Frameshift Mutagens Research Articles

S(+)-(2E)-N-(2-Hydroxypropyl)-3-Phenylprop-2-Enamide (KM-568): A Novel Cinnamamide Derivative with Anticonvulsant Activity in Animal Models of Seizures and Epilepsy.

Epilepsy is one of the most frequent neurological disorders affecting about 1% of the world’s human population. Despite availability of multiple treatment options including antiseizure drugs, it is estimated that about 30% of seizures still remain resistant to pharmacotherapy. Searching for new antiseizure and antiepileptic agents constitutes an important issue within modern medicinal chemistry. Cinnamamide derivatives were identified in preclinical as well as clinical studies as important drug candidates for the treatment of epilepsy. The cinnamamide derivative presented here: S(+)-(2E)-N-(2-hydroxypropyl)-3-phenylprop-2-enamide (S(+)-N-(2-hydroxypropyl)cinnamamide, compound KM-568) showed anticonvulsant activity in several models of epilepsy and seizures in mice and rats. It was active in a genetic animal model of epilepsy (Frings audiogenic seizure-susceptible mouse model, ED50 = 13.21 mg/kg, i.p.), acute seizures induced electrically (maximal electroshock test ED50 = 44.46 mg/kg mice i.p., ED50 = 86.6 mg/kg mice p.o., ED50 = 27.58 mg/kg rats i.p., ED50 = 30.81 mg/kg rats p.o., 6-Hz psychomotor seizure model 32 mA ED50 = 71.55 mg/kg mice i.p., 44 mA ED50 = 114.4 mg/kg mice i.p.), chronic seizures induced electrically (corneal kindled mouse model ED50 = 79.17 mg/kg i.p., hippocampal kindled rat model ED50 = 24.21 mg/kg i.p., lamotrigine-resistant amygdala kindled seizure model in rats ED50 = 58.59 mg/kg i.p.), acute seizures induced chemically (subcutaneous metrazol seizure threshold test ED50 = 104.29 mg/kg mice i.p., ED50 = 107.27 mg/kg mice p.o., ED50 = 41.72 mg/kg rats i.p., seizures induced by picrotoxin in mice ED50 = 94.11 mg/kg i.p.) and the pilocarpine-induced status epilepticus model in rats (ED50 = 279.45 mg/kg i.p., ED97 = 498.2 mg/kg i.p.). The chemical structure of the compound including configuration of the chiral center was confirmed by NMR spectroscopy, LC/MS spectroscopy, elemental analysis, and crystallography. Compound KM-568 was identified as a moderately stable derivative in an in vitro mouse liver microsome system. According to the Ames microplate format mutagenicity assay performed, KM-568 was not a base substitution or frameshift mutagen. Cytotoxicity evaluation in two cell lines (HepG2 and H9c2) proved the safety of the compound in concentrations up to 100 µM. Based on the results of anticonvulsant activity and safety profile, S(+)-(2E)-N-(2-hydroxypropyl)-3-phenylprop-2-enamide could be proposed as a new lead compound for further preclinical studies on novel treatment options for epilepsy.

Structure of an Unusual Tetracyclic Deoxyguanosine Adduct: Implications for Frameshift Mutagenicity of ortho-Cyano Nitroanilines.

Nitroaromatic compounds represent a major class of industrial chemicals that are also found in nature. Polycyclic derivatives are regarded as potent mutagens and carcinogens following bioactivation to produce nitrenium electrophiles that covalently modify DNA to afford N-linked C8-2'-deoxyguanosine (C8-dG) lesions that can induce frameshift mutations, especially in CpG repeat sequences. In contrast, their monocyclic counterparts typically exhibit weak mutagenicity or a lack thereof, despite also undergoing bioactivation to afford N-linked C8-dG adducts. Recently, it has been reported that cyano substitution can greatly increase the mutagenicity of nitroaniline derivatives that are components of azo dyes. The basis of this "cyano effect" may be rooted in the formation of a novel polycyclic adduct arising from initial formation of the N-linked C8-dG adduct followed by a cyclization process involving N7 of dG and the ortho-CN group of the attached C8-aryl moiety to generate a quinazolinimine ring as part of a fused tetracyclic C8,N7-dG adduct structure. The present work structurally characterizes this novel cyclic adduct using a combination of optical spectroscopies, NMR analysis, density functional theory (DFT) calculations, and molecular dynamics (MD) simulations. Our data indicate that this highly fluorescent cyclic adduct adopts the promutagenic syn conformation and can stabilize the slipped mutagenic intermediate (SMI) within the CpG repeat of the NarI sequence, which is a hotspot for frameshift mutagenesis mediated by polycyclic N-linked C8-dG adducts. In contrast, the open para-CN (4-aminobenzontrile-derived) N-linked C8-dG adduct is less likely to disrupt the canonical B-form. Together, our results provide a rationale for the potent mutagenicity of cyano-substituted nitroaniline derivatives recently reported in frameshift-sensitive tester strains.

Genotoxicity of airborne PM2.5 assessed by salmonella and comet assays in five cities of the Emilia-Romagna (Italy) mutagenicity monitoring network.

Airborne particulate matter (PM) has long been recognized as a potential health hazard and in 2013 was classified as carcinogenic to humans by the International Agency for Research on Cancer. In this study we evaluate and compare mutagenic and genotoxic potencies of PM2.5 collected in three seasons, from 2012 to 2015, in five Italian cities. Mutagenicity was evaluated through the Ames test on TA98 and TA100 strains and, for the measurement of PM clastogenicity, Comet assay was carried out on cultured human lung cells (A549). Organic matter, extracted from urban particulate matter, was also characterized for polycyclic aromatic hydrocarbons (PAHs) and their derivatives content. Samples collected in the colder seasons show the presence of both base pair substitution and frameshift mutagens, with enhanced mutagenic response in the absence of enzyme activation. The highest DNA damage detected with the Comet assay was induced by winter extracts, but different from Salmonella, the relative increase per cubic meter in comet tail for November samples was comparable to July ones. Comparing mutagenicity and genotoxicity with chemical concentrations we found that data from the Salmonella assay correlate with mass concentration and, to a lesser extent, with PAHs, but no association was found with their derivatives, whereas DNA damage correlate only with PAHs measured at one site. These findings demonstrate that to assess the mutagenicity and genotoxicity of complex mixtures it's necessary to use bioassays and that the chemical analysis of pollutants does not take into account the possible inhibitory or synergic effects of exposure. Environ. Mol. Mutagen. 58:719-729, 2017. © 2017 Wiley Periodicals, Inc.

Synergistic antimutagenic effect of isothiocyanates against varied mutagens

Although plant foods provide an array of nutrients in the human diet, our knowledge of how these nutrients are interacting among each other at molecular level is limited. Among these, glucosinolates are the most important secondary metabolites, which are readily hydrolyzed to a variety of products including isothiocyanates. The current study emphasizes on the antimutagenic potential of three isothiocyanates (ITCs) viz. allyl, benzyl and 3-butenyl ITCs (individually and in binary combinations) in Ames Salmonella histidine reversion assay using Salmonella typhimurium TA98 and TA100 tester strains. Three different mutagens were used in the study including two direct acting mutagens [4-nitro-o-phenylenediamine (frame shift mutagen) and sodium azide (base substitution mutagen)] and one indirect acting mutagen [2-aminofluorene]. Furthermore, S9 fraction from rat liver microsomes was used to mimic the mammalian system. The study points towards the ability of ITCs to act as potent inhibitors of mutagenicity induced by different mutagens. Benzyl ITC was found to be the most effective among the three. Computation of combination effects was done on the basis of combination index values. It was observed that ITCs in combination induced a stronger antimutagenic response and that too at relatively low concentrations, without any signs of toxicity.

Mutagenicity of Wastewater Extracts from Pulp and Paper Industry

Wastewater samples were collected from pulp and paper mill located in Kashipur (India) and were extracted using dichloromethane (DCM), chloroform and hexane solvents (all were HPLC-grade). The extracts were assayed for their mutagenic potential using Ames Salmonella mutagenicity assay. TA98 strain was found to be the most responsive, in terms of induction factor (Mi) and slope (m) of the initial linear dose-response curve as determined by linear regression analysis up to the increasing doses indicating the presence of frame shift mutagens in the test samples. Mutagenicity of different extracts is arranged as follows: dichloromethane extracted water samples > hexane extracted water samples > chloroform extracted water samples. Hexane extract exhibited maximum mutagenic index of 13.0 and induction factor (Mi) 2.48 with TA98. The order of responsiveness based on the mutagenic index and induction factor for the test samples was in the following order: TA98 > TA97a > TA100 > TA102 > TA104. Our findings suggest that TA97a, TA98, TA100, TA102, TA104 were sensitive towards the wastewater extracts and showed considerable mutagenicity.

Characterization of urban aerosol: seasonal variation of mutagenicity and genotoxicity of PM2.5, PM1 and semi-volatile organic compounds

Urban particulate matter (PM) is an environmental public health concern as it has been classified by the IARC as carcinogenic to humans (group 1) and it's well known that pollutants are more associated with the finest fractions of PM.In this study we characterize urban aerosol in Bologna, county town of Emilia-Romagna in the north of Italy, collecting PM2.5, PM1 and semi-volatile organic compounds using polyurethane foam.Samples were collected in three different seasons (winter, summer and autumn) and were extracted with acetone. On these three fractions we assessed mutagenicity using Salmonella reverse mutation test and genotoxicity by alkaline comet assay and micronucleus assay in human lung cancer cell line, A549. Organic extracts were also characterized for alkanes, polycyclic aromatic hydrocarbons (PAHs), nitrated and oxygenated PAHs. We also evaluated associations between the physicochemical parameters of samples and their genotoxicity.The particulate samples, collected in autumn and winter, indicated the presence of both base pair substitution and frameshift mutagens using TA98 and TA100 strains of Salmonella typhimurium and the mutagenicity was more associated with the finest fraction. Enhanced mutagenic response was observed in the absence of enzyme activation. Only a third of comet and a half of micronucleus assays gave positive results that, unlike Salmonella's ones, are not season-related. These results were compared with environmental chemicals concentrations and we found that Salmonella's data correlated with PAHs detected on PM filters and with mass concentrations, whereas the DNA damage correlate only with PAHs extracted from polyurethane foams.The use of different assays was sensitive to detect and identify different classes of airborne mutagenic/genotoxic compounds present in aerosol, showing that monitoring air quality using this methodology is relevant.

Assessment of the Mutagenicity of Sediments from Yangtze River Estuary Using Salmonella Typhimurium/Microsome Assay.

Sediments in estuaries are of important environmental concern because they may act as pollution sinks and sources to the overlying water body. These sediments can be accumulated by benthic organisms. This study assessed the mutagenic potential of sediment extracts from the Yangtze River estuary by using the Ames fluctuation assay with the Salmonella typhimurium his (−) strain TA98 (frameshift mutagen indicator) and TA100 (baseshift mutagen indicator). Most of the sediment samples were mutagenic to the strain TA98, regardless of the presence or absence of exogenous metabolic activation (S9 induction by β-naphthoflavone/phenobarbital). However, none of the samples were mutagenic to the strain TA100. Thus, the mutagenicity pattern was mainly frameshift mutation, and the responsible toxicants were both direct (without S9 mix) and indirect (with S9 mix) mutagens. The mutagenicity of the sediment extracts increased when S9 was added. Chemical analysis showed a poor correlation between the content of priority polycyclic aromatic hydrocarbons and the detected mutagenicity in each sample. The concept of effect-directed analysis was used to analyze possible compounds responsible for the detected mutagenic effects. With regard to the mutagenicity of sediment fractions, non-polar compounds as well as weakly and moderately polar compounds played a main role. Further investigations should be conducted to identify the responsible components.

Potent mutagenicity in the Ames test of 2-cyano-4-nitroaniline and 2,6-dicyano-4-nitroaniline, components of disperse dyes.

Genotoxicity data on commercial azo dyes and their components remain sparse, despite their widespread use. We have tested the mutagenicity of 2-cyano-4-nitroaniline (CNNA) and 2,6-dicyano-4-nitroaniline (CNCNNA), components of azo dyes such as Disperse Blue 165 and Disperse Red 73, in Ames test strains. Both compounds are extraordinarily potent frameshift mutagens, with much greater activity than structurally similar dihalonitroanilines and halodinitroanilines. Analysis of the responses of strains over-expressing or deficient in bioactivation enzymes shows that bacterial nitroreductase and acetyl CoA: arylamine N-acetyltransferase are important mediators of the mutagenicity of CNNA and CNCNNA.

Mutagenicity of drinking water sampled from the Yangtze River and Hanshui River (Wuhan section) and correlations with water quality parameters.

A total of 54 water samples were collected during three different hydrologic periods (level period, wet period, and dry period) from Plant A and Plant B (a source for Yangtze River and Hanshui River water, respectively), and several water parameters, such as chemical oxygen demand (COD), turbidity, and total organic carbon (TOC), were simultaneously analyzed. The mutagenicity of the water samples was evaluated using the Ames test with Salmonella typhimurium strains TA98 and TA100. According to the results, the organic compounds in the water were largely frame-shift mutagens, as positive results were found for most of the tests using TA98. All of the finished water samples exhibited stronger mutagenicity than the relative raw and distribution water samples, with water samples collected from Plant B presenting stronger mutagenic strength than those from Plant A. The finished water samples from Plant A displayed a seasonal-dependent variation. Water parameters including COD (r = 0.599, P = 0.009), TOC (r = 0.681, P = 0.02), UV254 (r = 0.711, P = 0.001), and total nitrogen (r = 0.570, P = 0.014) exhibited good correlations with mutagenicity (TA98), at 2.0 L/plate, which bolsters the argument of the importance of using mutagenicity as a new parameter to assess the quality of drinking water.

Assessing the Mutagenic Potential of Surface Sediments from Beijing Guanting Reservoir to Salmonella typhimurium

Mutagenicity of organic extracts from Beijing Guanting Reservoir sediments was investigated with TA98 and TA100 of Salmonella typhimurium. TA98 and TA100 were employed to detect frameshift mutation and base-pair substitution mutation, respectively. For TA100, no positive result was found, while TA98 was more sensitive and pro-mutagenic frameshift mutagens were mainly detected in sediments. Sediments from northern and southern Guanting Reservoir were at potential mutagenic risk. No mutagenicity was found in the sediments from the entrance of the tributaries, but strong mutagenicity was observed in the sediments from the outlet of the reservoir. Chemical analysis was also performed, and poor correlation was found between mutagenicity and organochlorine pesticides (OCPs). However, significant positive correlation was found for polycyclic aromatic hydrocarbons (PAHs) (r = 0.603–0.946), which showed that PAHs were dominated for the tested mutagenicity in the sediments. Polychlorinated biphenyls (PCBs) might induce mutagenicity or promote the mutagenicity of other substances.

Chemical characteristics and mutagenic activity of PM2.5 at a site in the Indo-Gangetic plain, India

Airborne fine particulate matter PM2.5 was collected from May 2010 to December 2012 at Agra, a semi-urban site in north-central India. PM2.5 samples were chemically characterized for 16 polycyclic aromatic hydrocarbons by gas chromatography. PM2.5 values varied between 8.4 and 300µgm−3 with 55% of the values exceeding the 24h average NAAQ (National Ambient Air Quality) standard of 65µgm−3. Particle associated total PAHs ranged between 8.9 and 2065ngm−3 with a mean value of 880.8ngm−3 during the sampling period, indicated an alarming level of pollution in Agra. Strong relationship was observed between PM2.5 and total PAHs (r=0.88), suggesting an increasing PAHs concentration with increasing PM2.5 mass. On a mass basis 3-ring and 4-ring compounds were dominant. Seasonal variation in mass concentration of PAHs was observed with high concentration in winter followed by post monsoon, summer and monsoon. This seasonal pattern could be attributed to differences in source strength and climatic conditions. PAHs concentration were also observed to be negatively correlated with the meteorological parameters i.e. temperature, solar radiation, relative humidity and wind speed. Molecular diagnostic ratios revealed vehicular emissions and combustion of wood and coal as the probable sources. The estimated carcinogenicity of PAHs in terms of benzo(a)pyrene toxic equivalency (B[a]PTEQ) was assessed and confirmed that benzo[a]pyrene was the dominant PAH contributor (3.64%). Health risk of adults and children by way of PAHs was assessed by estimating the lifetime average daily dose (LADD) and corresponding incremental lifetime cancer risk (ILCR) using USEPA guidelines. The assessed cancer risk (ILCR) was found to be within the acceptable range (10−6–10−4). The particulate samples indicated the presence of both base pair and frame shift mutagens using TA98 and TA100 strains of Salmonella typhimurium. Enhanced mutagenic response was observed in the presence of enzyme activation.

Re-Examination of the Genotoxic Activity of Water Taken From the Songhua River in P. R. China

The Songhua River, in northeast China, has heavy organic contamination due to domestic sewage and industrial wastewater. Thus, it is important to further determine its genotoxic activity, which is a potential hazard for human health. Short-term genotoxic bioassays using Salmonella, the cytokinesis-block micronucleus cytome assay, and mouse liver cell comet assay were employed to further examine the genotoxic activity of diethyl ether extracts of water samples taken from the Songhua River. Ames test results showed that there were still frame-shift mutagens, both direct and indirect, in water samples at doses of 5.0 or 7.0L water equivalent/plate. The mutagenicity seems to be less when compared with the results from 2002 to 2003. A dose-response relationship was also obtained between DNA damage in mouse liver cells by comet assay and micronuclei formation by CBMN assay. These results indicate that the water samples showed genotoxic activity with a mutagenic potency. 88 and 104 compounds, respectively, were identified in summer and winter water sample extracts by gas chromatography-mass spectrometry analysis. Four priority pollutants listed by the United States Environmental Protection Agency and six priority pollutants listed by the Chinese Environment Protection Agency were found in summer or winter water samples, respectively. The results indicate that the diethyl ether extracts of surface water samples taken from the Songhua River still show genotoxic activity (≥3.0L water). The risks of potential carcinogenicity for human health in the Songhua River should be studied further.

Ruthenium porphyrin and oxidant convert N-nitrosodialkylamines into direct-acting mutagen in the Ames assay

The Ames assay is used for short-term screening of mutagens/carcinogens that induce DNA damage. Most mutagens/carcinogens require enzymatic activation through oxidation by cytochrome P450 in an S-9 mix to exert their mutagenicity. Chemical models for cytochrome P450, consisting of water-soluble or water-insoluble iron porphyrin plus an oxidant, have been used to produce frameshift mutagens from aromatic amines, heterocyclic amines and polyaromatic hydrocarbons. In this study, the mutagenicity of N-nitrosodialkylamines was assayed in the presence of a chemical model, which consists of 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)porphyrinatoruthenium(IV) dichloride (RuMe3) and 2,6-dichloropyridine N-oxide (Cl2pyNO). The chemical model activated symmetrical N-nitrosodialkylamines (alkyl = methyl, ethyl, propyl, butyl), and unsymmetrical N-nitroso-N-methylalkylamine (alkyl = propyl, butyl) in Salmonella typhimurium YG7108. Furthermore, the mutagenicity of N-nitrosodipropylamine (NDP) in S. typhimurium YG7108 was higher than that in S. typhimurium TA1535, suggesting that the mutagenicity derived from NDP using the chemical model was due to DNA alkylation. The results showed that the chemical model can activate N-nitrosodialkylamines to induce base substitution mutations.

The Investigation of Mutagenic and Carcinogenic Effects by the Ames Test

Aim: Research has shown that the increased use of chemicals which are offered to consumers, sometimes without sufficient testing, has impacted human health and natural resources negatively. For this reason, many researchers have developed cost-effective test systems which can examine the carcinogenic and mutagenic activity of chemicals in a short time. Ames is an example of such a test system which can detect mutations at cellular level. Also the Ames test is accepted as a reliable method for specifically testing the toxic and mutagenic-carcinogenic effects of raw materials to be used in pharmaceuticals. Material and Methods: In this study, the mutagenic and carcinogenic effect of methylphenidate, that is used for the treatment of Attention-Deficit Hyperactivity Disorder, was investigated by the Ames Salmonella/microsome test in the absence and presence of metabolic activation. The Ames Salmonella/microsome test can play an important role to identify the mutagenic effects of carcinogenic compounds and is used for the research and development of drugs. TA 98 and TA 100 strains were used in experiments. TA 98 is designed for frame-shift mutagens and TA 100 is designed for base-pair mutagens. The mutagenic activity was screened in two groups with or without S9 metabolic activation. The results were evaluated and the mean values were compared with positive and negative controls. Results: According to the results of experiments conducted with TA98 and TA100, revertant colony count was not found higher than those spontaneous revertant colony count among all of the concentrations and as well as under the conditions of with and without S9 (p>0.05). Conclusion: In conclusion, it was shown that methylphenidate was non-mutagenic for TA 98 and TA 100 with or without S9 metabolic activation. Key words: Ames test, carcinogenicity, methylphenidate, S9 fraction, mutagenicity

Antimutagenic evaluation of vitamins B1, B6 and B12 in vitro and in vivo, with the Ames test

The aim of this work is to evaluate vitamins B antimutagenic effect against alkylatings methyl-N-nitro-N-nitrosoguanidine (MNNG), ethyl-N-nitro-N′- nitrosoguanidine (ENNG), frameshift mutagens 2-aminoanthracene (2AA) and 2-acetyl-amino-fluorene (2AF) and ROS-generating antibiotics norfloxacin (NOR) and nalidixic acid (NLX), using the in vitro Ames test. In vivo antimutagenesis studies were performed against urinary mutagens induced by NOR (70mg/kg) or NLX (100mg/kg) in CD1 mice.Vitamin B1 was antimutagenic against alkylatings MNNG (P<0.05) or ENNG (P<0.001). In fact as per the results observed during the current study, none of the vitamins reduced mutagenesis caused by frameshift mutagens. All of them reduced mutagenesis of NOR or NLX (P<0.001). In vivo studies showed that vitamins B1 and B6 (10 or 100mg/kg) reduced urinary mutagens from NOR (P<0.001) or NLX (P<0.02) either free or β-glucoronidase-conjugates. None of the studied samples were toxic for the employed antimutagenic system. Vitamin B12 (4mg/kg) reduced urinary mutagens of NOR or NLX (P<0.02).Vitamins B inhibited DNA mutations induced by ROS generated by NLX or NOR, both in vitro and in vivo. Vitamin B1is antimutagenic against mutations induced by the alkylating MNNG or ENNG. Based on the observations, employment of vitamins B in vivo can be a promising alternative to reduce genotoxic risk exposure to ROS.

Cultivation of Pleurotus citrinopileatus on handmade paper and cardboard industrial wastes

The study deals with the cultivation of Pleurotus citrinopileatus on the sludge of handmade paper and cardboard industrial waste. These industrial wastes are rich in cellulosic and lignocellulosic pulp residues which can be used as a novel substrate for the cultivation of mushrooms. These industrial wastes were used alone and in combination with wheat straw for the cultivation of mushroom. To assess suitability of mushroom (carpophores) for consumption, cultivated carpophores analyzed for nutritional content and genotoxicity by standard AOAC methods and Ames test, respectively. A significant decrease in the biological efficiency, protein and fat of the said mushroom (only in the mentioned sludges) was observed, nevertheless, carpophores possessed a high amount of frameshift mutagens and thus being non-consumable. Contrastingly, the carpophores that were developed on the absolute equal combination of industrial sludge and wheat straw were found to possess high biological efficiency, protein, carbohydrate and fat content whereas decrease frameshift mutagens. On boiling the aqueous extract of mushroom, a further decrease in frameshift mutagens was observed. In conclusion, the use of combination of sludge and wheat straw not only increased the biological efficiency but also provided less mutagenic carpophores and mutagenicity of these carpophores further reduced on boiling.

Characterization and Mutagenicity Assessment of PM2.5 and PM10 PAH at Agra, India

Fine airborne particulate matter and bound chemical compounds are potential mediators of adverse health effects. In this study, PM2.5 and PM10 were characterized for bound polycyclic aromatic hydrocarbons (PAHs) and the mutagenic potential of extracts was assessed. PM2.5 and PM10 samples were collected on glass fiber filters at Agra from July to December 2010 using a fine particulate sampler (Envirotech, APM 550). The content of PAH was analyzed by gas chromatography and the extract were tested for mutagenicity by the Ames test without using S9. Individual PAH concentration varied from 13–172 ng m−3 with concentration for Chrysene and a dominance of low molecular weight compounds. Both PM and PAH concentrations were higher in the winter and were negatively correlated with temperature and wind speed. Diagnostic ratio analysis indicated contributions from vehicular exhaust and emissions from combustion of domestic fuel like coal and wood. Mutagenicity assays indicated the presence of mutagens capable of causing base pair and frame shift mutagenicity; however, within the range of tested concentrations no significant toxic effects were detected.

Comparison of BTX Profiles and Their Mutagenicity Assessment at Two Sites of Agra, India

In the present study, the concentrations of three volatile organic compounds (VOCs), namely, acronym for benzene, toluene, and xylenes (BTX) were assessed because of their role in the tropospheric chemistry. Two representative sites, a roadside and a petrol pump, were chosen for sample collection. VOCs were collected using SKC-activated charcoal tubes and SKC personal sampler and characterized by gas chromatograph using flame ionization detector. Among BTX, benzene had the highest concentration. At the roadside, mean concentration of benzene, toluene, o-,m-xylene, and p-xylene were 14.7 ± 2.4 μgm−3, 8.1 ± 1.2 μgm−3, 2.1 ± 0.8 μgm−3, and 5.1 ± 1.2 μgm−3, respectively. At the petrol pump, the mean concentrations of benzene, toluene, o-,m-xylene and p-xylene were 19.5 ± 3.7 μgm−3, 12.9 ± 1.1 μgm−3, 3.6 ± 0.5 μgm−3 and 11.1 ± 1.5 μgm−3, respectively, and were numerically higher by a fraction of 2. Monthly variation of BTX showed maximum concentration in winter. Inter-species ratios and inter-species correlation indicated traffic as the major source of BTX. Extracts of samples were positive in both Salmonella typhimurium tester strains TA98 and TA100 without metabolic activation suggesting the presence of direct mutagens in ambient air that can cause both frame-shift and base-pair mutation. The mutagenic response was greater for TA100 than TA98 suggesting greater activity for base-pair mutagenicity than frame-shift mutagenicity and was found to be statistically significant.

Aerobic Treatment of Handmade Paper Industrial Effluents by White Rot Fungi

Modernization of handmade paper industries has led to increase in production capacity for fulfilling demand. This also leads to the use of chemicals and dyes to make attractive and colourful papers. These industries recycle white and coloured cotton rags procured from textile industries. After processing and making paper, these industries discharge large amount of effluent in nearby water sources and deteriorate quality of water. Therefore, it is an urgent need to treat waste water in order to reduce the effect on the human beings as well as on the environment. The present study deals with physicochemical and genotoxicological analysis of Large Scale Handmade Paper industrial (LS-HMP) and Small Scale Handmade Paper industrial (SS-HMP) effluents before and after treating them with White Rot Fungi (WRF) in nutrient amended and non-amended condition. SS-HMP and LS-HMP were found to possess basic pH i.e. 7.54 and 8 respectively. These industrial effluents were found to possess colour revealed by 11293.3 (SS-HMP) and 11880 (LS-HMP) colour units and high COD revealed by 1132.6mg/l (SS-HMP) and 12371.7mg/l (LS-HMP), on initial day which reduced significantly to the safe discharge limits by white rot fungi. Similarly, basepair and frameshift mutagenicity were reduced significantly on treatment. Among all WRF, P. chrysosporium was found to be equally effective in both nutrient amended and non-amended condition in reducing all parameters of SS-HMP and LS-HMP effluent. Thus, P. chrysosporium can be used for the treatment of handmade paper industrial effluent without nutrient supplementation

Polycyclic Aromatic Hydrocarbon Emissions and Mutagenicity Assessment of Exhaust from a Diesel Generator

Diesel fuel and diesel exhaust are known to be highly mutagenic partly because of the presence of polyaromatic hydrocarbons (PAHs) and their derivatives. The present study investigated the PAHs content in the diesel fuel fed to a diesel generator and also in the gas and particulate phase of generator emissions. Mutagenicity of the exhaust was also determined. Exhaust emissions were collected by a stack sampler: gas phase on XAD-2 resin while particulate phase on glass fibre thimble. PAHs were characterized by a gas chromatograph by using a flame ionization detector. The low molecular weight PAHs dominated in the fuel, whereas the high molecular weight PAHs dominated in the exhaust with a greater emission factor in the particulate phase. The results reveal the pyrosynthesis of high molecular weight PAHs during the combustion process. Emissions also increased with increase in load. Extract of exhaust emissions were positive in both Salmonella typhimurium tester strains TA 98 and TA 100 without metabolic activation, suggesting the presence of direct mutagens that can cause both frame-shift and base-pair mutation. The mutagenic response was greater for TA 100 than TA 98, suggesting greater activity for base-pair mutagenicity than frame-shift mutagenicity. Mutagenic activity increased with the increase in load.