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The Expert Panel for Cosmetic Ingredient Safety reviewed newly available studies since their original assessment in 1998, along with updated information regarding product types and concentrations of use and confirmed that EDTA and certain salts are safe as cosmetic ingredients in the practices of use and concentration as described in this report., Competing Interests: Declaration of Conflicting InterestThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: The articles in this supplement were sponsored by the Cosmetic Ingredient Review.

Hormone therapy (HT) is one of the most effective treatments for osteoporosis. However, the nonselective accumulation of hormone in organs such as breast, heart and uterus other than bones causes serious side effects, which impedes the application of HT. Hence, it is critically important to develop a HT strategy with reduced non-specific enrichment of hormone drugs in non-target tissues and enhanced bone-targeting ability. Methods : Herein, a 17β-estradiol (E 2 )-laden mesoporous silica-coated upconversion nanoparticle with a surface modification of ethylenediaminetetraacetic acid (EDTA) (NaLuF 4 :Yb,Tm@NaLuF 4 @mSiO 2 -EDTA-E 2 , E 2 -csUCNP@MSN-EDTA) is developed for bone-targeted osteoporosis hormone therapy. EDTA was attached onto the surface of E 2 upconversion nanocomposite to enhance its affinity and efficiency targeting bone tissue and cells to optimize hormone replacement therapy for osteoporosis. We characterized the size, cytotoxicity, loading and release efficiency, in situ and ex vivo imaging. Further, in vitro and in vivo osteogenic ability was tested using preosteoblast and ovariectomy mouse model of osteoporosis. Results : The upconversion core of E 2 -csUCNP@MSN-EDTA nanoparticle serves as an excellent imaging agent for tracking the loaded hormone drug in vivo . The mesoporous silica layer has a high loading efficiency for E 2 and provides a relatively long-lasting drug release within 50 h. EDTA anchored on the silica layer endows the nanocomposite with a bone targeting property. The nanocomposite effectively reverses estrogen deficiency-induced osteoporosis and reduces the damage of hormone to the uterus. The bone mineral density in the nanocomposite treatment group is nearly twice that of the ovariectomized (OVX) group. Compared with the E 2 group, the uterine weight and luminal epithelial height were significantly lower in the nanocomposite treatment group. Conclusion : This work demonstrated that E 2 -csUCNP@MSN-EDTA alleviates the side effect of hormone therapy while maintaining its therapeutic efficacy, which has great potential for developing the next generation of methods for osteoporosis treatment., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Advanced oxidation processes (AOPs) can degrade heavy metal complexes in wastewater to improve the removal efficiency of metals. However, the influences of AOP treatments on toxicity induced by metal complexes are not well understood. This study compared the toxicity induced by EDTA-copper (Cu) after UV/persulfate (PS) and UV/H 2 O 2 treatments on luminescent bacteria and human HepG2 cells. The results showed that EDTA-Cu complexes decreased Cu toxicity in luminescent bacteria but increased the cytotoxicity in HepG2 cells, indicating species-specific toxicity. The UV/PS and UV/H 2 O 2 treatments under most pH values and [oxidant]/[EDTA-Cu] conditions decreased the toxicity of EDTA-Cu in HepG2 cells but increased the toxicity in luminescent bacteria. When the ratio of [oxidant] to [EDTA-Cu] was 10, low toxicity in treated solutions was observed in both UV treatment processes. The alkaline precipitation treatment had a significant influence on toxicity reduction after UV/PS treatment; however, it had minimal influence on the UV/H 2 O 2 treatment system. The Cu and total organic carbon (TOC) removal efficiency cannot completely explain the results of toxicity assays. EDTA-Cu intermediates might play important roles in changing the toxicity of EDTA-Cu after both UV treatments. This study provides insights into evaluating the treatment efficiency of UV/PS and UV/H 2 O 2 on EDTA-Cu decomplexation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Colon organoids (colonoids) are known to be similar to colon tissue in structure and function, which makes them useful in the treatment of intestinal de-epithelialized disease. Matrigel, which is used as a transplantation scaffold for colonoids, cannot be used in clinical applications because of its undefined composition and tumorigenicity. This study identifies clinically available scaffolds that are effective for colonoid transplantation in damaged intestinal mucosa. The colon crypt was isolated and cultured from C57BL/6-Tg[CAG enhanced green fluorescent protein (EGFP)131Osb/LeySopJ mice into EGFP + colonoids and subsequently transplanted into the EDTA colitis mouse model using gelatin, collagen, or fibrin glue scaffolds. To identify scaffolds suitable for colonoid engraftment in injured colon mucosa, the success rates of transplantation and secondary EGFP colonoid formation were measured, and the scaffolds' mediated toxicity in vitro and in vivo was observed in recipient mice. When colonoids were transplanted with gelatin, collagen, and fibrin glue into the EDTA colitis mouse model, all groups were found to be successfully engrafted. Fibrin glue, especially, showed significant increase in the engrafted area compared with Matrigel after 4 wk. The scaffolds used in the study did not induce colonic toxicity after transplantation into the recipients' colons and were thus deemed safe when locally administrated. This study suggests new methods for and provides evidence of the safety and utility of the clinical application of colonoid-based therapeutics. Furthermore, the methods introduced in this study will be helpful in developing cell treatment using the esophagus or a stomach organoid for various digestive-system diseases.-Jee, J., Jeong, S. Y., Kim, H. K., Choi, S. Y., Jeong, S., Lee, J., Ko, J. S., Kim, M. S., Kwon, M.-S., Yoo, J. In vivo evaluation of scaffolds compatible for colonoid engraftments onto injured mouse colon epithelium.

As a commonly used chelator, ethylenediaminetetraacetic acid (EDTA) enters soil environment inevitably and has the potential to cause negative effects on soil organisms. The objective of the current study was to investigate the effects of EDTA on earthworm growth, survival and activities of antioxidant enzymes. The assessment for EDTA toxicity toward earthworms (Eisenia fetida) was conducted on day 14 and 35 after exposure to four concentrations (0, 5, 10, 15 mmol kg -1 ) of EDTA under turfgrass growing conditions. Exposure to EDTA resulted in a significant decrease of earthworm growth and survival. The toxicity of EDTA increased with the increase in concentration and exposure duration. The activities of antioxidant enzymes increased at low concentration and decreased at high concentration, which indicates that oxidative stress was induced by EDTA addition. These results suggest EDTA is highly toxic and ecologically dangerous to earthworms., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Up till now, despite of well-developed ornamental market, very little information is available on Petunia hybrida L. tolerance against heavy metals (HMs), which can contribute in both beautification of urban dwellings, as well as potential in phytoremediation. Therefore, hydroponic study was conducted to check the effects of Cd, Cr, Cu, Ni and Pb individually (50 and 100 μM) and with co-application of EDTA (2.5 mM) in Hoagland's nutrient solution. Results indicated higher uptake of Cd, Cr, Ni and Pb in above ground parts, and Cu in roots, further the co-application of EDTA enhanced HMs uptake in P. hybrida L. This uptake accompanied changes in biochemical stress indicators, included significantly higher MDA, H 2 O 2 contents and electrolyte leakage with reduced chlorophyll a, chlorophyll b, total chlorophyll and carotenoid content. Upon exposure to HMs increased antioxidant enzyme activities (CAT, POX, GST, APX, and SOD) were noted. Though selected HMs can be removed by using P. hybrida L., the findings of current study indicated that the direct exposure of P. hybrida L. to Cd, Cr, Cu, Ni and Pb damaged the plant's aesthetics, and to use P. hybrida L. for beautification of urban landscape or phytoremediation, appropriate soil modification should be included.

Purpose: Preservatives are used in multi-dose ophthalmic topical medications in order to prevent contamination by bacteria and fungi. However, prolonged use of preserved eye drops, as it may happen in dry eye or glaucoma, may damage cells of the ocular surface. Therefore, an important goal is to find preservatives with low toxicity which are mild to host cells, still able to prevent drug contamination so to maintain their sterility and efficacy. Hence, aim of this study has been to compare the relative toxicity on a rabbit corneal cell line of a new preservative, made by the association of N-hydroxy-methyl-glycinate (NIG) with disodium-ethylene diamine tetra-acetate (EDTA), with other known and widely used eye-drops preservatives., Materials and Methods: Rabbit corneal cells (SIRC) were tested either in 96-well plates or in suspension culture. Treatments with preservatives (used at known bacteriostatic concentrations) included: benzalkonium chloride (BAK), polyquaternium-1 (PQ-1), sodium perborate (SP: NaBO 3 * H 2 O), and NIG ± EDTA at different concentrations (0.001% and 0.002%), and different treatment times (from 30 minutes to 120 hours). At the end of treatment, cell survival was evaluated by a specific spectrophotometric method through the metabolic conversion of MTT [3-(4,5-dimethylthiazol-2-yl) 2, 5-diphenyltetrazolium bromide] into formazan crystals., Results: Almost no cell toxicity was evident for NIG and SP at either concentration (0.001% or 0.002%), while a low toxicity was observed for PQ-1 (62% at the highest dose at 120 hours). BAK, as expected, showed the highest toxicity (60-80% at 30 minutes, and over 90% from eight hours onward). EDTA 0.1% alone or in combination with NIG 0.002%, showed no toxicity at 24 hours, and even resulted in cell growth promotion (46% and 38%, respectively), after 48 hours of treatment., Conclusions: These data show that the new preservative NIG/EDTA, at doses known to have effective antimicrobial properties, has a very low toxicity on corneal cells, and so it can be safely used in multi-dose eye drops.

Ethylenediaminetetraacetic acid (EDTA) used with electrokinetic (EK) to remediate heavy metal-polluted soils is a toxic chelate for soil microorganisms. Therefore, this study aimed to evaluate the effects of alternative organic chelates to EDTA on improving the microbial properties of a heavy metal-polluted soil subjected to EK. Cow manure extract (CME), poultry manure extract (PME) and EDTA were applied to a lead (Pb) and zinc (Zn)-polluted calcareous soil which were subjected to two electric intensities (1.1 and 3.3 v/cm). Soil carbon pools, microbial activity, microbial abundance (e.g., fungal, actinomycetes and bacterial abundances) and diethylenetriaminepentaacetic acid (DTPA)-extractable Pb and Zn (available forms) were assessed in both cathodic and anodic soils. Applying the EK to soil decreased all the microbial variables in the cathodic and anodic soils in the absence or presence of chelates. Both CME and PME applied with two electric intensities decreased the negative effect of EK on soil microbial variables. The lowest values of soil microbial variables were observed when EK was combined with EDTA. The following order was observed in values of soil microbial variables after treating with EK and chelates: EK + CME or EK + PME > EK > EK + EDTA. The CME and PME could increase the concentrations of available Pb and Zn, although the increase was less than that of EDTA. Overall, despite increasing soil available Pb and Zn, the combination of EK with manures (CME or PME) mitigated the negative effects of using EK on soil microbial properties. This study suggested that the synthetic chelates such as EDTA could be replaced with manures to alleviate the environmental risks of EK application.

Copper (Cu) parenteral administration is used in a beef cow-calf operations to prevent or correct Cu deficiency in bovines. At present, Zinc (Zn) salts have been incorporated to complement Cu antioxidant effect. A risk of hepatotoxicity generated by overdose is a negative consequence of injectable Cu application. Cu-Zn EDTA appears as an alternative; however, data about its toxicity is unknown. The aim of this study was to assess toxicity risk of different doses of Cu-Zn EDTA in calves. Thirty two Aberdeen Angus calves of 162 (±20) kg BW were assigned to 4 groups (n = 8), homogeneous in weight, sex, and age. Cu-Zn EDTA was administrated in doses of 0.3 mg/kg BW (group 1X); 0.6 mg/kg BW (group 2X); 0.9 mg/kg BW (group 3X) and sterile saline solution (control group-with no treatment). Clinical and blood parameters in animals were monitored during 28 days. In groups' control, 1X and 2X there were no alterations in the assessed parameters. In group 3X, one of the animals showed depression, permanent decubitus, and muscular twitching; that animal had to be killed in extremis for humanitarian reasons. Necropsy and Cu tissue concentration findings confirmed intoxication in the clinically affected animal. The rest of the animals in group 3X showed only a temporary increase in liver enzymes. The results indicate that a dose of 0.9 mg/kg BW of Cu as Cu-Zn EDTA is potentially hepatotoxic, this dose is similar to other soluble salts of parenteral administration.

Zinc-complexing ligands are prospective anti-biofilm agents because of the pivotal role of zinc in the formation of Staphylococcus aureus biofilm. Accordingly, the potential of a thiosemicarbazone (compound C1) and a benzothiazole-based ligand (compound C4) in the prevention of S. aureus biofilm formation was assessed. Compound C1 displayed a bimodal activity, hindering biofilm formation only at low concentrations and promoting biofilm growth at higher concentrations. In the case of C4, a dose-dependent inhibition of S. aureus biofilm growth was observed. Atomic force microscopy analysis suggested that at higher concentrations C1 formed globular aggregates, which perhaps formed a substratum that favored adhesion of cells and biofilm formation. In the case of C4, zinc supplementation experiments validated zinc complexation as a plausible mechanism of inhibition of S. aureus biofilm. Interestingly, C4 was nontoxic to cultured HeLa cells and thus has promise as a therapeutic anti-biofilm agent. The essential understanding of the structure-driven implications of zinc-complexing ligands acquired in this study might assist future screening regimes for identification of potent anti-biofilm agents., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Several methods for evaluating the toxicity and biodegradability of hazardous pollutants (chlorinated compounds, chemical additives and pharmaceuticals) have been studied in this work. Different bioassays using representative bacteria of marine and terrestrial ecosystems such as Vibrio fischeri and Pseudomonas putida have been used to assess the ecotoxicity. Activated sludge was used to analyse the effect of those pollutants in a biological reactor of a sewage treatment plant (STP). The results demonstrate that none of the compounds is toxic to activated sludge, except ofloxacin to P. putida. The additives tested can be considered moderately toxic according to the more sensitive V. fischeri assays, whereas the EC50 values of the pharmaceuticals depend on the specific microorganism used in each test. Regarding the biodegradability, respirometric measurements were carried out for fast biodegradability assessment and the Zahn-Wellens test for inherent biodegradability. The evolution of the specific oxygen uptake rate (SOUR) showed that only diethyl phthalate was easily biodegradable and acetylsalicylic acid was partially biodegradable (98% and 65% degradation, respectively). The persistence of dichloromethane, ofloxacin and hidrochlorothiazide was confirmed along the 28 days of the Zahn-Wellens test whereas 1,1,1-trichloroethane showed inherent biodegradability (74% removal). Most of the chlorinated compounds, pharmaceuticals, bisphenol A and ethylenediaminetetraacetic acid were partially degraded in 28 d with total organic carbon (TOC) reduction ranging from 21% to 51%. Sulphamethoxazole showed certain biodegradation (50% removal) with TOC decrease around 31%, which indicates the formation of non-biodegradable by-products.

As a part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the in vivo alkaline comet assay (comet assay), we examined DNA damage in the liver, stomach, and bone marrow of rats dosed orally three times with up to 2000 mg/kg of benzene, di(2-ethylhexyl) phthalate, and trisodium ethylenediamine tetraacetic acid monohydrate. All three compounds gave negative results in the liver and stomach. In addition, a bone marrow comet and micronucleus analysis revealed that benzene, but not di(2-ethylhexyl) phthalate or trisodium ethylenediamine tetraacetic acid monohydrate induced a significant increase in the median % tail DNA and micronucleated polychromatic erythrocytes, compared with the respective concurrent vehicle control. These results were in good agreement with the previously reported genotoxicity findings for each compound. The present study has shown that combining the micronucleus test with the comet assay and carrying out these analyses simultaneously is effective in clarifying the mechanism of action of genotoxic compounds such as benzene., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Carcinogenic formaldehyde is produced by endogenous protein oxidation and various exogenous sources. With formaldehyde being both ubiquitous in the ambient environment and one of the most common reactive carbonyls produced from endogenous metabolism, quantifying formaldehyde exposure is an essential step in risk assessments. We present in this study an approach to assess the risk of exposure to oxidative stress by quantifying thiazolidine-4-carboxylic acid (TA), a cysteine-conjugated metabolite of formaldehyde in toxicant-exposed Escherichia coli. The method entails TA derivatization with ethyl chloroformate, addition of isotope-labeled TA derivatives as internal standards, solid-phase extraction of the derivatives, and quantification by liquid chromatography-mass spectrometry (LC-MS). After validating for accuracy and precision, the developed method was used to detect TA in oxidizing agent-exposed E. coli samples. Dose-dependent TA formation was observed in E. coli exposed to hydroxyl radical mediators Fe(2+)-EDTA, H2O2, and NaOCl, indicating the potential use of TA as a biomarker of exposure to oxidative stress and disease risk.

Microcalorimetric technique was applied to assess the toxic effect of EDTA-chelated trivalent iron on Pseudomonas putida (P. putida) (bacterium), Candida humicola (C. humicola) (fungus) and their mixture in sterilized soil. Microbial growth rate constant k, total heat evolution Q T, metabolic enthalpy ∆H met, mass specific heat rate J Q/S, microbial biomass C and inhibitory ratio I were calculated. Results showed that microcalorimetric indexes decreased with the increasing Fe(III)-EDTA complex concentration. Comparing the single and mixed strains, the effect of Fe(III) on bacterium-fungus interaction was dominant at lower dose, whereas, the metal toxicity at high dose of Fe was the main factor affecting P. putida and C. humicola activity. Thus, the mixture had moderate tolerance to the iron overload, and exhibit synergistic interaction in exponential growth phase (0-0.3 mg g(-1)). The results of glucose degradation showed that glucose was consumed totally at the end of exponential phase of microbial growth.

Zebrafish (Danio rerio) is increasingly employed for evaluating toxicity and drug discovery assays. Commonly experimental approaches for biotoxicity assessment are based on visual inspection or video recording. However, these techniques are limited for large-scale assays, as they demand either a time-consuming detailed inspection of the animals or intensive computing resources in order to analyze a considerable amount of screenshots. Recently, we have developed a simple methodology for tracking the locomotor activity of small animals cultured in microtiter plates. In this work, we implemented this automatic methodology, based on infrared (IR) microbeam scattering, for measuring behavioral activity in zebrafish larvae. We determined the appropriate culture conditions, number of animals and stage of development to get robust results. Furthermore, we validated this methodology as a rapid test for evaluating toxicity. By measuring the effects of reference compounds on larvae activity, we were able to estimate the concentration that could cause a 50% decrease in activity events values (AEC₅₀), showing a strong linear correlation (R²  = 0.91) with the LC₅₀ values obtained with the standard DarT test. The toxicity order of the measured compounds was CuSO4  > 2,4-dinitrophenol > 3,4-dichloroaniline > SDS > sodium benzoate > EDTA > K₂CrO4 ; regarding solvents, EtOH ≈ DMSO. In this study, we demonstrate that global swimming behavior could be a simple readout for toxicity, easy to scale-up in automated experiments. This approach is potentially applicable for fast ecotoxicity assays and whole-organism high-throughput compound screening, reducing the time and money required to evaluate unknown samples and to identify leading pharmaceutical compounds., (Copyright © 2013 John Wiley & Sons, Ltd.)

In this study, a promising bioremediation approach was developed to remove [Co(III)-EDTA](-) complex that is generated during the waste management process. Though several studies have been reported on bioremediation of cobalt, the removal of [Co(III)-EDTA](-) complex has not been tested. A [Co(III)-EDTA](-) resistant bacterium, Pseudomonas aeruginosa SPB-1 was isolated from the solar-salt-pan and physical parameters were optimized for its growth. The various studies showed that the removal of [Co(III)-EDTA](-) from the bulk liquid was due to the adsorption of the complex by the biomass. Using absorption/desorption isotherm over a range of pH (1-8), the maximum adsorption of [Co(III)-EDTA](-) was found to be at pH 7.0 and maximum desorption from the biomass occurred at pH 1.0, thus rendering an ion exchange property to P. aeruginosa SPB-1 biomass. P. aeruginosa SPB-1 biomass could be used as bio-resin that showed 80.4±3.27% adsorption capacity up to fourth cycle and the biomass was viable till the ninth cycle with 10.5±7.3% adsorption. Radiation tolerance potential i.e. D10 value for the strain was found to be ~300 Gy, which suggests the potential use of the bacterium in bioremediation of moderately active nuclear waste., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Objective: The aim of this study was to determine the feasibility of using snake venom thrombin-like enzyme (SVTLE) and/or ethylenediaminetetraacetic acid (EDTA) to dissolve calcium oxalate stones in vitro., Methods: Seven calcium oxalate stones were incubated with various chemolytic agents [EDTA, Tris-HCl/EDTA (TE) buffer or SVTLE diluted in TE buffer]. The pH, calcium concentration, stone weight and stone surface integrity were recorded, as well as related pathological changes to bladder mucosae., Results: Compared to all other solutions, those containing SVTLE and buffered EDTA had higher concentrations of mobilized calcium and caused significantly more stone weight loss, stone fragility and gaps in the calcium crystals. Also, there were no adverse pathological effects on rabbit bladder mucosae from any of the solutions., Conclusions: The data indicate that buffered EDTA and SVTLE can be used to dissolve calcium oxalate stones and, at the concentrations used here, do not damage tissue., (2013 S. Karger AG, Basel.)

Gadolinium chelates are used in increasing amounts as contrast agents in magnetic resonance imaging, and their fate in wastewater treatment has recently become the focus of research. Oxidative processes, in particular the application of ozone, are currently discussed or even implemented for advanced wastewater treatment. However, reactions of the gadolinium chelates with ozone are not yet characterized. In this study, therefore, rate constants with ozone were determined for the three commonly used chelates Gd-DTPA, Gd-DTPA-BMA, and Gd-BT-DO3A, which were found to be 4.8 ± 0.88, 46 ± 2.5, and 24 ± 1.5 M(-1) s(-1), respectively. These low rate constants indicate that a direct reaction with ozone in wastewater is negligible. However, application of ozone in wastewater leads to substantial yields of (•)OH. Different methods have been applied and compared for determination of k((•)OH+Gd chelate). From rate constants determined by pulse radiolysis experiments (k((•)OH+Gd-DTPA) = 2.6 ± 0.2 × 10(9) M(-1) s(-1), k((•)OH+Gd-DTPA-BMA) = 1.9 ± 0.7 × 10(9) M(-1) s(-1), k((•)OH+Gd-BT-DO3A) = 4.3 ± 0.2 × 10(9) M(-1) s(-1)), it is concluded that a reaction in wastewater via (•)OH radicals is feasible. Toxicity has been tested for educt and product mixtures of both reactions. Cytotoxicity (MTT test) and genotoxicity (micronuclei assay) were not detectable.

Objectives: This study aims to evaluate and compare the genotoxic and apoptotic effect of aqueous solutions of ethylenediaminetetraacetic acid (EDTA) with that of maleic acid (MA) using Chinese hamster lung fibroblast (V79) cells growing in vitro., Materials and Methods: Exponentially growing V79 cells were treated with various concentrations of EDTA or MA alone for 30 min, and genotoxic effect was analyzed by micronucleus as well as comet assays and the type of cell death by apoptotic cell measurements using microscopic and flow cytometric methods. For all the experiments, H2O2 was used as a positive control., Results: Treatment of V79 cells with H2O2 resulted in significantly (P < 0.001) increased micronuclei and levels of DNA damage, whereas, EDTA/MA alone treated cells did not show significant increase of MN frequencies and comet parameters even at their higher concentrations when compared with that of untreated control. V79 cells treated with EDTA/MA for 30 min showed a nonsignificant increase in the percentage of apoptotic and necrotic cells at their lower concentrations (0.025 and 0.05 % for EDTA and MA, respectively). However, at higher concentrations, i.e., >IC50 (0.1 and 0.5 %) for EDTA and MA resulted in increased number of apoptotic and necrotic cells when compared with the untreated group., Conclusions: This study clearly demonstrates that MA and EDTA are not potentially genotoxic agents and MA induced lesser apoptotic/necrotic death than that of EDTA at their clinically relevant doses., Clinical Relevance: MA may have a better clinical acceptability with comparable smear layer removal ability. Hence, the results presented here might be an additional supporting evidence for the use of MA in endodontic practice.

The influence of complexation by ethylenediaminetetraacetic acid (EDTA) on the toxicity of Cd(II), Cu(II), Cd(II), and Ni(II) was investigated. Result of the Microtox test, which is based on measuring the decrease of light emitted by Vibrio fischeri bacterium when exposed to a toxicant, was used as an indication of toxicity. The effect of pH and EDTA molar ratio that might potentially modify the percentage of chemical species in solution on toxicity was evaluated. In general, results indicate that toxicity decreases when increasing the pH value as well as the EDTA molar ratio. Chemical modeling was used to predict metal speciation and correlation analysis to relate chemical species with the obtained toxicity results. The species that most contribute to toxicity resulted to be MeCl(+) (Me = metal), which is formed as a consequence of the presence of the bioassay medium (2 % NaCl). A model that predicts metal-solution toxicity by using the chemical species, which most contribute to toxicity is proposed as a useful tool for toxicity assessment in waters containing metal ions and EDTA.

Titanium(IV) compounds are excellent anticancer drug candidates, but they have yet to find success in clinical applications. A major limitation in developing further compounds has been a general lack of understanding of the mechanism governing their bioactivity. To determine factors necessary for bioactivity, we tested the cytotoxicity of different ligand compounds in conjunction with speciation studies and mass spectrometry bioavailability measurements. These studies demonstrated that the Ti(IV) compound of N,N'-di(o-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) is cytotoxic to A549 lung cancer cells, unlike those of citrate and naphthalene-2,3-diolate. Although serum proteins are implicated in the activity of Ti(IV) compounds, we found that these interactions do not play a role in [TiO(HBED)](-) activity. Subsequent compound characterization revealed ligand properties necessary for activity. These findings establish the importance of the ligand in the bioactivity of Ti(IV) compounds, provides insights for developing next-generation Ti(IV) anticancer compounds, and reveal [TiO(HBED)](-) as a unique candidate anticancer compound.

The urban-water cycle modifies natural stream hydrology, and domestic and commercial activities increase the burden of endocrine-disrupting chemicals, such as steroidal hormones and 4-nonylphenol, that can disrupt endocrine system function in aquatic organisms. This paper presents a series of integrated chemical and biological investigations into the occurrence, fate, and effects of endocrine-disrupting chemicals in the City of Boulder Colorado's WWTF and Boulder Creek, the receiving stream. Results are presented showing the effects of a full-scale upgrade of the WWTF (that treats 0.6 m(3) s(-1) of sewage) from a trickling filter/solids contact process to an activated sludge process on the removal of endocrine-disrupting compounds and other contaminants (including nutrients, boron, bismuth, gadolinium, and ethylenediaminetetraacetic acid) through each major treatment unit. Corresponding impacts of pre- and postupgrade effluent chemistry on fish reproductive end points were evaluated using on-site, continuous-flow experiments, in which male fathead minnows (Pimephales promelas) were exposed for 28 days to upstream Boulder Creek water and WWTF effluent under controlled conditions. The upgrade of the WWTF resulted in improved removal efficiency for many endocrine-disrupting chemicals, particularly 17β-estradiol and estrone, and fish exposed to the postupgrade effluent indicated reduction in endocrine disruption relative to preupgrade conditions.

The aim of the present study was to evaluate the effect of the cell isolation process in the alkaline comet assay using epidermal skin cells. When we explored the cell isolation method for the alkaline comet assay using the 3-dimensional (3D) human epidermal skin model, we found that DNA damage and cytotoxicity were induced during the cell isolation process. In particular, trypsin 5 min treatment with ethylene diamine tetraacetic acid (EDTA) showed about 5 times %DNA in the tail value compared to without EDTA treatment. In general, EDTA is commonly used for cell isolation, but it is known to induce genotoxicity due to secondary effects. We therefore evaluated the effect of EDTA and pH in the alkaline comet assay on a monolayer culture of rat keratinocytes. As a result, there was a significant increase of %DNA in tail values by treatment with 0.1 w/v% EDTA for 60 min; however, there was no difference in the %DNA in tail values between 0.1 w/v% EDTA/PBS(-) (pH 6.8) and 0.1 w/v% EDTA/PBS(-) (pH 7.4). These data imply that there is a need to control the EDTA conditions for cell isolation in the epidermal skin cells.

The aim of the present study was to evaluate the capacity of some root canal irrigants to induce genetic damage and/or cellular death in vitro. Murine fibroblast cells were exposed to ethylenediaminetetraacetic acid (EDTA), sodium hypochlorite (NaOCl), MTAD™ and citric acid in increasing concentrations for 3 h at 37ºC. The negative control group was treated with vehicle control (phosphate buffer solution - PBS) for 3 h at 37°C, and the positive control group was treated with methylmetanesulfonate, 1 μM. for 3 h at 37°C. Cytotoxicity was assessed by the trypan blue test and genotoxicity was evaluated by the single cell gel (comet) assay. The results showed that exposure to 2.5% and 5% NaOCl and 8.5% citric acid resulted in a significant cytotoxic effect. NaOCl, EDTA and citric acid did not produce genotoxic effects with respect to the comet assay data for all evaluated concentrations. Although MTAD was not a cytotoxic agent, it showed significant genotoxic effects at all tested concentrations (ANOVA and Tukey's test; p<0.05). NaOCl, EDTA and citric acid were found to be cytotoxic in a dose-dependent manner, but they were not genotoxic. MTAD did not cause cell death, but presented genotoxic effects.

The interaction of native calf thymus DNA with ethylenediaminetetraaceticacid (EDTA) in Tris-HCl buffer at pH = 7.8 (at this pH EDTA forms a disodium salt) was investigated. EDTA is widely used in medicine, food technology, and the chemical industry. The DNA binding mode of EDTA was monitored by absorption spectrophotometry, circular dichrosim, viscometry, and gel electrophoresis. Ultraviolet spectra of DNA showed small hyperchromicity with increase in EDTA concentration. The circular dichrosim signals at 245 and 280 nm indicated structural changes in DNA structure, and no significant effect on DNA viscosity was observed in the presence of increasing amounts of EDTA. Results are indicative of an outside, nonintercalative binding mode of EDTA to DNA. Moreover, gel electrophoresis studies showed considerable oxidative cleavage of plasmid DNA by EDTA. Mechanistic aspects of the chemical nuclease reactions were investigated using the OH radical quencher dimethylsulfoxide. In the presence of selenium, DNA cleavage by EDTA was inhibited.

Literature data on the influence of complexing compound ethylenediaminetetraacetate (EDTA) on environmental and ecological risks related with its application were analyzed and summarized. Methods of abiotic and biotic degradation of EDTA were systemized. Special attention was paid to microbiological degradation of EDTA was paid. Data on EDTA transport and metabolism pathways in aerobic bacteria are represented. The practical aspects of application of aerobic bacteria-destructors of EDTA in ecobiotechnology were discussed.

Oxidation of the C5'-position of DNA results in direct strand scission. The 3'-fragments produced contain DNA lesions at their 5'-termini. The major DNA lesion contains an aldehyde at its C5'-position, but its nucleobase is unmodified. Excision of the lesion formed from oxidation of thymidine (T-al) is achieved by strand displacement synthesis by DNA polymerase β (Pol β) in the presence or absence of flap endonuclease 1 (FEN1). Pol β displaces T-al and thymidine with comparable efficiency, but less so than a chemically stabilized abasic site analogue (F). FEN1 cleaves the flaps produced during strand displacement synthesis that are two nucleotides or longer. A ternary complex containing T-al is also a substrate for the bacterial UvrABC nucleotide excision repair system. The sites of strand scission are identical in ternary complexes containing T-al, thymidine, or F. UvrABC incision efficiency of these ternary complexes is comparable as well but significantly slower than a duplex substrate containing a bulky substituted thymidine. However, cleavage occurs only on the 5'-fragment and does not remove the lesion. These data suggest that unlike many lesions the redundant nature of base excision and nucleotide excision repair systems does not provide a means for removing the major damage product produced by agents that oxidize the C5'-position. This may contribute to the high cytotoxicity of drugs that oxidize the C5'-position in DNA.

In 2004, an invasive mat-forming freshwater diatom, Didymosphenia geminata (didymo), was found in New Zealand causing concern with regard to potential consequences for local freshwater ecosystems. A four-stage research program was initiated to identify methods to control D. geminata. This article reports the results of Stage 2, in which four potential control compounds [Gemex™ (a chelated copper formulation), EDTA, Hydrothol®191, and Organic Interceptor™ (a pine oil formulation)] selected in Stage 1 were evaluated for their biocidal efficacy on D. geminata and effects on non-target organisms using both artificial stream and laboratory trials. Artificial stream trials evaluated the mortality rates of D. geminata and fishes to three concentrations of the four biocides, whereas laboratory toxicity trials tested the response of green alga and cladocera to a range of biocide concentrations and exposure times. In artificial stream trials, Gemex and Organic Interceptor were the most effective biocides against D. geminata for a number of measured indices; however, exposure of fishes to Organic Interceptor resulted in high mortality rates. Laboratory toxicity testing indicated that Gemex might negatively affect sensitive stream invertebrates, based on the cladoceran sensitivity at the proposed river control dose. A decision support matrix evaluated the four biocides based on nine criteria stipulated by river stakeholders (effectiveness, non-target species impacts, stalk removal, degradation profile, risks to health and safety, ease of application, neutralization potential, cost, and local regulatory requirements) and Gemex was identified as the product warranting further refinement prior to an in-river trial.

No pro-apoptotic effect of dinitrosyl iron complexes (DNIC) with glutathione, cysteine or thiosulfate was established after incubation of HeLa cells in Eagle's medium. However, DNIC with thiosulfate manifested pro-apoptotic activity during incubation of HeLa cells in Versene's solution supplemented with ethylene diamine tetraacetate (EDTA) known to induce the decomposition of these DNIC. The water-soluble о-phenanthroline derivative bathophenanthroline disulfonate (BPDS) had a similar effect on DNIC with glutathione during incubation of HeLa cells in Eagle's medium. It was assumed that EDTA- or BPDS-induced pro-apoptotic effect of DNIC with thiosulfate or glutathione is coupled with the ability of decomposing DNIC to initiate S-nitrosylation of proteins localized on the surface of HeLa cells. Presumably, the pro-apoptotic effect of S-nitrosoglutathione (GS-NO) on HeLa cells preincubated in Eagle's medium is mediated by the same mechanism, although the pro-apoptotic effect based on the ability of GS-NO to initiate the release of significant amounts of NO and its oxidation to cytotoxic peroxynitrite in a reaction with superoxide should not be ruled out either. No apoptotic activity was found in the presence of bivalent iron and glutathione favoring the conversion of GS-NO into DNIC with glutathione. It is suggested that interaction of HeLa cells with intact DNIC with glutathione or thiosulfate results in the formation of DNIC bound to cell surface proteins., (Copyright © 2011. Published by Elsevier Inc.)

Interest in contrast agent's (CA) neurotoxicity has greatly increased due to the growing need of new compounds dedicated to brain imaging. Magnetic resonance imaging (MRI) CA have been evaluated by means of different toxicological assays with cultured rat primary neurons (evaluation of neurite specific parameters via immunostaining of the cells and LDH leakage). To determine the potential neurotoxicity of a precise paramagnetic ion in a defined structure (architecture and molecular weight), novel hydrosoluble dendritic Manganese (II) and Gadolinium (III) complexes derived from diethylenetriamine pentaacetic acid (DTPA) have been studied and compared to a linear homologue (same molecular weight) and commercially available low molecular weight MRI CA like Mn-DPDP (Teslascan, GE Healthcare) and Gd-DTPA (Magnevist, Schering). The range of CA concentrations studied was 0.1-10mM, suitable for MRI examinations. This set of experiments allows a toxicity ranking of these reagents as a function of molecular structure and nature of the paramagnetic ion. We could determine that the architecture (linear vs. dendritic) does not play an important role in the in vitro neurotoxicity, whereas the structure of the chelating cage is of greater importance., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

Salmonella enterica subsp. enterica serovar Enteritidis is a leading causative agent of gastroenteritis in humans. This pathogen also colonizes the intestinal tracts of poultry and can spread systemically in chickens. Transfer to humans usually occurs through undercooked or improperly handled poultry meat or eggs. The bacterial twin-arginine transport (Tat) pathway is responsible for the translocation of folded proteins across the cytoplasmic membrane. In order to study the role of the Tat system in the infection and colonization of chickens by Salmonella Enteritidis, we constructed chromosomal deletion mutants of the tatB and tatC genes, which are essential components of the Tat translocon. We observed that the tat mutations affected bacterial cell morphology, motility, and sensitivity to albomycin, sodium dodecyl sulfate (SDS), and EDTA. In addition, the mutant strains showed reduced invasion of polarized Caco-2 cells. The wild-type phenotype was restored in all our Salmonella Enteritidis tat mutants by introducing episomal copies of the tatABC genes. When tested in chickens by use of a Salmonella Enteritidis Delta tatB strain, the Tat system inactivation did not substantially affect cecal colonization, but it delayed systemic infection. Taken together, our data demonstrated that the Tat system plays a role in Salmonella Enteritidis pathogenesis.

Earthworm fibrinolytic enzymes (EFEs), an ideal drug for cardiovascular diseases, have a very low oral bioavailability. In order to improve the absorption of EFEs, six different enhancers were selected to increase the intestinal absorption of EFEs. In vitro (Caco-2 monolayers) and in vivo (mice) experiments were carried out to find the optimum concentration and action time of these enhancers for EFE absorption. We found that EFEs could be transported into blood across intestinal endothelial membrane after administration via intragastric administration with low bioavailability. These results obtained from in vitro experiments were similar to those in vivo. Moreover, menthol and glucose showed absorption enhancement properties with a relatively low cytotoxicity.

Preservatives are used in ocular medications to prevent microbial contamination. The use of benzalkonium chloride (BAC), the most widely used preservative in ocular medications, has been scrutinized with a number of studies indicating its toxicity to monolayer cultures of corneal and conjunctival epithelial cells. The purpose of this study was to evaluate and compare the toxicity of BAC and other preservatives and common components of ocular formulations on monolayer and stratified air-lifted cultures of Chang conjunctival cells. Air-lifting Chang cells grown on transwell filters increased stratification as assessed by transepithelial electrical resistance and histology. Unlike monolayer cultures in which ocular medications containing BAC caused near complete loss of cell viability, stratified, air-lifted cultures were not affected by the presence of BAC in ocular medications with up to 30-min exposures. Stratification shifted the dose-response curve to the right for benzalkonium chloride, thimerosal, chlorhexidine digluconate, potassium sorbate and EDTA. These results demonstrate that stratification significantly affects cell viability of Chang conjunctival cells in response to preservatives and additives of ophthalmic preparations., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Objective: The objective of this study was to compare aqueous solutions of ethylenediaminetetraacetic acid (EDTA) with that of maleic acid (MA) for their cytotoxic effect on Chinese hamster fibroblasts (V79) cells growing in vitro., Study Design: Exponentially growing V79 cells were treated with various concentrations of EDTA (0.05% to 1.0%) or MA (0.05% to 1.0%) alone for 30 minutes. After treatment, the media was removed, cells were trypsinized, and the cytotoxic effect of EDTA or MA was analyzed by Pratt Willis test and MTT assay. Similarly surviving fraction (clonogenic assay) was performed by treating the V79 cells with different concentrations of EDTA (0.0025% to 0.25%) or MA (0.025% to 0.25%) for 30 minutes. The statistical significance between the various groups was evaluated using the one-way analysis of variance (ANOVA) and Student t test (unpaired) for 2 group comparisons., Results: There was a significant (P < .01) decrease in the cell viability in a dose-dependent manner indicating the cytotoxic effect of both EDTA and MA when compared with the control group. However, all the dilutions of EDTA were significantly (P < .01) more cytotoxic over that of MA in all 3 assays., Conclusion: This study for the first time, clearly demonstrated the significantly less toxic effect of MA at a comparable dose of EDTA, suggesting its potential for use as root canal irrigant.

Purpose: To investigate the possible role of Zn as a trigger for NSF we were using a previously established preclinical model. The depletion of endogenous Zinc ions (Zn) caused by the administration of gadolinium-based contrast agents (GBCAs) has been suggested as a possible pathomechanism for nephrogenic systemic fibrosis (NSF)., Materials and Methods: In the Zn supplementation study, rats were injected with Gadodiamide, Omniscan, and Magnevist with or without Zn supplementation. In the Zn depletion study, animals were kept on a Zn-deficient diet or a special control diet and received injections of Omniscan, OptiMARK, Magnevist, Gadovist, and Gd-EDTA. Gd, Zn, and Cu concentrations in tissue were measured and histology of the skin was performed., Results: As seen in earlier studies, a difference in Gd concentration in the skin was observed following treatment with the different GBCAs. High Gd concentration in the skin correlated with the occurrence of NSF-like skin lesions. We observed no differences in the occurrence of skin lesions between the Zn supplementation and the Zn-deficient groups compared to their respective control groups., Conclusion: We found no significant effect of Zn on the initiation of NSF-like skin lesions. The results further support data from previous studies highlighting the importance of complex stability of the investigated GBCAs., ((c) 2009 Wiley-Liss, Inc.)

Introduction: Endodontic chelators may extrude to apical tissues during instrumentation activating cellular events on periapical tissues. This study assessed in vitro the expression of nitric oxide (NO) concentrations by murine peritoneal macrophages after contact with MTAD (Dentsply/Tulsa, Tulsa, OK), Tetraclean (Ogna Laboratori Farmaceutici, Muggio, Italy), Smear Clear (Sybron Endo, Orange, CA), and EDTA (Biodinâmica, Ibiporã, PR, Brazil)., Methods: Macrophage cells were obtained from Swiss mice after peritoneal lavage. Chelators were diluted in distilled water obtaining 12 concentrations, and MTT assay identified the concentrations, per group, displaying the highest cell viability (analysis of variance, p < 0.01). Selected concentrations were tested for NO expression using Griess reaction. Culture medium and lipopolysaccharide (LPS) were used as controls., Results: Analysis of variance and Tukey tests showed that all chelators displayed elevated NO concentrations compared with the negative control (p < 0.01). MTAD induced the lowest NO expression, followed by Tetraclean, EDTA, and Smear Clear. No difference was observed between MTAD and Tetraclean (p > 0.01), Tetraclean and EDTA (p > 0.01), and EDTA and Smear Clear (p > 0.01). LPS ranked similar to both EDTA and Smear Clear (p > 0.01)., Conclusion: The tested endodontic chelators displayed severe proinflammatory effects on murine-cultured macrophages. Citric acid-based solutions induce lower NO release than EDTA-based irrigants.

Copper ions are vital to human health, and mis-trafficking of them can result in many diseases including Wilson's, Menkes', and Alzheimer's diseases. Coherent anti-Stokes Raman scattering (CARS) microscopy can be used to observe changes in lipid phenotype in a noninvasive manner and is employed here to show that copper accumulation in hepatic cells results in rapid changes in lipid storage and lipid droplet density. The increase in lipid storage is dependent on the coordination environment of the copper to which the cells are exposed and changes in toxicity, lipid phenotype, and rate of copper accumulation upon treatment vary using different Cu species.

The purpose of this study was to compare the effect of 10 different endodontic irrigation and chelating treatments on dental pulp stem cell (DPSC) attachment to root canal surfaces. Thirty-eight extracted human nondiseased single-canal teeth were cleaned and shaped using ProTaper and ProFile rotary instrumentation (Tulsa Dentsply, Tulsa, OK). The irrigation treatments investigated were 6% sodium hypochlorite, 2% chlorhexidine gluconate, Aquatine Endodontic Cleanser, and Morinda citrifolia juice. The irrigation treatments were used in conjunction with EDTA or MTAD. The instrumented teeth were immediately placed in cell culture with confluent DPSCs for 1 week. The number of attached DPSCs appeared to be correlated with the cytotoxicity of the root canal irrigating solution (analysis of variance, p < 0.0001). The presence or absence of the smear layer had little influence on DPSC activity (chi-square, p > 0.05). The results suggest that biocompatible irrigants are needed to promote DPSC attachment to root canal dentin, which is essential to accomplish some regenerative endodontic therapies.

We have carried out a preclinical toxicological investigation (acute toxicity evaluation) of Mangascan (0.5 M solution of manganese(II) - EDTA complex) and Pentamang (0.5 M solution of manganese(II) - DTPA complex), a new paramagnetic contrast agents for MRI procedures. In 14 days after single intravenous introduction of Mangascan (10.0 ml/kg) or Pentamang (5.0 ml/kg) to rats, no any toxic influence of the studied agents was detected in the general condition, bone marrow, cardiovascular and central nervous systems, and liver and kidney functions of experimental animals. No pathological changes were observed in the functional activity and morphology of the internal organs and systems. The results showed that both Mangascan and Pentamang belong to the class of low toxicity substances.

Chromium poses a potential threat to coastal ecosystems. We used standard toxicity bioassays (semi-static, chronic) to evaluate EDTA as a chelating agent for reducing trivalent and hexavalent chromium toxicity on Petrolisthes laevigatus. Crab survival decreased linearly with increased chromium concentrations and dropped significantly beginning at 40 mg/L Cr (VI) and 80 mg/L Cr (III). No significant differences were observed with Cr (III) + EDTA as compared with untreated controls. Cr (VI) toxicity was greater than that of Cr (III), with low individual survival rates. The protective effect of EDTA in the medium increased crab survival by 41%-48%.

Phytoextraction is a promising technique to remediate heavy metals from contaminated wastewater. However, the interactions of multi-contaminants are not fully clear. This study employed cadmium, Triton X-100 (TX-100), and EDTA to investigate their interactions on phytotoxicity and Cd phytoextraction of Ipomoea aquatica (water spinach) in simulated wastewater. The Cd speciation was estimated by a chemical equilibrium model and MINEQL+. Statistic regression was applied to evaluate Cd speciation on Cd uptake in shoots and stems of I. aquatica. Results indicated that the root length was a more sensitive parameter than root weight and shoot weight. Root elongation was affected by Cd in the Cd-EDTA solution and TX-100 in the Cd-TX-100 solution. Both the root length and the root biomass were negatively correlated with the total soluble Cd ions. In contrast, Cd phytoextraction of I. aquatic was correlated with the aqueous Cd ions in the free and complex forms rather than in the chelating form. Additionally, the high Cd bioconcentration factors of I. aquatica (375-2227 l kg(-1) for roots, 45-144 l kg(-1) for shoots) imply that I. aquatica is a potential aquatic plant to remediate Cd-contaminated wastewater.

Ethylenediaminetetraacetic acid (EDTA) is widely used in food and other industries to sequester metal ions and to prevent their disadvantageous effects. The objective of the current study was to evaluate the protective effect of Panax ginseng extract standardized with ginsenoside Rg3 (ginsenoside Rg3 content was 3.6% w/w, i.e., 36 microg/mg P. ginseng extract) and garlic against EDTA-induced biochemical, genotoxic, and histological changes in rats. Forty male rats were divided into eight treatment groups and treated for 7 days as follows: the control group, the group treated with EDTA (20 mg/kg b.w) and the groups treated with P. ginseng extract (20 mg/kg b.w), garlic (5 mg/kg b.w), P. ginseng plus garlic alone or in combination with EDTA. In vivo bone marrow micronucleus test and random amplified polymorphism DNA-PCR (RAPD-PCR) method were performed to assess the antigenotoxic effect of both protective agents. The results indicated that EDTA administration caused a significant decrease in the serum biochemical parameters and antioxidant enzymes activity. The administration also increased lipid peroxidation and the incidence of micronucleated polychromatic erythrocytes (MnPCEs), caused appearance of some changes in polymorphism band patterns, and induced different histopathological lesions in the livers, kidneys, and testis. Treatment with P. ginseng, garlic alone or plus EDTA significantly improved all the tested parameters. Moreover, P. ginseng extract was found to be more effective than garlic in restoring the parameters that were altered by EDTA.

Phytoextraction, the use of plants to extract contaminants from soils and groundwater, is a promising approach for cleaning up soils contaminated with heavy metals. In order to enhance phytoextraction the use of chelating agents has been proposed. This study aims to assess whether ethylene diamine disuccinate (EDDS), a biodegradable chelator, can be used for enhanced phytoextraction purposed, as an alternative to ethylene diamine tetraacetate (EDTA). EDDS revealed a higher toxicity to tobacco (Nicotiana tabacum) in comparison to EDTA, but no toxicity to microorganisms. The uptake of Cu was increased by the addition of EDTA and EDDS, while no increase was observed in the uptake of Cd. Both chelating agents showed a very low root to shoot translocation capability and the translocation factor was lower than the one of the control. Heavy metals where significantly more phytoavailable than in the control, even after harvesting, resulting in a high heavy metal leaching possibility, probably owing to a low biodegradation rate of EDDS. New seedlings which were transplanted into the EDDS treated pots 7d after the phytoextraction experiment, showed signs of necrosis and chlorosis, which resulted in a significantly lower biomass in comparison to the control. The seedlings on the EDTA treated pots showed no toxicity signs. Contrary to previous opinions the results of this study revealed the chelating agents EDTA and EDDS as unsuitable for enhanced phytoextraction using tobacco.

Aim: To assess the ex vivo cytotoxicity of EDTA and citric acid solutions on macrophages., Methodology: The cytotoxicity of 17% EDTA and 15% citric acid was evaluated on murine macrophage cultures using MTT-Tetrazolium method [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide]. A total of 5 x 10(5) cells were plated in medium culture with 17% EDTA or 15% citric acid. Fresh medium was used as a control. Toxicity values were analysed statistically by anova and Tukey's test (P<0.05) at short (0, 6, 12, 24 h) and medium periods (1, 3, 5, 7 days), using ELISA absorbance., Results: On the short term, both EDTA (0.253 nm) and citric acid (0.260 nm) exhibited cytotoxic effects on macrophage cultures (P<0.05). On the medium term, statistical differences were observed (P<0.05) between the groups. EDTA (0.158 nm) and citric acid (0.219 nm) were cytotoxic when compared with the control group; EDTA-reduced macrophage viability significantly more than citric acid (P<0.05)., Conclusions: Both EDTA and citric acid had effects on macrophages cells ex vivo, but citric acid was less toxic in periods from 1 to 7 days of use.

A chemical absorption-biological reduction integrated process can be used to remove nitrogen oxides (NOx) from flue gas. In such a process, nitric oxide (NO) can be effectively absorbed by the ferrous chelate of ethylenediaminetetraacetate (Fe(II)EDTA) to form Fe(II)EDTA-NO, which can be biologically regenerated by denitrifying bacteria. However, in the course of these processes, part of the Fe(II)EDTA is also oxidized to Fe(III)EDTA. The reduction of Fe(III)EDTA to Fe(II)EDTA depends on the activity of iron-reducing bacteria in the system. Therefore, the effectiveness of the system relies on how to effectively bioreduce Fe(III)EDTA and Fe(II)EDTA-NO in the system. In this paper, a strain identified as Escherichia coli FR-2 (iron-reducing bacterium) was used to investigate the reduction rate of Fe(III)EDTA. The experimental results indicate that Fe(III)EDTA-NO and Fe(II)EDTA in the system can inhibit both the FR-2 cell growth and thus affect the Fe(III)EDTA reduction. The FR-2 cell growth rate and Fe(III)EDTA reduction rate decreased with increasing Fe(II)EDTA-NO and Fe(II)EDTA concentration in the solution. When the concentration of Fe(II)EDTA-NO reached 3.7 mM, the FR-2 cell growth almost stopped. A mathematical model was developed to explain the cell growth and inhibition kinetics. The predicted results are close to the experimental data and provide a preliminary evaluation of the kinetics of the biologically mediated reactions necessary to regenerate the spent scrubber solution.

Oxidative renal tubular injuries and carcinogenesis induced by Fe(III)-nitrilotriacetate (NTA) and Fe(III)-ethylenediamine-N,N'-diacetate (EDDA) have been reported in rodent kidneys, but the identity of iron coordination structure essential for renal carcinogenesis, remains to be clarified. We compared renal tubular injuries caused by various low molecular weight aminocarboxylate type chelators with injuries due to NTA and EDDA. We found that Fe(III)-iminodiacetate (IDA), a novel iron-chelator, induced acute tubular injuries and lipid peroxidation to the same extent. We also prepared Fe(III)-IDA solutions at different pHs, and studied resultant oxidative injuries and physicochemical properties. The use of Fe(III)-IDA at pH 5.2, 6.2, and 7.2 resulted in renal tubular necrosis and apoptotic cell death, but neither tubular necrosis nor apoptosis was observed at pH 8.2. Spectrophotometric data suggested that Fe(III)-IDA had the same dimer structure from pH 6.2 to 7.2 as Fe(III)-NTA; but at a higher pH, iron polymerized and formed clusters. Fe(III)-IDA was crystallized, and this was confirmed by X-ray analysis and magnetic susceptibility measurements. These data indicated that Fe(III)-IDA possessed a linear mu-oxo bridged dinuclear iron (III) around neutral pH.

Copper bioavailability in the tissues of goldfish and antioxidant defenses in the liver of fish were investigated in vivo following 40 days of exposure to different species of copper solutions at different concentrations. Copper seemed to be more concentrated in the gill than in the liver after Cu(2+) and copper-ethylenediaminetetraacetate (Cu-EDTA) exposure. The addition of EDTA markedly affected copper adsorption in the gill but had no significant effects in the liver. We also found that in the fish exposed to the concentration of Cu(2+) below the Chinese national fishery water quality standard of 0.01 mg/L, superoxide dismutase (SOD) and glutathione S-transferase (GST) activities in liver were stimulated and catalase (CAT) and Se-dependent glutathione peroxidase (Se-GPx) activities were inhibited after 40 days of exposure. Compared to copper exposure, the addition of EDTA did not affect SOD and GST significantly. However, CAT and GPx activity with Cu(2+) exposure were significantly different from those with Cu-EDTA exposure.

To assess the genotoxicity of 14 chemical agents used as locally applied agents in dental practice, the ability of these agents to elicit chromosome aberrations was examined using Syrian hamster embryo (SHE) cells. Chromosome aberrations in SHE cells were induced by treatment with three of eight chemical agents used as endodontic medicaments, i.e. ethylenediaminetetraacetic acid (EDTA), formocresol (a mixture of formalin and tricresol), and sodium arsenite. The other five chemical agents, i.e. chloramphenicol, p-chlorophenol, p-phenolsulfonic acid, sodium hypochlorite, and tetracycline hydrochloride exhibited a negative response for chromosome aberrations. Assessment of three dyes used for disclosing dental plaque showed chromosome aberrations induced by basic fuchsin but not by acid fuchsin and erythrosine B. Three local anesthetics, lidocaine hydrochloride, prilocaine hydrochloride, and procaine hydrochloride, were negative for chromosome aberrations. Among the ten chemical agents that exhibited a negative response in the assay, p-chlorophenol, sodium hypochlorite, and erythrosine B induced chromosome aberrations in SHE cells when treated in the presence of exogenous metabolic activation. The percentages of cells with polyploidy or endoreduplication were enhanced by formocresol, sodium arsenite, p-chlorophenol, p-phenolsulfonic acid, sodium hypochlorite, erythrosine B, prilocaine hydrochloride, and procaine hydrochloride in the absence or presence of exogenous metabolic activation. Our results indicate that the chemical agents that had a positive response in the present study are potentially genotoxic to mammalian cells.

Phenoloxidase (PO) from hemolymph of Charybdis japonica was purified by gel-filtration and ion-exchange chromatography, and characterized in terms of its molecular mass and enzymatic properties by using L-dihydroxyphenylalanine (L-DOPA) as the specific substrate. It was found that prophenoloxidase (proPO), isolated as a monomeric protein, had a molecular mass of 69.5 kDa, and a 64.5 kDa PO molecule was often contained in preparations. The PO activity showed optimal pH of 6.0, optimal temperature of 40 degrees C, and an apparent Km value of 3.41 on L-DOPA, and 7.97 on catechol. PO activity was extremely sensitive to sodium sulfite and 1-phenyl-2-thiourea, and very sensitive to thiourea and benzoic acid. Based on its inhibition characteristics and the substrate affinity, this PO was classified as a kind of o-diphenoloxidase. The PO activity was also strongly inhibited by Zn(2+), Mg(2+), ethylenediaminetetraacetic acid (EDTA) and diethyldithiocarbamate (DETC). The results with EDTA, DETC, and some metal ions, combined with the perfect recovery effect of Cu(2+) on DETC-inhibited PO activity, indicate that Charybdis PO is most probably a copper-containing metalloenzyme.