Genotoxic Potential Research Articles

Assessment of Genotoxicity of Zinc Oxide Nanoparticles Using Mosquito as Test Model.

The widespread applications of ZnO NPs in the different areas of science, technology, medicine, agriculture, and commercial products have led to increased chances of their release into the environment. This created a growing public concern about the toxicological and environmental effects of the nanoparticles. The impact of these NPs on the genetic materials of living organisms is documented in some cultured cells and plants, but there are only a few studies regarding this aspect in animals. In view of this, the present work regarding the assessment of the genotoxicity of zinc oxide nanoparticles using the mosquito Culex quinquefaciatus has been taken up. Statistically significant chromosomal aberrations over the control are recorded after the exposure of the fourth instar larvae to a dose of less than LD20 for 24 h. In order to select this dose, LD20 of ZnO NPs for the mosquito is determined by Probit analysis. Lacto-aceto-orcein stained chromosomal preparations are made from gonads of adult treated and control mosquitoes. Both structural aberrations, such as chromosomal breaks, fragments, translocations, and terminal fusions, resulting in the formation of rings and clumped chromosomes, and numerical ones, including hypo- and hyper-aneuploidy at metaphases, bridges, and laggards at the anaphase stage are observed. The percentage frequency of abnormalities in the shape of sperm heads is also found to be statistically significant over the controls. Besides this, zinc oxide nanoparticles are also found to affect the reproductive potential and embryo development as egg rafts obtained from the genetic crosses of ZnO nanoparticle-treated virgin females and normal males are small in size with a far smaller number of eggs per raft. The percentage frequencies of dominant lethal mutations indicated by the frequency of unhatched eggs are also statistically significant (p < 0.05) over the control. The induction of abnormalities in all of the three short-term assays studied during the present piece of work indicates the genotoxic potential of ZnO NPs, which cannot be labeled absolutely safe, and this study pinpoints the need to develop strategies for the protection of the environment and living organisms thriving in it.

Genotoxicity Evaluation of Titanium Dioxide Nanoparticles In Vivo and In Vitro: A Meta-Analysis.

Recent studies have raised concerns about genotoxic effects associated with titanium dioxide nanoparticles (TiO2 NPs), which are commonly used. This meta-analysis aims to investigate the potential genotoxicity of TiO2 NPs and explore influencing factors. This study systematically searched Chinese and English literature. The literature underwent quality evaluation, including reliability evaluation using the toxicological data reliability assessment method and relevance evaluation using routine evaluation forms. Meta-analysis and subgroup analyses were performed using R software, with the standardized mean difference (SMD) as the combined effect value. A total of 26 studies met the inclusion criteria and passed the quality assessment. Meta-analysis results indicated that the SMD for each genotoxic endpoint was greater than 0. This finding implies a significant association between TiO2 NP treatment and DNA damage and chromosome damage both in vivo and in vitro and gene mutation in vitro. Subgroup analysis revealed that short-term exposure to TiO2 NPs increased DNA damage. Rats and cancer cells exhibited heightened susceptibility to DNA damage triggered by TiO2 NPs (p < 0.05). TiO2 NPs could induce genotoxicity, including DNA damage, chromosomal damage, and in vitro gene mutations. The mechanism of DNA damage response plays a key role in the genotoxicity induced by TiO2 NPs.

Mortality and toxicity of a commercial formulation of cypermethrin in Physalaemus gracilis tadpoles

This study evaluated the lethal, sublethal, and toxic of a commercial formulation of cypermethrin in the anuran species Physalaemus gracilis. In the acute test, concentrations of 100–800 μg L−1 were tested over 96 h. In the chronic test, cypermethrin concentrations recorded in nature (1, 3, 6, and 20 μg L−1) were tested for mortality and then used for the micronucleus test and erythrocyte nuclear abnormalities over a 7-days period. The LC50 determined for P. gracilis for the commercial cypermethrin formulation was 273.41 μg L−1. In the chronic test, a mortality of more than 50% was observed at the highest concentration (20 μg L−1), as it caused half of the tadpoles studied to die. The micronucleus test showed significant results at concentrations of 6 and 20 μg L−1 and recorded the presence of several nuclear abnormalities, indicating the genotoxic potential of the commercial cypermethrin formulation for P. gracilis. Cypermethrin presented a high risk to the species, indicating that it has the potential to cause several problems in the short and long term and to affect the dynamics of this ecosystem. Therefore, it can be concluded that the commercial formulation of cypermethrin had toxicological effects on P. gracilis.

Genotoxicity and cytotoxicity potential of organoselenium compounds in human leukocytes in vitro

In the current work, cytotoxicity and genotoxicity of different organoselenium compounds were examined using Trypan blue exclusion and alkaline comet assays with silver staining respectively. Leukocytes were subjected to a 3-hour incubation with organoselenium compounds at concentrations of 1, 5, 10, 25, 50, and 75 μM, or with the control vehicle (DMSO), at a temperature of 37 °C. The viability of the cells was evaluated using the Trypan blue exclusion method, while DNA damage was analyzed through the alkaline comet assay with silver staining. The exposure of leukocytes to different organoselenium compounds including i.e. (Z)-N-(pyridin-2-ylmethylene)-1-(2-((2-(1-((E)-pyridin-2-ylmethyleneamino)ethyl)phenyl)diselanyl)phenyl)ethanamine (C1), 2,2′(1Z,1′E)-(1,1′-(2,2′-diselanediylbis(2,1-phenylene))bis(ethane-1,1-diyl)) bis(azan-1-yl-1-ylidene)bis -methan-1-yl-1-ylidene)diphenol (C2), and dinaphthyl diselenide (NapSe)2, At concentrations ranging from 1 to 5 μM, no significant DNA damage was observed, as indicated by the absence of a noteworthy increase in the Damage Index (DI).Our results suggest that the organoselenium selenium compounds tested were not genotoxic and cytotoxic to human leukocytes in vitro at lower concentration. This study offers further insights into the genotoxicity profile of these organochalcogens in human leukocytes. Their genotoxicity and cytotoxicity effects at higher concentration are probably mediated through reactive oxygen species generation and their ability to catalyze thiol oxidation.

Metagenomic insights into the microbial cooperative networks of a benz(a)anthracene-7,12-dione degrading community from a creosote-contaminated soil

Genotoxicity of PAH-contaminated soils can eventually increase after bioremediation due to the formation and accumulation of polar transformation products, mainly oxygenated PAHs (oxy-PAHs). Biodegradation of oxy-PAHs has been described in soils, but information on the microorganisms and mechanisms involved is still scarce. Benz(a)anthracene-7,12-dione (BaAQ), a transformation product from benz(a)anthracene frequently detected in soils, presents higher genotoxic potential than its parent PAH. Here, using sand-in-liquid microcosms we identified a specialized BaAQ-degrading subpopulation in a PAH-contaminated soil. A BaAQ-degrading microbial consortium was obtained by enrichment in sand-in-liquid cultures with BaAQ as sole carbon source, and its metagenomic analysis identified members of Sphingobium, Stenotrophomonas, Pusillimonas, Olivibacter, Pseudomonas, Achromobacter, and Hyphomicrobiales as major components. The integration of data from metabolomic and metagenomic functional gene analyses of the consortium revealed that the BaAQ metabolic pathway was initiated by Baeyer-Villiger monooxygenases (BVMOs). The presence of plasmid pANTQ-1 in the metagenomic sequences, identified in a previous multi-omic characterization of a 9,10-anthraquinone-degrading isolate recovered from the same soil, suggested the occurrence of a horizontal gene transfer event. Further metagenomic analysis of the BaAQ-degrading consortium also provided insights into the potential roles and interactions within the consortium members. Several potential auxotrophies were detected, indicating that relevant nutritional interdependencies and syntrophic associations were taking place within the community members, not only to provide suitable carbon and energy sources, but also to supply essential nutrients and cofactors. Our work confirms the essential role that BVMO may play as a detoxification mechanism to mitigate the risk posed by oxy-PAH formation during bioremediation of contaminated soils.

Cytogenetic Infractions of Latex Extract of the Floristic Dumbcane (Dieffenbachia amoena) on Mitotic Chromosomes of Onion (Allium cepa)

Background: Diffenbachia amoena commonly called dumb cane is a houseplant found in homes, offices, banks and landscape premises as ornamental plants. This family of plants has shown high levels of acute and chronic toxicities with high cytogenic, mutagenic, carcinogenic, genotoxic potentials. Several studies had implicated some phytochemicals contained in the whitish latex sap including saponins, glycosides, tannins and oxalates to be responsible for the toxicity of this houseplant to plant cells and proteins. Methods: Cytological investigation protocol was used to determine cytogenetic infractions such as chromosome stickiness, lagging chromosomes, bridged chromosomes, deletions and chromosomal aberrations. The phytochemicals contained in the latex were determined using high performance liquid chromatography while computational biology approach was used to determine the latex phytochemicals interactions with the onion plant proteins using SIB stitch of expasy.org. Result: Cytogenetic studies reveals that Dumb cane causes significant effect and infractions in the cytogenetics of onion cells ranging from chromatid-type breakage-fusion-bridge, chromosome stickiness, lagging chromosomes, bridged chromosomes, deletions and chromosomal aberrations. The latex sap from the stem contains oxalates, saponins, glycosides, tannins, alkaloids to varying degree which impairs photosynthetic and biochemical processes in the plant system. Phytochemicals-proteins interactions revealed that oxalates impairs and inhibits the formation and functionality of alanine glycoxylatetransferase (GRHPR), Chromobox homolog 5 chromosome (CBX5), alpha ketaglutarate dehydrogenase (AGXT) and glyoxylate reductase (OGDH) genes. Hence, there is need for enlightenment of the public on the dangers and toxicity of this houseplant in rural community households, urban cities, offices, recreational parks, business centers where the use of this deadly plant as ornamental is still very predominant.

Acute, subchronic toxicity and genotoxicity studies of JointAlive, a traditional Chinese medicine formulation for knee osteoarthritis.

In vivo and in vitro toxicity tests of JointAlive® were studied in animal models to support the safe use of JointAlive® as a drug for knee osteoarthritis treatment. The acute toxicity study in Sprague Dawley (SD) rats was conducted at a 20 g/kg bw/day dose of JointAlive®. For 13-week subchronic toxicity tests, SD rats were orally dosed daily with 0.5, 1.5 and 5 g/kg bw/day of JointAlive®. To assess the potential genotoxicity, Ames test, cellular chromosome aberration and mouse micronucleus test in vivo were carried out. Based on a lack of notable findings other than histopathology finding of co-incidental prostate inflammation at the high dose, the "No Observed Adverse Effect Level (NOAEL)" of JointAlive® was concluded as 5 g/kg bw/day in males and females. Results also indicated that JointAlive® has no risk of genotoxicity. General toxicity and genotoxicity studies empirically demonstrated that JointAlive® poses a low risk of potential health risks, providing safety supports for the application of JointAlive® as a potential drug candidate to treat knee osteoarthritis.

Acetaldehyde as a Food Flavoring Substance: Aspects of Risk Assessment.

The Senate Commission on Food Safety (SKLM) of the German Research Foundation (DFG) has reviewed the currently available data in order to assess the health risks associated with the use of acetaldehyde as a flavoring substance in foods. Acetaldehyde is genotoxic in vitro. Following oral intake of ethanol or inhalation exposure to acetaldehyde, systemic genotoxic effects of acetaldehyde in vivo cannot be ruled out (induction of DNA adducts and micronuclei). At present, the key question of whether acetaldehyde is genotoxic and mutagenic in vivo after oral exposure cannot be answered conclusively. There is also insufficient data on human exposure. Consequently, it is currently not possible to reliably assess the health risk associated with the use of acetaldehyde as a flavoring substance. However, considering the genotoxic potential of acetaldehyde as well as numerous data gaps that need to be filled to allow a comprehensive risk assessment, the SKLM considers that the use of acetaldehyde as a flavoring may pose a safety concern. For reasons of precautionary consumer protection, the SKLM recommends that the scientific base for approval of the intentional addition of acetaldehyde to foods as a flavoring substance should be reassessed.

Genotoxicity evaluation in workers occupationally exposed to the pollutants of Dhi- Qar oil refinery

Background: Workers are occupationally and environmentally exposed to diverse forms of xenobiotics as gases and vapors. Career publicity to those compounds can trade the prooxidants/oxidants and antioxidants equilibrium throughout oxidative toxic stress (OTS). Pollutants might also cause genotoxicity by oxidative DNA. This work was conducted in AL-Nasiriya at the Thi-Qar Oil refinery in Thi-Qar province, south of Iraq. Samples have been amassed from the refinery workers and Campus college students and workforce as control. Seventy blood samples from the refinery people running within the asphalt, laboratory, and refining units and samples from Campus students and staff as control have been collected. The 8- OHDG was measured using the ELISA technique. The serum 8- OHdG of refinery workers was notably higher than that of individuals of control subjects (p&lt; 0.001*). A higher level of serum 8-OHdG was quantified in the blood samples of all exposed subjects. The significant feature that resulted in an enhanced genotoxic potential was the years of exposure to the oil refinery environment, which led to an increase in the 8-OHdG formation. Keywords: Genotoxicity ; workers occupationally ; pollutants ; Dhi- Qar ; oil refinery

EFFECT OF BITTER MELON AGAINST CISPLATIN AND VALPROIC ACID-INDUCED GENOTOXICITY IN Drosophila melanogaster Meigen

In human body, which is exposed to number of chemicals and physical agents in daily life, malfunctions may occur from time to time in detoxification mechanisms that will prevent the harmful effects of genotoxic agents, whose negative effects cannot be eliminated. In this study, the genoprotective effects of bitter melon (Momordica charantia L.) seed and fruit extracts against the genotoxic potential of the antineoplastic agent cisplatin and the antiepileptic drug valproic acid in 72±4 hours old transheterozygous larvae of the fruit fly Drosophila melanogaster Meigen were determined by the Somatic Mutation and Recombination Test (SMART). The results showed that the mutation frequencies approached the negative control values by inhibiting the formation of chemical agent-induced mutant clones in all doses in the experimental groups in which plant extracts were applied at doses of 1.25, 2.5 ve 5 mg/mL, while the mutation frequency increased only in the groups that applied cisplatin and valproic acid. These results show that co-administration of cisplatin and valproic acid reduces the genotoxic effect of M. charantia.

Differential DNA damage response and cell fate in human lung cells after exposure to genotoxic compounds

DNA damage can impair normal cellular functions and result in various pathophysiological processes including cardiovascular diseases and cancer. We compared the genotoxic potential of diverse DNA damaging agents, and focused on their effects on the DNA damage response (DDR) and cell fate in human lung cells BEAS-2B. Polycyclic aromatic hydrocarbons [PAHs; benzo[a]pyrene (B[a]P), 1-nitropyrene (1-NP)] induced DNA strand breaks and oxidative damage to DNA; anticancer drugs doxorubicin (DOX) and 5-bromo-2′-deoxyuridine (BrdU) were less effective. DOX triggered the most robust p53 signaling indicating activation of DDR, followed by cell cycle arrest in the G2/M phase, induction of apoptosis and senescence, possibly due to the severe and irreparable DNA lesions. BrdU not only activated p53, but also increased the percentage of G1-phased cells and caused a massive accumulation of senescent cells. In contrast, regardless the activation of p53, both PAHs did not substantially affect the cell cycle distribution or senescence. Finally, a small fraction of cells accumulated only in the G2/M phase and exhibited increased cell death after the prolonged incubation with B[a]P. Overall, we characterized differential responses to diverse DNA damaging agents resulting in specific cell fate and highlighted the key role of DNA lesion type and the p53 signaling persistence.

Lowering the pH leads to the disaggregation of NiO and ZnO nanoparticles and modifies the mutagenic response.

In a changing environmental scenario, acid rain can have a significant impact on aquatic ecosystems. Acidification is known to produce corrosion in metals, hence increasing their harmful effects on the environment, organisms and human health. The prevalent use of metallic nanoparticles (NPs) in everyday products raises concerns regarding exposure and nanotoxicity even in these acidified conditions. We thus report on the cytotoxic and genotoxic potential of nickel oxide (NiO-NP) and zinc oxide (ZnO-NP) NPs when suspended in aqueous media in light of pH variations (7.5 and 5). A modified microsuspension method of the Salmonella/microsome assay was adopted, and strains (TA97a, TA98, TA100, TA102) were exposed to NPs (10-1280 μg/plate) with and without a metabolization fraction. The acidic condition favored disaggregation and caused a decrease in NPs size. Mutagenicity was observed in all samples and different strains, with greater DNA base pair substitution damage (TA100 and TA102), but extrinsic conditions (pH) suggest different action mechanisms of NiO-NP and ZnO-NP on genetic content. Mutagenic activity was found to increase upon metabolic activation (TA98, TA100, and TA102) demonstrating the bioactivity of NiO-NP and ZnO-NP in relation to metabolites generated by the mammalian p450 system in vitro. Modifications in the Salmonella assay methodology increased cell exposure time. The observed responses recommend this modified assay as one of the methodologies of choice for nanoecotoxicological evaluation. These findings emphasize the significance of incorporating the environmental context when evaluating the toxicity of metal-based NPs.

Plant cytogenetics tests can predict toxic effects on human cells: genotoxic and mutagenic effects of Tityus serrulatus scorpion venom on vegetal and human cells

The effects of Tityus serrulatus venom was accessed on the cell cycle and genetic material of the Lactuca sativa L. and compared with the damages to human leukocytes, in order to evaluate the genotoxic and mutagenic potential of toxins on cell types very different. The occurrence of cell cycle alterations and DNA fragmentation was evaluated in Lactuca sativa. Incubations of venom with human leukocytes were also held with subsequent evaluation of cell proliferation index, micronucleus and fragmented DNA. The T. serrulatus venom showed cytogenotoxic, reducing mitotic index and induced alterations in the cell cycle and micronuclei formation. The occurrence of cell death was evidenced by the detection of condensed nuclei, positive TUNEL signals, and presence of DNA fragmentation on lettuce cells. The scorpion venom induced DNA fragmentation and micronuclei in leukocytes. Further, the role of peptides and proteases from this venom in inducing the observed damage was discussed.

Identification of Cutinolytic Esterase from Microplastic-Associated Microbiota Using Functional Metagenomics and Its Plastic Degrading Potential.

Plastic pollution has threatened biodiversity and human health by shrinking habitats, reducing food quality, and limiting the activities of organisms. Therefore, global interest in discovering novel enzymes capable of degrading plastics has increased considerably. Within this context, the functional metagenomic approach, which allows for unlocking the functional potential of uncultivable microbial biodiversity, was used to discover a plastic-degrading enzyme. First, metagenomic libraries derived from microplastic-associated microbiota were screened for esterases capable of degrading both tributyrin and polycaprolactone. Clone KAD01 produced esterase highly active against p-nitrophenyl esters (C2-C16). The gene corresponding to the enzyme activity showed moderate identity (≤ 55.94%) to any known esterases/cutinases. The gene was extracellularly expressed with a 6× histidine tag in E. coli BL21(DE3), extracellularly. Titer of the enzyme (CEstKAD01) was raised from 21.32 to 35.17U/mL by the statistical optimization of expression conditions and media components. CEstKAD01 was most active at pH 7.0 and 30°C. It was noteworthy stable over a wide pH (6.0-10.0) and temperature (20-50°C). The enzyme was active and stable in elevated NaCl concentrations up to 12% (w/v). Pre-incubation of CEstKAD01 with Mg2+, Mn2+, and Ca2+ increased the enzyme activity. CEstKAD01 displayed an excellent tolerance against various chemicals and solvents. It was determined that 1mg of the enzyme caused the release of 5.39 ± 0.18mM fatty acids from 1g apple cutin in 120min. Km and Vmax values of CEstKAD01 against p-nitrophenyl butyrate were calculated to be 1.48mM and 20.37µmol/min, respectively. The enzyme caused 6.94 ± 0.55, 8.71 ± 0.56, 7.47 ± 0.47, and 9.22 ± 0.18% of weight loss in polystyrene, high-density polyethylene, low-density polyethylene, and polyvinyl chloride after 30-day incubation. The scanning electron microscopy (SEM) analysis indicated the formation of holes and pits on the plastic surfaces supporting the degradation. In addition, the change in chemical structure in plastics treated with the enzyme was determined by Fourier Transform Infrared Spectroscopy (FTIR) analysis. Finally, the degradation products were found to have no genotoxic potential. To our knowledge, no cutinolytic esterase with the potential to degrade polystyrene (PS), high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polyvinyl chloride (PVC) has been identified from metagenomes derived from microplastic-associated microbiota.

Cytogenetic damage by vanadium(IV) and vanadium(III) on the bone marrow of mice

Vanadium is a strategic metal that has many important industrial applications and is generated by the use of burning fossil fuels, which inevitably leads to their release into the environment, mainly in the form of oxides. The wastes generated by their use represent a major health hazard. Furthermore, it has attracted attention because several genotoxicity studies have shown that some vanadium compounds can affect DNA; among the most studied compounds is vanadium pentoxide, but studies in vivo with oxidation states IV and III are scarce and controversial. In this study, the genotoxic and cytotoxic potential of vanadium oxides was investigated in mouse bone marrow cells using structural chromosomal aberration (SCA) and mitotic index (MI) test systems. Three groups were administered vanadium(IV) tetraoxide (V2O4) intraperitoneally at 4.7, 9.4 or 18.8 mg/kg, and three groups were administered vanadium(III) trioxide (V2O3) at 4.22, 8.46 or 16.93 mg/kg body weight. The control group was treated with sterile water, and the positive control group was treated with cadmium(II) chloride (CdCl2). After 24 h, all doses of vanadium compounds increased the percentage of cells with SCA and decreased the MI. Our results demonstrated that under the present experimental conditions and doses, treatment with V2O4 and V2O3 induces chromosomal aberrations and alters cell division in the bone marrow of mice.

Difluoromethyl-1,3,4-oxadiazoles Are Selective, Mechanism-Based, and Essentially Irreversible Inhibitors of Histone Deacetylase 6.

Histone deacetylase 6 (HDAC6) is an important drug target in oncological and non-oncological diseases. Most available HDAC6 inhibitors (HDAC6i) utilize hydroxamic acids as a zinc-binding group, which limits therapeutic opportunities due to its genotoxic potential. Recently, difluoromethyl-1,3,4-oxadiazoles (DFMOs) were reported as potent and selective HDAC6i but their mode of inhibition remained enigmatic. Herein, we report that DFMOs act as mechanism-based and essentially irreversible HDAC6i. Biochemical data confirm that DFMO 6 is a tight-binding HDAC6i capable of inhibiting HDAC6 via a two-step slow-binding mechanism. Crystallographic and mechanistic experiments suggest that the attack of 6 by the zinc-bound water at the sp2 carbon closest to the difluoromethyl moiety followed by a subsequent ring opening of the oxadiazole yields deprotonated difluoroacetylhydrazide 13 as active species. The strong anionic zinc coordination of 13 and the binding of the difluoromethyl moiety in the P571 pocket finally result in an essentially irreversible inhibition of HDAC6.

Green synthesis of silver nanoparticles from Wrightia arborea: Physiochemical profiling and genotoxic potency

Green synthesis of silver nanoparticles from Wrightia arborea: Physiochemical profiling and genotoxic potency

Chemical characterization of Callingcard Vine (Entada polystachya (L.) DC. var. polystachya) aqueous seed extract and evaluation of its cytotoxic, genotoxic and mutagenic properties.

Callingcard Vine (Entada polystachya (L.) DC. var. polystachya - Fabaceae) is a common plant in coastal thickets from western Mexico through Central America to Colombia and Brazil, especially in Amazon biome. It has been popularly used as a urinary burning reliever and diuretic. However, the plant chemical constituents are poorly understood and Entada spp. genotoxic potential have not been previously investigated. In the present study we determined the chemical composition of the aqueous E. polystachya crude seed extract (EPCSE) and evaluated the cytotoxic, genotoxic and mutagenic properties of EPCSE in Salmonella typhimurium and Chinese hamster fibroblast (V79) cells. Cytotoxic activity was also evaluated in tumor cell lines (HT29, MCF7 and U87) and non-malignant cells (MRC5). The chemical analysis by High Resolution Mass Spectrometry (HRMS) of EPCSE indicated the presence of saponin and chalcone. The results of the MTT and clonal survival assays suggest that EPCSE is cytotoxic to V79 cells. Survival analysis showed higher IC50 in non-tumor compared with tumor cell lines. EPCSE showed induction of DNA strand breaks as revealed by the alkaline comet assay and micronucleus test. Using the modified comet assay, it was possible to detect the induction of oxidative DNA base damage by EPCSE in V79 cells. Consistently, the extract induced increase lipid peroxidation (TBARS), superoxide dismutase (SOD) and catalase (CAT) activities in V79 cells. In addition, EPCSE induced mutations in S. typhimurium TA98 and TA100 strains, confirming a mutagenic potential. Taken together, our results suggest that EPCSE is cytotoxic and genotoxic to V79 cells and mutagenic to S. typhimurium. These properties can be related to the pro-oxidant ability of the extract and induction of DNA lesions. Additionally, EPCSE could inhibit the growth of tumor cells, especially human colorectal adenocarcinoma (HT29) cell line, and can constitute a possible source of antitumor natural agents.

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.

Assessment of the in vivo genotoxic potential of three smoke flavoring primary product mixtures.

Smoke flavorings are mixtures generated from wood pyrolysis that are filtered to remove tar and are often considered healthier alternatives to conventional smoking processes. While the latter is mostly unregulated, smoke-flavoring primary products (SFPPs) are undergoing the 10-year required re-evaluation in the European Union (EU). To comply with recent smoke flavor guidance, in vivo micronucleus studies in rats and transgenic rodent (TGR) mutation assays in Muta™Mice were conducted on three SFPPs. For most studies, typical limit doses were exceeded to comply with regulatory requests. Exposure to SFPPs by oral gavage did not result in significant increases in bone marrow micronucleus formation. Except for one group, exposure to SFPPs via feed for 28 days did not result in significant increases in mutant frequency (MF) in the glandular stomach or liver. One group exposed to a maximal feasible dietary dose of 50,000 ppm (>10,000 mg/kg bodyweight per day) exhibited a statistically significant increase in liver MF; however, the MF in all mice in this group were within the historical vehicle control 95% quantile confidence intervals and therefore not considered biologically relevant. Based on estimates of human dietary exposure to each SFPP, the margin of exposure (MOE) values in the TGR assays exceed 10,000. The MOE for one unintentionally present constituent, 2,5(H)-furanone, also exceeds 10,000. Collectively, these data indicate that these SFPPs pose no genotoxic risk and are safe alternatives to conventional smoking.