Search

Pyraclostrobin-based fungicides play an effective role in controlling fungal diseases and are extensively used in agriculture. However, there is concern regarding the potential adverse effects attributed to exposure to these fungicides on non-target organisms and consequent influence exerted on ecosystem functioning. Thus, it is essential to conduct studies with model organisms to determine the impacts of these fungicides on different groups of living organisms. The aim of this study was to examine the ecotoxicity associated with exposure to commercial fungicides containing pyraclostrobin. The focus of the analysis involved germination and initial development of seedlings of 4 plant models ( Lactuca sativa , Raphanus sativus, Pennisetum glaucum and Triticum aestivum ), in addition to determining the population growth rate and total carbohydrate content in microalga Raphidocelis subcapitata . The fungicide pyraclostrobin adversely influenced growth and development of the tested plants, indicating a toxic effect. The fungicide exerted a significant impact on the initial development of seedlings of all model species examined with T. aestivum plants displaying the greatest susceptibility to pyraclostrobin. Plants of this species exhibited inhibitory effects on both aerial parts and roots when treated with a concentration of 4.75 mg/L pyraclostrobin. In addition, the green microalga R. subcapitata was also significantly affected by the fungicide, especially at relatively high concentrations as evidenced by a reduction in total carbohydrate content. This commercial fungicide demonstrated potential phytotoxicity for the tested plant models and was also considered toxic to the selected microalgae, indicating an ecotoxic effect that might affect other organisms in aquatic environments.

Corn is the second most cultivated crop in Brazil, the number-one country in pesticide consumption. Chemical control of weeds is performed using herbicides such as S-metolachlor with pre- and post-emergence action and thus the toxicity of herbicides constitutes a matter of great concern. The present investigation aimed to examine the effects of an S-metolachlor-based herbicide on Lactuca sativa L. (lettuce) and Zea mays L. (maize) utilizing various bioassays. The test solutions were prepared from commercial products containing the active ingredient. Seeds from the plant models were exposed in petri dishes and maintained under biochemical oxygen demand (BOD) at 24°C. Distilled water was negative and aluminium positive control. Macroscopic analyses (germination and growth) were conducted for both plant species, and microscopic analysis (cell cycle and chromosomal alterations) were performed for L. sativa root tip cells. Detrimental interference of S-metolachlor-based herbicide was noted with lettuce for all parameters tested reducing plant germination by over 50% and the germination speed by over 45% and showing a significant decrease in mitotic index, from 16.25% to 9,28% even on the lowest concentration tested. In maize, there was no significant interference in plant germination; however, speed of germination was significantly hampered, reaching a 51.22% reduction for the highest concentration tested. Data demonstrated that the herbicide was toxic as evidenced by its phyto- and cytotoxicity in L. sativa L. and Z. mays L.

Natural products are usually considered harmless; however, these substances need to be consumed with caution. Biological assays with plant models are a suitable alternative for prospective studies to assess natural product-initiated toxicity. The aim of this study was to examine the toxic potential of leaf and flower extracts derived from Tropaeolum majus L. a widely used plant in traditional medicine. Seeds of Lactuca sativa L. were exposed to T. majus extracts and based upon the seedling growth curve values, the 50% Inhibition Concentration (IC 50 ) was calculated and applied for cell cycle analysis exposure. Both extracts contained organic acids, proteins, amino acids, and terpene steroids. Sesquiterpene lactones and depside were detected in leaf extracts. The higher concentration tested exhibited a marked phytotoxic effect. The extracts induced clastogenic, aneugenic cytotoxic, and potential mutagenic effects. The possible relationships between the classes of compounds found in the extracts and effects on cells and DNA were determined.

Herbicides are agrochemicals applied in the control of weeds. With the frequent and repetitive use of these substances, serious problems have been reported. Compounds of natural origin and their derivatives are attractive options to obtain new compounds with herbicidal properties. By aiming to develop compounds with potentiated herbicidal activity, phenoxyacetic acids were synthesized from eugenol and guaiacol. The synthesized compounds were characterized and the herbicidal potential of phenoxyacetic acids and precursors was evaluated through bioassays regarding the germination and initial development of Lactuca sativa and Sorghum bicolor seedlings, with the induction of DNA damage. The induction of changes in the mitotic cycle of meristematic cells of roots of L. sativa was also analyzed. At the concentration of 3 mmol L-1, phenols and their respective phenoxyacetic acids presented phytotoxic and cytotoxic activities in L. sativa and S. bicolor. Eugenol and guaiacol also presented genotoxic action in L. sativa. The toxic effect of eugenoxyacetic acid was more pronounced in L. sativa than in S. bicolor, similar to the commercial 2,4-D herbicide. Molecular properties of the phenols and their derivatives phenoxyacetic acids were compared with the ones obtained for the herbicide 2,4-D, where it was found a correlation between their molecular properties and bioactivity.

The rampant use of pesticides can cause serious environmental problems. They can be contaminating surface water and groundwater, affecting the surrounding micro and macro biota. In this sense, this work aimed to evaluate the effects of a tebuconazole-based fungicide through endpoints accessed in Lactuca sativa bioassays. Germinated-seeds with roots upon 2 mm were treated with a fungicide containing Tebuconazole (TBZ) as active compound. The final concentration of TBZ in the tested solutions were 0.025 (C1); 0.05 (C2); 0.1 (C3); 0.2 (C4) and 0.4 g/L (C5). L. sativa roots were exposed for 24 h to these solutions and Petri dishes containing the treated seeds were kept in incubation chamber at 24 °C. Two positive controls (PC,) the herbicide trifluralin (0.84 mg/L) and Methanesulfonate (4 ×10 -4 mol/L), were applied. Distilled water was negative control (NC). The following endpoints were analyzed: root growth (RG), cytogenotoxic potential by cell cycle analysis, induction of DNA damage through TUNEL and comet assays. The obtained data were submitted to one-way variance analysis (ANOVA) and then to Tukey or Kruskal Wallis (P < 0.05) tests. The concentrations (C1, C2, C4 and C5) affected negatively the RG of L. sativa, in comparison with the NC. The mitotic index was reduced by 25% from NC to C1 and in the rest of treatments it did not present significant modifications. However, from C3 to C5 great amount of chromosome alterations were observed, in comparison with the NC. TBZ-based fungicide also induced DNA fragmentation as measured by TUNEL and comet assays. Thus, TBZ-based fungicide in some concentrations can have phytotoxic, cytotoxic and genotoxic effects in roots and meristematic cells of L. sativa., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Arsenic (As) is a metalloid and a toxicant that is found naturally in many environmental compartments, soils included. Soils with high levels of As occur worldwide and might pose a threat not only to humans, but also to many ecosystems. Considering the scarcity of studies regarding cytogenotoxic effects of model plants in As-contaminated soil, mainly in tropical areas, this study proposes the use of Allium cepa root tip bioassays for a fast-track assessment of As toxicity in tropical soils. For this end, root tip cells of A. cepa were exposed to an Oxisol, an Inceptisol and a Tropical Artificial Soil (TAS) contaminated with increasing doses of As (0, 8, 14.5, 26, 46.5, 84, 150, and 270 mg kg -1 ). The effects of As on cell cycle, micronucleus formation, and DNA fragmentation were evaluated. In general, root tip cells exposure to As increases the frequency of chromosome abnormalities and micronucleus, in turn, decreasing the frequency of mitotic index. As-treated cells also presented an increase in the percentage of DNA damage observed in comet assay. Overall, the effects of As in TAS were more pronounced, than in the Oxisol, being the Inceptisol the less toxic. A discussion of each As effect in cells and the link with the soil type is presented and reveals that clastogenic effects of As in A. cepa cells seemed to be the mode of action of this soil contaminant., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Spent pot liner (SPL) is a toxic solid waste generated in the aluminum mining and processing industry. SPL is considered as an environmental pollution agent when is dumped on environment. Thus, it is important to access its toxicological risk for the exposed organisms. The comet assay and micronucleus test are efficient tests to detect genotoxic/mutagenic compounds by DNA damage observation. Therefore, in the present study, the genotoxic potential of SPL was evaluated through the micronucleus and comet assay on human leukocytes. After ethics committee approval (COEP-UFLA n°. CAAE 11355312.8.0000.5060), blood aliquots collected from healthy volunteers were exposed to increasing concentrations of SPL (from 0.1 to 80 g L -1 ). All SPL treatments, including the lowest concentration applied (0.1 g L -1 ), significantly increased the micronucleus frequency. The frequency of DNA damage was determined by visual scores (from 0 to 4) and the results were expressed on percentage of damage and arbitrary units (AU). CaCl 2 (0.01 M) was applied as negative control (NC) and doxorubicin (10 μg mL -1 ) as positive control (PC). It was observed a dose-dependency between SPL treatments: as SPL concentration for cell incubation increases, the frequency of damage on DNA also increases. Cells incubated on the NC presented nucleoids class 0 to 2, while those exposed to SPL presents nucleoids class 0 to 4. SPL-incubated cells increasing significantly the frequency of nucleoids class 4. For the PC, the UA of damage was 267.74, which is lower than the one observed for the treatments with high doses of SPL (40-287.40 g L -1 and 80-315.30 g L -1 ). Thus, it was demonstrated that the SPL is a genotoxic agent that induces DNA damage on exposed organisms.

Plants are rich in biologically active compounds. They can be explored for the production of bioherbicides. In this context, the present work aimed to evaluate the allelopathic effect of hydroalcoholic extracts from two Solanaceae species: Solanum muricatum Ait. and Solanum betaceum Cav. For this end, we conducted phytochemical screening and biological assays, determining the effects of the extracts on germination, early development, cell cycle, and DNA fragmentation in plantlets and meristematic cells of the plant model Lactuca sativa L. (lettuce). The percentage of seeds germinated under effect of S. muricatum extract did not differ from the control, but plantlet growth was reduced at the highest concentrations. For S. betaceum extract, dose dependence was observed for both germination and plantlet development, with the highest concentrations inhibiting germination. The growth curves revealed the concentrations of 2.06 and 1.93 g/L for S. muricatum and S. betaceum extracts, respectively, as those reducing 50% of root growth (RG). At these concentrations, both extracts presented mitodepressive effect, besides inducing significant increase in the frequency of condensed nuclei, associated to DNA fragmentation and cytoplasmic shrinkage. The frequency of chromosome alterations was not significant. We further discuss the mechanisms of action related to the chemical composition of the extracts, which presented organic acids, reducing sugars, proteins, amino acids, and tannins, besides catechins and flavonoids, only found in the extract of S. betaceum.

In this study the phytotoxic, cytotoxic, genotoxic and mutagenic effects of two commercial fungicide-active compounds, procymidone (PR) and iprodione (IP), were determined. The parameters evaluated were germination and root growth, mitotic index, chromosomal and nuclear aberrations, and molecular analyses were also performed in the model plant Allium cepa L. The results demonstrated that the active compounds PR and IP were phytotoxic, delaying germination and slowing the development of A. cepa seedlings. Moreover, PR and IP showed cytogenotoxicity towards A. cepa meristematic cells, inducing chromosomal changes and cell death. The mutagenic activity of the active compounds was demonstrated by the detection of DNA changes in simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) markers in the treated cells compared to the negative control. Together, these results contribute to a better understanding of the damage caused by these substances in living organisms and reveal a promising strategy for prospective studies of the toxic effects of environmental pollutants.

On November 2015, one of Brazil's most important watersheds was impacted by the mine waste from Fundão dam collapse in Mariana. The mine waste traveled over 600 km along the Doce River before reaching the sea, causing severe devastation along its way. Here we assessed trace element concentrations and cytogenotoxic effects of the released mine waste. Water samples were collected along the Doce River ten days after the disaster in two impacted sites and one non-impacted site. Sampling points were located hundreds of kilometers downstream of the collapsed dam. Water samples were used for trace element quantification and to run an experiment using Allium cepa to test cytogenotoxicity. We found extremely high concentrations of particulate Fe, Al, and Mn in the impacted sites. We observed cytogenotoxic effects such as alterations in mitotic and phase indexes, and enhanced frequency of chromosomal aberrations. Our results indicate interferences in the cell cycle in impacted sites located hundreds of kilometers downstream of the disaster. The environmental impacts of the dam collapse may not only be far-reaching but also very likely long-lasting, because the mine waste may persist in the Doce River sediment for decades., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Spent potliner (SPL) is a solid residue generated by the aluminum industry. Its composition is variable and complex, containing fluoride and cyanide salts as well as aluminum, which contributes to its toxicity. SPL is sometimes released directly into the soil, where it is prone to leaching and has the potential to cause alterations and damage to DNA. Considering that polymorphism analysis of simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) DNA markers is an interesting tool to determine the mutagenicity of an environmental pollutant, the present study adopted this approach to verify the mutagenic potential of SPL and its main toxic components (aluminum, fluoride, and cyanide) on root tip cells of Lactuca sativa and Allium cepa. Alterations in ISSR and SSR regions were identified by DNA fingerprinting (gain and loss of bands and changes in band intensity). The estimated dissimilarities indicated differences between treatments and the negative control. Furthermore, the relationship between the amplification profile of the markers and alterations in cell mitosis was discussed., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Spent pot liner (SPL) is a solid waste generated during the primary smelting of aluminum, and its toxicity is attributed to the presence of fluoride, cyanide, and aluminum salts, which can be leached into aquatic ecosystems. Since the effects of this waste on aquatic life forms have not yet been investigated, the objective of our study was to evaluate the toxicity of simulated leachates of SPL on zebrafish (Danio rerio). Animals were exposed to 0 (control), 0.32, 0.64, or 0.95 g L -1 of SPL for 24, 72, and 96 h, and genotoxicity was accessed through micronucleus and comet assays. All of the tested treatments induced DNA fragmentation, and the observed frequency of micronuclei and damaged nucleoids generally increased with increasing SPL concentration. The highest frequency of micronuclei (3.3 per 3000 erythrocytes) was detected after 96 h of exposure with 0.95 g L -1 SPL. In the comet assay, nucleoids classified with highest level of damage in relation to the control were observed principally after 24 and 96 h of exposure. The data obtained in this study confirm the genotoxicaction and mutagenic potential of SPL and indicate that open-air deposits of the waste material could represent a health risk to humans and ecosystems alike.

Spent potliner (SPL) is a solid waste generated in the aluminum mining and processing industry. It is sometimes dumped into the environment and leach in contact with water, thereupon affecting living beings, which are likely to be exposed to the waste for long periods. Considering this, we aimed to evaluate the effects of extended exposure to SPL through bioassays using Allium cepa as plant model system. Seeds of A. cepa were either directly exposed to SPL (continuous exposure) or first germinated in water and then exposed to SPL (discontinuous exposure). The germination rate was determined from 24 to 192 h of exposure. The maximum effects of SPL on germination were observed after 96 h in both exposure approaches. For the parameter root elongation, the discontinuous treatment was more efficient in demonstrating differences among the applied SPL concentrations (60% of reduction). Microscopic analysis was carried out in root tip cells discontinuously exposed to SPL for 96 h. A mitodepressive effect was observed (above 50%), as well as increased rate of chromosome abnormalities (up to 100-fold) and induction of cell death. The consequences of exposure to SPL for longer periods are discussed.

Comet assay is an efficient test to detect genotoxic compounds based on observation of DNA damage. The aim of this work was to compare the results obtained from the comet assay in two different type of cells extracted from the root tips from Lactuca sativa L. and human blood. For this, Spent Pot Liner (SPL), and its components (aluminum and fluoride) were applied as toxic agents. SPL is a solid waste generated in industry from the aluminum mining and processing with known toxicity. Three concentrations of all tested solutions were applied and the damages observed were compared to negative and positive controls. It was observed an increase in the frequency of DNA damage for human leukocytes and plant cells, in all treatments. On human leukocytes, SPL induced the highest percentage of damage, with an average of 87.68%. For root tips cells of L. sativa the highest percentage of damage was detected for aluminum (93.89%). Considering the arbitrary units (AU), the average of nuclei with high levels of DNA fragmentation was significant for both cells type evaluated. The tested cells demonstrated equal effectiveness for detection of the genotoxicity induced by the SPL and its chemical components, aluminum and fluoride. Further, using a unique method, the comet assay, we proved that cells from root tips of Lactuca sativa represent a reliable model to detect DNA damage induced by genotoxic pollutants is in agreement of those observed in human leukocytes as model. So far, plant cells may be suggested as important system to assess the toxicological risk of environmental agents., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Coffee wastewater (CWW) is an effluent produced through wet processing of coffee containing high concentration of organic matter, nutrients, salts and also agrochemicals. It is released directly into the argillaceous soil or into decantation tanks for later disposal into soils, by fertigation, subsurface infiltration or superficial draining. However, this practice is not followed by the monitoring the toxicity potential of this effluent. In this sense, the present work aimed to evaluate the phytotoxic, cytogenotoxic and mutagenic potential of CWW on seed germination, root elongation and cell cycle alterations in the plant model Lactuca sativa L. The effluent (CWW) collected was diluted in distilled water into six concentrations solutions (1.25%, 1.66%, 2.5%, 5.0%, 10%, 20%). A solution of raw CWW (100%) was also applied. Distilled water was used as negative control), and the DNA alkylating agent, metilmetano sulfonate (4×10(-4)M) as positive control. Physico-chemical parameters of the CWW was accessed and it was found that the effluent contained total phenols and inorganic matter in amounts within the limits established by the National Environment Council (CONAMA). Nevertheless, the biologicals assays performed demonstrated the phytotoxicity and cytogenotoxicty of CWW. Seed germination was totally inhibited after exposure of raw CWW. In addition, a decrease in seed germination speed as well as in root growth dose-dependently manner was noticed. Moreover, nuclear and chromosomal alterations were observed in the cell cycle, mostly arising from aneugenic action., (Copyright © 2016 Elsevier Inc. All rights reserved.)

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., (Copyright © 2016. Published by Elsevier Inc.)

Spent Pot Liner (SPL) is a solid waste from the aluminum industry frequently disposed of in industrial landfills; it can be leached and contaminate the soil, sources of drinking water and plantations, and thus may pose a risk to human health and to ecosystems. Its composition is high variable, including cyanide, fluoride and aluminum salts, which are highly toxic and environmental pollutants. This study evaluated the effect of SPL and its main components on root growth and the mitosis of Lactuca sativa, by investigating the mechanisms of cellular and chromosomal alterations with the aid of immunolocalization. To this end, newly emerged roots of L. sativa were exposed to SPL and its main components (solutions of cyanide, fluoride and aluminum) and to calcium chloride (control) for 48h. After this, root length was measured and cell cycle was examined by means of conventional cytogenetics and immunolocalization. Root growth was inhibited in the treatments with SPL and aluminum; chromosomal and nuclear alterations were observed in all treatments. The immunolocalization evidenced normal dividing cells with regular temporal and spatial distribution of histone H3 phosphorylation at serine 10 (H3S10ph). However, SPL and its main components inhibited the phosphorylation of histone H3 at serine 10, inactivated pericentromeric regions and affected the cohesion of sister chromatids, thus affecting the arrangement of chromosomes in the metaphase plate and separation of chromatids in anaphase. In addition, these substances induced breaks in pericentromeric regions, characterized as fragile sites., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Guava (Psidium guajava L.) is a plant often employed in popular medicine. Recently several studies have alerted about the toxicity of substances present in medicinal plants, which can pose risks to the human health. In this sense, the present work aimed to investigate the phytotoxic, cytotoxic and genotoxic action of three guava varieties - Paluma, Pedro Sato and Roxa ("purple") - on the plant test system Lactuca sativa L. Thus, macro- and microscopic evaluations were carried out for five infusion concentrations (2.5, 5.0, 10.0, 20.0 and 40.0 g.L(-1)) prepared from each variety. Distilled water was used as negative control. Chromatographic and spectroscopic analysis by HPLC-PAD indicated that the chemical composition of the infusion of Roxa is different than that of the infusions of the varieties Paluma and Pedro Sato. It was observed that seed germination and root growth in L. sativa exposed to infusions decreased with increasing infusion concentration, regardless of the tested cultivar. For the mitotic index, no statistical differences were observed. On the other hand, a significant increase in the frequency of cell cycle alterations was verified, especially for the highest concentrations tested. The cytogenotoxic effect was significant. Therefore, guava should not be used indiscriminately in popular medicine.

The genus Pennisetum (Richard, 1805) includes two economically important tropical forage plants: Pennisetum purpureum (Schumacher, 1827) (elephant grass), with 2n = 4x = 28 chromosomes and genomes A'A'BB, and Pennisetum glaucum (Linnaeus, 1753) (pearl millet), with 2n = 2x = 14 chromosomes and genomes AA. The genetic proximity between them allows hybrids to be obtained (2n = 3x = 21) that yield forage of higher quality in relation to the parents. The study of genomic relationships provides subsidies for the knowledge about phylogenetic relations and evolution, and is useful in breeding programs seeking gene introgression. Concerning elephant grass and pearl millet, the homeology between the genomes A and A', and between these and the genome B, has been reported by conventional cytogenetic techniques. The objective of the present study was to demonstrate the degree of homeology between these genomes by means of genomic in situ hybridization (GISH). The results confirmed the homeology between the genomes A of pearl millet and A'B of elephant grass, and showed that there are differences in the distribution and proportion of homologous regions after hybridization. Discussion regarding the evolutionary origin of P. purpureum and P. glaucum was also included.

Spent pot-liner (SPL) is a hazardous solid waste produced by the aluminum industry. Although its composition may vary, fluoride and cyanide salts as well as aluminum are predominant components. A seed-germination and root-elongation test was performed with Lactuca sativa seeds as a test system. SPL induced decrease of seed germination rate and root elongation. The concentration of 26.5g/L SPL was established from a regression curve as the IC50 (inhibition concentration 50%). Through chemical analyses, the concentrations of fluoride, cyanide and aluminum in SPL solutions of 26.5g/L (IC50), 39.75g/L (1.5IC50) and 13.25g/L (0.5IC50) were determined. Further, a cell-cycle test was conducted with root tips of L. sativa exposed to these same SPL solutions. All test chemicals presented toxic effects on meristematic cells of L. sativa. Aluminum was identified as the SPL component mainly responsible for reduction of the mitotic index. Chromosomal alterations resulted from the interactions among the three main chemical components of SPL, without a clear predominantly responsible agent. Induction of condensed nuclei was mainly due to effects of aluminum and fluoride, and may serve as an indicator of induced cell death., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Jatropha curcas L. (Euphorbiaceae) is important for biofuel production and as a feed ingredient for animal. However, the presence of phorbol esters in the oil and cake renders the seeds toxic. The toxicity of J. curcas oil is currently assessed by testing in animals, leading to their death. The identification of toxic and nontoxic improved varieties is important for the safe use of J. curcas seeds and byproducts to avoid their environmental toxicity. Hence, the aim of this study was to propose a short-term bioassay using a plant as a model to screen the toxicity of J. curcas oil without the need to sacrifice any animals. The toxicity of J. curcas oil was evident in germination, root elongation and chromosomal aberration tests in Lactuca sativa. It was demonstrated that J. curcas seeds contain natural compounds that exert phyto-, cyto- and genotoxic effects on lettuce, and that phorbol esters act as aneugenic agents, leading to the formation of sticky chromosomes and c-metaphase cells. In conclusion, the tests applied have shown reproducibility, which is important to verify the extent of detoxification and to determine toxic doses, thus reducing the numbers of animals that would be used for toxicity tests.

Industrial waste usually contains complex mixtures of mutagenic chemicals. Spent Pot Liner (SPL) is a complex solid waste from the aluminum industry, which is composed of organics, fluoride salts, inorganic cyanides, metals, and sodium. Due to the toxicity of these compounds, this study sought to use cytogenetics and flow cytometry to assess the effects of SPL on cell cycle parameters and DNA content in meristematic cells of Allium cepa. Three concentrations of leachates from SPL-soil mixtures were used for the study: 0, 10, and 25%. Roots were collected and analyzed after 4, 8, 12, 24, and 36 h of exposure to the above SPL leachates. The results showed an overall mitodepressive effect accompanied by an increased percentage of condensed nuclei and genomic instability as evidenced by the presence of cellular/chromosomal abnormalities. Terminal deoxynucleotidyl transferase dUTP nick end labeling revealed nuclei with fragmented DNA, a marker of programmed cell death. This study also addressed the question of reversibility of the effects of SPL and found that 36 h of exposure to 25% SPL seemed to be the point at which the effects on the induction of apoptosis became irreversible., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Spent Pot Liner (SPL) is a solid waste product generated in the process of aluminum production. Tradescantia micronuclei (Trad-MN) and stamen hair mutation (Trad-SHM) bioassays are very useful tests to assess genotoxicity of environmental pollutants. In the present study, we intended to investigate the genotoxicity of this waste with Tradescantia bioassays using leachates of SPL simulating the natural leachability of SPL in soil. The formation of micronuclei (MN) was found to be concentration dependent. MN frequency enhanced significantly with SPL treatment. In addition, SPL also appeared to increase the percentage of dyads and triads. Trad-SHM assay showed that SPL increases pink mutation events as SPL concentration increases. These results demonstrated that SPL is a cytogenotoxic agent that affects different genetic end-points (induction of micronuclei and point mutations) even at low concentration (2% and 3%)., (Copyright © 2011 Elsevier Inc. All rights reserved.)

There are various toxic effects of environmental pollutants, including apoptosis and carcinogenesis. Spent Pot Liner (SPL) is solid waste from the aluminum industry. It has a highly variable composition, including cyanide, fluoride, organics and metals. Preliminary characterizations of the effect of SPL on Allium cepa show the presence of condensed nuclei. Thus, the aim of this study was to analyze the toxic effect of SPL in A. cepa root meristem in the context of programmed cell death (PCD). A lot of specific features of this process such as DNA fragmentation, condensed chromatin, spherical nuclei and the formation of apoptotic-like bodies were observed in root meristem after SPL treatment. Root meristem treated with SPL 25% solution exhibited an alteration in antioxidant enzyme activities; a reduction in NCR as a consequence of high percentage of condensed nuclei; DNA fragmentation, detected by electrophoresis and TUNEL assay; cytoplasm vacuolization and also a disturbance in root morphology. These features are associated with programmed cell death (PCD) under abiotic stress. Therefore, these data show that SPL induces apoptosis-like PCD in root meristem cells of A. cepa., (Copyright © 2010 Elsevier Inc. All rights reserved.)