1
|
Narayanan R, Sivadas S, Kurien AA. NELL-1-associated membranous nephropathy linked to skin fairness cream use: insights from an Indian case series. Kidney Int 2024:S0085-2538(24)00263-1. [PMID: 38615743 DOI: 10.1016/j.kint.2024.03.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 02/28/2024] [Accepted: 03/19/2024] [Indexed: 04/16/2024]
Affiliation(s)
- Ranjit Narayanan
- Department of Nephrology, Aster MIMS Hospital, Kottakkal, Kerala, India.
| | - Sajeesh Sivadas
- Department of Nephrology, Aster MIMS Hospital, Kottakkal, Kerala, India
| | - Anila Abraham Kurien
- Department of Pathology, Renopath, Center for Renal and Urological Pathology, Chennai, India
| |
Collapse
|
2
|
Sather RN, Lee MS. Toxic Optic Neuropathy Due to Mercury in Skin Lightening Products. Neuroophthalmology 2023; 47:281-284. [PMID: 38145039 PMCID: PMC10745285 DOI: 10.1080/01658107.2023.2251580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 08/14/2023] [Indexed: 12/26/2023] Open
Abstract
Mercury has been described as been in daily household items such as soaps, skin-lightening creams (SLC), and topical disinfectants. Mercury exposure can reportedly cause damage to the optic nerve and retina. A 30-year-old Somali woman presented with decreased vision and was found to have bilateral optic atrophy. Neuroimaging and laboratory work-up for nutritional deficiencies, heavy metals, and syphilis were performed. Evaluation revealed normal neuroimaging and laboratory work-up except for elevated serum and urine mercury levels. Mercury levels at the initial blood test was 11.1 ug/L (normal limits < 10.0 ug/L) and was 15.7 ug/L on repeat testing. A 24-h urine test showed elevated mercury at 16 ug/24 h (normal limits < 2 ug/24 h). Evaluation of an unlabelled SLC that she was using showed the presence of mercury. It is worth testing for heavy metals in the work-up of bilateral optic atrophy. Clinicians should consider cosmetic products as a potential source of mercury exposure and recommend discontinuation if mercury is present.
Collapse
Affiliation(s)
- Richard N. Sather
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Michael S. Lee
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| |
Collapse
|
3
|
Dudeja P, Dudeja KK, Grover S, Singh H, Jabin Z. Pathway to mercury-free dentistry: an insight into past, present, and future. Eur Oral Res 2023; 57:60-67. [PMID: 37525858 PMCID: PMC10387142 DOI: 10.26650/eor.20231050091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 07/20/2022] [Accepted: 08/09/2022] [Indexed: 08/02/2023] Open
Abstract
Purpose The popularity of dental amalgam arises from its excellent long-term performance, ease of use, and low cost. However, there is a concern about the potential adverse health effects arising from exposure to mercury in amalgam. This review article critically discusses the safety of dental amalgam as a restorative material and our preparedness for a mercury-free road ahead. Materials and methods A database search was performed on PubMed and Google scholar using the keywords: "mercury-free dentistry", "mercury toxicity", "amalgam substitutes", "amalgam mercury toxicity". Inclusion and exclusion criteria were specified clearly. Relevant literature was also searched in the dental textbooks. Results Around 40 articles, highlighting mercury exposure among dental professionals and patients were included. Despite the overwhelming body of scientific evidence demonstrating amalgam to be a safe restorative material, concerns about the toxic effects of mercury persist. Conclusion The real challenge is to find a suitable amalgam substitute and to follow the mercury hygiene measures closely.
Collapse
Affiliation(s)
- Pooja Dudeja
- Department of Conservative Dentistry and Endodontics,
ESIC Dental College and Hospital, Rohini, DelhiIndia
| | | | - Shibani Grover
- Department of Conservative Dentistry and Endodontics,
ESIC Dental College and Hospital, Rohini, DelhiIndia
| | - Harpreet Singh
- Department of Orthodontics and Dentofacial Orthopedics,
ESIC Dental College and Hospital Rohini, DelhiIndia
| | - Zohra Jabin
- Department of Pedodontics and Preventive Dentistry,
Institute of Dental Studies and Technologies,Modinagar, Ghaziabad, Uttar Pradesh,India
| |
Collapse
|
4
|
Łuczkowski M, Padjasek M, Ba Tran J, Hemmingsen L, Kerber O, Habjanič J, Freisinger E, Krężel A. An Extremely Stable Interprotein Tetrahedral Hg(Cys) 4 Core Forms in the Zinc Hook Domain of Rad50 Protein at Physiological pH. Chemistry 2022; 28:e202202738. [PMID: 36222310 PMCID: PMC9828754 DOI: 10.1002/chem.202202738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Indexed: 11/09/2022]
Abstract
In nature, thiolate-based systems are the primary targets of divalent mercury (HgII ) toxicity. The formation of Hg(Cys)x cores in catalytic and structural protein centers mediates mercury's toxic effects and ultimately leads to cellular damage. Multiple studies have revealed distinct HgII -thiolate coordination preferences, among which linear HgII complexes are the most commonly observed in solution at physiological pH. Trigonal or tetrahedral geometries are formed at basic pH or in tight intraprotein Cys-rich metal sites. So far, no interprotein tetrahedral HgII complex formed at neutral pH has been reported. Rad50 protein is a part of the multiprotein MRN complex, a major player in DNA damage-repair processes. Its central region consists of a conserved CXXC motif that enables dimerization of two Rad50 molecules by coordinating ZnII . Dimerized motifs form a unique interprotein zinc hook domain (Hk) that is critical for the biological activity of the MRN. Using a series of length-differentiated peptide models of the Pyrococcus furiosus zinc hook domain, we investigated its interaction with HgII . Using UV-Vis, CD, PAC, and 199 Hg NMR spectroscopies as well as anisotropy decay, we discovered that all Rad50 fragments preferentially form homodimeric Hg(Hk)2 species with a distorted tetrahedral HgS4 coordination environment at physiological pH; this is the first example of an interprotein mercury site displaying tetrahedral geometry in solution. At higher HgII content, monomeric HgHk complexes with linear geometry are formed. The Hg(Cys)4 core of Rad50 is extremely stable and does not compete with cyanides, NAC, or DTT. Applying ITC, we found that the stability constant of the Rad50 Hg(Hk)2 complex is approximately three orders of magnitude higher than those of the strongest HgII complexes known to date.
Collapse
Affiliation(s)
- Marek Łuczkowski
- Department of Chemical BiologyFaculty of BiotechnologyUniversity of WrocławJoliot-Curie 14a50-383WrocławPoland
| | - Michał Padjasek
- Department of Chemical BiologyFaculty of BiotechnologyUniversity of WrocławJoliot-Curie 14a50-383WrocławPoland
| | - Józef Ba Tran
- Department of Chemical BiologyFaculty of BiotechnologyUniversity of WrocławJoliot-Curie 14a50-383WrocławPoland
| | - Lars Hemmingsen
- Department of ChemistryUniversity of CopenhagenUniversitetsparken 52100København ØDenmark
| | - Olga Kerber
- Department of Chemical BiologyFaculty of BiotechnologyUniversity of WrocławJoliot-Curie 14a50-383WrocławPoland
| | - Jelena Habjanič
- Department of ChemistryUniversity of ZurichWinterthurerstrasse 1908057ZürichSwitzerland
| | - Eva Freisinger
- Department of ChemistryUniversity of ZurichWinterthurerstrasse 1908057ZürichSwitzerland
| | - Artur Krężel
- Department of Chemical BiologyFaculty of BiotechnologyUniversity of WrocławJoliot-Curie 14a50-383WrocławPoland
| |
Collapse
|
5
|
Bhardwaj V, Nurchi VM, Sahoo SK. Mercury Toxicity and Detection Using Chromo-Fluorogenic Chemosensors. Pharmaceuticals (Basel) 2021; 14:123. [PMID: 33562543 PMCID: PMC7915024 DOI: 10.3390/ph14020123] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 02/03/2021] [Accepted: 02/03/2021] [Indexed: 12/27/2022] Open
Abstract
Mercury (Hg), this non-essential heavy metal released from both industrial and natural sources entered into living bodies, and cause grievous detrimental effects to the human health and ecosystem. The monitoring of Hg2+ excessive accumulation can be beneficial to fight against the risk associated with mercury toxicity to living systems. Therefore, there is an emergent need of novel and facile analytical approaches for the monitoring of mercury levels in various environmental, industrial, and biological samples. The chromo-fluorogenic chemosensors possess the attractive analytical parameters of low-cost, enhanced detection ability with high sensitivity, simplicity, rapid on-site monitoring ability, etc. This review was narrated to summarize the mercuric ion selective chromo-fluorogenic chemosensors reported in the year 2020. The design of sensors, mechanisms, fluorophores used, analytical performance, etc. are summarized and discussed.
Collapse
Affiliation(s)
- Vinita Bhardwaj
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology (SVNIT), Surat 395007, India;
| | - Valeria M. Nurchi
- Dipartimento di Scienze della Vita e dell’Ambiente, Università di Cagliari, Cittadella Universitaria, 09042 Monserrato-Cagliari, Italy
| | - Suban K. Sahoo
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology (SVNIT), Surat 395007, India;
| |
Collapse
|
6
|
Ahmad H, Sharfan IIB, Khan RA, Alsalme A. Effective Enrichment and Quantitative Determination of Trace Hg 2+ Ions Using CdS-Decorated Cellulose Nanofibrils. Nanomaterials (Basel) 2020; 10:nano10112218. [PMID: 33171741 PMCID: PMC7694963 DOI: 10.3390/nano10112218] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 10/31/2020] [Accepted: 11/04/2020] [Indexed: 12/03/2022]
Abstract
Water pollution caused by metal contamination is of serious concern. Direct determination of trace metal ions in real water samples remains challenging. A sample preparation technique is a prerequisite before analysis. Herein, we report the facile water-based hydrothermal synthesis of cadmium sulfide nanoparticles on a cellulose nanofiber surface to prepare a new adsorbent material. Field emission scanning electron microscopy, high-resolution tunneling electron microscopy, elemental mapping and X-ray photoelectron microscopy were used to characterize the surface morphology, structural determination, elemental composition and nature of bonding. The nanoadsorbent (cadmium-sulfide-decorated cellulose nanofibrils (CNFs@CdS)) was employed for the solid-phase extraction and determination of trace Hg(II) from aqueous media. The experimental conditions were optimized systematically and the data show a good Hg(II) adsorption capacity of 126.0 mg g−1. The CNFs@CdS adsorbent shows the selective removal of Hg(II) accordingly to the hard and soft acid–base theory of metal–ligand interaction. A high preconcentration limit of 0.36 µg L−1 was obtained with a preconcentration factor of 580. The lowest level of trace Hg(II) concentration, which was quantitatively analyzed by the proposed method, was found to be 0.06 µg L−1. No significant interferences from the sample matrix were observed in the extraction of Hg(II). Analysis of the standard reference material (SRM 1641d) was carried out to validate the proposed methodology. Good agreement between the certified and observed values indicates the applicability of the developed methodology for the analysis of Hg(II) in tap water, river water and industrial wastewater samples.
Collapse
Affiliation(s)
- Hilal Ahmad
- Division of Computational Physics, Institute for Computational Science, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam;
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam
| | - Ibtisam I. Bin Sharfan
- Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; (I.I.B.S.); (R.A.K.)
| | - Rais Ahmad Khan
- Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; (I.I.B.S.); (R.A.K.)
| | - Ali Alsalme
- Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; (I.I.B.S.); (R.A.K.)
- Correspondence: ; Tel.: +96-654-051-8430
| |
Collapse
|
7
|
Vecchi Brumatti L, Rosolen V, Mariuz M, Piscianz E, Valencic E, Bin M, Athanasakis E, D'Adamo P, Fragkiadoulaki E, Calamandrei G, Dinckol Ö, Barbone F, Ronfani L. Impact of Methylmercury and Other Heavy Metals Exposure on Neurocognitive Function in Children Aged 7 Years: Study Protocol of the Follow-up. J Epidemiol 2020; 31:157-163. [PMID: 32249266 PMCID: PMC7813770 DOI: 10.2188/jea.je20190284] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Background The extent to which prenatal low-level mercury (Hg) exposure through maternal fish intake and heavy metals exposure affect children’s neurodevelopment is controversial and may appear in the long term. In 2007, a prospective cohort, the Northern Adriatic Cohort II (NAC-II), was established to investigate the association between prenatal Hg exposure from maternal fish consumption and child neurodevelopment. The study enrolled 900 pregnant women, and 632 and 470 children underwent neurodevelopmental evaluation at 18 and 40 months of age, respectively. The NAC-II cohort is a part of the Mediterranean cohort in the “Public health impact of long-term, low-level, mixed element exposure in susceptible population strata” project. Methods This protocol describes the follow-up assessment of the effects of prenatal low level Hg and other heavy metals exposure on the developing nervous system of the children born within the NAC-II who reached the age of 7 years. Child diet components are estimated through a Diet Diary. Child hair and urine are collected for determination of Hg level. In addition, levels of other potentially neurotoxic metals, namely Manganese, Cadmium, Lead, Arsenic, and Selenium, are also measured in the same matrices. Discussion This protocol extends to the first years of schooling age the evaluation of the neurotoxicant effect of Mercury and of the other heavy metals on children’s neurodevelopment, adjusting for the potential confounders, such as the lifestyles and social economic status of children’s families. Longitudinal analysis of neurodevelopment, assessed in different ages (18 months, 40 months, and 7 years), are performed.
Collapse
Affiliation(s)
| | | | - Marika Mariuz
- Department of Medical and Biological Sciences, University of Udine and Institute of Hygiene and Clinical Epidemiology, University Hospital of Udine
| | - Elisa Piscianz
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo"
| | - Erica Valencic
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo"
| | - Maura Bin
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo"
| | | | - Pio D'Adamo
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo".,Department of Medical Sciences, University of Trieste
| | | | | | | | - Fabio Barbone
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo"
| | - Luca Ronfani
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo"
| |
Collapse
|
8
|
Afrifa J, Opoku YK, Gyamerah EO, Ashiagbor G, Sorkpor RD. The Clinical Importance of the Mercury Problem in Artisanal Small-Scale Gold Mining. Front Public Health 2019; 7:131. [PMID: 31192183 PMCID: PMC6549531 DOI: 10.3389/fpubh.2019.00131] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 05/08/2019] [Indexed: 11/17/2022] Open
Abstract
Artisanal small-scale mining is widely operated in various countries serving as a livelihood to many rural communities. However, it is a significant source of environmental mercury contamination which affects human health. Amalgamation and amalgam smelting, two significant steps in the artisanal small-scale mining operations generate lots of mercury vapors, leading to chronic exposure among miners. Thus, this article seeks to provide a topical review of recent findings on organ damage and metabolic disorders among mercury-exposed artisanal small-scale miners with emphasis on the contributing factors such as personal protective equipment usage and artisanal small-scale gold mining-specific occupational activities. Also, insights into the effect of mercury intoxication and mechanisms of action on organ and metabolic systems among exposed individuals are provided.
Collapse
Affiliation(s)
- Justice Afrifa
- Department of Medical Laboratory Science, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana.,Scientific Research Center, Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yeboah Kwaku Opoku
- Department of Biomedical Science, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana.,Biopharmaceutical Laboratory, College of Life Sciences, Northeast Agricultural University, Harbin, China
| | - Eric Ofori Gyamerah
- Department of Biochemistry, School of Biological Sciences, University of Cape Coast, Cape Coast, Ghana
| | - George Ashiagbor
- Department of Wildlife and Range Management, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | |
Collapse
|
9
|
Cortes J, Peralta J, Díaz‐Navarro R. Acute respiratory syndrome following accidental inhalation of mercury vapor. Clin Case Rep 2018; 6:1535-1537. [PMID: 30147899 PMCID: PMC6099007 DOI: 10.1002/ccr3.1656] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 05/19/2018] [Accepted: 05/30/2018] [Indexed: 11/30/2022] Open
Abstract
Although the manufacture of glass mercury thermometers is now prohibited, they are still present in daily life and represent a source of accidental mercury intoxication. Physicians should be able to recognize the clinical manifestations of mercury poisoning caused by accidental exposure and know the appropriate treatment for this toxicological emergency.
Collapse
Affiliation(s)
- Jorge Cortes
- Departamento de Medicina InternaUniversidad de ValparaísoViña del MarChile
| | - Jaime Peralta
- Departamento de Medicina InternaUniversidad de ValparaísoViña del MarChile
| | | |
Collapse
|
10
|
Gökçe G, Arun MZ, Ertuna E. Ergothioneine prevents endothelial dysfunction induced by mercury chloride. Exp Ther Med 2018; 15:4697-4702. [PMID: 29805489 PMCID: PMC5958736 DOI: 10.3892/etm.2018.6079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/22/2018] [Indexed: 01/23/2023] Open
Abstract
Exposure to mercury has detrimental effects on the cardiovascular system, particularly the vascular endothelium. The present study aimed to investigate the effects of ergothioneine (EGT) on endothelial dysfunction induced by low-dose mercury chloride (HgCl2). Agonist-induced contractions and relaxations were evaluated in isolated aortic rings from 3-month-old male Wistar rats treated by intra-muscular injection to caudal hind leg muscle with HgCl2 (first dose, 4.6 µg/kg; subsequent doses, 0.07 µg/kg/day for 15 days) and optionally with EGT (2 µg/kg for 30 days). Reactive oxygen species (ROS) in aortic rings were measured by means of lucigenin- and luminol-enhanced chemiluminescence. The protein level of endothelial nitric oxide synthase was evaluated by ELISA. Blood glutathione (GSH) and catalase levels, lipid peroxidation and total nitrite were measured spectrophotometrically. The results indicated that low-dose HgCl2 administration impaired acetylcholine (ACh)-induced relaxation and potentiated phenylephrine- and serotonin-induced contractions in rat aortas. In addition, HgCl2 significantly increased the levels of ROS in the aortic tissue. EGT prevented the loss of ACh-induced relaxations and the increase in contractile responses. These effects were accompanied by a significant decrease in ROS levels. EGT also improved the ratio of reduced GSH to oxidized GSH and catalase levels with a concomitant decrease in lipid peroxidation. In conclusion, to the best of our knowledge, the present study was the first to report that EGT prevents endothelial dysfunction induced by low-dose HgCl2 administration. EGT may serve as a therapeutic tool to reduce mercury-associated cardiovascular complications via improving the antioxidant status.
Collapse
Affiliation(s)
- Göksel Gökçe
- Department of Clinical Pharmacy, Faculty of Pharmacy, Ege University, Izmir 35040, Turkey
| | - Mehmet Zuhuri Arun
- Department of Clinical Pharmacy, Faculty of Pharmacy, Ege University, Izmir 35040, Turkey
| | - Elif Ertuna
- Department of Clinical Pharmacy, Faculty of Pharmacy, Ege University, Izmir 35040, Turkey
| |
Collapse
|
11
|
Stratton A, Ericksen M, Harris TV, Symmonds N, Silverstein TP. Mercury(II) binds to both of chymotrypsin's histidines, causing inhibition followed by irreversible denaturation/aggregation. Protein Sci 2017; 26:292-305. [PMID: 27859834 PMCID: PMC5275735 DOI: 10.1002/pro.3082] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/14/2016] [Accepted: 11/16/2016] [Indexed: 11/10/2022]
Abstract
The toxicity of mercury is often attributed to its tight binding to cysteine thiolate anions in vital enzymes. To test our hypothesis that Hg(II) binding to histidine could be a significant factor in mercury's toxic effects, we studied the enzyme chymotrypsin, which lacks free cysteine thiols; we found that chymotrypsin is not only inhibited, but also denatured by Hg(II). We followed the aggregation of denatured enzyme by the increase in visible absorbance due to light scattering. Hg(II)-induced chymotrypsin precipitation increased dramatically above pH 6.5, and free imidazole inhibited this precipitation, implicating histidine-Hg(II) binding in the process of chymotrypsin denaturation/aggregation. Diethylpyrocarbonate (DEPC) blocked chymotrypsin's two histidines (his40 and his57 ) quickly and completely, with an IC50 of 35 ± 6 µM. DEPC at 350 µM reduced the hydrolytic activity of chymotrypsin by 90%, suggesting that low concentrations of DEPC react with his57 at the active site catalytic triad; furthermore, DEPC below 400 µM enhanced the Hg(II)-induced precipitation of chymotrypsin. We conclude that his57 reacts readily with DEPC, causing enzyme inhibition and enhancement of Hg(II)-induced aggregation. Above 500 µM, DEPC inhibited Hg(II)-induced precipitation, and [DEPC] >2.5 mM completely protected chymotrypsin against precipitation. This suggests that his40 reacts less readily with DEPC, and that chymotrypsin denaturation is caused by Hg(II) binding specifically to the his40 residue. Finally, we show that Hg(II)-histidine binding may trigger hemoglobin aggregation as well. Because of results with these two enzymes, we suggest that metal-histidine binding may be key to understanding all heavy metal-induced protein aggregation.
Collapse
Affiliation(s)
| | | | | | - Nick Symmonds
- Chemistry DepartmentWillamette UniversitySalemOregon97301
| | | |
Collapse
|
12
|
de Pomerai DI, Iqbal N, Lafayette I, Nagarajan A, Kaviani Moghadam M, Fineberg A, Reader T, Greedy S, Smartt C, Thomas DWP. Microwave fields have little effect on α-synuclein aggregation in a Caenorhabditis elegans model of Parkinson's disease. Bioelectromagnetics 2016; 37:116-29. [PMID: 26879225 DOI: 10.1002/bem.21959] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 01/22/2016] [Indexed: 12/24/2022]
Abstract
Potential health effects of radiofrequency (RF) radiation from mobile phones arouse widespread public concern. RF fields from handheld devices near the brain might trigger or aggravate brain tumors or neurodegenerative diseases such as Parkinson's disease (PD). Aggregation of neural α-synuclein (S) is central to PD pathophysiology, and invertebrate models expressing human S have helped elucidate factors affecting the aggregation process. We have recently developed a transgenic strain of Caenorhabditis elegans carrying two S constructs: SC tagged with cyan (C) blue fluorescent protein (CFP), and SV with the Venus (V) variant of yellow fluorescent protein (YFP). During S aggregation in these SC+SV worms, CFP, and YFP tags are brought close enough to allow Foerster Resonance Energy Transfer (FRET). As a positive control, S aggregation was promoted at low Hg(2+) concentrations, whereas higher concentrations activated stress-response genes. Using two different exposure systems described previously, we tested whether RF fields (1.0 GHz CW, 0.002-0.02 W kg(-1); 1.8 GHz CW or GSM, 1.8 W kg(-1)) could influence S aggregation in SC+SV worms. YFP fluorescence in similar SV-only worms provided internal controls, which should show opposite changes due to FRET quenching during S aggregation. No statistically significant changes were observed over several independent runs at 2.5, 24, or 96 h. Although our worm model is sensitive to chemical promoters of aggregation, no similar effects were attributable to RF exposures.
Collapse
Affiliation(s)
| | - Nooria Iqbal
- School of Biology, University of Nottingham, Nottingham, United Kingdom
| | - Ivan Lafayette
- School of Biology, University of Nottingham, Nottingham, United Kingdom
| | - Archana Nagarajan
- School of Biology, University of Nottingham, Nottingham, United Kingdom
| | | | - April Fineberg
- School of Biology, University of Nottingham, Nottingham, United Kingdom
| | - Tom Reader
- School of Biology, University of Nottingham, Nottingham, United Kingdom
| | - Steve Greedy
- Department of Electrical and Electronic Engineering, University of Nottingham, Nottingham, United Kingdom
| | - Chris Smartt
- Department of Electrical and Electronic Engineering, University of Nottingham, Nottingham, United Kingdom
| | - David W P Thomas
- Department of Electrical and Electronic Engineering, University of Nottingham, Nottingham, United Kingdom
| |
Collapse
|
13
|
Kothari S, Choughule N. Ameliorative stroke of selenium against toxicological effects of mercuric chloride in liver of freshwater catfish Heteropneustes fossilis (Bloch). Environ Toxicol 2015; 30:927-936. [PMID: 24500973 DOI: 10.1002/tox.21967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 01/24/2014] [Accepted: 01/24/2014] [Indexed: 06/03/2023]
Abstract
Mercury, a prevalent and unrelenting toxin, occurs in a variety of forms in freshwater as well as, in marine life. Mercury is an important inducer of oxidative stress in fish leading to formation of reactive oxygen species. Selenium is an essential micronutrient for animals and has antagonistic effect against mercuric toxicity in fishes. Present study has been made to evaluate toxic effect of HgCl2 (0.15 mg/L) on liver of freshwater catfish Heteropneustes fossilis (Bl.). Protective ability of selenium has been investigated by simultaneous exposure of fish with sodium selenite (0.15 mg/L) along with mercuric chloride. For present study Fishes were divided into three groups of ten fishes each the first group served as control, while the second group fish were exposed to HgCl2 . Animals of third group were treated with HgCl2 and Na2 SeO3 . Results reveal that mercury induced lipid peroxidation and in response to this, antioxidants reduced glutathione (GSH) and Catalase (CAT) were reduced whereas, Glutathione reductase (GR) level was enhanced. These antioxidants scavenge the reactive oxygen radicals. Hg induced histopathological damage and elevation in alkaline phosphatase (ALP) and transaminases and reduction in protein and glucose contents were evidently seen in catfish liver. Intriguingly, results indicate that under stress of mercury, the fish actively generate oxidative stress and antioxidant responses, which can be used as biomarkers of pollution. Simultaneous exposure to Selenium along with Hg suppressed Hg uptake and lipid peroxidation. Histological architecture and all biochemical parameters were maintained near normal in the presence of selenium in liver of the catfish.
Collapse
Affiliation(s)
- Suresh Kothari
- School of Studies in Zoology and Biotechnology, Vikram University, Ujjain, 465010, India
| | - Neha Choughule
- School of Studies in Zoology and Biotechnology, Vikram University, Ujjain, 465010, India
| |
Collapse
|
14
|
Affiliation(s)
- Jeff Wilson
- School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Wales, UK
| |
Collapse
|
15
|
Hamann CR, Boonchai W, Wen L, Sakanashi EN, Chu CY, Hamann K, Hamann CP, Sinniah K, Hamann D. Spectrometric analysis of mercury content in 549 skin-lightening products: is mercury toxicity a hidden global health hazard? J Am Acad Dermatol 2014; 70:281-7.e3. [PMID: 24321702 DOI: 10.1016/j.jaad.2013.09.050] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 09/22/2013] [Accepted: 09/23/2013] [Indexed: 11/23/2022]
Abstract
BACKGROUND Cosmetic skin lightening is practiced worldwide. Mercury is a well-documented melanotoxin added to some lightening products. However, mercury can cause many dermatologic, renal, and neurologic problems. The Food and Drug Administration limits the amount of mercury in cosmetic products to trace amounts, 1 ppm. OBJECTIVE The objective of this study was to quantitatively evaluate a large international sample of lightening products for mercury content, focusing on products available to US consumers either online or in stores. METHODS A total of 549 skin-lightening products, manufactured in 32 countries, were purchased online in the United States, Taiwan, and Japan and in stores in the United States, China, Taiwan, Thailand, Japan, and Sri Lanka. Cosmetics were screened for mercury content above 200 ppm using a low-cost portable x-ray fluorescence spectrometer. RESULTS Of the 549 tested products, 6.0% (n = 33) contained mercury above 1000 ppm. In all, 45% of mercury-containing samples contained mercury in excess of 10,000 ppm. Of lightening products purchased in the United States, 3.3% were found to contain mercury in excess of 1000 ppm. LIMITATIONS Our study did not evaluate creams for other melanosuppressive ingredients. Only 1 sample of each product was tested. CONCLUSION Our study confirms the national and global presence of mercury in skin-lightening products.
Collapse
|
16
|
Clarke D, Buchanan R, Gupta N, Haley B. Amelioration of Acute Mercury Toxicity by a Novel, Non-Toxic Lipid Soluble Chelator N,N'bis-(2-mercaptoethyl)isophthalamide: Effect on Animal Survival, Health, Mercury Excretion and Organ Accumulation. Toxicol Environ Chem 2012; 94:616-640. [PMID: 22573916 PMCID: PMC3346673 DOI: 10.1080/02772248.2012.657199] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The toxic effects of mercury are known to be complex with specific enzyme inhibitions and subsequent oxidative stress adding to the damaging effects. There are likely other factors involved, such as the development of impaired metal ion homeostasis and depletion of thiol and selenium based metabolites such as cysteine and selenium. Much of the toxicity of mercury occurs at the intracellular level via binding of Hg(2+) to thiol groups in specific proteins. Therefore, amelioration of mercury toxicity by the use of chelation would likely be enhanced by the use of a chelator that could cross the cell membrane and the blood brain barrier. It would be most favorable if this compound was of low toxicity, had appropriate pharmacokinetics, bound and rendered mercury cation non-toxic and had antioxidant properties. Herein we report on such a chelator, N,N'-bis(2-mercaptoethyl)isophthalamide (NBMI), and, using an animal model, show that it prevented the toxic effects associated with acute exposure induced by injected mercury chloride.
Collapse
Affiliation(s)
- David Clarke
- Environmental Sciences, Arkansas State University and Graduate Program in Molecular Biosciences, Arkansas Biosciences Institute, Arkansas State University, State University, AK 72467
| | - Roger Buchanan
- Environmental Sciences, Arkansas State University and Graduate Program in Molecular Biosciences, Arkansas Biosciences Institute, Arkansas State University, State University, AK 72467
| | - Niladri Gupta
- Department of Chemistry, University of Kentucky, Lexington, KY 40506
- CTI Sciences, Inc. 2430 Palumbo Drive, Lexington, KY 40509
| | - Boyd Haley
- Department of Chemistry, University of Kentucky, Lexington, KY 40506
- CTI Sciences, Inc. 2430 Palumbo Drive, Lexington, KY 40509
| |
Collapse
|
17
|
Abstract
Mercury is toxic heavy metal. It has many characteristic features. Health care organizations have used mercury in many forms since time immemorial. The main uses of mercury are in dental amalgam, sphygmomanometers, and thermometers. The mercury once released into the environment can remain for a longer period. Both acute and chronic poisoning can be caused by it. Half of the mercury found in the atmosphere is human generated and health care contributes the substantial part to it. The world has awakened to the harmful effects of mercury. The World Health Organization and United Nations Environmental Programme (UNEP) have issued guidelines for the countries’ health care sector to become mercury free. UNEP has formed mercury partnerships between governments and other stakeholders as one approach to reducing risks to human health and the environment from the release of mercury and its compounds to the environment. Many hospitals are mercury free now.
Collapse
Affiliation(s)
- Neeti Rustagi
- Department of Community Medicine, Maulana Azad Medical College, New Delhi, India
| | | |
Collapse
|