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

Investigation of the protective role of Ginkgo biloba L. against phytotoxicity, genotoxicity and oxidative damage induced by Trifloxystrobin

Trifloxystrobin (TFS) is a widely used strobilurin class fungicide. Ginkgo biloba L. has gained popularity due to its recognized medicinal and antioxidant properties. The aim of this study was to determine whether Ginkgo biloba L. extract (Gbex) has a protective role against TFS-induced phytotoxicity, genotoxicity and oxidative damage in A. cepa. Different groups were formed from Allium cepa L. bulbs subjected to tap water (control), 200 mg/L Gbex (Gbex1), 400 mg/L Gbex (Gbex2), 0.8 g/L TFS solution (TFS), 200 mg/L Gbex + 0.8 g/L TFS (TFS + Gbex1) and 400 mg/L Gbex + 0.8 g/L TFS (TFS + Gbex2), respectively. The phenolic composition of Gbex and alterations in the morphological, physiological, biochemical, genotoxicity and anatomical parameters were evaluated. Rutin, protocatechuic acid, catechin, gallic acid, taxifolin, p-coumaric acid, caffeic acid, epicatechin, syringic acid and quercetin were the most prevalent phenolic substances in Gbex. Rooting percentage, root elongation, weight gain, chlorophyll a and chlorophyll b decreased by approximately 50%, 85%, 77%, 55% and 70%, respectively, as a result of TFS treatment compared to the control. In the TFS group, the mitotic index fell by 28% compared to the control group, but chromosomal abnormalities, micronuclei frequency and tail DNA percentage increased. Fragment, vagrant chromosome, sticky chromosome, uneven chromatin distribution, bridge, vacuole-containing nucleus, reverse polarization and irregular mitosis were the chromosomal abnormalities observed in the TFS group. The levels of proline (2.17-fold) and malondialdehyde (2.71-fold), as well as the activities of catalase (2.75-fold) and superoxide dismutase (2.03-fold) were increased by TFS in comparison to the control. TFS-provoked meristematic disorders were damaged epidermis and cortex cells, flattened cell nucleus and thickened cortex cell wall. Gbex combined with TFS relieved all these TFS-induced stress signs in a dose-dependent manner. This investigation showed that Gbex can play protective role in A. cepa against the phytotoxicity, genotoxicity and oxidative damage caused by TFS. The results demonstrated that Gbex had this antioxidant and antigenotoxic potential owing to its high phenolic content.

Ecofriendly Approach on the Removal of Reactive Orange 107 from Aqueous Solutions Using Cladophora Species as a Novel Biosorbent

The efficiency of Cladophora species for the removal of Reactive Orange 107 (RO107) from the aqueous solution was evaluated through batch adsorption studies by optimising various process parameters such as pH (3-8), dye concentration (100-500 mg/l), biosorbent concentration (100-500 mg/l), temperature (25-45 °C) and contact time (12-108 h). The results revealed that the optimum conditions for RO107 decolourisation (87%) was found on 72 h of incubation with 100 mg/l dye concentration amended with 200 mg/l biosorbent at pH 6 at 25 °C. The mechanism of dye adsorption was evaluated using isotherms, kinetics and thermodynamic models. The experimental data fitted well with Langmuir isotherm and pseudo-second-order kinetic models. Thermodynamic studies revealed that the adsorption process was endothermic, spontaneous and feasible in nature. Recovery of RO107 from the Cladophora sp. was maximum when 0.1 M HNO3 was used as an eluent. UV-Visible, FT-IR and SEM analyses reveal the interaction between the biosorbent-adsorbate and confirm the process of decolourisation by Cladophora sp. In order to evaluate the nature of the untreated and treated dye solutions, toxicological studies were conducted and the results revealed that the treated dye solution was non- toxic as compared with untreated dye solution. The results of the docking study proved that there was a substantial binding energy between RO107 and the protein (Cytochrome C6) of Cladophora sp. Hence, Cladophora sp. proves to be a promising biosorbent to decolourise RO107 and its potential can be explored in the textile sectors.

Assessing phytotoxicity and cyto-genotoxicity of two insecticides using a battery of in-vitro biological assays

Intensive use of chemical pesticides in agriculture poses environmental risks and may have negative impacts on agricultural productivity. The potential phytotoxicity of two chemical pesticides, chlorpyrifos (CPS) and fensulfothion (FSN), were evaluated using Cicer arietinum and Allium cepa as model crops. Different concentrations (0-100 μgmL-1) of both CPS and FSN decreased germination and biological attributes of C. arietinum. High pesticide doses significantly (p ≤ 0.05) caused membrane damage by producing thiobarbituric acid reactive substances (TBARS) and increasing proline (Pro) content. Pesticides elevated ROS levels and substantially increased the superoxide anions and H2O2 concentrations, thus aggravating cell injury. Plants exposed to high pesticide dosages displayed significantly higher antioxidant levels to combat pesticide-induced oxidative stress. Ascorbate peroxidase (APX), guaiacol peroxidase (GPX), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) increased by 48%, 93%, 71%, 52% and 94%, respectively, in C. arietinum roots exposed to 100 µgFSNmL-1. Under CLSM, pesticide-exposed C. arietinum and 2',7'-dichlorodihydrofluorescein diacetate (2'7'-DCF) and 3,3'-diaminobenzidine stained roots exhibited increased ROS production in a concentration-dependent manner. Additionally, enhanced Rhodamine 123 (Rhd 123) and Evan's blue fluorescence in roots, as well as changes in mitochondrial membrane potential (ΔΨm) and cellular apoptosis, were both associated with high pesticide dose. Allium cepa chromosomal aberration (CAs) assay showed a clear reduction in mitotic index (MI) and numerous chromosomal anomalies in root meristematic cells. Additionally, a-dose-dependent increase in DNA damage in root meristematic cells of A. cepa and conversion of the super-coiled form of DNA to open circular in pBR322 plasmid revealed the genotoxic potential of pesticides. The application of CPS and FSN suggests phytotoxic and cyto-genotoxic effects that emphasize the importance of careful monitoring of current pesticide level in soil before application and addition at optimal levels to soil-plant system. It is appropriate to prepare both target-specific and slow-release agrochemical formulations for crop protection with concurrent safeguarding of agroecosystems.

Allium cytogenetics: a critical review on the Indian taxa

The genus Allium Linnaeus, 1753 (tribe Allieae) contains about 800 species worldwide of which almost 38 species are reported in India, including the globally important crops (onion, garlic, leek, shallot) and many wild species. A satisfactory chromosomal catalogue of Allium species is missing which has been considered in the review for the species occurring in India. The most prominent base number is x=8, with few records of x=7, 10, 11. The genome size has sufficient clues for divergence, ranging from 7.8 pg/1C to 30.0 pg/1C in diploid and 15.16 pg/1C to 41.78 pg/1C in polyploid species. Although the karyotypes are seemingly dominated by metacentrics, substantial variation in nucleolus organizing regions (NORs) is noteworthy. The chromosomal rearrangement between A.cepa Linnaeus, 1753 and its allied species has paved way to appreciate genomic evolution within Allium. The presence of a unique telomere sequence and its conservation in Allium sets this genus apart from all other Amaryllids and supports monophyletic origin. Any cytogenetic investigation regarding NOR variability, telomere sequence and genome size in the Indian species becomes the most promising field to decipher chromosome evolution against the background of species diversity and evolution, especially in the Indian subcontinent.

Treated tannery effluent and its impact on the receiving stream water: physicochemical characterization and cytogenotoxic evaluation using the Allium cepa test

Tanneries are considered some of the most polluting industries due to the heavy use of toxic compounds, most of which are released into water bodies, thus exerting adverse effects on aquatic biota. However, the effects on organisms of treated effluents when released into the natural environment are rarely evaluated. This study aims to assess the physicochemical parameters of a tannery effluent after treatment (TE) at a Common Effluent Treatment Plant as well as the water of the receiving stream and to evaluate cytogenotoxic effects in Allium cepa. Three sampling sites (A: TE discharge point; B: 100 m downstream from site A along the receiving stream; C: 100 m upstream from site A along the stream) were selected. Onion bulbs were exposed to TE (100%, 80%, 60% v/v), water samples from sites B and C, and tap water for 72 h. Chromosomal aberration and mitotic index were analyzed on the root cells of A. cepa. The TE was above the standard limits for ammoniacal nitrogen, COD, and total nitrogen. No cytogenotoxicity was observed in A. cepa exposed to samples from sites A and C. However, the stream water sampled downstream from the TE discharge site significantly reduced the mitotic index, indicating a cytotoxic effect. Therefore, this demonstrates the effects of interactions between the receiving water and the complex chemical mixtures in the TE. The findings thus showed that the toxicity assessment of treated effluents along with the receiving water body would provide valuable and more realistic information about the joint toxicity of chemical pollutants in aquatic environments.

Degradation of Praguicide Disulfoton Using Nanocompost and Evaluation of Toxicological Effects

Organophosphates (OPPs) are an important element of modern agriculture; however, because they are being used excessively, their residues are leaching and accumulating in the soil and groundwater, contaminating aquatic and terrestrial food chains. An important OPP called disulfoton is frequently used to eradicate pests from a wide range of crops, including Brazil's coffee crops. Additionally, it does not easily degrade in the environment, and as such, this compound can slowly build up in living organisms such as humans. Moreover, this compound has been classified as "extremely hazardous" by the World Health Organization. This study evaluated the degradation efficiency of disulfoton using a Fenton-like reaction catalyzed by magnetite nanoparticles and determined the toxicity of the by-products of the degradation process using the bioindicator Allium cepa. Further, the removal efficiency of disulfoton was determined to be 94% under optimal conditions. On the other hand, the Allium cepa bioassay showed different toxic, cytotoxic, genotoxic, and mutagenic outcomes even after the remediation process. In conclusion, the Fenton process catalyzed by magnetite nanoparticles presents great efficiency for the oxidation of disulfoton. However, it is important to highlight that the high degradation efficiency of the Fenton-based process was not sufficient to achieve detoxification of the samples.

Preparation and Phytotoxicity Evaluation of Cellulose Acetate Nanoparticles

The use of biocompatible and low-cost polymeric matrices to produce non-phytotoxic nanoparticles for delivery systems is a promising alternative for good practices in agriculture management and biotechnological applications. In this context, there is still a lack of studies devoted to producing low-cost polymeric nanoparticles that exhibit non-phytotoxic properties. Among the different polymeric matrices that can be used to produce low-cost nanoparticles, we can highlight the potential application of cellulose acetate, a natural biopolymer with biocompatible and biodegradable properties, which has already been used as fibers, membranes, and films in different agricultural and biotechnological applications. Here, we provided a simple and low-cost route to produce cellulose acetate nanoparticles (CA-NPs), by modified emulsification solvent evaporation technique, with a main diameter of around 200 nm and a spherical and smooth morphology for potential use as agrochemical nanocarriers. The non-phytotoxic properties of the produced cellulose acetate nanoparticles were proved by performing a plant toxic test by Allium cepa assay. The cytotoxicity and genotoxicity tests allowed us to evaluate the mitotic process, chromosomal abnormalities, inhibition/delay in root growth, and micronucleus induction. In summary, the results demonstrated that CA-NPs did not induce phytotoxic, cytotoxic, or genotoxic effects, and they did not promote changes in the root elongation, germination or in the mitotic, chromosomal aberration, and micronucleus indices. Consequently, the present findings indicated that CA-NPs can be potentially used as environmentally friendly nanoparticles.

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.

Evaluating Potential Ecological Risks of Heavy Metals of Textile Effluents and Soil Samples in Vicinity of Textile Industries

The present study pertains to assessing the heavy metal (Cd, Cr, Co, Cu, Pb, and Zn) contents of untreated and treated effluents of two textile industries and agricultural soil samples in the vicinity of these industries located in Ludhiana, Punjab (India). The genotoxicity of the effluents samples was estimated using Allium cepa root chromosomal aberration assay. The exposure of Allium cepa roots to untreated effluents from both industries resulted in the reduction of mitotic index (MI) and increase in chromosomal aberrations in the root tip meristematic cells when compared to those that were exposed to the treated effluents indicating the significant genotoxic potential of untreated effluents. Risk characterization of soil sample was carried out by calculating the potential ecological and human health risks of heavy metals. The hazard index was observed to be less than 1, indicating there was no potential health risk of heavy metals in soil samples. Furthermore, bioaccumulation potential studies on plant species grown in the vicinity of these industries have shown that bioaccumulation factor (BAF) varied as Ricinus communis L. > Chenopodium album L. > Cannabis sativa L. with Co and Pb having maximum and minimum values, respectively.

Detection and characterization of refractory organic and inorganic pollutants discharged in biomethanated distillery effluent and their phytotoxicity, cytotoxicity, and genotoxicity assessment using Phaseolus aureus L. and Allium cepa L

The color effluent discharged by alcohol distilleries comprises very high pollution loads due to the plethora of refractory chemicals even after anaerobic treatment and causing adverse effects to the environment. The present study aimed to examine the phytotoxic, cytotoxic, and genotoxic potential of the identified refractory organic and inorganic pollutants discharged in bio-methanated distillery effluent (BMDE). Physico-chemical analyses revealed that BMDE retains high BOD, COD, TDS along with heavy metals like Fe (572.64 mg L^-1), Mn (4.269 mg L^-1), Cd (1.631 mg L^-1), Zn (2.547 mg L^-1), Pb (1.262 mg L^-1), (Cr 1.257 mg L^-1), and Ni (0.781 mg L^-1) beyond the permissible limits for effluent discharge. GC-MS analysis revelaed the presence of hexadecanoic acid, TMS ester; octadecanoic acid, TMS ester; 2,3 bis[(TMS)oxy]propyl ester; stigmasterol TMS ether; β-sitosterol TMS ester; hexacosanoic acid; and tetradecanoic acid, TMS ester as major refractory organic pollutants, which are listed as potential endocrine disruptor chemicals (EDCs) as per USEPA. Furthermore, phytotoxicity assessment with Phaseolus aureus L. showed the toxic nature of BMDE as it inhibited various seedling growth parameters, seed germination, and suppression of α-amylase activity in seed germination experiment. Moreover, genotoxicity and cytotoxicity evaluation of the discharged BMDE evidenced in root-tip meristematic cells of Allium cepa L. where chromosomal aberration such as disturbed metaphase, c-mitosis, laggard chromosomes, sticky chromosomes, prolonged prophase, polyploid cells, and apoptotic bodies etc. were observed. Thus, this study's results suggested that BMDE discharged without adequate treatment poses potential risk to environment and may cause a variety of serious health threats in living beings upon exposure.

A study on water quality monitoring of Buddha Nullah, Ludhiana, Punjab (India)

Diverse genotoxic agents, entering the aquatic environment through natural and anthropogenic events, pose serious threats to its biotic components. The present study involves the monitoring of water quality by assessing the genotoxic effects and physico-chemical parameters including heavy metals of 10 surface water samples collected from different locations of Buddha Nullah, a tributary of Sutlej flowing through Ludhiana, Punjab (India). Genotoxicity was evaluated following Allium cepa root chromosomal aberration assay and DNA nicking assay using plasmid (pBR322) whilst the metal (cadmium, chromium, cobalt, copper, lead, nickel and zinc) analysis was conducted using atomic absorption spectrophotometer. All water samples collected from the study area had cobalt and lead content more than the permissible limits (0.04 and 0.01, respectively) recommended by the Bureau of Indian Standards and the World Health Organization. The samples also induced genotoxicity following both bioassays. The water samples collected from Gaunspur (GP), a site approx. 75.53 km upstream of the Sutlej-Buddha Nullah joining point, has shown the maximum genotoxic effect, i.e. 38.62% in terms of per cent total aberrant cells during A. cepa assay and 100% DNA damage during DNA nicking assay. The Pearson correlation indicated that genotoxicity had a significant positive correlation with the content of cobalt (at p ≤ 0.5). During cluster analysis, the samples from 10 sites formed four statistically significant clusters based on the level of pollution that was dependent on two factors like similarity in physico-chemical characteristics and source of pollution at a specific site.

Water assessment of the Itapemirim River/Espírito Santo (Brazil): abiotic and toxicogenetic aspects

The Itapemirim River is considered one of the most important water resources in the state of Espírito Santo, Brazil. However, environmental problems due to continuous anthropogenic contamination are threatening its potential use. This study assessed water quality by analyzing abiotic and toxicogenetic aspects of the water from four stations along the river. Samples were collected in both dry and rainy seasons. Most of the abiotic variables were below the threshold established by CONAMA Resolution No. 357/2005, and so were most of the metals. However, Al and Cu contents were above those allowed by legislation, ranging from 0.2 to 0.9 mg/L. Regarding toxicogenetic aspects, genotoxic effects were observed in meristematic cells of Allium cepa, in micronucleus test and comet assay of Oreochromis niloticus, and CHO-K1 cells. Mutagenic effects were significant at RI 02 (0.34), RI 03 (0.46), and RI 04 (0.12) stations on the first campaign in A. cepa F1 cells, compared to the negative control (0.0). The second campaign revealed the same results, but with the addition of samples from RI 01 (0.17) and RI 03 (0.18) showing mutagenicity in the micronucleus test with fish erythrocytes when compared to the negative control (0.3). Essentially, all the samples evaluated in both campaigns showed damage in A. cepa, O. niloticus, and CHO-K1 cells, thus demonstrating that the water quality of the Itapemirim River is compromised and requires action plans for its recovery.

Chromosomal Abnormalities in Allium cepa Induced by Treated Textile Effluents: Spatial and Temporal Variations

Appropriate effluent treatment processes are expected to significantly reduce the toxicity of effluents before they are released to the natural environment. The present study was aimed to assess the spatial and temporal variations of the physical and chemical water quality parameters of a natural water body receiving treated textile effluents and to assess the chromosomal abnormalities induced by the treated textile effluents. Four sampling sites (A: effluent discharge point; B: 100 m downstream from site A along the tributary; C: 200 m downstream from site A along the tributary; D: 100 m upstream from site A along the tributary) were selected associated to a tributary that received treated textile effluent. The physical and chemical water quality parameters were measured in the composite water samples collected from the study sites, and Allium cepa bioassay was conducted using aged tap water as the control. Sampling was conducted in both rainy and dry seasons. The conductivity, TDS, COD, and colour intensity of the water samples collected from the study sites were significantly higher during the dry season compared to those in the rainy season. Allium cepa root meristematic cells exposed to water samples from sites A, B, and C showed a significantly high interphase and prophase indices compared to those exposed to aged tap water and upstream site during both rainy and dry seasons. The mitotic index of the root tip cells of Allium cepa bulbs exposed to the water samples collected from the effluent discharge point (site A) and from the 100 m downstream site from site A (site B) was significantly lower than that of the other sites in both rainy and dry seasons. However, the mitotic index of the root tip cells of Allium cepa bulbs exposed to the water samples from the upstream site was not significantly different from that of the control treatment during both sampling seasons. The bioassay indicated that the mitotic index and phase index of the root meristematic cells of Allium cepa can be affected by the treated textile effluents released to the water body and the occurrence of C metaphase, chromosomal adherence, bridges, disturbed anaphase, vagrant chromosomes, and chromosomal breaks indicated that the treated textile effluent receiving tributary can possibly contain genotoxic and mutagenic compounds which can induce chromosomal abnormalities.

Application of cytogenetic model Allium cepa for screening potential cytogenotoxicity of herbal-based hair dyes

Plant models may be useful as test organisms for initial screening of potential toxicity of personal care products. The objective of the present study was to assess the efficacy of the Allium cepa (common onion) test system as a bioanalytical tool for screening potential cytotoxicity and genotoxicity of herbal-based hair dye formulations. Exposure of black hair dye formulations for 48 hours resulted in root growth retardation and mitosis suppression in the root meristems of A. cepa bulbs indicating concentration dependent cytotoxicity. At the 72 hour post exposure, cytotoxic effects on the roots were reduced but not recovered completely signifying prolong toxic action of the hair dyes. The condensed nuclei was the most frequent nuclear abnormality found in the dye exposed root meristematic cells indicating the cell death process. Induction of micronuclei and chromosomal aberrations in the root meristematic cells even at the post exposure stage indicates persistent genotoxicity of the hair dyes which may be attributed to the interactive effects of chemical mixtures present in the commercial hair dye formulations. The results revealed that A. cepa test system is an effective bioanalytical tool for screening cytogenotoxicity of commercial hair dye formulations.

Chemical characterization, phytotoxic, and cytotoxic activities of essential oil of Mentha longifolia

The present study assessed the phytotoxic and cytotoxic potential of the essential oil (EO) extracted from aboveground parts of Mentha longifolia (L.) Huds. Gas chromatography-mass spectrometry revealed 39 compounds constituting 99.67% of the EO. The EO was rich in monoterpenoids (mostly oxygenated monoterpenes), which accounted for 89.28% of the oil. The major components in EO were monoterpene ketones such as piperitone oxide (53.83%) and piperitenone oxide (11.52%), followed by thymol (5.80%), and (E)-caryophyllene (4.88%). The phytotoxic activities of EO were estimated against Cyperus rotundus, Echinochloa crus-galli, and Oryza sativa (rice) through pre- and post-emergence assays at concentrations ranging from 10 to 250 μg/ml and 0.5-5%, respectively. In pre-emergence assay, the phytotoxic effect of EO was most pronounced on C. rotundus, thereby significantly affecting percent germination, plantlet growth, and chlorophyll content. On the contrary, the impact was comparatively lesser on rice, with ~ 40% germination in response to 250 μg/ml of EO treatment. In the post-emergence assay, the spray treatment of EO caused a loss of chlorophyll and wilting in test plants, and subsequently affected the growth of plants, even leading to death in some cases. The cytotoxic activity of EO (at 2.5-50 μg/ml) was studied in meristem cells in onion (Allium cepa L.) root tips. EO exposure to the onion roots induced various chromosomal aberrations such as chromosomal bridges, c-mitosis, stickiness, vagrant chromosomes, etc., and negatively affected the mitotic index. At 50 μg/ml, EO treatment triggered the complete death of roots. The study concludes that M. longifolia EO has phytotoxic activities due to the mito-depressive effect, along with other physiological effects on target plants. Therefore, EO of M. longifolia could be developed into a novel bioherbicide for sustainable management of weeds in agricultural systems.

Cytogenotoxic potential of a hazardous material, polystyrene microparticles on Allium cepa L

Plastic pollution represents a global concern for the biodiversity conservation, ecosystem and public health. The polystyrene is one of the dominant pollutants in both terrestrial and aquatic ecosystem. This work measured the hazardous nature of 100 nm micropolystyrene (MPS) using 25, 50, 100, 200, and 400 mg/L concentrations in terms of oxidative stress, morphotoxicity and cytogenotoxicity in Allium cepa. The results were compared with the positive control (PC) (400 mg/L chlorpyrifos). MPS significantly (p < 0.05) reduced the root length while induced the production of hydroxyl, superoxide radicals with a concomitant increase in DPPH scavenging activity and lipid peroxidation as compared to the negative control. The significant decrease in mitotic index with respect to the negative control (MI: 23.855 ± 5.336 %; lowest MI: 3.88 ± 1.042 %) showed the cytotoxic nature of MPS. Genotoxicity was assessed by various chromosomal and nuclear aberrations. The highest 3.029 ± 0.403 % (PC: 3.09 ± 0.535 %) chromosomal abnormality index and 2.31 ± 0.338 % (PC: 1.178 ± 0.095 %) nuclear abnormality index were observed. MPS down-regulated the expression of plant CDKA encoding gene: cdc2, an important cell cycle regulator. The overall results indicated that MPS could induce cytogenotoxicity through the exacerbation of ROS production and inhibition of cdc2.

Treated Textile Effluents: Cytotoxic and Genotoxic Effects in the Natural Aquatic Environment

Textile effluent treatment methods use biological and chemical treatments to reduce the toxicity and to comply with standard effluent discharge limits. However, trace amounts of pollutants can affect the biological organisms in the receiving environment. The present study used Allium cepa bio assay to assess the cytotoxic and genotoxic effects of treated textile effluents discharged to the natural environment. The results of the bioassay indicated that treated textile effluents can induce alterations in the mitotic index. Also nuclear buds, bi nuclei, condensed nuclei, were recorded in the bioassay and the severity of them decreased towards downstream of the effluent discharge point. Therefore, it can be concluded that even the discharged effluents comply with the standard limits, there is a possibility of causing cytotoxic and genotoxic effects in the organisms living in the natural environment.

Mutagenicity, genotoxicity and oxidative stress induced by pesticide industry wastewater using bacterial and plant bioassays

Atomic absorption spectrophotometer and gas chromatography analysis revealed the presence of heavy metals, organochlorine and organophosphate pesticides in industrial wastewater. XAD, Dichloromethane and n-Hexane extracted wastewater were analysed for genotoxic potential using Ames Salmonella/mammalian microsome test. The XAD concentrated sample displayed remarkable mutagenic activity compared to solvent assisted liquid-liquid extraction. Strain TA98 was found utmost sensitive towards all extracts. Wastewater induced chromosomal aberrations in roots of Allium cepa showed significant (p < 0.05) decrease in mitotic index. Seeds of Vigna radiata germinated on soft agar plates treated with different concentration of wastewater showed significant reduction in germination (52 %), seedling vigor index (76 %), radicle length (56 %), plumule length (47 %), biomass of radicle (64 %) and plumule (57%) at highest wastewater concentration. Propidium iodide stained V. radiata roots showed oxidative stress induced by wastewater under CLS microscopy. Further, genotoxicity of wastewater was confirmed by plasmid nicking assay using pBR322 plasmid.

Assessing the efficiency in assisted depuration of coffee processing wastewater from mixed wild microbial selected inoculum

This work evaluated the efficiency of bacterial bio-augmentation to the biological treatment of coffee processing wastewater (CPWW) in a pilot wastewater treatment plant (WTP). Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) values were the basis for the treatment efficiency. Serratia marcescens CCMA 1010 and CCMA 1013, Corynebacterium flavescens CCMA 1006 and Acetobacter indonesiensis CCMA 1002 were previously selected. The microbial cocktail was inoculated and persisted in CPWW during all treatments. The richness of wild species was a little altered over time and up to nine species were found in each sampled season. The microbiota composition presented variation of a total of 13 species, despite the inoculation of the microbial inoculum. The biodegradability index of effluent, close to 0.5, was favourable to biological treatment. The pollution parameters of CPWW were decreased in function of the variation of community composition and microbial activity. The greatest reduction of BOD (~ 33%) and COD (~ 25%) was observed between 72 h and 8 days of the biological treatment. The CPWW toxicity in Allium cepa seeds was lower by up to 60%, and the germination index (GI) exceeded 100% in the treated CPWW. The results of the CPWW biological treatment by bio-augmentation from native micro-organisms in the pilot-scale WTP indicated the greatest efficiency relating to the spontaneous biological treatment of CPWW. After this treatment, the discharge of effluent in the environment would not have toxic effects on the plants.

Allium cepa Bio Assay to Assess the Water and Sediment Cytogenotoxicity in a Tropical Stream Subjected to Multiple Point and Nonpoint Source Pollutants

The present study was conducted to assess the cytotoxicity of water and sediments of an industrial effluent receiving water body in the western province of Sri Lanka using Allium cepa bioassay. Six sampling sites (Site A: Urban; B: Industrial; C: Water intake for public water supply; D: Industrial; E: Agricultural; F: Reference) were selected from the study area. Ten replicate water and sediment samples were collected from each site, and physical and chemical parameters were measured using standard analytical methods. Cytotoxicity of water and sediment elutriates were measured using Allium cepa bioassay. Despite the significant spatial variations, the overall water and sediment quality parameters of the study sites were in accordance with the standard ambient environment parameters to sustain a healthy aquatic life. In the A. cepa bulbs exposed to water samples, significant root growth variations were not observed within 48 hours of exposure. However, significant root length variations were observed in A. cepa bulbs exposed to sediment elutriates within the 48-hour exposure and the percentage root growth inhibition increased with increase of exposure time. Similar trend was observed in mitotic activity indicating significantly lower mitotic indices (compared to that of the reference site) in A. cepa root tip cells exposed to sediment elutriates than those exposed to water samples. Further, the highest number of nuclear abnormalities was recorded from root tip cells of A. cepa exposed to water and sediment samples from sites B, C, and D. Therefore, it is of extreme importance to identify the composition and speciation of these cytogenotoxic compounds in the tropical climatic conditions and to propose possible clean-up or treatment solutions to overcome this environmental and public health risk associated problem.

Mutagenicity and genotoxicity evaluation of textile industry wastewater using bacterial and plant bioassays

Textile industrial wastewater samples were taken from the Panki site 5 industrial area of Kanpur city, India. Atomic Absorption spectrophotometer and Gas Chromatography-Mass spectrometry techniques have shown that the wastewater contained several heavy metals and organic pollutants (Khan and Malik, 2017) [1]. Further, in order to explore the potential toxicity of these pollutants present in the effluent, a battery of short-term biological assays (Ames test, DNA repair defective mutation assay and Allium cepa chromosomal aberration test) were used. Wastewater samples were concentrated with XAD-4/8 resins and liquid-liquid extraction procedure. XAD-concentrated samples were more mutagenic than the liquid-liquid extracted samples. Ames TA98 and polA (SOS defective) strains were the most responsive strains. The wastewater also resulted in significant decline in mitotic index and induced chromosomal aberrations in A. cepa roots. The findings thus showed that the combination of physico-chemical analysis alongwith the toxicity assessment (using short term biological assays) would provide valuable and more realistic information about the joint toxicity of chemical pollutants present in the textile effluent.

Morphotoxicity and cytogenotoxicity of pendimethalin in the test plant Allium cepa L. - A biomarker based study

Pesticides have brought tremendous benefits to mankind by increasing food production and controlling various crop diseases. But their prolonged and extensive use has been reported to induce toxicity. Biological markers used for the evaluation of toxic effects of pesticides have increased these days. The aim of this study was to determine the morphotoxic and cytogenotoxic effects of pesticide pendimethalin applied to the soil by using morphological and genotoxic biomarkers in the test plant Allium cepa L. A pot experiment was set up in which pendimethalin was added to soil at the rate of 0, 0.033, 0.044, 0.055 and 0.066 g kg^-1 soil. Similar sized onion bulbs were planted in each pot and 3 replicates were maintained for each dose of pendimethalin at 1, 7, 15, 30 and 45 days after treatment. Average root number (ARN) and average length of roots (ALR) of onion bulbs were recorded and on the day 3 of sowing roots were harvested and fixed for cytological analysis. Morphological biomarkers revealed significant concentration and duration dependent inhibition of ARN and ALR as compared to control which shows the morphotoxicity of pendimethalin. The results also showed inhibitory effect on the mitotic index (%) of A. cepa while relative abnormality rate (%) increased. Further, we observed aberrations in both the dividing and non-dividing cells along with spotting of few ring chromosomes. Reduced mitotic index, increased relative abnormality rate; various chromosomal and interphase nuclear aberrations all being mitosis endpoint markers reflect the cytogenotoxicity of pendimethalin, even at lower concentrations.

The effects of organophosphorus insecticides and heavy metals on DNA damage and programmed cell death in two plant models

The ubiquity of pollutants, such as agrochemicals and heavy metals, constitute a serious risk to human health. To evaluate the induction of DNA damage and programmed cell death (PCD), root cells of Allium cepa and Vicia faba were treated with two organophosphate insecticides (OI), fenthion and malathion, and with two heavy metal (HM) salts, nickel nitrate and potassium dichromate. An alkaline variant of the comet assay was performed to identify DNA breaks; the results showed comets in a dose-dependent manner, while higher concentrations induced clouds following exposure to OIs and HMs. Similarly, treatments with higher concentrations of OIs and HMs were analyzed by immunocytochemistry, and several structural characteristics of PCD were observed, including chromatin condensation, cytoplasmic vacuolization, nuclear shrinkage, condensation of the protoplast away from the cell wall, and nuclei fragmentation with apoptotic-like corpse formation. Abiotic stress also caused other features associated with PCD, such as an increase of active caspase-3-like protein, changes in the location of cytochrome C (Cyt C) toward the cytoplasm, and decreases in extracellular signal-regulated protein kinase (ERK) expression. Genotoxicity results setting out an oxidative via of DNA damage and evidence the role of the high affinity of HM and OI by DNA molecule as underlying cause of genotoxic effect. The PCD features observed in root cells of A. cepa and V. faba suggest that PCD takes place through a process that involves ERK inactivation, culminating in Cyt C release and caspase-3-like activation. The sensitivity of both plant models to abiotic stress was clearly demonstrated, validating their role as good biosensors of DNA breakage and PCD induced by environmental stressors.

Monitoring of morphotoxic, cytotoxic and genotoxic potential of mancozeb using Allium assay

The present experiment was designed to monitor the morphotoxic, cytotoxic and genotoxic potential of Mancozeb (fungicide) in non-target plants using bulbs of Allium cepa. Mancozeb is classified as a contact fungicide and is registered for use on a variety of crop plants. In the present monitoring, Allium cepa bulbs were exposed to different concentrations of mancozeb viz., 10, 30, 50, 70, 90, 110, 130 and 150 ppm for 24 and 48 h. The potential morphotoxic and cytotoxic effects of mancozeb were examined by determining the average root number, average root length, mitotic index, relative abnormality rate (%) and frequency of abnormalities (%). A progressive significant concentration and time dependent inhibition of the average root number, average root length indicated the morphotoxic nature. The cytotoxic effect was significantly increased for 48 h treatment as compared to 24 h treatment time, by reducing the mitotic index of meristematic cells. The results indicated an indirect genotoxic effect by inducing different types of chromosomal abnormalities, likely sticky, disoriented and fragmented chromosomes. Thus indicating that the investigated fungicide have genotoxic potential due to abnormal DNA condensation and chromosome coiling by spindle inactivation. The observations of cyto and genotoxic effects suggest that the fungicide mancozeb is clastogenic agent. Thus the different concentrations used in the field could be harmful for the end-receptors of food-chain and needs constant monitoring and management for the better development of crop plants.

Bioassessment of the Effluents Discharged from Two Export Oriented Industrial Zones Located in Kelani River Basin, Sri Lanka Using Erythrocytic Responses of the Fish, Nile Tilapia (Oreochromis niloticus)

Complex effluents originating from diverse industrial processes in industrial zones could pose cytotoxic/genotoxic hazards to biota in the receiving ecosystems which cannot be revealed by conventional monitoring methods. This study assessed potential cytotoxicity/genotoxicity of treated effluents of two industrial zones which are discharged into Kelani river, Sri Lanka combining erythrocytic abnormality tests and comet assay of the tropical model fish, Nile tilapia. Exposure of fish to the effluents induced erythrocytic DNA damage and deformed erythrocytes with serrated membranes, vacuolations, nuclear buds and micronuclei showing cytotoxic/genotoxic hazards in all cases. Occasional exceedance of industrial effluent discharge regulatory limits was noted for color and lead which may have contributed to the observed cytotoxicity/genotoxicity of effluents. The results demonstrate that fish erythrocytic responses could be used as effective bioanalytical tools for cytotoxic/genotoxic hazard assessments of complex effluents of industrial zones for optimization of the waste treatment process in order to reduce biological impacts.

In vitro and in vivo investigation of the genotoxic potential of waters from rivers under the influence of a petroleum refinery (São Paulo State - Brazil)

In recent years concern about the chemical composition of wastewater generated by the oil refining industry has increased, even after its treatment. These wastewaters contain substances that can harm both the entire aquatic ecosystem and the health of any exposed organisms. The aim of this study was to evaluate the genotoxic and mutagenic potentials of the effluent generated by the largest Brazilian petroleum refinery, the effectiveness of the treatments used by the refinery, and whether its effluent can compromise the water quality of the river where it is discarded. Chromosomal aberration and micronucleus assays were performed in Allium cepa and micronucleus test in mammalian cell culture (CHO-K1). The samples were collected in three sites at the refinery: one site on the Jaguari River and two sites on the Atibaia Rivers (upstream and downstream of the discharged effluent), under three different climatic conditions. Tests with A. cepa showed increased frequencies of chromosomal aberrations and micronuclei in meristematic cells for the effluent after physico-chemical treatment, but the samples after treatment biological and stabilization pond presented none of these abnormalities. It was observed that the induced damage in the meristematic cells was not observed in the F₁ cells of A. cepa roots. The micronucleus test performed with mammalian cell culture also indicated that the effluent, after physico-chemical treatment, induced a significant increase in micronucleus frequencies. Plant and hamster cells exposed to the other samples collected inside the refinery and in the Jaguari and Atibaia Rivers did not present evidence of genotoxicity and mutagenicity in the tests performed. This study showed that the effluent treated carried out by the refinery (biological treatment followed by a stabilization pond) proved to be efficient for the removal of the toxic load still present after the physico-chemical treatment, since no change in the quality of the Atibaia River was observed. However, because this is an industry with a high production of effluent with toxic potential, its effluents must be constantly monitored, so that there is no compromise of the water quality of the receiving river.

Combination of physico-chemical analysis, Allium cepa test system and Oreochromis niloticus erythrocyte based comet assay/nuclear abnormalities tests for cyto-genotoxicity assessments of treated effluents discharged from textile industries

Bioassays for cyto-genotoxicity assessments are generally not required in current textile industry effluent discharge management regulations. The present study applied in vivo plant and fish based toxicity tests viz. Allium cepa test system and Oreochromis niloticus erythrocyte based comet assay and nuclear abnormalities tests in combination with physico-chemical analysis for assessing potential cytotoxic/genotoxic impacts of treated textile industry effluents reaching a major river (Kelani River) in Sri Lanka. Of the treated effluents tested from two textile industries, color in the Textile industry 1 effluents occasionally and color, biochemical oxygen demand and chemical oxygen demand in the Textile industry 2 effluents frequently exceeded the specified Sri Lankan tolerance limits for discharge of industrial effluents into inland surface waters. Exposure of A. cepa bulbs to 100% and 12.5% treated effluents from both industries resulted in statistically significant root growth retardation, mito-depression, and induction of chromosomal abnormalities in root meristematic cells in comparison to the dilution water in all cases demonstrating cyto-genotoxicity associated with the treated effluents. Exposure of O. niloticus to the 100% and 12.5% effluents, resulted in erythrocytic genetic damage as shown by elevated total comet scores and induction of nuclear abnormalities confirming the genotoxicity of the treated effluents even with 1:8 dilution. The results provide strong scientific evidence for the crucial necessity of incorporating cyto-genotoxicity impact assessment tools in textile industry effluent management regulations considering human health and ecological health of the receiving water course under chronic exposure.