The improved Allium/Vicia root tip micronucleus assay for clastogenicity of environmental pollutants

Evaluation of herbicides action on plant bioindicators by genetic biomarkers: a review

The use of pesticides has increased worldwide, owing to the demand for products of good quality and to satisfy a growing population. Herbicides represent almost half of the total amount of pesticides used. Although important to the reduction of costs and an increase of productivity, their indiscriminate use, as well as that of the other pesticides, is a global environmental problem, since they affect the living organisms. To evaluate the damage caused by herbicides to the environment, different organisms have been used as bioindicators, especially higher plants, due to several advantages. This is a literature review on herbicidal actions in plant bioindicators, as assessed by genetic biomarkers. Also, the present manuscript aimed to characterize the main organisms (Allium cepa, Vicia faba and Tradescantia spp.) and the most used biomarkers (mitotic index, chromosome aberrations, micronuclei, sister chromatid exchange and mutations). We concluded that herbicides induce cytotoxicity and genotoxicity in the assessed bioindicators. The data corroborate the existing warnings of the risks that the indiscriminate and increasing use of pesticides poses to the environment and its biodiversity.

Chemical and toxicological characterisation of anticancer drugs in hospital and municipal wastewaters from Slovenia and Spain

Anticancer drugs are continuously released into hospital and urban wastewaters, where they, most commonly, undergo conventional treatment in wastewater treatment plants (WWTPs). Wastewaters contain complex mixtures of substances including parent compounds, their metabolites and transformation products (TPs). In this study, samples of hospital effluents and WWTP influents and effluents from Slovenia and Spain were analyzed for twenty-two selected anticancer drugs, their metabolites and transformation products. Acute and chronic toxicity tests were performed on the crustacean Ceriodaphnia dubia, genotoxicity was determined with Tradescantia and Allium cepa micronucleus (MN) assays and in vitro comet assay in zebrafish (Danio rerio) liver cell line (ZFL cells). Sixty of the two hundred-twenty determinations revealed detectable levels of anticancer drug residues. Among the targeted compounds, platinum based were most frequently detected (90%). Furthermore, erlotinib was detected in 80%, cyclophosphamide and tamoxifen in 70% and methotrexate in 60% of the samples. Seven of ten samples were toxic to C. dubia after acute exposure, whereas after chronic exposure all samples reduced reproduction of C. dubia at high sample dilutions. Allium cepa proved insensitive to the potential genotoxicity of the tested samples, while in Tradescantia increased MN frequencies were induced by a hospital effluent and WWTP influents. In ZFL comet assay all but one sample induced a significant increase of DNA strand breaks. Correlations of chemotherapeutics or their TPs were detected for all bioassays except for Allium cepa genotoxicity test, however for each test the highest correlations were found for different substances indicating differential sensitivities of the test organisms.

Contaminant bioavailability in soil and phytotoxicity/genotoxicity tests in Vicia faba L.: a case study of boron contamination

In this work, the model plant for genotoxicity studies Vicia faba L. was used to investigate the relation between Boron (B) content and bioavailability in soil and plant genotoxic/phytotoxic response. A total of nine soil samples were investigated: two soil samples were collected from a B-polluted industrial area in Cecina (Tuscany, Italy), the other samples were obtained by spiking control soil (from a not polluted area of the basin) with seven increased doses of B, from about 20 to 100 mg B kg^-1. As expected, B availability, evaluated by chemical extraction, was higher (twofold) in spiked soils when compared with collected polluted soils with the same B total content. To analyze the phytotoxic effects of B, seed germination, root elongation, biomass production, and B accumulation in plant tissues were considered in V. faba plants grown in the various soils. Moreover, the cytotoxic/genotoxic effects of B were investigated in root meristems by mitotic index (MI) and micronuclei frequency (MCN) analysis. The results highlighted that V. faba was a B-sensitive plant and the appearance of phytotoxic effects, which altered plant growth parameters, were linearly correlated to the bioavailable B concentration in soils. Concerning the occurrence of cytotoxic/genotoxic effects induced by B, no linear correlation was observed even if MCN frequency was logarithmic correlated with the concentration of B bioavailable in soils.

Cytotoxicity of Spent Pot Liner on Allium cepa root tip cells: A comparative analysis in meristematic cell type on toxicity bioassays

Spent Pot Liner (SPL) is a waste generated during the production of aluminum. It is comprised of a mixture of substances most of which, like cyanide, aluminum and fluoride, are toxic. Previous studies indicate the highly toxic nature of SPL. However studies using cells of the differentiation/elongation zone of the root meristem (referred as M2 cells in this study) after a proper recovery period in water were never considered. Using these cells could be useful to further understanding the toxicity mechanisms of SPL. A comparative approach between the effects on M2 cells and meristematic cells of the proximal meristem zone (referred as M1 cells in this study) could lead to understanding how DNA damage caused by SPL behaves on successive generations of cells. Allium cepa cells were exposed to 4 different concentrations of SPL (2.5, 5, 7.5 and 10gL(-1)) mixed with soil and diluted in a CaCl2 0.01M to simulate the ionic forces naturally encountered on the environment. A solution containing only soil diluted on CaCl2 0.01M was used as control. M1 and M2 cells were evaluated separately, taking into account four different parameters: (1) mitotic alterations (MA); (2) presence of condensed nuclei (CN); (3) mitotic index (MI); (4) presence of micronucleus (MCN). Significant differences were observed between M1 and M2 roots tip cells for these four parameters accessed. M1 cells was more prompt to reveal citogenotoxicity through the higher frequency of MA observed. Meanwhile, for M2 cells higher frequencies of MCN and CN was noticed, followed by a reduction of MI. Also, it was possible to detect significant differences between the tested treatments and the control on every case. These results indicate SPL toxic effects carries on to future cells generations. This emphasizes the need to properly manage this waste. Joint evaluation of cells from both M1 and M2 regions was proven valuable for the evaluation of a series of parameters on all toxicity tests.

Pure anatase and rutile + anatase nanoparticles differently affect wheat seedlings

TiO2-nanoparticles (TiO2-NPs) are increasingly released to the environment. The present work investigates the cytotoxicity, genotoxicity and uptake of TiO2-NPs in Triticum aestivum. Wheat seeds were exposed to 5-150 mg L(-1) of anatase (ana) or rutile + anatase (rut + ana) TiO2-NPs for 5 d. After exposure, germination and growth rates were determined. Cytotoxic effects were evaluated by changes in the cell cycle dynamics and in the membrane integrity. Genotoxicity was assessed by ploidy mutations and DNA-damage, and by mitotic abnormalities. NP uptake was analyzed by Energy Dispersive X-ray Spectroscopy (EDS). Ana-TiO2 revealed higher toxicity regarding the rate of germination, but no negative effects were detected concerning growth. Although roots and shoots showed no EDS-detectable levels of Ti, despite cyto- and genotoxicity was observed in ana and rut + ana-NPs exposed roots. Cell cycle profile was formulation dependent with rut + ana presenting a higher capability to induce a cell cycle arrest at G0/G1. Both formulations induced genotoxic effects by increasing micronucleated cells: for rut + ana a dose-dependent response is evident and seems to be more genotoxic than ana at lower concentrations. Rut + ana also increased membrane permeability. The observed higher cytotoxicity of rut + ana may be explained by the higher photoactivity of this mixture. Overall, these data indicate that during germination, TiO2-NPs induce severe cyto/genotoxic effects, which are dependent on the TiO2-NP formulation.

Cytotoxic, genotoxic and mutagenic effects of sewage sludge on Allium cepa

The objective of this study was to ascertain the cytotoxic, genotoxic and mutagenic potential of sewage sludge using Allium cepa bioassay. Solubilized and crude sludge from two sewage treatment stations (STSs), herein named JM and M, were tested. In addition, sanitized, crude and solubilized sludge were also analyzed from STS M. The treatments showed positive response to phytotoxicity, cytotoxicity, genotoxicity and/or mutagenicity. Despite negative results for MN F1 (micronuclei counted in F1 root cells, derived from meristematic cells), the monitoring of genotoxic and mutagenic activities of sewage sludge are recommended because in agricultural areas this residue is applied in large scale and continuously. Based on our results we advise caution in the use of sewage sludge in agricultural soils.

Hexavalent chromium-induced differential disruption of cortical microtubules in some Fabaceae species is correlated with acetylation of α-tubulin

The effects of hexavalent chromium [Cr(VI)] on the cortical microtubules (MTs) of five species of the Fabaceae family (Vicia faba, Pisum sativum, Vigna sinensis, Vigna angularis, and Medicago sativa) were investigated by confocal laser scanning microscopy after immunolocalization of total tubulin with conventional immunofluorescence techniques and of acetylated α-tubulin with the specific 6-11B-1 monoclonal antibody. Moreover, total α-tubulin and acetylated α-tubulin were quantified by Western immunoblotting and scanning densitometry. Results showed the universality of Cr(VI) detrimental effects to cortical MTs, which proved to be a sensitive and reliable subcellular marker for monitoring Cr(VI) toxicity in plant cells. However, a species-specific response was recorded, and a correlation of MT disturbance with the acetylation status of α-tubulin was demonstrated. In V. faba, MTs were depolymerized at the gain of cytoplasmic tubulin background and displayed low α-tubulin acetylation, while in P. sativum, V. sinensis, V. angularis, and M. sativa, MTs became bundled and changed orientation from perpendicular to oblique or longitudinal. Bundled MTs were highly acetylated as determined by both immunofluorescence and Western immunoblotting. Tubulin acetylation in P. sativum and M. sativa preceded MT bundling; in V. sinensis it followed MT derangement, while in V. angularis the two phenomena coincided. Total α-tubulin remained constant in all treatments. Should acetylation be an indicator of MT stabilization, it is deduced that bundled MTs became stabilized, lost their dynamic properties, and were rendered inactive. Results of this report allow the conclusion that Cr(VI) toxicity disrupts MTs and deranges the MT-mediated functions either by depolymerizing or stabilizing them.

Genotoxic and mutagenic effects of sewage sludge on higher plants

Sewage treatment yields sludge, which is often used as a soil amendment in agriculture and crop production. Although the sludge contains elevated concentrations of macro and micronutrients, high levels of inorganic and organic compounds with genotoxic and mutagenic properties are present in sludge. Application of sludge in agriculture is a pathway for direct contact of crops to toxic chemicals. The objective of this study was to compile information related to the genotoxic and mutagenic effects of sewage sludge in different plant species. In addition, data are presented on toxicological effects in animals fed with plants grown in soils supplemented with sewage sludge. Despite the benefits of using sewage sludge as organic fertilizer, the data showcased in this review suggest that this residue can induce genetic damage in plants. This review alerts potential risks to health outcomes after the intake of food cultivated in sewage sludge-amended soils.

Induction of mitotic and chromosomal abnormalities on Allium cepa cells by pesticides imidacloprid and sulfentrazone and the mixture of them

To evaluate the cytotoxic and genotoxic effects of low concentrations of pesticides in non-target organisms, seeds of Allium cepa were exposed for 24 h to the imidacloprid insecticide, sulfentrazone herbicide and to the mixture of them, followed by recovery periods of 48 and 72 h. Imidacloprid results indicated an indirect genotoxic effect by inducing different types of chromosome aberration (CA), mainly bridges and chromosomal adherences. Cells with micronucleus (MN) were not significant in the analyzed meristems. Moreover, the 72-h recovery tests indicated that the two lower concentrations of the insecticide (0.036 and 0.36 g L(-1)) had their genotoxic effects minimized after discontinuation of treatment, differently to the observed for the field concentration (3.6 g L(-1)). Sulfentrazone herbicide at field concentration (6 g L(-1)) caused cytotoxic effects by inducing nuclear fragmentation and inhibition of cell division. The other concentrations (0.06, 0.6 and 1.2 g L(-1)) indicated genotoxic effects for this herbicide. The concentration of 0.06 g L(-1) induced persistent effects that could be visualized both by the induction of CA in the recovery times as by the presence of MN in meristematic and F1 cells. The induction of MN by this lowest concentration was associated with the great amount of breakage, losses and chromosomal bridges. The mixture of pesticides induced genotoxic and cytotoxic effects, by reducing the MI of the cells. The chromosomal damage induced by the mixture of pesticides was not persistent to the cells, since such damage was minimized 72 h after the interruption of the exposure.

The assessment of WWTP performance: Towards a jigsaw puzzle evaluation?

A chemical and bio-analytical protocol is proposed as a holistic monitoring framework for the assessment of WWTPs (Wastewater Treatment Plants) performance. This combination of tests consists of: i) an analysis of emerging contaminants, to be added to the established physico-chemical parameters in order to understand the causes of (new) pollution phenomena and ii) some of the bio-analytical tools most widely applied in the field of wastewater research, which provide information on groups of chemicals with a common mode of toxic action (baseline toxicity, estrogenicity and mutagenicity/genotoxicity, selected as the most representative for human health). The negative effects of the discharge can thus be highlighted directly and used to assess the global environmental impact of WWTPs. As a validation, this multi-tiered approach was applied to a full-scale WWTP (150,000 p.e.), where different measurements were carried out: EDCs (Endocrine Disrupting Compounds) detection; algal growth inhibition, bioluminescence inhibition and acute toxicity test (for baseline toxicity); an E-Screen-like assay (for estrogenic activity); Ames, Allium cepa and Comet tests (for mutagenic/genotoxic activity). As a result, the WWTP showed good performance for all these issues, displaying its ability to enhance effluent quality, except for residual mutagenic behaviour, probably due to the by-products generated by the tertiary ozonation.

Efficacy of Allium cepa test system for screening cytotoxicity and genotoxicity of industrial effluents originated from different industrial activities

Efficacy of Allium cepa test system for screening cytotoxicity and genotoxicity of treated effluents originated from four types of industrial activities (two textile industries, three rubber based industries, two common treatment plants of industrial zones, and two water treatment plants) was assessed. Physico-chemical parameters including the heavy metal/metalloid levels of the effluents varied depending on the industry profile, but most of the measured parameters in the effluents were within the specified tolerance limits of Sri Lankan environmental regulations for discharge of industrial effluents into inland surface waters. In the A. cepa test system, the undiluted effluents induced statistically significant root growth retardation, mitosis depression, and chromosomal aberrations in root meristematic cells in most cases in comparison to the dilution water and upstream water signifying effluent induced cytotoxicity and genotoxicity. Ethyl methane sulphonate (a mutagen, positive control) and all the effluents under 1:8 dilution significantly induced total chromosomal aberrations in root meristematic cells in comparison to the dilution water and upstream water indicating inadequacy of expected 1:8 dilutions in the receiving waters for curtailing genotoxic impacts. The results support the use of a practically feasible A. cepa test system for rapid screening of cytotoxicity and genotoxicity of diverse industrial effluents discharging into inland surface waters.

A Biotechnological Approach for the Development of New Antifungal Compounds to Protect the Environment and the Human Health

Background.

In the Po Valley aflatoxins play a relevant role: the local food economy is heavily based on cereal cultivations for animal feed and human nutrition. Aims of this project are the identification of new compounds that inhibit Aspergillus proliferation, the development of new inhibitors of aflatoxins production, and the set-up a practical screening procedure to identify the most effective and safe compounds.

Design and Methods.

New compounds will be synthetized with natural origin molecules as ligands and endogenous metal ions to increase their bioavailability for the fungi as metal complexes. A biotechnological high-throughput screening will be set up to identify efficiently the most powerful substances. The newly synthesized compounds with effective antifungal activities, will be evaluated with battery of tests with different end-points to assess the toxic potential risk for environmental and human health.

Expected impact of the study for public health.

The fundamental step in the project will be the synthesis of new compounds and the study of their capability to inhibit aflatoxin biosynthesis. A new, simple, inexpensive and high-throughput method to screen the anti-fungine and anti-mycotoxin activity of the new synthesised compounds will be applied. The evaluation of possible risks for humans due to toxic and genotoxic activities of the molecules will be made with a new approach using different types of cells (bacteria, plants and human cells).

Potential cytotoxic effect of Anilofos by using Allium cepa assay

Cytogenetic effects of Anilofos which was widely used in agriculture, was evaluated in Allium cepa root meristematic cells. In the Allium root growth inhibition test EC50 value was determined 50 ppm and 1/2× EC50 (25 ppm), EC50 (50 ppm) and 2 × EC50 (100 ppm) concentrations of Anilofos were applied to onion roots. A negative and positive control were used in the experiment in parallel. According to results mitotic index decreased with increasing the Anilofos concentrations in all application groups and each exposure time, while disturbed anaphase-telophase, choromosome laggard(s), stickiness and anaphase bridge(s) were observed. In anaphase-telophase cells, c-metaphase, disturbed nucleus and binuclear cells were observed in other anomalies. The results were also analyzed statistically by using Dunnett t test (2-tailed) and all concentrations of Anilofos were found significant.

Analysis of the genotoxic potential of low concentrations of Malathion on the Allium cepa cells and rat hepatoma tissue culture

Based on the concentration of Malathion used in the field, we evaluated the genotoxic potential of low concentrations of this insecticide on meristematic and F1 cells of Allium cepa and on rat hepatoma tissue culture (HTC cells). In the A. cepa, chromosomal aberrations (CAs), micronuclei (MN), and mitotic index (MI) were evaluated by exposing the cells at 1.5, 0.75, 0.37, and 0.18mg/mL of Malathion for 24 and 48hr of exposure and 48hr of recovery time. The results showed that all concentrations were genotoxic to A. cepa cells. However, the analysis of the MI has showed non-relevant effects. Chromosomal bridges were the CA more frequently induced, indicating the clastogenic action of Malathion. After the recovery period, the higher concentrations continued to induce genotoxic effects, unlike the observed for the lowest concentrations tested. In HTC cells, the genotoxicity of Malathion was evaluated by the MN test and the comet assay by exposing the cells at 0.09, 0.009, and 0.0009mg/5mL culture medium, for 24hr of exposure. In the comet assay, all the concentrations induced genotoxicity in the HTC cells. In the MN test, no significant induction of MN was observed. The genotoxicity induced by the low concentrations of Malathion presented in this work highlights the importance of studying the effects of low concentrations of this pesticide and demonstrates the efficiency of these two test systems for the detection of genetic damage promoted by Malathion.

Analysis of genetic and epigenetic effects of maize seeds in response to heavy metal (Zn) stress

Conditions of environmental stress are known to lead genetic and epigenetic variability in plants. DNA methylation is one of the important epigenetic mechanisms and plays a critical role in epigenetic control of gene expression. Thus, the aim of the study was to investigate the alteration of genome methylation induced by zinc stress by using coupled restriction enzyme digestion-random amplification (CRED-RA) technique in maize (Zea mays L.) seedlings. In addition, to determine the effect of zinc on mitotic activity and phytohormone level, high-pressure liquid chromatography (HPLC) and mitotic index analysis were utilized. According to the results, mitotic index decreased in all concentrations of zinc except for 5 mM dose and chromosome aberrations such as c-mitosis, stickiness, and anaphase bridges were determined. It was also observed that increasing concentrations of zinc caused an increase in methylation patterns and decrease in gibberellic acid (GA), zeatin (ZA), and indole acetic acid (IAA) levels in contrast to abscisic acid (ABA) level. Especially increasing of ABA levels under zinc stress may be a part of the defense system against heavy metal accumulation in plants.

Aberration of mitosis by hexavalent chromium in some Fabaceae members is mediated by species-specific microtubule disruption

Because the detrimental effects of chromium (Cr) to higher plants have been poorly investigated, the present study was undertaken to verify the toxic attributes of hexavalent chromium [Cr(VI)] to plant mitotic microtubules (MTs), to determine any differential disruption of MTs during mitosis of taxonomically related species and to clarify the relationship between the visualized chromosomal aberrations and the Cr(VI)-induced MT disturbance. For this purpose, 5-day-old uniform seedlings of Vicia faba, Pisum sativum, Vigna sinensis and Vigna angularis, all belonging to the Fabaceae family, were exposed to 250 μM Cr(VI) supplied as potassium dichromate (K₂Cr₂O₇) for 24, 72 and 120 h and others in distilled water serving as controls. Root tip samples were processed for tubulin immunolabelling (for MT visualization) and DNA fluorescent staining (for chromosomal visualization). Microscopic preparations of cell squashes were then examined and photographed by confocal laser scanning microscopy (CLSM). Cr(VI) halted seedling growth turning roots brown and necrotic. Severe chromosomal abnormalities and differential disturbance of the corresponding MT arrays were found in all mitotic phases. In particular, in V. faba MTs were primarily depolymerized and replaced by atypical tubulin conformations, whereas in P. sativum, V. sinensis and V. angularis they became bundled in a time-dependent manner. In P. sativum, the effects were milder compared to those of the other species, but in all cases MT disturbance adversely affected the proper aggregation of chromosomes on the metaphase plate, their segregation at anaphase and organization of the new nuclei at telophase. Cr(VI) is very toxic to seedling growth. The particular effect depends on the exact stage the cell is found at the time of Cr(VI) entrance and is species-specific. Mitotic MT arrays are differentially deranged by Cr(VI) in the different species examined, even if they are taxonomically related, while their disturbance underlies chromosomal abnormalities. Results furthermore support the view that MTs may constitute a reliable, sensitive and universal subcellular marker for monitoring heavy metal toxicity.

Too much is bad--an appraisal of phytotoxicity of elevated plant-beneficial heavy metal ions

Heavy metal ions such as cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), and zinc (Zn) are considered essential/beneficial for optimal plant growth, development, and productivity. However, these ions readily impact functions of many enzymes and proteins, halt metabolism, and exhibit phytotoxicity at supra-optimum supply. Nevertheless, the concentrations of these heavy metal ions are increasing in agricultural soils worldwide via both natural and anthropogenic sources that need immediate attention. Considering recent breakthroughs on Co, Cu, Fe, Mn, Mo, Ni, and Zn in soil-plant system, the present paper: (a) overviews the status in soils and their uptake, transport, and significance in plants; (b) critically discusses their elevated level-mediated toxicity to both plant growth/development and cell/genome; (c) briefly cross talks on the significance of potential interactions between previous plant-beneficial heavy metal ions in plants; and (d) highlights so far unexplored aspects in the current context.

Mutagenic and genotoxic effects of Guelma's urban wastewater, Algeria

Assessment of water pollution and its effect upon river biotic communities and human health is indispensable to develop control and management strategies. In this study, the mutagenicity and genotoxicity of urban wastewater of the city of Guelma in Algeria were examined between April 2012 and April 2013. For this, two biological tests, namely Amesand chromosomal aberrations (CA) test in Allium cepa root tips were employed on the samples collected from five different sampling stages (S1-S5). In Ames test, two strains of Salmonella typhimurium TA98 and TA100 with or without metabolic activation (S9-mix) were used. All water samples were found to be mutagenic to S. typhimurium TA98 with or without S9-mix. A significant decrease in mitotic index (MI) was observed with a decrease in the percentage of cells in the prophase and an increase in the telophase. Main aberrations observed were anaphase bridges, disturbed anaphase-telophase cells, vagrants and stickiness in anaphase-telophase cells. All treatments of wastewater in April 2012, at S5 in July 2012, at S1 and S5 in November 2012, at S5 in February 2013, and at S1 in April 2013 induced CA when compared to the negative control. Some physicochemical parameters and heavy metals (Cd, Pb, and Cu) were also recorded in the samples examined.

Soil genotoxicity assessment--results of an interlaboratory study on the Vicia micronucleus assay in the context of ISO standardization

The Vicia micronucleus assay was standardized in an international protocol, ISO 29200, "Assessment of genotoxic effects on higher plants-Vicia faba micronucleus test," for soil or soil materials (e.g., compost, sludge, sediment, waste, and fertilizing materials). The aim of this interlaboratory study on the Vicia micronucleus assay was to investigate the robustness of this in vivo assay in terms of its applicability in different countries where each participant were asked to use their own seeds and reference soil, in agreement with the ISO 29200 standard. The ISO 29200 standard protocol was adopted for this study, and seven laboratories from three countries (France, Italy, and Brazil) participated in the study. Negative and positive controls were correctly evaluated by 100 % of the participants. In the solid-phase test, the micronucleus frequency (number of micronuclei/1,000 cells) varied from 0.0 to 1.8 for the negative control (i.e., Hoagland's solution) and from 5.8 to 85.7 for the positive control (i.e., maleic hydrazide), while these values varied from 0.0 to 1.7 for the negative control and from 14.3 to 97.7 for the positive control in the case of liquid-phase test. The variability in the data obtained does not adversely affect the robustness of the protocol assessed, on the condition that the methodology described in the standard ISO 29200 is strictly respected. Thus, the Vicia micronucleus test (ISO 29200) is appropriate for complementing prokaryotic or in vitro tests cited in legislation related to risk assessment of genotoxicity potential.

Do cancer cells in human and meristematic cells in plant exhibit similar responses toward plant extracts with cytotoxic activities?

We examined the effect of water extracts of Persea americana fruit, and of the leaves of Tabernamontana divericata, Nerium oleander and Annona cherimolia (positive control) on Vicia faba root cells. We had confirmed in our previously published data the cytotoxicity of these plant extracts on four human cancer cell lines: liver (HepG-2), lung (A549), colon (HT-29) and breast (MCF-7). Vicia faba roots were soaked in plant extracts at dilutions of 100, 1,250, 2,500, 5,000, 10,000, 20,000 ppm for 4 and 24 h. All treatments resulted in a significant reduction in the mitotic index in a dose dependant manner. Root cells treated with T. divericata, N. oleander and A. cherimolia exhibited a decrease in prophase cell percentage, increase in micronuclei and chromosomal abnormalities as concentration increased. The P. americana treatment showed the highest cytotoxic effect on cancer cells, prophase cell percentage increased linearly with the applied concentration and no micronuclei were detected. This study shows that root tip assay of beans can be used in initial screening for new plant extracts to validate their use as candidates for containing active cytotoxic agents against malignant cells. This will greatly help in exploring new plant extracts as drugs for cancer treatment.

Cytokinesis block micronucleus assay in field plants for monitoring radiation-induced genotoxicity of the environment

Effective biomonitoring for detection of radiation-induced genotoxicity of contaminants in natural environments involves testing of field plants for cytogenetic changes. To increase the efficiency and precision of cytogenetic analyses of field plants that have naturally high individual variability, an improved micronucleus assay is proposed that employs a cytokinesis block technique similar to the lymphocyte test system used in mammals. In seed embryonic meristems of the Japanese cedar, application of a methylxanthine derivative, 3-isobutyl-1-methylxanthine (IBMX), was found to be effective in inhibiting cytokinesis to make once-divided cells easily recognizable by their binucleate appearance. In the meristem of IBMX-treated seminal roots from X-ray-irradiated seeds, variation in micronucleus frequency in the binucleate cell population was reduced compared to that in the total cell population. The highest efficiency of measurement of micronucleus frequencies was obtained in the root meristems where 0.2- to 1.5-mm-long seminal roots were incubated with IBMX for 24 h. This result indicated that this root elongation stage corresponded to the first divisions of the root meristematic cells, and was therefore suitable for obtaining reliable estimations of accumulated genetic damage in the seeds. This cytokinesis block assay applied specifically at the root elongation stage was then used to examine dose-response relationships in Japanese cedar seeds irradiated either acutely with X-rays or chronically with γ-rays. The resulting dose-response curve for the acute X-ray irradiation was fitted onto a linear-quadratic regression curve, whereas the dose-response curve for the chronic γ-irradiation matched a linear regression line better. Both dose-response curves were consistent with the target theory of classical radiation biology. The good agreement of the micronucleus data to a simple dose-response model indicates the proposed accuracy of the cytokinesis block micronucleus assay for plant monitoring.

Acute toxic and genotoxic activities of widely used cytostatic drugs in higher plants: Possible impact on the environment

Cytostatic drugs are highly toxic pharmaceuticals and it was repeatedly postulated that they may cause adverse effects in ecosystems. The acute toxic and genotoxic properties of these drugs have not been adequately investigated in higher plants so far; therefore, we studied the most widely used drugs (5-flurouracil, 5FU; etoposide, Et; cisplatin, CisPt; carboplatin, CaPt; vincristine sulfate, VinS and cyclophosphamide monohydrate, CP) in micronucleus (MN) assays with meiotic pollen tetrad cells of Tradescantia and with root cells from Allium cepa. MNi are formed as a consequence of chromosome breaks and aneuploidy. We monitored also the acute toxic properties of the drugs, i.e. inhibition of cell division (mitotic indices and retardation of root growth) in the latter species. All compounds caused in both indicator plants genotoxic effects. The order of genotoxic potencies expressed as NOELs in µM was CisPt (0.1)≥ Et (0.5)>CP (1.0)>CaPt (10)>5FU (30)>VinS (100) in Tradescantia. A similar order was seen in Allium MN but Et was less active (5.0µM). Four compounds caused alterations of the mitotic indices under the present conditions namely CisPt (0.5), Et (10.0), 5FU (10.0) and VinS (100). Inhibition of root growth decreased in the order CisPt (0.5)>Et (1.0)≥VinS (1.0)>5FU (5.0)>CaPt (33.0)>CP (>1000). Comparisons of the NOELs with the predicted environmental concentrations (PEC) show that the latter values are at least 5 orders of magnitude lower and indicate that it is unlikely that their release in the environment may cause adverse effects in higher plants. However, it is notable that the levels of both platinum compounds and of 5FU in hospital effluents may reach levels which may induce damage of the genetic material.

Evaluation of an aerobic treatment for olive mill wastewater detoxification

Olive mill wastewater (OMWW) is a by-product of the olive oil extraction industry. Its dumping creates severe environmental problems in the Mediterranean countries. The phytoxicity of OMWW is due to the phenolic substances and is evaluated through a genotoxicity method. An aerobic treatment of OMWW was conducted during 45 days. Different concentrations of raw and treated OMWW were tested using the Vicia faba micronuclei test. Results showed that raw OMWW induced significant micronuclei formation at 10% of OMWW dilution. At 20% of dilution, no mitosis was recorded. The 45 days aerobic treatment OMWW showed an important decrease in the genotoxicity and also in the toxicity that was observed at 10% and 20% OMWW dilution. This could be correlated with the biodegradation of 76% of the total phenols. Indeed, qualitative analysis by high performance liquid chromatography shows the disappearance of the majority of phenolic compounds after 45 days of treatment. This study was completed by an agricultural test with V. faba plant. Data showed significant growth yield of 36.3% and 29.9% after being irrigated with 5 and 10 t/ha, respectively. These results supported the positive role of aerobic treatment on OMWW and their capacity to ameliorate the agronomic potential of these effluents.

Assessment of genotoxicity and acute toxic effect of the imatinib mesylate in plant bioassays

Imatinib mesylate (IM) is at present one of the most widely used cytostatic drugs in developed countries but information on its ecotoxicological activities is scarce. This article describes the results of the first investigation in which genotoxic and acute toxic properties of the drug were studied in higher plants. IM was tested in two widely used plant bioassays namely in micronucleus (MN) assays with meiotic tetrad cells of Tradescantia (clone #4430) and in mitotic root tip cells of Allium cepa. Additionally, acute toxic effects (inhibition of cell division and growth of roots) were monitored in the onions. Furthermore, we studied the impact of the drug on the fertility of higher plants in pollen abortion experiments with three wildlife species (Chelidonium majus, Tradescantia palludosa and Arabidopsis thaliana). In MN assays with Tradesacantia a significant effect was seen with doses ⩾10μM; the Allium MN assay was even more sensitive (LOEL⩾1.0μM). A significant decrease of the mitotic indices was detected at levels ⩾10μM in the onions and reduction of root growth with ⩾100μM. In the pollen fertility assays clear effects were observed at doses ⩾147.3mgkg(-1). Data concerning the annual use of the drug in European countries (France, Germany, Slovenia) enable the calculation of the predicted environmental concentration (PEC) values which are in the range between 3.3 and 5.0ngL(-1). Although comparisons with the genotoxic potencies of other commonly used cytostatic drugs and with highly active heavy metal compounds show that IM is an extremely potent genotoxin in higher plants, it is evident that the environmental concentrations are ⩾5 orders of magnitude lower as the levels which are required to cause adverse effects.

Assessment of cytotoxic and genotoxic potential of pyracarbolid by Allium test and micronucleus assay

The present study evaluates the cytotoxic and genotoxic potential of pyracarbolid using both micronuleus (MN) assay, in human lymphocytes, and Allium cepa assay, in the root meristem cells. In Allium test, EC50 value was determined in order to selecting the test concentrations for the assay and the root tips were treated with 25 ppm (EC50/2), 50 ppm (EC50) and 100 ppm (EC50 × 2) concentrations of pyracarbolid. One percent of dimethyl sulphoxide (DMSO) and methyl methane sulfonate (MMS) were used as negative and positive controls, respectively. In the micronucleus assay, the cultures were treated with four concentrations (250, 500, 750 and 1000 µg/ml) of pyracarbolid for 24 and 48 h, negative and positive controls were also used in the experiment parallely. The results showed that mitotic index (MI) significantly reduced with increasing the pyracarbolid concentration at each exposure time. It was also obtained that prophase and metaphase index decreased significantly in all concentration at each exposure time. Anaphase index decreased as well and results were found to be statistically significant, except 24 h. A significant increase was observed in MN frequency in all concentrations and both treatment periods when compared with the controls. Pyracarbolid also caused a significant reduction in the cytokinesis block proliferation index (CBPI) in all concentration and both exposure time.

Assessment of the chemical, microbiological and toxicological aspects of post-processing water from underground coal gasification

The purpose of this paper is to provide a comprehensive characterisation (including chemical, microbiological and toxicological parameters) of water after the underground coal gasification (UCG) process. This is the first report in which these parameters were analysed together to assess the environmental risk of the water generated during the simulation of the underground coal gasification (UCG) process performed by the Central Mining Institute (Poland). Chemical analysis of the water indicated many hazardous chemical compounds, including benzene, toluene, ethylbenzene, xylene, phenols and polycyclic aromatic hydrocarbons (PAHs). Additionally, large quantities of inorganic compounds from the coal and ashes produced during the volatilisation process were noted. Due to the presence of refractory and inhibitory compounds in the post-processing water samples, the microbiological and toxicological analyses revealed the high toxicity of the UCG post-processing water. Among the tested microorganisms, mesophilic, thermophilic, psychrophilic, spore-forming, anaerobic and S-oxidizing bacteria were identified. However, the number of detected microorganisms was very low. The psychrophilic bacteria dominated among tested bacteria. There were no fungi or Actinomycetes in any of the water samples. Preliminary study revealed that hydrocarbon-oxidizing bacteria were metabolically active in the water samples. The samples were very toxic to the biotests, with the TU50 reaching 262. None of biotests was the most sensitive to all samples. Cytotoxicity and genotoxicity testing of the water samples in Vicia uncovered strong cytotoxic and clastogenic effects. Furthermore, TUNEL indicated that all of the water samples caused sporadic DNA fragmentation in the nuclei of the roots.

Red mud a byproduct of aluminum production contains soluble vanadium that causes genotoxic and cytotoxic effects in higher plants

Red mud (RM) is a byproduct of aluminum production; worldwide between 70 and 120 million tons is produced annually. We analyzed RM which was released in the course of the Kolontar disaster in Hungary into the environment in acute and genotoxicity experiments with plants which are widely used for environmental monitoring. We detected induction of micronuclei which reflect chromosomal damage in tetrads of Tradescantia and in root cells of Allium as well as retardation of root growth with contaminated soils and leachates. Chemical analyses showed that RM contains metals, in particular high concentrations of vanadium. Follow-up experiments indicated that vanadate causes the effects in the plants. This compound causes also in humans DNA damage and positive results were obtained in carcinogenicity studies. Since it was found also in RM from other production sites our findings indicate that its release in the environment is a global problem which should be studied in more detail.

CAPSULE ABSTRACT

Our findings indicate that the red mud causes genotoxic effect in plants probably due to the presence of vanadate which is contained at high concentrations in the residue.

Response to copper bromide exposure in Vicia sativa L. seeds: analysis of genotoxicity, nucleolar activity and mineral profile

Copper bromide (CuBr2) effects on seed germination and plantlet development of Vicia sativa L. are evaluated through mitotic index, chromosome aberrations, nucleolar activity and mineral profile. CuBr2 induces a significant presence of micronuclei, sticky and c-metaphases, anaphase bridges and chromosome breaks. Increased number of nucleoli and scattering of AgNOR proteins from the nucleolus in the nuclear surface at CuBr2 1mM and in the cytoplasm at CuBr2 5mM, goes along with the decrease of root growth. In V. sativa embryo the content of many macro and micronutrients increases up to copper 1mM in agreement with reserve mobilization while at CuBr2 5mM some elements are present in lower amount. We hypothesize that inhibitory effects observed at 5mM are due either to a nutrient shortage or to a direct influence of copper on root cell division, evidenced by low mitotic index, high occurrence of chromosome aberrations and loss of material from the nucleolus.

Photoprotection of Buddleja cordata extract against UVB-induced skin damage in SKH-1 hairless mice

Background

In recent years, there has been considerable interest in using botanical agents to prevent skin damage resulting from solar UV-irradiation. Buddleja cordata is a plant that is known as “tepozan”. Some people in Mexico use the leaves of this plant to treat tumours, abscesses, sores and burns. The purpose of this study is to investigate the photoprotective properties of Buddleja cordata methanolic extract (BCME) against UVB-induced skin damage in SKH-1 hairless mice at the macroscopic and histological levels.

Methods

BCME was characterised to determine its spectroscopic, chromatographic and antioxidant (DPPH, superoxide and hydroxyl radicals) properties. To conduct the photoprotection studies, BCME was applied topically to the skin of SKH-1 mice before acute exposure to UVB for 10 minutes. The murine skin samples were used for macroscopic and histological studies to assess tissue damage. Penetration of active components of BCME into stratum corneum on the dorsal area of mice was investigated in vivo by the tape stripping method. Moreover, genotoxicity of BCME was evaluated in a Vicia faba cell root micronucleus model.

Results

BCME displayed absorbance over the entire UVB spectrum, and its principal components included verbascoside and linarin. BCME exhibited antioxidant activity and significantly scavenged hydroxyl radicals. BCME reduced erythema, sunburn cell production, vessel congestion and epidermal thickening of UVB irradiated mouse skin. BCME penetrate the skin of mice. BCME did not exhibit genotoxic activity in the micronucleus test.

Conclusion

The topical administration of BCME protected against acute UVB-induced damage in mouse SKH-1 skin, and our results suggest that BCME may potentially prevent photodamage.

Genotoxicity of sulcotrione pesticide and photoproducts on Allium cepa root meristem

Contamination by toxic agents in the environment has become matters of concern to agricultural countries. Sulcotrione, a triketone herbicide used to control dicotyledonous weeds in maize culture is rapidly photolyzed on plant foliage and generate two main photoproducts the xanthene-1,9-dione-3,4-dihydro-6-methylsulfonyl and 2-chloro-4-mesylbenzoic acid (CMBA). The aim of this study was to analyze the potential toxicity of the herbicide and the irradiated herbicide cocktail. Cytotoxicity and genotoxicity of non irradiated and irradiated sulcotrione were investigated in Allium cepa test. The sulcotrione irradiation was monitored under sunlight simulated conditions to reach 50% of phototransformation. Concentrations of sulcotrione in the range 5 × 10(-)(9)-5 × 10(-)(5)M were tested. Cytological analysis of root tips cells showed that both non irradiated and irradiated sulcotrione caused a dose-dependent decrease of mitotic index with higher cytotoxicity for the irradiated herbicide which can lead to 24.2% reduction of mitotic index compared to water control. Concomitantly, chromosomal aberrations were observed in A.cepa root meristems. Both non irradiated sulcotrione and irradiated sulcotrione induced a dose-dependent increase of chromosomal abnormalities frequencies to a maximal value of 33.7%. A saturating effect in anomaly frequencies was observed in meristems treated with high concentrations of non irradiated sulcotrione only. These data suggest that photolyzed sulcotrione cocktail have a greater cytotoxicity and genotoxicity than parent molecule and question about the impact of photochemical process on environment.

Risk assessment of petroleum-contaminated soil using soil enzyme activities and genotoxicity to Vicia faba

Pollution caused by petroleum is one of the most serious problems worldwide. To better understand the toxic effects of petroleum-contaminated soil on the microflora and phytocommunity, we conducted a comprehensive field study on toxic effects of petroleum contaminated soil collected from the city of Daqing, an oil producing region of China. Urease, protease, invertase, and dehydrogenase activity were significantly reduced in microflora exposed to contaminated soils compared to the controls, whereas polyphenol oxidase activity was significantly increased (P < 0.05). Soil pH, electrical conductivity, and organic matter content were correlated with total petroleum hydrocarbons (TPHs) and a correlation (P < 0.01) existed between the C/N ratio and TPHs. Protease, invertase and catalase were correlated with TPHs. The Vicia faba micronucleus (MN) test, chromosome aberrant (CA) analyses, and the mitotic index (MI) were used to detect genotoxicity of water extracts of the soil. Petroleum-contaminated samples indicated serious genotoxicity to plants, including decreased index level of MI, increased frequency of MN and CA. The combination of enzyme activities and genotoxicity test via Vicia faba can be used as an important indicator for assessing the impact of TPH on soil ecosystem.

Allium cepa L. as a bioindicator to measure cytotoxicity of surface water of the Quatorze River, located in Francisco Beltrão, Paraná, Brazil

Due to an increase in water consumption in the industrial sector and within the Brazilian population, surface water that receives wastewater from industries, domestic sewage, agricultural industries, and sewage treatment stations can pollute water bodies when not properly treated. The water quality has been linked to catchment characteristics and intensity of agricultural activities. Thus, the aim of this study was to monitor the cytotoxic potential of the water of the Quatorze River, located in the town of Francisco Beltrão, Paraná, Brazil, along its route in the rural area, using the root meristematic cells of Allium cepa L. as a bioindicator. The results showed that the water at points 2, 3, and 4 were not cytotoxic because the rates of A. cepa cell division were unaltered. Point 1 had presented a mitotic index that was statistically larger than the negative control, indicating that this water contained substances with mitogenic capacity, as demonstrated by elevated values in chemical oxygen demand (COD) and biochemical oxygen demand (BOD). However, the mitotic index values decreased along the route of the river (point 1 to point 4), possibly indicating a mechanism of self-purification, despite having received other sources of pollution. Thus, the results of this study show that the water of the Quatorze River should undergo periodic environmental monitoring at different times of the year, including cytotoxicity analysis, to evaluate the principal sources of contamination to maintain the quality of the river water and, consequently, to maintain human health and equilibrium of the entire ecosystem.

Assessment of safety and efficiency of nitrogen organic fertilizers from animal-based protein hydrolysates--a laboratory multidisciplinary approach

BACKGROUND

Protein hydrolysates or hydrolysed proteins (HPs) are high-N organic fertilizers allowing the recovery of by-products (leather meal and fluid hydrolysed proteins) otherwise disposed of as polluting wastes, thus enhancing matter and energy conservation in agricultural systems while decreasing potential pollution. Chemical and biological characteristics of HPs of animal origin were analysed in this work to assess their safety, environmental sustainability and agricultural efficacy as fertilizers. Different HPs obtained by thermal, chemical and enzymatic hydrolytic processes were characterized by Fourier transform infrared spectroscopy and sodium dodecyl sulfate polyacrylamide gel electrophoresis, and their safety and efficacy were assessed through bioassays, ecotoxicological tests and soil biochemistry analyses.

RESULTS

HPs can be discriminated according to their origin and hydrolysis system by proteomic and metabolomic methods. Three experimental systems, soil microbiota, yeast and plants, were employed to detect possible negative effects exerted by HPs. The results showed that these compounds do not significantly interfere with metabolomic activity or the reproductive system.

CONCLUSION

The absence of toxic and genotoxic effects of the hydrolysates prepared by the three hydrolytic processes suggests that they do not negatively affect eukaryotic cells and soil ecosystems and that they can be used in conventional and organic farming as an important nitrogen source derived from otherwise highly polluting by-products.

Signal regulation involved in sulfur dioxide-induced guard cell apoptosis in Hemerocallis fulva

Chronic and acute exposure to SO₂ is associated with increased risks of various damages to plants. In the present study, epidermal strip experiment was employed to investigate SO₂-induced guard cells apoptosis and the signal regulation in Hemerocallis fulva. The results showed that with the increase of treatment concentrate of SO₂ derivates (a mixture of sodium sulfite and sodium bisulfite, 3:1, mmol L⁻¹/mmol L⁻¹, 1.0-5.0 mmol L⁻¹), the physiological activity of the guard cells declined and cell death occurred. While the concentration of SO₂ derivatives exceeded 2.0 mmol L⁻¹, the percentage of cell death increased significantly (P<0.05). Typical features of apoptosis including nuclear condensation, nuclear elongation, fragmentation etc. were found. Meanwhile, concomitant presence of nitric oxide (NO), reactive oxygen species (ROS) and Ca²⁺ level increment appeared. However, SO₂-induced cell death can be effectively blocked by either of the following substances with their respective optimal concentrations: antioxidant ascorbic acid (Asc; 0.05 mmol L⁻¹) or catalase (CAT; 200 U mL⁻¹), nitric oxide (NO) scavenger 2-(4-carboxyphenyl)-4, 4, 5, 5- tetramethylmidiazoline-1-oxyl-3-oxide (c-PTIO; 0.20 mmol L⁻¹), nitrate reductase inhibitor NaN₃ (0.20 mmol L⁻¹), Ca²⁺ chelating agent EGTA (0.05 mmol L⁻¹) or plasma membrane Ca²⁺ channel blocker LaCl₃ (0.05 mmol L⁻¹). In addition to a significant decrease in cell death rate, a reduction in the levels of reactive oxygen species (ROS), NO and Ca²⁺ was observed. Further study showed that compared to treatment with SO₂ alone, Asc treatment led to a decrease in NO and Ca²⁺ levels and NaN₃ treatment led to a decrease in ROS and Ca²⁺ levels, but the NO and ROS levels of the LaCl₃ treatment changed little. All results suggested that NO, ROS and Ca²⁺ were involved in the apoptosis induced by SO₂ in H. fulva. The process might be related to the burst of NO or ROS, which would activate the plasma Ca²⁺ channel and result in the increase of intercellular Ca²⁺.

Mutagenicity, genotoxicity, and estrogenic activity of river porewaters

We investigated mutagenicity, genotoxicity, and estrogenic activity in the porewaters of two river basins in southern Italy that had different features. Three samples from each site were collected in different seasons from 7 sites for a total of 21 samples. Mutagenicity was measured with the Ames test with and without metabolic activation (S9) using Salmonella typhimurium TA98 and TA100 strains. Genotoxicity was measured with two tests: one involved a chromophore that detected DNA damage in Escherichia coli PQ37 (SOS chromotest), and the other measured micronuclei formation in the root cells of Vicia faba. Estrogenic activity was measured with a yeast-based estrogen receptor assay and an MCF-7 cell-based, estrogen-sensitive proliferation assay. We also applied chemical analyses to detect alkylphenols, pesticides, natural and synthetic hormones, and heavy metals. The porewaters of both river sediments showed mutagenic/genotoxic activity on V. faba test and Ames test, the latter both with and without S9 liver fraction. The SOS chromotest without metabolic activation was not sufficiently sensitive to detect genotoxicity of the porewaters, but the SOS DNA repair system in E. coli PQ37 was activated in the presence of S9 mix. Good correlations were found between mutagenicity/genotoxicity and the concentration of cadmium and between estrogenic activity and the presence of copper. This study assessed the chemical concentrations of some bioavailable pollutants in porewater and detected the overall effects of multiple pollutants that contributed to mutagenicity, genotoxicity, and estrogenic activity of these two basin porewaters, thus increasing our understanding of the environmental consequences of polluted aquatic ecosystems.

Mutagenicity and genotoxicity assessment of industrial wastewaters

The genotoxicity of industrial wastewaters from Jajmau (Kanpur), was carried out by Ames Salmonella/microsome test, DNA repair-defective mutants, and Allium cepa anaphase-telophase test. Test samples showed maximum response with TA98 strain with and without metabolic activation. Amberlite resins concentrated wastewater samples were found to be more mutagenic as compared to those of liquid-liquid extracts (hexane and dichloromethane extracts). The damage in the DNA repair defective mutants in the presence of Amberlite resins concentrated water samples were found to be higher to that of liquid-liquid-extracted water samples at the dose level of 20 μl/ml culture. Among all the mutants, polA exhibited maximum decline with test samples. Mitotic index (MI) of root tip meristematic cells of A. cepa treated with 5, 10, 25, 50, and 100 % (v/v) wastewaters were significantly lower than the control. Complementary to the lower levels of MI, the wastewaters showed higher chromosomal aberration levels in all cases investigated.

EDCs, estrogenicity and genotoxicity reduction in a mixed (domestic + textile) secondary effluent by means of ozonation: a full-scale experience

WWTP (wastewater treatment plant) effluents are considered to be a major source for the release in the aquatic environment of EDCs (Endocrine-Disrupting Compounds), a group of anthropogenic substances able to alter the normal function of the endocrine system. The application of conventional processes (e.g. activated sludge with biological nitrogen removal) does not provide complete elimination of all these micropollutants and, consequently, an advanced treatment should be implemented. This experimental work was conducted on the tertiary ozonation stage of a 140,000 p.e. activated sludge WWTP, treating a mixed domestic and textile wastewater: an integrated monitoring, including both chemical (nonylphenol, together with the parent compounds mono- and di-ethoxylated, and bisphenol A were chosen as model EDCs) and biological (estrogenic and genotoxic activities) analyses, was carried out. Removal efficiencies of measured EDCs varied from 20% to 70%, depending on flow conditions (ozone dosage being 0.5 gO3/gTOC). Biological tests, furthermore, displayed that the oxidation stage did not significantly reduce (only by 20%) the estrogenicity of the effluent and revealed the presence and/or formation of genotoxic compounds. These results highlight the importance of the application of an integrated (biological+chemical) analytical procedure for a global evaluation of treatment suitability; poor performances recorded in this study have been attributed to the presence of a significant industrial component in the influent wastewater.

Evaluation of phytotoxicity and genotoxicity of nitrobenzene with a battery of Vicia faba assay system

Nitrobenzene (NB) is an important organic compound intermediate that is used widely in industry. In the present study, to evaluate the phytotoxicity and genotoxicity of NB on plants, Vicia faba was exposed to increasing concentrations of NB (5 mg L(-1) , 10 mg L(-1) , 25 mg L(-1) , 50 mg L(-1) , and 100 mg L(-1) ). The data revealed that germination rate and radicle length of V. faba seedlings were promoted by low NB concentrations and short exposure periods, whereas these parameters were inhibited at greater NB concentrations and longer exposures. When assessed by mitotic index, micronucleus, and chromosomal aberration assays, NB showed dose-dependent genotoxicity at 0 mg L(-1) to 50 mg L(-1).

Genotoxicity of polycyclic aromatic hydrocarbons and nitro-derived in respirable airborne particulate matter collected from urban areas of Rio de Janeiro (Brazil)

Air pollution toxic effects are mainly attributed to small inhalable particulates with an aerodynamic diameter of less than 2.5 µ m (PM 2.5). Our objective was to investigate mutagenic and clastogenic activity in PM samples collected in Rio de Janeiro. Samples were collected using a high-volume sampler at three sites: with low traffic and (2) and (3) with a heavy traffic. Six polycyclic aromatic hydrocarbons (PAHs) were quantified by gas chromatography/mass spectrometry (GC/MS). Salmonella typhimurium TA98 and the derivative strains YG1021 and YG1024 were used in mutagenicity assays in the presence of organic extracts (10-50 µ g/ plate) with and without exogenous metabolization. Allium cepa test was performed to evaluate possible cytotoxic and clastogenic activities. The highest PM 2.5 µ m (132.73 µ m/m(3)) and PAH values (1.22 ng/m(3) for benzo(a)pyrene) were detected at site 3. High mutagenic frameshift responses in absence and presence of metabolic activation were detected at site 3. The participation of nitroarenes and dinitroarenes was detected in the total mutagenicity of the extracts studied. The cytotoxic effect and the abnormalities detected by Allium cepa test can be attributed to the PAH nitroderivatives in the organic extracts. Evaluation of the genotoxicity of urban airborne particulate matter is important as a basis for decision making by regulatory authorities.

Evaluation of the genotoxic potential of reactive black 5 solutions subjected to decolorizing treatments by three fungal strains

The genotoxic potential of solutions of the textile dye "Reactive Black 5" that were subjected to decolorizing treatments with the fungal strains Coriolopsis polyzona MUCL33483, Penicillium sp. MUBA001 and Pycnoporus sp. MUBA002 was tested. The genotoxicity of the solutions was determined by evaluation of micronuclei formation in Vicia faba root cells and calculation of a damage index (MN(ID)). Non-treated Reactive Black 5 solutions (50-1000 ppm) caused a statistically significant increase in micronuclei formation and, by then, in damage index. Solutions of dye treated with C. polyzona MUCL33483 and Pycnoporus sp. MUBA002 showed color loss, probably due to enzymatic breakdown of the colorant, but maintenance or even an increase in genotoxicity. On the other hand, the Penicillium sp. strain MUBA001 caused decolorization of the dye, apparently by adsorption on mycelia, and, for solutions that initially contained 50 ppm of colorant, an elimination of the genotoxicity was observed after three weeks of treatment.

Toxicity and genotoxicity of hospital laundry wastewaters treated with photocatalytic ozonation

The aim of the present study was to assess the efficiency of advanced oxidative processes based on photocatalytic ozonation (O(3), UV, UV/O(3), UV/O(3)/Fe(2+) 50 mg L(-1) and 150 mg L(-1)) in the treatment of hospital laundry wastewaters. The analysis of the investigated wastewater revealed high chemical oxygen demand (COD - 3343.8 mg L(-1)), biochemical oxygen demand (BOD(5) - 1906.4 mg L(-1)), total Kjeldahl nitrogen (TKN - 79.8 mg L(-1)) and Daphnia magna toxicity (EC50=1.73). Genotoxic effects were also detected for Allium cepa. Reductions of some parameters occurred after photocatalytic ozonation. The UV/O(3)/Fe(2+) 150 mg L(-1) method was more efficient in reducing COD (59.1%), BOD(5) (50.3%) and TKN (86.8%). There was significant reduction (p<0.05) in D. magna toxicity, O(3) (EC50=47.3%), UV (EC50=50.6%) and UV/O(3)/Fe(2+) 150 mg L(-1) (EC50=45.4%) processes. Normalization of the mitotic index and reduction of micronucleated cells were observed in A. cepa after the treatments. Results demonstrate that these methods were efficient in the degradation of hospital laundry wastewaters, representing a thriving alternative for the removal of pollutants that cause toxicity and genotoxicity.

Alterations observed in the endothelial HUVEC cell line exposed to pure Cylindrospermopsin

The cyanobacterial toxin Cylindrospermopsin (CYN) is receiving great interest due to its increasing presence in waterbodies, which has lead to recognize it as a potential threat to drinking water safety. CYN is a potent inhibitor of protein and glutathione synthesis. The present work studies for the first time the effects of CYN in endothelial cells. The basal cytotoxicity endpoints studied at 24 and 48 h were total protein content (PC), neutral red (NR) uptake and the tretazolium salt, MTS, reduction. Moreover, the effect of subcytotoxic concentrations of CYN on the generation of intracellular reactive oxygen species (ROS), the activity of γ-glutamylcysteine synthetase (GCS) and glutathione (GSH) content have been investigated. In addition, morphological alterations of HUVEC cells subsequent to CYN exposure were recorded. The cytotoxicity endpoints revealed a decrease in the cellular viability in a time and concentration-dependent way. The most sensitive cytotoxicity endpoint was NR uptake assay, with reductions in cell viability of 95% at 48 h of exposure to 40 μg mL(-1) CYN. Intracellular ROS production was increased only at the lowest concentration assayed, while GCS activity and GSH content underwent concentration-dependent enhancements. The most remarkable morphological alterations observed were: nucleolar segregation with altered nuclei, degenerated Golgi apparatus, increases in the presence of granules and apoptosis.

Biodegradability, toxicity and mutagenicity of detergents: Integrated experimental evaluations

The widespread use of detergents has raised concern with regard to the environmental pollution caused by their active ingredients, which are biorefractory, toxic and persistent. Since detergents are complex mixtures of different substances, in which synergistic effects may occur, we aimed to assess the mutagenicity of different detergent formulations, taking into account aquatic toxicity and ready biodegradability. We performed a ready biodegradability test (OECD 301 F), Daphnia magna and Vibrio fischeri toxicity tests, and mutagenicity tests (Salmonella/microsome test, Allium cepa test and comet assay). Six detergent formulations were examined, 3 pre-manufacture and 3 commercially available. All detergents presented ready biodegradability. EC50 values varied for all products, according to the marker organism used, but were always higher than the more stringent value considered for aquatic toxicity assessment (V. fischeri 10-60 mg/L; D. magna 25-300 mg/L; A. cepa 250-2000 mg/L). None of the detergents caused mutations in bacteria. However, one commercial ecolabelled product induced an increase in micronucleus frequency in A. cepa root cells. All pre-manufacture detergents and one commercial one, which gave negative results in the Ames and A. cepa tests, induced DNA damage in human leukocytes. A more accurate evaluation of the environmental impact of complex mixtures such as detergents requires a battery of tests to describe degradation, as well as toxicological and mutagenic features.