Investigation of multidirectional toxicity induced by high-dose molybdenum exposure with Allium test.

In this study, the multifaceted toxicity induced by high doses of the essential trace element molybdenum in Allium cepa L. was investigated. Germination, root elongation, weight gain, mitotic index (MI), micronucleus (MN), chromosomal abnormalities (CAs), Comet assay, malondialdehyde (MDA), proline, superoxide dismutase (SOD), catalase (CAT) and anatomical parameters were used as biomarkers of toxicity. In addition, detailed correlation and PCA analyzes were performed for all parameters discussed. On the other hand, this study focused on the development of a two hidden layer deep neural network (DNN) using Matlab. Four experimental groups were designed: control group bulbs were germinated in tap water and application group bulbs were germinated with 1000, 2000 and 4000 mg/L doses of molybdenum for 72 h. After germination, root tips were collected and prepared for analysis. As a result, molybdenum exposure caused a dose-dependent decrease (p < 0.05) in the investigated physiological parameter values, and an increase (p < 0.05) in the cytogenetic (except MI) and biochemical parameter values. Molybdenum exposure induced different types of CAs and various anatomical damages in root meristem cells. Comet assay results showed that the severity of DNA damage increased depending on the increasing molybdenum dose. Detailed correlation and PCA analysis results determined significant positive and negative interactions between the investigated parameters and confirmed the relationships of these parameters with molybdenum doses. It has been found that the DNN model is in close agreement with the actual data showing the accuracy of the predictions. MAE, MAPE, RMSE and R2 were used to evaluate the effectiveness of the DNN model. Collective analysis of these metrics showed that the DNN model performed well. As a result, it has been determined once again that high doses of molybdenum cause multiple toxicity in A. cepa and the Allium test is a reliable universal test for determining this toxicity. Therefore, periodic measurement of molybdenum levels in agricultural soils should be the first priority in preventing molybdenum toxicity.

Advanced methods for insect nets: red-colored nets contribute to sustainable agriculture.

Development of advanced pest control methods that do not rely on insecticides is an important issue for sustainable agriculture. Particularly with regards to micro pests that are not only highly resistant to various insecticides but also because we are running out of options for which insecticide to use against them, resulting in enormous economic damage worldwide. Here we report that the effectiveness of the conventional insect net can be greatly advanced by changing their color to red that helps significantly reduce pesticide use. We demonstrate the red effect using Onion thrips, Thrips tabaci a main vector of Iris Yellow Spot Virus (IYSV) and Tomato Spotted Wilt Virus (TSWV) that cause serious damage to various vegetables. New red nets succeeded in suppressing the invasion rates and damages (white spots on the leaves) in a Welsh onion greenhouse with minimum use of pesticides. We discuss how red nets are compatible with labor-saving, sustainable agriculture and the future potential of "optical pest control" based on insect color vision and its behavioral response.

Investigating the therapeutic potential of Allium cepa extract in combating pesticide exposure induced ocular damage.

The ocular surface is subject to a range of potentially hazardous environmental factors and substances, owing to its anatomical location, sensitivity, and physiological makeup. Xenobiotic stress exerted by chronic pesticide exposure on the cornea is primarily responsible for ocular irritation, excessive tear production (hyper-lacrimation), corneal abrasions and decreased visual acuity. Traditional medicine hails the humble onion (Allium cepa) for its multi-faceted properties including but not limited to anti-microbial, antioxidant, anti-inflammatory and wound healing. However, there is a lacuna regarding its impact on the ocular surface. Thereby, the current study investigated whether topical application of crude extract of Allium cepa aided in mitigating pesticide-induced damage to the ocular surface. The deleterious effects of pesticide exposure and their mitigation through the topical application of herbal extract of Allium cepa were analysed initially through in vitro evaluation on cell lines and then on the ocular surface via various in-vivo and ex-vivo techniques. Pathophysiological alterations to the ocular surface that impacted vision were explored through detailed neurophysiological screening with special emphasis on visual acuity wherein it was observed that the murine group treated with topical application of Allium cepa extract had comparable visual capacity to the non-pesticide exposed group. Additionally, SOD2 was utilized as an oxidative stress marker along with the expression of cellular apoptotic markers such as Bcl-xL to analyse the impact of pesticide exposure and subsequent herbal intervention on oxidative stress-induced corneal damage. The impact on the corneal epithelial progenitor cell population (ABCG2 and TERT positive cells) was also flowcytometrically analysed. Therefore, from our observations, it can be postulated that the topical application of Allium cepa extract might serve as an effective strategy to alleviate pesticide exposure related ocular damage.

Detection of heavy metal contamination in Batlama Stream (Turkiye) and the potential toxicity profile.

In this study, heavy metal pollution in Batlama stream flowing into the Black Sea from Giresun (Turkiye) province and the toxicity induced by this pollution were investigated by Allium test. Heavy metal concentrations in stream water were analyzed by using ICP-MS. Germination percentage, weight gain, root length, micronucleus (MN), mitotic index (MI), chromosomal abnormalities (CAs), proline, chlorophyll, malondialdehyde (MDA), antioxidant enzyme activities were used as indicators of physiological, cytogenetic and biochemical toxicity. In addition, Comet assay was performed for detecting DNA fragmentation. Anatomical changes caused by heavy metals in the root meristem cells were observed under the microscope. A. cepa bulbs are divided into two groups as control and treatment. The bulbs in the control group were germinated with tap water and the bulbs in the treatment group were germinated with stream water. As a result, heavy metals such as Al, Ti and Co and radioactive heavy metals such as Rb, Sr, Sb and Ba were detected in the stream water above the acceptable parametric values. Heavy metals in the water caused a decrease in germination, root elongation, weight gain, MI and chlorophyll values, and an increase in MDA, proline, SOD, CAT, MN and CAs values. Comet assays indicated the presence of severe DNA damage. In addition, heavy metals in stream water caused different types of CAs and anatomical damage in root meristem cells. As a result, it was determined that there is intense heavy metal pollution in the stream water and this pollution promotes multi-dimensional toxicity in A. cepa, which is an indicator organism. For this reason, the first priority should be to prevent pollution of water resources in order to prevent heavy metal-induced toxicity in water.

Toxicity of methylparaben and its chlorinated derivatives to Allium cepa L. and Eisenia fetida Sav.

Methylparaben, chloro-methylparaben, and dichloro-methylparaben were evaluated in Allium cepa at 5, 10, 50, and 100 µg/L and in Eisenia fetida at 10 and 100 µg/L. In A. cepa roots, 100 µg/L methylparaben and 50 and 100 µg/L chlorinated methylparabens reduced cell proliferation, caused cellular changes, and reduced cell viability in meristems, which caused a reduction in root growth. Furthermore, they caused drastic inhibition of catalase, ascorbate peroxidase, and superoxide dismutase; activated guaiacol peroxidase and promoted lipid peroxidation in meristematic root cells. In earthworms, after 14 days exposure to the three compounds, there were no deaths, and catalase, ascorbate peroxidase, and superoxide dismutase were not inhibited. However, guaiacol peroxidase activity and lipid peroxidation were observed in animals exposed to dichloro-methylparaben. Soils with dichloro-methylparaben also caused the escape of earthworms. It is inferred that the recurrent contamination of soils with these methylparabens, with emphasis on chlorinated derivatives, can negatively impact different species that depend directly or indirectly on soil to survive.

Alkaline-extracted cyanide from cassava wastewater and its sole induction of chromosomal aberrations in Allium cepa L. root tips.

Cassava, a staple crop in Nigeria, processed by numerous factories in rural and suburban locations is known to contain some level of cyano compounds. Lack of stringent environmental regulations on the management of cassava wastewater (CWW) from cassava-processing factories had led to its indiscriminate discharge on the environment. CWW samples were obtained from cassava-processing factories from selected states (Lagos (A), Oyo (B), Ogun 1 (C1), Ogun 2 (C2) and Cross River (D)) in Nigeria to determine the cytotoxic and genotoxic effects of extracted cyanide from the wastewaters. The cyanide was hydrolysed via chemical degradation utilizing 1.25 M NaOH and subsequently titrated using silver nitrate with p-dimethylaminobenzalrhodamine as indicator. Further, in order to explore the potential toxicity of this pollutant present in the effluent, a battery of short-term biological assay (Allium cepa chromosomal aberration test) was used. Bulbs with roots of Allium cepa L. were treated with different concentrations (0.05%, 0.1%, 0.2%, 0.4% and 0.8%) of CWW, and after 48 h, the root tips were processed for cytological studies by the aceto-orcein squash procedure. The results revealed that cyanide concentrations on re-fluxing were in the range of 1.0 and 1.3 mg/L. All concentrations induced a number of chromosomal aberrations in the root tip cells. The mitotic index decreased significantly (p < 0.05) with increasing concentration. The cytotoxic effects showed strong concentration-dependent root growth inhibition with EC50 values of 30%, 20%, 37%, 43% and 22% for A, B, C1, C2 and D, after 72 h. The findings thus indicate that alkali treatment is very efficient in degrading the cyanide content of CWW and has shown that the combination of physico-chemical analysis along with the sole toxicity assessment could provide valuable information about the sole toxicity of cyanide as a chemical pollutant present in the cassava effluent.

Interactive effects of plant growth-promoting rhizobacteria and a seaweed extract on the growth and physiology of Allium cepa L. (onion).

Detrimental effects caused by the overuse of synthetic agrochemicals have led to the development of natural biostimulants such as seaweed extracts and plant growth-promoting rhizobacteria (PGPR) being used as an alternative, environmentally-friendly technology to improve crop growth and increase agricultural yields. The present study aimed to investigate the interactions between PGPR and a commercial seaweed extract on the growth and biochemical composition of onion (Allium cepa). A pot trial was conducted under greenhouse conditions where onion plants were treated individually with the two PGPR, namely Bacillus licheniformis (BL) and Pseudomonas fluorescens (PF) and a seaweed extract Kelpak® (KEL) and combinations of KEL + BL and KEL + PF. Growth and yield parameters were measured after 12 weeks. KEL-treated plants showed the best growth response and overcame the inhibitory effects of BL treatment. KEL-treated plants also had the highest chlorophyll content. PGPR application improved the mineral nutrition of onion with these plants having the highest mineral content in the leaves and bulb. All biostimulant treatments increased the endogenous cytokinin and auxin content with the highest concentrations generally detected in the PF-treated plants. These results suggest that co-application of different biostimulant classes with different modes of action could further increase crop productivity with an improvement in both growth and nutrition content being achieved in onion with the co-application of a seaweed extract and PGPR.

Antioxidants and Bioactive Compounds in Licorice Root Extract Potentially Contribute to Improving Growth, Bulb Quality and Yield of Onion (Allium cepa).

The increasing culinary use of onion (Alium cepa) raises pressure on the current production rate, demanding sustainable approaches for increasing its productivity worldwide. Here, we aimed to investigate the beneficial effects of licorice (Glycyrrhiza glabra) root extract (LRE) in improving growth, yield, nutritional status, and antioxidant properties of two high-yielding onion cultivars, Shandaweel and Giza 20, growing under field conditions in two consecutive years. Our results revealed that pretreatments of both onion cultivars with LRE exhibited improved growth indices (plant height and number of leaves) and yield-related features (bulb length, bulb diameter, and bulb weight) in comparison with the corresponding LRE-devoid control plants. Pretreatments with LRE also improved the nutritional and antioxidant properties of bulbs of both cultivars, which was linked to improved mineral (e.g., K+ and Ca2+) acquisition, and heightened activities of enzymatic antioxidants (e.g., superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase, and glutathione S-transferase) and increased levels of non-enzymatic antioxidants (e.g., ascorbic acid, reduced glutathione, phenolics, and flavonoids). LRE also elevated the contents of proline, total free amino acids, total soluble carbohydrates, and water-soluble proteins in both onion bulbs. In general, both cultivars displayed positive responses to LRE pretreatments; however, the Shandaweel cultivar performed better than the Giza 20 cultivar in terms of yield and, to some extent, bulb quality. Collectively, our findings suggest that the application of LRE as biostimulant might be an effective strategy to enhance bulb quality and ultimately the productivity of onion cultivars under field conditions.

The individual and interactive role of arbuscular mycorrhizal fungi and Trichoderma viride on growth, protein content, amino acids fractionation, and phosphatases enzyme activities of onion plants amended with fish waste.

The Green Revolution faced a great cost to meet ever-increasing demands for food, where indiscriminate use of agrochemicals resulted in non-friendly habitats. Therefore, the development of a sustainable approach to better crop production of onion seeds (Allium cepa L.) is very crucial. It is time to use organic waste as a replacement for agrochemicals by using arbuscular mycorrhizal fungi (AMF) and Trichoderma. Fish waste as representative of food waste acts as a leading cause of contamination of the environment. The interaction of AMF and Trichoderma viride on biomass, total soluble protein, mycorrhizal colonization, amino acids, phosphatases and phosphorus and nitrogen contents of onion plants grown in fish waste amended soil was studied. Fish waste has caused a slight increase in onions biomass, total free amino acids, and soluble protein content while with AMF and T. viride dual inoculation more increments were recorded; such increases were related to an increase in mycorrhizal colonization. T. viride application significantly increased the mycorrhizal colonization levels, but these were significantly reduced with waste addition. Analysis of amino acids in plants showed that their concentrations had changed as a result of waste addition combined with AMF and/or T. viride. The effectiveness of fish waste combined with low cost and health/environmental safety leads to a prediction that the introduction of fish waste coupled with fungi will become a more popular feature of agriculture in the future.

Investigating the underlying mechanism of cadmium-induced plant adaptive response to genotoxic stress.

Plants as sessile organisms have developed some unique strategies to withstand environmental stress and adaptive response (AR) is one of them. In the present study Cadmium (Cd)-induced AR was evaluated to ameliorate the genotoxicity of a known chemical mutagen ethyl methanesulphonate (EMS) based on cytotoxicity, genotoxicity and oxidative stress in two model plant systems Allium cepa L. and Vicia faba L. Priming the plants with cadmium chloride (CdCl2, 25 and 50 µM) reduced the genotoxicity of EMS (0.25 mM). Cd-induced AR was evident by the magnitude of adaptive response (MAR) values calculated for cytotoxicity, genotoxicity and biochemical parameters. In addition the involvement of some major metabolic pathways and epigenetic modifications in AR was investigated. Metabolic blockers of protein kinase cascades, DNA repair, oxidative stress and de novo translation interfered with the adaptive response implying their role in AR whereas, inhibitors involved in post-replication repair and autophagy were ineffective implicating that they probably have no role in the AR studied. Moreover to find the role of DNA methylation in AR, methylation-sensitive comet assay was carried out. Simultaneously 5-methyl- 2'-deoxycytidine (5mdC) levels were quantified by HPLC (high performance liquid chromatography). AR was eliminated in cells treated with a demethylating agent, 5-aza- 2'deoxycytidine (AZA). Results implied a contribution of DNA hypermethylation. To the best of our knowledge this is a first report correlating DNA methylation to Cd-induced adaptive response in plants undergoing genotoxic stress.

Assembly of a simple scalable device for micromechanical testing of plant tissues.

Tensile testing is widely used to evaluate the mechanical properties of biological materials including soft primary plant tissues. Commercially available platforms for tensile testing are often expensive and limited in customizability. In this chapter, we provide a guide for the assembly and use of a simple and low-cost micromechanical testing apparatus suitable for research and educational purposes. The build of the setup is presented with scalability and universality in mind and is based on a do-it-yourself mind frame towards mechanical tests on plant organs and tissues. We discuss hardware and software requirements with practical details on required components, device calibration and a script to run the device. Further, we provide an example in which the device was used for the uniaxial tensile test of onion epidermis.

Toxicity of Explosive Effluent by Alliumcepa and Germination Test.

In this work the toxicity caused by explosive industries effluent (yellow water) at different levels of toxicity (genetic, cellular and organismal level) was evaluated by the Allium cepa test and the Sorghum sudanense germination. The results showed that the effluent paralyze the mitotic process, keeping the cells in the interphase, decreasing the mitotic index in A. cepa. Chromosomal abnormalities such as c-metaphases, adhesions, breaks, early ascending chromosomes and irregular nucleus were observed for this receptor species. The germination of S. sudanense was reduced, and the development of the radicles were affected, showing reduced tolerance index at the highest concentrations of the effluent. Thus, it is concluded that the effluent from the explosive industry is extremely toxic to the tested organisms, both in cellular and chromosomal level and also for seed germination.

PBAT biodegradable mulch films: Study of ecotoxicological impacts using Allium cepa, Lactuca sativa and HepG2/C3A cell culture.

Biodegradable mulch films are an alternative to polyethylene films used in agriculture for weed control, improving crop productivity. This change could minimize the residue production and costs related to the final disposal. Nevertheless, the environmental safety of these biodegradable products is scarcely investigated. In this work, samples of poly(butylene adipate-co-terephthalate)-PBAT mulch films, with and without UV stabilizer additives, were prepared. Aqueous extracts of soil samples, where mulch films were disposed, were investigated using bioassays with Lactuca sativa, Allium cepa, and cell culture HepG2/C3A. As PBAT is expected to suffer photodegradation and biodegradation, soil samples mixed with films before and after these processes were evaluated. Soil aqueous extracts promoted root grown (mainly hypocotyl) of L. sativa, probably due to presence of nutrients. So, to evaluate toxicity potential, in this case it was necessary to use aqueous extract prepared with soil instead of ultrapure water as the control. After doing this analysis it was observed that no adverse impacts due to PBAT films occurred. No chromosomal abnormalities were observed in A. cepa bioassay for any of tested samples. The absence of genotoxic potential was confirmed by comet assay and micronucleus test using human hepatocarcinoma cell line HepG2/C3A. These results showed that the soil did not induce damage to the tested organisms, before and after degradation of PBAT films.

The relationship between cyto-genotoxic damage and oxidative stress produced by emerging pollutants on a bioindicator organism (Allium cepa): The carbamazepine case.

The carbamazepine (CBZ) is one of the most frequently detected anticonvulsant drugs in water bodies. Although there are reports of its ecotoxicological effects in the scientific literature, toxicity studies have not focused on establishing the mechanism by which CBZ produces its effect at environmentally relevant concentrations. The objective of this work was to evaluate cyto-genotoxicity and its relationship with oxidative stress produced by carbamazepine in the Allium cepa model. The cytotoxicity and genotoxicity, as well as the biomarkers of oxidative stress were analyzed in the roots of A. cepa, exposed to 1 and 31.36 µg L-1 after 2, 6, 12, 24, 48 and 72 h. The results show that genotoxic capacity of this drug in the roots of A. cepa is related to the generation of oxidative stress, in particular with production of hydroperoxides and oxidized proteins. Also, the cytotoxic effect has a high correlation with DNA damage. The results of the present study clearly indicate that bioassays with sensitive plants such as A. cepa are useful and complementary tools to evaluate the environmental impact of emerging contaminants.

Cytotoxic evaluation of glyphosate, using Allium cepa L. as bioindicator.

Glyphosate is a chemical compound used mainly as a broad spectrum herbicide, it is recognized for its proven effectiveness and easy handling. It represents more than 60% of the world market of non-selective herbicides and is used in both agricultural fields and family gardens. The present study was designed to test the cytogenotoxic potential of glyphosate using the Allium cepa test as toxicity bioindicator. Consequently, bulbs of A. cepa were exposed to different concentrations of glyphosate (5, 10, 15, 25 and 30 mgL-1) and a control (deionized water), for 72 h; root development was also studied in this period of time. The cytogenotoxic potential of glyphosate was determined by calculating the mitotic index (MI), cellular anomalies (CA) and registering the roots longitudinal growth at 24, 48 and 72 h. Regarding root development, a greater growth was observed in the control treatment in the three measurement times. The mitotic phases analysis, determined that the higher the concentration, the lower the mitotic index, in addition the inhibition of the telophase Mitotic Index (TMI) was observed in any of the concentrations. The results indicate that the exposure to glyphosate of A. cepa meristematic cells induces diverse types of chromosomal anomalies, such as micronuclei (MN), chromosome breaking (CB), nuclear notch (Nn), among others. Therefore, in demonstrates that glyphosate has a highly cytogenotoxic effect for any of the concentrations used.

Resveratrol ameliorates the physiological, biochemical, cytogenetic, and anatomical toxicities induced by copper(II) chloride exposure in Allium cepa L.

Excessive copper (Cu) exposure ultimately results in toxicosis in all organisms. The protective potential of resveratrol compound against the CuCl2 toxicity was evaluated in Allium cepa L. root tip cells. For this aim, A. cepa bulbs were divided into six groups and the groups were treated with tap water, 400 mg/L resveratrol, 800 mg/L resveratrol, 20 µM CuCl2, 400 mg/L resveratrol + 20 µM CuCl2, and 800 mg/L resveratrol + 20 µM CuCl2 solutions, respectively for 72 h. The first group irrigated with tap water was accepted as control. All groups were screened for the germination percentage, root elongation, total bulb weight gain, micronucleus (MN) frequency, mitotic index (MI), chromosomal aberrations, and anatomical changes. Furthermore, superoxide dismutase (SOD) and catalase (CAT) activities as well as malondialdehyde (MDA) level as an indicator of lipid peroxidation were investigated. It was found that CuCl2 exposure alone triggered a definite negative effects on all parameters examined. On the other hand, the groups treated with resveratrol did not have statistically different values compared to the control group. Resveratrol doses induced a remarkable recovery in growth parameters including germination percentage, root elongation, and total bulb weight gain when applied with CuCl2. In these groups, MN frequency, chromosomal aberrations, and anatomical abnormalities were alleviated, whereas the MI levels increased significantly. Moreover, lipid peroxidation level and antioxidant enzyme activities showed a marked amelioration when resveratrol and CuCl2 were applied together. Copper compounds have become common pollutants due to their direct uses as pesticides in agricultural areas as well as their spreading to natural areas from industrial fields. The study clearly demonstrated the therapeutic potential of resveratrol against the harmful effects of CuCl2 exposure in Allium roots. So, resveratrol could be considered as a plant-derived restorative agent for the reduction of the risks from the other copper compounds.

Individual and interactive role of Trichoderma viride and arbuscular mycorrhizal fungi on growth and pigment content of onion plants.

The study of interactions between beneficial micro-organisms associated with plant roots is important, because such interactions might either enhance or inhibit the beneficial effects of individual species. The effect of the combined inoculation of arbuscular mycorrhizal (AM) fungi and a biocontrol fungus (Trichoderma viride) on different growth parameters and chlorophyll a,b, carotenoids, total chlorophyll and total pigments of onion (Allium cepa) plants was studied under glasshouse conditions. The results proved that AM fungi and T. viride are compatible with each other and their combined use was effective not only in improving onion growth parameters such as fresh and dry weights, root and shoot lengths and leaf area but also increasing total chlorophyll, carotenoids and total pigments content in onion leaves. Where, inoculation of onion plants by AM fungi and T. viride alone or in combination significantly increased bulb diameters of onion plants 20, 12·5 and 17·5% increase; respectively, when compared with control ones. Also percentage of AM fungal colonization increased greatly with T. viride inoculation. Therefore, AM fungi and T. viride could be a good alternate of chemical fertilizer for improving the growth of onion. SIGNIFICANCE AND IMPACT OF THE STUDY: Significance and Impact of the Study: The need for increasing agricultural productivity and quality has led to an excessive use of chemical fertilizers; creating serious threats to human health and the environment. The use of biofertilizers is an alternative for sustaining high production with low ecological impact. Thus the goal of this study was to propose a biological technique using arbuscular mycorrhizal symbiosis and Trichoderma viride (plant-microbe interaction) for increasing plant growth that represent a great opportunities for recent agricultural practices. This may be an indication displaying the AM and Trichoderma significance for plant progress and growth.

Effects of landscape complexity on pollinators are moderated by pollinators' association with mass-flowering crops.

Conserving and restoring semi-natural habitat, i.e. enhancing landscape complexity, is one of the main strategies to mitigate pollinator decline in agricultural landscapes. However, we still have limited understanding of how landscape complexity shapes pollinator communities in both crop and non-crop habitat, and whether pollinator responses to landscape complexity vary with their association with mass-flowering crops. Here, we surveyed pollinator communities on mass-flowering leek crops and in nearby semi-natural habitat in landscapes of varying complexity. Surveys were done before and during crop bloom and distinguished between pollinators that visit the crop frequently (dominant), occasionally (opportunistic), or not at all (non-crop). Forty-seven per cent of the species in the wider landscape were also observed on leek flowers. Crop pollinator richness increased with local pollinator community size and increasing landscape complexity, but relationships were stronger for opportunistic than for dominant crop pollinators. Relationships between pollinator richness in semi-natural habitats and landscape complexity differed between groups with the most pronounced positive effects on non-crop pollinators. Our results indicate that while dominant crop pollinators are core components of crop pollinator communities in all agricultural landscapes, opportunistic crop pollinators largely determine species-richness responses and complex landscapes are local hotspots for both biodiversity conservation and potential ecosystem service provision.

CTAB Surfactant Assisted and High pH Nano-Formulations of CuO Nanoparticles Pose Greater Cytotoxic and Genotoxic Effects.

Toxicity of synthesized nanoparticles is the area of concern to all the researchers due to their possible health implications. Here we synthesized copper oxide nanoparticles (CuO NPs) without surfactant at pH value of 2, 7, 10 and with cetyletrimethylammoniumbromide (CTAB) surfactant at pH 7. Synthesized nanoparticles were characterized for various structural parameters including crystallite size, lattice parameters, strain, phase analysis using X-ray diffraction analysis, and morphological aspects have been analyzed using FESEM and HRTEM imaging. All the four nano-formulations were analyzed for their toxic potential using Allium cepa L. at three different concentrations (0.1, 0.01 and 0.001 g/100 ml). Cytological and genetic parameters including mitotic index, mitotic inhibition, aberrant cells, binucleated cells, micronucleated cells, chromosomal bridges, fragmentation, stickiness, laggards, vagrants, c-mitosis and disturbed spindle were analyzed. Our results revealed a dose dependent increase in cytotoxic parameters including decreased total dividing cells, mitotic index, and increased mitotic inhibition. Genotoxic parameters also increased at higher treatment concentrations including chromosomal aberrations and percent aberrant cells. The pH value at the time of particle synthesis has significant influence on the crystallite size and agglomeration as assessed by XRD, FESEM and HRTEM analysis. The NPs synthesized at pH 2 and 10 were found to be of smaller size and posed more toxic effects as compared to particles synthesized at neutral pH. On the other hand, CTAB assisted CuO NPs synthesized at pH 7 revealed even smaller crystallite sizes and thus boost the toxicity in all the parameters as compared to NPs synthesized without CTAB. The present study suggested an increase in toxic parameters of synthesized CuO NPs with respect to crystallite size which is pH dependent. Addition of CTAB at pH 7 decreased the crystallite as well as particle size and enhanced the toxic potential. Further studies are recommended to analyze the effect of surfactant addition in toxicological studies on CuO NPs.

Toxicity of wastewater from health care facilities assessed by different bioassays.

OBJECTIVES: The purpose of this study was to determine toxicity of wastewater from hospitals in the Czech Republic using traditional and alternative toxicological methods. The pilot study comprised weekly dynamics of sewage ecotoxicity of treated wastewater from one hospital in two different seasons. A detailed investigation of wastewater ecotoxicity, genotoxicity and reprotoxicity followed in five different hospitals. METHODS: The seven following bioassays were used in this study: algal growth inhibition test (ISO 8692), Vibrio fischeri test (ISO 11348-2), Daphnia magna acute toxicity test (ISO 6341), Allium cepa assay, Ames test (OECD TG 471), Comet assay and YES/YAS assay. RESULTS: The wastewater ecotoxicity during one week showed no differences in separate working days, however, higher toxicity values were recorded in May compared to November. In the following study, samples from two of the five hospitals were classified as toxic, the others as non toxic. Genotoxicity has not been confirmed in any sample. In several cases, wastewater samples exhibited agonist activity to the estrogen and androgen receptors. CONCLUSION: The study demonstrated different levels of toxicity of treated hospital wastewater. Variable sensitivity of individual bioassays for tested wastewater samples was recognized. A more extensive study including proposal for improvement of hospital wastewater treatment within the Czech Republic can be recommended with the aim to decrease the discharge of toxic chemicals into the local sewage system and the environment.