which experimental data are lacking and isotherm models have not been verified in previous works. Pb2+ removal of up to 83% was demonstrated at concentrations comparable to those in municipal wastewater, at pH 2. SDBC showed superior Pb2+ sorption capacity (maximum ~2 mg/g at pH 2) compared to WDBC and AC (<0 and (3.5 ± 0.4) × 10−3 mg/g, respectively); however, at the lowest concentration investigated (0.005 mg/L), SDBC released Pb2+. The potential risk of release of other heavy metals (i.e., Ni, Cd, Cu, and Zn) needs to be further examined. The sorption capacity of SDBC over a metal concentration span of 0.005–150 mg Pb2+/L could be predicted with the Redlich–Peterson model. It was shown that experimental data at concentrations comparable to those in municipal wastewater are necessary to accurately model and predict the sorption capacity of SDBC at these concentrations.

scholarly journals Maternal Heavy Metal Exposure, Thyroid Hormones, and Birth Outcomes: A Prospective Cohort Study

2019 ◽  
Vol 104 (11) ◽  
pp. 5043-5052 ◽  
Author(s):  
Xiaojie Sun ◽  
Wenyu Liu ◽  
Bin Zhang ◽  
Xiantao Shen ◽  
Chen Hu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Thyroid Hormones ◽  
Birth Outcomes ◽  
Metal Exposure ◽  
Birth Size ◽  
Heavy Metal Exposure ◽  
Mediation Analyses ◽  
Maternal Thyroid

AbstractContextMaternal thyroid hormones during pregnancy play a critical role in fetal development. However, whether maternal heavy metal exposure affects their thyroid hormones and the effects on fetal growth are still unclear.ObjectiveTo explore the effect of heavy metal exposure on maternal thyroid hormones and the potential mediation role of thyroid hormones on birth outcomes.MethodsConcentrations of heavy metals in urine samples and thyroid hormones in blood samples of 675 pregnant women were measured during early pregnancy in a cohort study conducted in China. Multivariable linear regressions were applied to explore the associations of maternal urinary heavy metal levels with both maternal thyroid hormones and birth outcomes. Mediation analyses were performed to assess the mediation role of thyroid hormones in these associations.ResultsMaternal urinary vanadium (V) exhibited an inverse association with free T3 (FT3) and FT3/free T4 (FT4) ratio levels. Urinary arsenic (As) and lead (Pb) had inverse relationships with FT3. We also observed the positive associations of maternal FT3 and FT3/FT4 ratio with birthweight. The mediation analyses suggested that 5.33% to 30.57% of the associations among V, As, and Pb levels and birth size might be mediated by maternal FT3 or FT3/FT4 ratio.ConclusionsWe have shown that maternal exposures to V, As, and Pb at early pregnancy were associated with decreased maternal FT3 or FT3/FT4 ratio, which might contribute to reduced birthweight. Mediation analyses indicated that maternal thyroid hormone was a possible mediator of the association between urinary heavy metals and birth size.

scholarly journals Derivation of Predicted No Effect Concentrations (PNECs) for Heavy Metals in Freshwater Organisms in Korea Using Species Sensitivity Distributions (SSDs)

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 697
Author(s):  
Jinhee Park ◽  
Sang Don Kim
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Gumbel Distribution ◽  
Cumulative Distribution ◽  
Metal Exposure ◽  
Suitable Model ◽  
Toxicity Data ◽  
Species Sensitivity ◽  
Distribution Models ◽  
Freshwater Organisms

Natural and artificial heavy metal exposure to the environment requires finding thresholds to protect aquatic ecosystems from the toxicity of heavy metals. The threshold is commonly called a predicted no effect concentration (PNEC) and is thought to protect most organisms in an ecosystem from a chemical. PNEC is derived by applying a large assessment factor (AF) to the toxicity value of the most sensitive organism to a chemical or by developing a species sensitivity distribution (SSD), which is a cumulative distribution function with many toxicity data for a chemical of diverse organisms. This study developed SSDs and derived PNECs using toxicity data of organisms living in Korea for four heavy metals: copper (Cd), cadmium (Cu), lead (Pb), and zinc (Zn). Five distribution models were considered with log-transformed toxicity data, and their fitness and uncertainty were investigated. As a result, the normal distribution and Gumbel distribution fit the data well. In contrast, the Weibull distribution poorly accounted for the data at the lower tails for all of the heavy metals. The hazardous concentration for 5% of species (HC5) derived from the most suitable model for each heavy metal was calculated to be the preferred PNEC by AF 2 or AF 3. PNECs, obtained through a suitable SSD model with resident species and reasonable AF, will help protect freshwater organisms in Korea from heavy metals.

Heavy Metal Content in Feedstuffs and Feeds in Hubei Province, China

2020 ◽  
Vol 83 (5) ◽  
pp. 762-766
Author(s):  
CAN TAO ◽  
XIAOTIAN WEI ◽  
BEIYU ZHANG ◽  
MAN ZHAO ◽  
SHUAI WANG ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Contamination ◽  
Absorption Spectrometry ◽  
Hubei Province ◽  
Incidence Rates ◽  
Metal Exposure ◽  
Atomic Fluorescence Spectrometry ◽  
Republic Of China ◽  
Feed Management

ABSTRACT Heavy metal pollution threatens the health and life of animals and humans through the food chain. This study was performed to survey the heavy metal contamination in feedstuffs and feeds in Hubei Province, People's Republic of China, from 2012 to 2016. Samples were analyzed for cadmium (306 samples), mercury (117 samples), chromium (149 samples), and arsenic (4,358 samples) using atomic absorption spectrometry or atomic fluorescence spectrometry. The incidence rates of cadmium, mercury, chromium, and arsenic contamination of feedstuffs and feeds were high, and feeds were most often contaminated with chromium, followed by arsenic, cadmium, and mercury. The concentrations of heavy metals in samples positive for cadmium, mercury, chromium, and arsenic ranged from 0.001 to 1.200, 0.002 to 6.540, 0.060 to 8737.000, and 0.070 to 33.000 mg/kg, respectively. The mineral and additive samples had higher concentrations of heavy metals. The present study findings highlight the importance of monitoring heavy metals in feedstuffs and feeds and implementing feed management and bioremediation strategies to reduce heavy metal exposure. HIGHLIGHTS

scholarly journals Production of genome-edited Daphnia for heavy metal detection by fluorescence

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Takuto Arao ◽  
Yasuhiko Kato ◽  
Quang Dang Nong ◽  
Hiroshi Yamamoto ◽  
Haruna Watanabe ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Promoter Region ◽  
Fluorescent Protein ◽  
Water Quality Monitoring ◽  
Metal Exposure ◽  
Gfp Expression ◽  
Heavy Metal Detection ◽  
Metal Detection ◽  
Metal Monitoring

AbstractAquatic heavy metal pollution is a growing concern. To facilitate heavy metal monitoring in water, we developed transgenic Daphnia that are highly sensitive to heavy metals and respond to them rapidly. Metallothionein A, which was a metal response gene, and its promoter region was obtained from Daphnia magna. A chimeric gene fusing the promoter region with a green fluorescent protein (GFP) gene was integrated into D. magna using the TALEN technique and transgenic Daphnia named D. magna MetalloG were produced. When D. magna MetalloG was exposed to heavy metal solutions for 1 h, GFP expression was induced only in their midgut and hepatopancreas. The lowest concentrations of heavy metals that activated GFP expression were 1.2 µM Zn2+, 130 nM Cu2+, and 70 nM Cd2+. Heavy metal exposure for 24 h could lower the thresholds even further. D. magna MetalloG facilitates aqueous heavy metal detection and might enhance water quality monitoring.

scholarly journals The Yeast Ubiquitin Ligase SCFMet30Regulates Heavy Metal Response

2005 ◽  
Vol 16 (4) ◽  
pp. 1872-1882 ◽  
Author(s):  
James L. Yen ◽  
Ning-Yuan Su ◽  
Peter Kaiser
Keyword(s):  
Heavy Metals ◽  
Cell Cycle ◽  
Heavy Metal ◽  
Ubiquitin Ligase ◽  
Cellular Response ◽  
Acid Synthesis ◽  
S Phase ◽  
Cell Cycle Checkpoint ◽  
Yeast Cells ◽  
Metal Exposure

Cells have developed a variety of mechanisms to respond to heavy metal exposure. Here, we show that the yeast ubiquitin ligase SCFMet30plays a central role in the response to two of the most toxic environmental heavy metal contaminants, namely, cadmium and arsenic. SCFMet30inactivates the transcription factor Met4 by proteolysis-independent polyubiquitination. Exposure of yeast cells to heavy metals led to activation of Met4 as indicated by a complete loss of ubiquitinated Met4 species. The association of Met30 with Skp1 but not with its substrate Met4 was inhibited in cells treated with cadmium. Cadmium-activated Met4 induced glutathione biosynthesis as well as genes involved in sulfuramino acid synthesis. Met4 activation was important for the cellular response to cadmium because mutations in various components of the Met4-transcription complex were hypersensitive to cadmium. In addition, cell cycle analyses revealed that cadmium induced a delay in the transition from G1to S phase of the cell cycle and slow progression through S phase. Both cadmium and arsenic induced phosphorylation of the cell cycle checkpoint protein Rad53. Genetic analyses demonstrated a complex effect of cadmium on cell cycle regulation that might be important to safeguard cellular and genetic integrity when cells are exposed to heavy metals.

scholarly journals Geographic Analysis of Motor Neuron Disease Mortality and Heavy Metals Released to Rivers in Spain

2018 ◽  
Vol 15 (11) ◽  
pp. 2522 ◽  
Author(s):  
Germán Sánchez-Díaz ◽  
Francisco Escobar ◽  
Hannah Badland ◽  
Greta Arias-Merino ◽  
Manuel Posada de la Paz ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Motor Neuron ◽  
Motor Neuron Disease ◽  
Metal Exposure ◽  
Fine Grained ◽  
Relative Risks ◽  
Disease Mortality ◽  
Standardized Mortality Ratios ◽  
Log Linear

The etiology of motor neuron disease (MND) is still unknown. The aims of this study were to: (1) analyze MND mortality at a fine-grained level; and (2) explore associations of MND and heavy metals released into Spanish river basins. MND deaths were extracted from the Spanish nationwide mortality registry (2007–2016). Standardized mortality ratios (SMRs) for MND were estimated at a municipal level. Sites that emitted quantities of heavy metals above the regulatory thresholds were obtained from the European Pollutant Release and Transfer Register database (2007–2015). The relative risks for non-exposed and exposed municipalities (considering a downstream 20 km river section) by type of heavy metal were analyzed using a log-linear model. SMRs were significantly higher in central and northern municipalities. SMRs were 1.14 (1.10–1.17) higher in areas exposed to heavy metals than in non-exposed areas: 0.95 (0.92–0.96). Considering the different metals, we found the following increased MND death risks in exposed areas: 20.9% higher risk for lead, 20.0% for zinc, 16.7% for arsenic, 15.7% for chromium, 15.4% for cadmium, 12.7% for copper, and 12.4% for mercury. This study provides associations between MND death risk and heavy metals in exposed municipalities. Further studies investigating heavy metal exposure are needed to progress in MND understanding.

Exposure to heavy metals alters the surface topology of alveolar macrophages and induces respiratory dysfunction among Indian metal arc-welders

2018 ◽  
Vol 34 (12) ◽  
pp. 908-921 ◽  
Author(s):  
Subhabrata Moitra ◽  
Jayashree Ghosh ◽  
Jannatul Firdous ◽  
Arghya Bandyopadhyay ◽  
Monojit Mondal ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Dna Damage ◽  
Cell Surface ◽  
Alveolar Macrophages ◽  
Respiratory Health ◽  
Induced Sputum ◽  
Metal Exposure ◽  
Microscopic Evaluation ◽  
Metal Levels

Background: Despite the available clinico-epidemiological evidence of heavy metal-associated respiratory health hazards among metal arc-welders, experimental confirmation of such an association is lacking. Methods: In this study, we recruited 15 metal arc-welders and 10 referent workers without direct exposure. We assessed respiratory health through a questionnaire and spirometry; estimated manganese, nickel and cadmium levels in blood, urine and induced sputum; performed differential counts of sputum leucocytes and measured plasma malondialdehyde (MDA). We used atomic force and scanning electron microscopy to assess the physical property of the alveolar macrophages (AMs) obtained from induced sputum and analysed cell surface deposition of heavy metals using energy dispersion X-ray analysis (EDX). Sputum cellular DNA damage was assessed by DNA-laddering assay. Results: There was a higher body burden of manganese and nickel in the metal arc-welders than the referents. Among major spirometric indices, only the forced mid-expiratory flow rates (FEF25–75) were reduced in the welders compared with the referents (63.4 ± 14.7 vs. 89.2 ± 26.7, p < 0.01); this reduction was associated with both heavy metal levels ( β: −41.8, 95% CI: −78.5% to −5.1%) and plasma MDA (−0.37; −0.68 to −0.06). In metal arc-welders, significant physical and morphological changes were observed in AMs through microscopic evaluation while EDX analyses demonstrated higher deposition of heavy metals on the AM cell surface than the referents. We also observed a higher degree of DNA damage in the sputum cells of the exposed workers than the referents. Conclusion: Heavy metal exposure-induced adverse respiratory effects among metal arc-welders are mediated through haematological and cytological interactions.

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