Genotoxic and cytotoxic effects of pethoxamid herbicide on Allium cepa cells and its molecular docking studies to unravel genotoxicity mechanism

Pethoxamid is chloroacetamide herbicide. Pethoxamid is commonly used to kill different weeds in various crops. Pethoxamid can leach in the water and soil and can cause toxic effects to other non-target species. Current study is therefore aimed to perform the investigation of the cytotoxic and genotoxic effects of pethoxamid on Allium cepa cells.The root growth, mitotic index (MI), chromosomal aberrations (CAs), and DNA damage were assessed through root growth inhibition, A. cepa ana-telophase, and alkaline comet assays, respectively. Furthermore, molecular docking was performed to evaluate binding affinity of pethoxamid on DNA and very-long-chain fatty acid (VLCFA) synthases. In root growth inhibition test, onion root length was statistically significantly decreased in a concentration dependent manner. Concentration- and time-dependent decreases in MI were observed, whereas increase in CAs such as disturbed ana-telophase, chromosome laggards, stickiness, anaphase bridges, and DNA damage was caused by the pethoxamid on A. cepa root cells. Molecular docking revealed that pethoxamid binds selectively to GC-rich regions in the minor groove of the DNA structure and showed remarkable binding affinity against all synthases taking part in the sequential biosynthesis of VLCFAs. It was concluded that the pethoxamid-induced genotoxicity and cytotoxicity may be through multiple binding ability of this herbicide with DNA and VLCFA synthases.

Synthesis and characterization of single-walled carbon nanotube: Cyto-genotoxicity in Allium cepa root tips and molecular docking studies

Herein, single-walled carbon nanotubes (SWCNTs) were synthesized by the thermal chemical vapor deposition (CVD) method, and characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), Raman spectroscopy, dynamic light scattering (DLS), and thermo-gravimetric analysis (TGA). The results indicated that obtained nanotubes were SWCNTs with high crystallinity and their average diameter was 10.15 ± 3 nm. Allium cepa ana-telophase and comet assays on the root meristem were employed to evaluate the cytotoxic and genotoxic effects of SWCNTs by examining mitotic phases, mitotic index (MI), chromosomal aberrations (CAs), and DNA damage. A. cepa root tip cells were exposed to SWCNTs at concentrations of 12.5, 25, 50, and 100 μg/ml for 4 h. Distilled water and methyl methanesulfonate (MMS, 10 μg/ml) were used as the negative and positive control groups, respectively. It was observed that MIs decreased statistically significantly for all applied doses. Besides, CAs such as chromosome laggards, disturbed anaphase-telophase, stickiness and bridges and also DNA damage increased in the presence of SWCNTs in a concentration-dependent manner. In the molecular docking study, the SWCNT were found to be a strong DNA major groove binder showing an energetically very favorable binding free energy of -21.27 kcal/mol. Furthermore, the SWCNT interacted effectively with the nucleotides on both strands of DNA primarily via hydrophobic π and electrostatic interactions. As a result, cytotoxic and genotoxic effects of SWCNTs in A. cepa root meristematic cells which is a reliable system for assessment of nanoparticle toxicology were demonstrated in this study.

Cytotoxic and Genotoxic Evaluation of Biosynthesized Silver Nanoparticles Using Moringa oleifera on MCF-7 and HUVEC Cell Lines

Nowadays, green synthesized nanoparticles (NPs) are extensively investigated to explore their biological potential. They are being explored to treat different infectious and cancerous diseases. Therefore, the current study was designed to evaluate the cytotoxic and genotoxic effects of biosynthesized silver nanoparticles (AgNPs) from the medicinal plant Moringa oleifera on breast cancer (MCF-7) and HUVEC (human umbilical vein endothelial cells) cell lines. M. oleifera-mediated AgNPs were synthesized from the M. oleifera extract (MOE) and then characterized through the use of a scanning electron microscope (SEM), X-ray diffraction (XRD) and UV–vis spectrophotometer. Biosynthesized AgNPs and MOE were employed on MCF-7 and HUVEC cell lines to evaluate their cytotoxic and genotoxic effects. More cytotoxic effects were observed by AgNPs and MOE on MCF-7 cell lines. The IC₅₀ for biosynthesized AgNPs was found to be 5 μg/mL. DNA damage was also observed by the MOE and AgNPs on MCF-7 cell lines. However, non-significant DNA damage was observed by MOE and AgNPs on HUVEC cell lines. The findings of the current study revealed the cytotoxic and genotoxic effects of biosynthesized AgNPs on MCF-7 cell lines. However, these AgNPs were considered safe for normal HUVEC cell lines.

Cytotoxic and genotoxic evaluation of copper oxychloride through Allium test and molecular docking studies

Copper oxychloride gained great importance due to its broad-spectrum antifungal action to combat various fungal diseases of plants. However, excess quantity of cupric fungicides on plants causes enzymatic changes and toxic effects. Thus, the current study was aimed to investigate the cytotoxicity and genotoxicity of copper oxychloride on Allium cepa root cells. The root growth, mitotic index (MI), chromosomal aberrations (CAs), and DNA damage were assessed through root growth inhibition, A. cepa ana-telophase, and alkaline comet assays. Furthermore, molecular docking was performed to evaluate binding affinities of two copper oxychloride polymorphs (atacamite and paratacamite) on DNA. In root growth inhibition test, onion root length was statistically significantly decreased by changing the copper oxychloride concentration from lower (2.64±0.11 cm) to higher (0.92±0.12 cm). Concentration- and time-dependent decrease in MI was observed whereas increase in CAs such as disturbed ana-telophase, chromosome laggards, stickiness, anaphase bridges, and DNA damage were caused by the copper oxychloride on A. cepa root cells. Molecular docking results revealed that the two main polymorphs of copper oxychloride (atacamite and paratacamite) bind selectively to G and C nucleotides on the B-DNA structure. It is concluded that the atacamite- and paratacamite-induced DNA damage may be through minor groove recognition and intercalation. Findings of the current study revealed the cytotoxic and genotoxic effects of copper oxychloride on A. cepa root cells. However, further studies should be carried out at the molecular level to reveal the cyto-genotoxic mechanism of action of copper oxychloride in detail.

Cytotoxic and genotoxic effects of clopyralid herbicide on Allium cepa roots

Clopyralid is one of the synthetic pyridine-carboxylate auxin herbicides and used to control perennial and annual broadleaf weeds in wheat, sugar beets, canola, etc. In this study, dose-dependent cytotoxicity and genotoxicity of clopyralid at different concentrations (25, 50, and 100 μg/mL) have been evaluated on the Allium cepa roots. The evaluation has been performed at macroscopic (root growth) and microscopic levels [mitotic index (MI), chromosome aberrations (CAs) in ana-telophase cells, and DNA damage] using root growth inhibition, Allium ana-telophase, and comet tests. The percentage of root growth inhibition and concentration of reducing root growth by 50% (EC₅₀) of clopyralid were determined compared with the negative control by using various concentrations of clopyralid (6.25-1000 μg/L). The 96 h EC₅₀ of clopyralid was recorded as 50 μg/L. The gradual decrease in root growth and the MI reveals the cytotoxic effects of clopyralid. All the tested concentrations of clopyralid induced total CAs (polyploidy, stickiness, anaphase bridges, chromosome laggards, and disturbed ana-telophase) and DNA damage dose and time dependently. These results confirm the cytotoxic and genotoxic effects of clopyralid on non-target organism.

Cyto-genotoxicity, antibacterial, and antibiofilm properties of green synthesized silver nanoparticles using Penicillium toxicarium

The fungi are becoming the distinguished organisms utilized in the biological synthesis of metallic nanoparticles because of their metal bioaccumulation ability. Addressed herein, the extracellular synthesis of silver nanoparticles (AgNPs) was carried out by using the cell-free filtrate of Penicillium toxicarium KJ173540.1. P. toxicarium was locally isolated and identified using both classical and molecular methods according to ribosomal internal transcribed spacer area of 18S rDNA. The optimum conditions for the AgNPs synthesis were found as 0.25 mM AgNO₃ concentrations with pH 12 values at 45°C after 64 hr incubation in dark. Biosynthesized AgNPs were characterized via microscopic and spectroscopic techniques such as transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis, Fourier transform infrared spectrophotometer, and ultraviolet-visible spectroscopy. Zetasizer measurements presented that the high negative potential value (-18.1 mV) and PDI (0.495) supported the excellent colloidal nature of AgNPs with long-range stability and high dispersity. AgNPs exhibited cyto-genotoxicity in Allium cepa root meristem cells by decreasing mitotic index and increasing chromosome aberrations in a dose-dependent manner. Then, 100 and 50% concentration of biosynthesized AgNPs showed antibacterial activity on Staphylococcus aureus and Bacillus subtilis. A decreasing biofilm formation of Pseudomonas aeruginosa 80.69, 48.32, and 28.41% was also observed at 100, 50, and 25% of mycosynthesized AgNP, respectively.

Cytotoxic and genotoxic assessment of tungsten oxide nanoparticles in Allium cepa cells by Allium ana-telophase and comet assays

Tungsten oxide nanoparticles or nanopowder (WO₃NPs) is commonly used in various industries and also in biomedical applications such as additives, pigments, and biomedical sensors. Non-judicious excessive use of these nanoparticles (NPs) could be a serious human health concern. Therefore, the current study aimed to explore the cytotoxic and genotoxic assessment of WO₃NPs through Allium cepa anaphase-telophase and comet assays. Nanoparticles were characterized through the scanning and transmission electron microscopy (TEM), zetasizer, and energy-dispersive X-ray spectroscopy. The mean size and the average diameter of WO₃NPs were determined as 21.57 ± 2.48 nm and 349.42 ± 80.65 nm using TEM and a Zetasizer measurement system, respectively. Five concentrations (12.5 mg/L, 25 mg/L, 50 mg/L, 75 mg/L, and 100 mg/L) of WO₃NPs were employed on the Allium cepa (A. cepa) roots for 4 h. Significant (p ≤ 0.05) decrease in mitotic index (MI) was shown by WO₃NPs at all concentrations. The increase of chromosomal aberrations (CAs) was also observed in a concentration-dependent manner due to the WO₃NPs exposure. There was a significant increase (p ≤ 0.05) in DNA damage at all concentrations of WO₃NPs on the A. cepa cells. It was concluded that WO₃NPs had cytotoxic and genotoxic effects on A. cepa meristematic cells. Moreover, further cytogenetic effects of WO₃NPs should be investigated at the molecular level to assess its safety margin.

Cytogenetic and genotoxic assessment in Allium cepa exposed to imazalil fungicide

Imazalil (IMZ), a fungicide containing imidazole group, is extensively used for the prevention and treatment of fungal diseases in plants. Current study was performed to examine cyto-genotoxic potential of IMZ on Allium cepa roots by following Allium ana-telophase and single cell gel electrophoresis (comet) assays. The concentration which reduced the growth of the root tips of IMZ by 50% compared to the negative control group (EC₅₀) was found to be 1 μg/mL by Allium root growth inhibition test. 0.5, 1, and 2 μg/mL concentrations of IMZ were exposed to Allium roots for intervals of 24, 48, 72, and 96 h. 10 μg/mL of methyl methane sulfonate (MMS) and distilled water were used as control groups, both positive and negative. Statistical analysis was performed by using one-way ANOVA with Duncan's multiple comparison tests at p ≤ 0.05 and Pearson correlation test at p = 0.01. IMZ showed cytotoxic effect by statistically decreasing root growth and mitotic index (MI) and also genotoxic effect by statistically increasing chromosomal aberrations (CAs) and DNA damage compared to the negative control group. With these cyto-genotoxic effects, it should be used carefully and further cyto-genotoxic mechanisms should be investigated along with other toxicity tests.

Assessment of the cytotoxic and genotoxic potential of pillar[5]arene derivatives by Allium cepa roots and Drosophila melanogaster haemocytes

In this study pillar[5]arene (P5) and a quinoline-functionalized pillar[5]arene (P5-6Q) which is used for detecting radioactive element, gas adsorption and toxic ions were synthesized. These materials were characterized by Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared (FTIR), elemental analysis, melting point, Mass Spectroscopy, Scanning Electron Microscopy (SEM) and Zeta Potential. The cytotoxic and genotoxic potential of P5 and P5-6Q at distinct concentrations of 12.5, 25, 50, and 100 μg/mL were also investigated by Allium ana-telophase and comet assays on Allium cepa roots and Drosophila melanogaster haemocytes. P5 and P5-6Q showed dose dependent cytotoxic effect by decreasing mitotic index (MI) and genotoxic effect by increasing chromosomal aberrations (CAs such as disturbed anaphase-telophase, polyploidy, stickiness, chromosome laggards and bridges) and DNA damage at the exposed concentrations. These changes in P5-6Q were lower than P5. Further research is necessary to clarify the cytotoxic and genotoxic action mechanisms of P5 and P5-6Q at molecular levels.

Cytotoxic and Genotoxic Assessment of Silicon Dioxide Nanoparticles by Allium and Comet Tests

Silicon nanoparticles gained a great interest due to its use in biomedical research. It is considered as safe and has been used in nanomedicine. But literature still states its toxicity depending upon the size and dose of silicon nanoparticles. So, current study was aimed to evaluate the cytotoxicity and genotoxicity of silicon dioxide nanoparticles (SiO₂NPs) by Allium anaphase-telophase and Comet tests. Characterization of SiO₂NPs showed the particle size as 16.12 ± 3.07 nm. The mean diameter of SiO₂NPs was having range of 404.66 ± 93.39 nm in solution. Highest total anomalies (18.80 ± 0.45) were observed at 100 µg/mL, whereas least (11.2 ± 0.84) were observed by the 12.5 µg/mL concentration. There was concentration-response association in increased CAs and DNA damage. The highest concentration (100 µg/mL) of SiO₂NPs induced the significant DNA damage (149.67 ± 1.15), whereas the least was observed by the negative control (2.67 ± 0.58). The current study revealed the cytotoxic and genotoxic effects of SiO₂NPs on the root meristem cells of A. cepa.

The Effect of Ellagic Acid on Paraoxanase - 1 Activity and DNA Damage in Acute Exercise

The purpose of this study was to evaluate the correlation between exhaustive and intensive exercise with changes in paraoxonase-1 enzyme activity, oxidative DNA damage and the role of ellagic acid against possible damage. The study was carried out on 32 male and adult Spraque - Dawley rats at the Experimental Animal Research and Research Center of Afyon Kocatepe University. The experimental animals were equally divided into four groups. Swimming exercises were performed as acute exercises for once and experimental animals are made to swim in groups including two rats following the completion of the study and before the decapitation. At the end of the experiment, obtained blood samples; Paraoxonase-1 (PON-1), Malondialdehyde (MDA) and 8-HydroxyGuanine (8-OhdG) levels were measured to determine DNA damage and DNA damage was assessed by Comet Assay method. As a result, PON-1 levels in rats with intense swimming training were found to be significantly lower (p <0.05) than the control group. MDA and (8-OhdG) levels were significantly higher in the swimming group than in the control group (p <0.05). As to the DNA damage determination by COMET analysis, DNA damage was observed in the swimming groups according to the control groups. When the ellagic acid groups were compared with the swimming groups, there was a significant increase in PON-1 levels, and the levels of MDA and (8-OhdG) were significantly lower than the swimming groups. The DNA damage was also found to be low in these groups.

The effect of silver nanoparticles on the mutagenic and the genotoxic properties of the urban wastewater liquid sludges

Nanoparticles are very effective compounds to transform and detoxicate common environmental contaminants. For this reason, crude urban liquid wastewater sludges were treated by silver nanoparticles (Ag-NPs, 100 nm) for 24 h. Both Ag-NPs' treated and untreated sludges were examined for the evaluation if there are possible mutagenic/anti-mutagenic, cytotoxic, and genotoxic/anti-genotoxic effects by Ames and Allium cepa tests. The results were then subjected to statistical analyses by using SPSS software and p < 0.05 was accepted as a significant value. The data obtained from the Ames test showed that while untreated crude liquid sludge had a significant mutagenic effect, Ag-NP-treated one decreased its mutagenicity. Similar effects were also observed in the chromosome aberration-Allium cepa tests. Significant chromosome aberrations observed were C-metaphase, sticky metaphase, sticky anaphase, anaphase bridge, vagrant chromosome, and multipolar anaphases. Both tests demonstrated that silver nanoparticle treatment decreased the major mutagenicity and genotoxicity detected in the liquid wastewater sludges.

Synthesis of Morphine Loaded Hydroxyapatite Nanoparticles (HAPs) and Determination of Genotoxic Effect for Using Pain Management

Morphine is used as a standard analgesic for intensive pain relief. It relieves acute and chronic pain by acting directly on the central nervous system and to treat myocardial infarction and shortness of breath. However, the use of morphine for the alleviation of chronic pain is controversial because of the its adverse side effects. The overall success of this medicine in chronic therapy is due to the long-term activity of the drug at a reasonable concentration. Nanoparticle-based carriers have emerged as a new class of drug delivery systems that can overcome traditional drug side-effect limitations by reducing toxicity to a minimum. In this study, a morphine-loaded HAPs drug delivery system was investigated. Fouirer Transform Infrared Spektrofotometre (FTIR) analysis was used to characterize typical functional groups found in the chemical composition of Hydroxyapatite Nanoparticles (HAPs) and morphine loaded HAPs (HAP+M). Scanning electron microscopy (SEM) and Transmission electron microscope (TEM) analyzes were performed to examine the size, morphology, and porosity of morphine loaded HAPs. Characterization analysis showed that HAP nanoparticles were loaded with morphine. The effects of pH on release of morphine-loaded HAPs was determined. The release time of the entrapped morphine in the nanoparticle increased in all conditions, thus increasing the morphine time in the human body. Thus, patients will have to take less morphine. In addition, it was investigated whether the morphine loaded HAP cell produced oxidative stress and genotoxic effect on DNA. Findings presented in this paper suggested that morphine-loaded HAPs have a promising future as a nanocarrier for pain treatment.

Cytotoxicity and genotoxicity of cerium oxide micro and nanoparticles by Allium and Comet tests

Cerium oxide (CeO₂) is extensively used in a range of applications like in television tubes, glass/ceramic polishing agent, fuel cells, solar cells, gas sensor andultraviolet absorbents. In current study, Allium ana-telophase and comet assays were employed to evaluate the cytotoxic and genotoxic effects of CeO₂ microparticles (CMPs, <5 µm, bulk) and CeO₂ nanoparticles (CNPs, < 25 nm) on the root meristem cells of Allium cepa by using mitotic phases, mitotic index (MI), chromosomal aberrations (CAs), and DNA damage. A cepa roots were treated with the CMPs and CNPs at four different concentrations (12.5, 25, 50, and 100 ppm) for 4 h. Methyl methane sulphonate (MMS,10 ppm) and distilled water were used as positive and negative control groups, respectively. All the applied doses statistically decreased MIs. MI values of CMPs were found higher than CNPs. CMPs and CNPs significantly increased CAs such as chromosome laggards, disturbed anaphase-telophase, stickiness and bridges and also DNA damage. Characterization of CMPs and CNPs showed the particle size as 4.24 ± 0.7 µm and 20.28 ± 2.33 nm, respectively. The average diameter of CMPs and CNPs in solution were in the range of 372.75 ± 70.23 nm and 167.74 ± 38.7 nm, respectively. These results demonstrated that CMPs and CNPs had cytotoxic and genotoxic effects in A. cepa root meristematic cells.

Cytogenetic and genotoxic effects of 2-chlorophenol on Allium cepa L. root meristem cells

2-Chlorophenol (2-CP), a class of chlorinated organic pollutants like other chlorophenols, is used as intermediate in the synthesis of the higher chlorinated congeners, certain dyes, preservatives, herbicides, fungicides, and plastics. In this study, cytotoxic and genotoxic effects of 2-CP were investigated on the root meristem cells of Allium cepa for its effects on root growth, mitotic index (MI), mitotic phases, chromosomal abnormalities (CAs), and DNA damage by using Allium anaphase-telophase and Comet assays. EC₅₀ of 2-CP value was determined as approximately 25 mg/L by Allium root growth inhibition test. Three concentrations of 2-CP (12.5, 25, and 50 mg/L), distilled water (negative control), and methyl methane sulfonate (MMS, 10 mg/L, positive control) were applied to onion stem cells under different exposure periods (24, 48, 72, and 96 h). All the applied doses of 2-CP slightly decreased MIs. 2-CP induced total CAs such as disturbed anaphase-telophase, chromosome laggards, stickiness, and bridges and also DNA damage at significant levels. These results demonstrate that 2-CP has genotoxic effects in A. cepa root meristematic cells.

Cytogenetic and genotoxic effects of Rosmaniric Acid on Allium cepa L. root meristem cells

Rosmarinic acid (RA) is a natural polyphenol carboxylic acid, an ester of caffeic acid with 3,4-dihydroxyphenyllactic acid, found in many species. Current study was aimed to investigate the mitotic division, chromosomal and genotoxic effects of RA on Allium cepa root meristematic cells. In Allium root growth inhibition test, EC50 value was found as 100 ppm. Three concentrations (50, 100, and 200 ppm) of RA under different exposure periods (24, 48, 72 and 96 h) were employed to onion tuber roots. Distilled water and methyl methane sulfonate (MMS, 10 ppm) were used as a negative and positive control, respectively. 100 (except 24 h) and 200 ppm of RA significantly decreased mitotic index (MI). There was an increase of total chromosomal aberrations (CAs) at 50 ppm and simultaneous decrease of CAs at 200 ppm concentrations (p < 0.05). A significant increase in DNA damage was also observed at 200 ppm by Comet assay. Quantitative analysis of RA in A. cepa root meristem cells was also done by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Further investigations are required to explore the molecular mechanism involved in the cytotoxicity and genotoxicity of RA on plants.

Genotoxic Assessment of Different Sizes of Iron Oxide Nanoparticles and Ionic Iron in Earthworm (Eisenia hortensis) Coelomocytes by Comet Assay and Micronucleus Test

The current study was designed to evaluate genotoxicity of different sizes of iron oxide nanoparticles (IONPs) and ionic iron using coelomocytes of the earthworms Eisenia hortensis. Earthworms were exposed to different series of IONPs and ionic iron concentrations to find the respective LC50 of the chosen chemicals. LC₅₀ for < 50, <100 nm and the ionic iron of IONPs were 500, 200, 250 µg/mL respectively. Concentrations of LC₅₀/2 (250, 100, 125 µg/mL for < 50, <100 nm and the ionic iron respectively) and LC₅₀ for 48 h were used to perform the comet assay and micronucleus test. Statistically significant (p < 0.05) increase in DNA and chromosomal damage was observed for all sizes of IONPs and ionic iron. In the comet assay system, the greatest genotoxicity was observed in the treatments with < 100 nm IONPs, whereas the greatest numbers of micronuclei and binucleate cells were observed in the treatments with ionic iron. It was concluded that different types of nanoparticles (i.e. sizes, shapes) may have different genotoxic potencies in different assays with E. hortensis earthworms.

Mutagenic and genotoxic effects of Anilofos with micronucleus, chromosome aberrations, sister chromatid exchanges and Ames test

We aimed to evaluate the mutagenic effect of Anilofos, organophosphate pesticide, by using Ames/Salmonella/microsome test. Its cytotoxic and genotoxic effects were also determined by chromosome aberration (CA), sister chromatid exchange (SCE) and micronucleus (MN) test in human peripheral blood lymphocytes. In the Ames test, five different concentrations of Anilofos were examined on TA97, TA98, TA100 and TA102 strains in the absence and presence of S9 fraction. According to the results all concentrations of this pesticide have not shown any mutagenic activity on TA97, TA100 and TA102 strains in the absence and presence of S9 fraction. But, 10, 100 and 1000 µg/plate concentrations of Anilofos were determined to be mutagenic on TA98 strain without S9 fraction. Lymphocytes were treated with various concentrations (25, 50, 100 and 200 µg/ml) of Anilofos for 24 and 48 h. The results of the assays showed that Anilofos did not induce SCE frequency, replication index and MN formation at all concentrations for both treatment periods. Anilofos significantly increased CA frequency at 100 and 200 µg/ml concentrations at 24 h treatment periods and at 50, 100 and 200 µg/ml concentrations in 48 h treatment periods. Additionally, it was determined that this pesticide decreased mitotic index and nuclear division index significantly. It was concluded that Anilofos has genotoxic and cytotoxic effects in human peripheral lymphocytes.

Genotoxicity assessment of cobalt chloride in Eisenia hortensis earthworms coelomocytes by comet assay and micronucleus test

Cobalt and its different compounds are extensively used worldwide and considered as possible environmental pollutant. Earthworms are useful model organism and its different species are used to monitor soil pollution. No study has been found to detect cobalt chloride (CoCl2) genotoxicity in earthworms. So, current study aimed to evaluate CoCl2 induced genotoxicity in Eisenia hortensis earthworms coelomocytes by alkaline comet assay (CA) and micronucleus (MN) test. The earthworms (n = 10 for each group) were exposed to different series of CoCl2 concentrations (100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm, 600 ppm) to find LD50. The LD50 for CoCl2 was found at 226 ppm. Then, doses of LD50/2, LD50 and 2XLD50 for 48 h were used. CA and MN demonstrated the significant increase (P < 0.05) in DNA damage and chromosomal aberrations. Dose dependent relationship was found. Highest DNA damage and chromosomal aberrations were noticed at 2XLD50. The results concluded that CoCl2 induced DNA damage, cytokinesis failure and chromosomal aberrations in E. hortensis earthworms.

A mutagenicity and cytotoxicity study of limonium effusum aqueous extracts by Allium, Ames and MTT tests

Nowadays plants or plant extracts have become very important for alternative medicine. Plants and their extracts have many therapeutical advantages but some of them are potentially toxic, mutagenic, carcinogenic and teratogenic. Root, stem and leafparts of Limonium effusum were used in this study and this species is an endemic species for Turkey. Mutagenic and cytotoxic effects of root, stem and leaf aqueous extracts were observed with Allium, Ames and MTT tests. Allium root growth inhibition test and mitotic index studies showed that aqueous extracts have dose-dependent toxic effects. Chromosome aberration studies indicated that especially sticky chromosome, anaphase-telophase disorder and laggard chromosome anomalies were highly observed. Ames test performed with Limonium effusum root aqueous extracts, showed weak mutagenic effects in Salmonella typhimurium TA98 strain with S9. MTT test based on mitochondrial activity indicated that most of the aqueous extracts have cytotoxic effects. This study aimed to determine the possible mutagenic and cytotoxic effects of L. effusum aqueous extracts by using bacterial, plant and mammalian cells. This research showed that some low concentrations of the L. effusum extracts have inhibited cytotoxic effects but high concentrations have induced cytotoxicity. On the other hand only a weak mutagenic activity was identified by Ames test with TA98 S9(+).

Mutagenicity and genotoxicity of drinking water in Guelma region, Algeria

In this study, a battery of genotoxicity assays for monitoring drinking water was performed to assess the quality of the water resulting from the treatment plants. Five different types of samples were collected: raw water (P1), treated after pre-chlorination (P2), treated after decantation (P3), treated post-chlorination (P4), and consumers' taps (P5-P12). This study aims to evaluate the formation/occurrence of mutagenic and/or genotoxic compounds in surface drinking waters treated with chlorine disinfectant, during four seasonal experiments: summer, autumn, winter, and spring between 2012 and 2013 by bacterial reverse mutation assay in both Salmonella typhimurium TA98 and TA100 strains with or without metabolic activation system (S9 mix) and Allium cepa root meristematic cells, respectively. All of water samples, except at P1, P2, and P5 in summer; P1 in autumn; and P1 and P3-P12 in spring without S9 mix, and at P1 and P2 in summer and P6 and P8-P12 in spring with S9 mix, were found to be mutagenic in S. typhimurium TA98. However, only P11 and P12 in winter were found to be mutagenic for TA100 without S9 mix. The tested preparations in Allium anaphase-telophase test revealed a significant decrease in mitotic index (MI) and a simultaneous increase in chromosome aberrations (CAs) compared to the control. The bridge, stickiness, vagrant chromosomes, and disturbed chromosome aberrations were observed in anaphase-telophase cells. Physicochemical analysis, trihalomethanes (THMs), romoform (CHBr3), chloroform (CHCl3), bromodichloromethane (CHBrCl2), and dibromochloromethane (CHBr2Cl) levels in water samples were also determined. The results show also that this short-term battery tests are applicable in the routine monitoring of drinking water quality before and after distribution.

Mutagenic and genotoxic effects of Guelma's urban wastewater, Algeria

Assessment of water pollution and its effect upon river biotic communities and human health is indispensable to develop control and management strategies. In this study, the mutagenicity and genotoxicity of urban wastewater of the city of Guelma in Algeria were examined between April 2012 and April 2013. For this, two biological tests, namely Amesand chromosomal aberrations (CA) test in Allium cepa root tips were employed on the samples collected from five different sampling stages (S1-S5). In Ames test, two strains of Salmonella typhimurium TA98 and TA100 with or without metabolic activation (S9-mix) were used. All water samples were found to be mutagenic to S. typhimurium TA98 with or without S9-mix. A significant decrease in mitotic index (MI) was observed with a decrease in the percentage of cells in the prophase and an increase in the telophase. Main aberrations observed were anaphase bridges, disturbed anaphase-telophase cells, vagrants and stickiness in anaphase-telophase cells. All treatments of wastewater in April 2012, at S5 in July 2012, at S1 and S5 in November 2012, at S5 in February 2013, and at S1 in April 2013 induced CA when compared to the negative control. Some physicochemical parameters and heavy metals (Cd, Pb, and Cu) were also recorded in the samples examined.

Determination of genotoxic effects of Imazethapyr herbicide in Allium cepa root cells by mitotic activity, chromosome aberration, and comet assay

Imazethapyr (IM) is an imidazolinone herbicide that is currently used for broad-spectrum weed control in soybean and other legume crops. In this study, cytotoxic and genotoxic effects of IM were investigated by using mitotic index (MI), mitotic phases, chromosomal abnormalities (CAs) and DNA damage on the root meristem cells of Allium cepa. In Allium root growth inhibition test, EC50 value was determined as 20 ppm, and 0.5xEC50, EC50 and 2xEC50 concentrations of IM herbicide were introduced to onion tuber roots. Distilled water and methyl methane sulfonate (MMS, 10 mg/L) were used as a negative and positive control, respectively. As A. cepa cell cycle is 24 hours, so, application process was carried out for 24, 48, 72 and 96 hours. All the applied doses decreased MIs compared to control group and these declines were found to be statistically meaningful. Analysis of the chromosomes showed that 10 ppm IM except for 48 h induced CAs but 40 ppm IM except for 72 h decreased CAs. DNA damage was found significantly higher in 20 and 40 ppm of IM compared to the control in comet assay. These results indicated that IM herbicide exhibits cytotoxic activity but not genotoxic activity (except 10 ppm) and induced DNA damage in a dose dependent manner in A. cepa root meristematic cells.

Genotoxicity of indium tin oxide by Allium and Comet tests

Genotoxic effects of indium tin oxide (ITO) were investigated on root cells of Allium cepa by employing both Allium and Comet assays. A. cepa roots were treated with the aqueous dispersions of ITO at 5 different concentrations (12.5, 25, 50, 75, and 100 ppm) for 4 h. Exposure of ITO significantly increased mitotic index, and total chromosomal aberrations by the Allium test. While chromosome laggards, stickiness, disturbed anaphase-telophase and anaphase bridges were observed in anaphase-telophase cells, c-metaphase and binuclear cells were observed in other cells. A significant increase in DNA damage was also observed at all concentrations of ITO by the Comet assay. These results indicate that ITO exhibits genotoxic activity in A. cepa root meristematic cells.

Genotoxicity of drinking water disinfection by-products (bromoform and chloroform) by using both Allium anaphase-telophase and comet tests

Genotoxic effects of bromoform and chloroform, disinfection by-products of the chlorination of drinking water, were examined by using mitotic index (MI), mitotic phase, chromosome aberrations (CAs) and comet assay on root meristematic cells of Allium cepa. Different concentrations of bromoform (25, 50, 75 and 100 μg/mL) and chloroform (25, 50, 100 and 200 μg/mL) were introduced to onion tuber roots. Distilled water was used as a negative control and methyl methansulfonate (MMS-10 μg/mL) as positive control. All obtained data were subjected to statistical analyses by using SPSS 15.0 for Windows software. For comparison purposes, Duncan multiple range tests by using one-way analysis of variance were employed and p < 0.05 was accepted as significant value. Exposure of both chemicals (except 25 μg/mL applications of bromoform) significantly decreased MI. Bromoform and chloroform (except 25 μg/mL applications) increased total CAs in Allium anaphase-telophase test. A significant increase in DNA damage was also observed at all concentrations of both bromoform and chloroform examined by comet assay. The damages were higher than that of positive control especially at 75-100 μg/mL for bromoform and 100-200 μg/mL for chloroform.

Genotoxic effects of Bismuth (III) oxide nanoparticles by Allium and Comet assay

Genotoxic effects of Bismuth (III) oxide nanoparticles (BONPs) were investigated on the root cells of Allium cepa by Allium and Comet assay. A. cepa roots were treated with the aqueous dispersions of BONPs at five different concentrations (12.5, 25, 50, 75, and 100ppm) for 4h. Exposure of BONPs significantly increased mitotic index (MI) except 12.5ppm, total chromosomal aberrations (CAs) in Allium test. While stickiness chromosome laggards, disturbed anaphase-telophase and anaphase bridges were observed in anaphase-telophase cells, pro-metaphase and c-metaphase in other cells. A significant increase in DNA damage was also observed at all concentrations of BONPs except 12.5ppm by Comet assay. The results were also analyzed statistically by using SPSS for Windows; Duncan's multiple range test was performed. These results indicate that BONPs exhibit genotoxic activity in A. cepa root meristematic cells.

A laterally acquired galactose oxidase-like gene is required for aerial development during osmotic stress in Streptomyces coelicolor

Phylogenetic reconstruction revealed that most Actinobacterial orthologs of S. coelicolor SCO2837, encoding a metal-dependent galactose oxidase-like protein, are found within Streptomyces and were probably acquired by horizontal gene transfer from fungi. Disruption of SCO2837 (glxA) caused a conditional bld phenotype that could not be reversed by extracellular complementation. Studies aimed at characterising the regulation of expression of glxA showed that it is not a target for other bld genes. We provide evidence that glxA is required for osmotic adaptation, although independently from the known osmotic stress response element SigB. glxA has been predicted to be part of an operon with the transcription unit comprising the upstream cslA gene and glxA. However, both phenotypic and expression studies indicate that it is also expressed from an independent promoter region internal to cslA. GlxA displays an in situ localisation pattern similar to that one observed for CslA at hyphal tips, but localisation of the former is independent of the latter. The functional role of GlxA in relation to CslA is discussed.

Testing of the mutagenicity and genotoxicity of metolcarb by using both Ames/Salmonella and Allium test

Mutagenic and genotoxic effects of metolcarb were investigated by both bacterial reverse mutation assay in Salmonella typhimurium TA97, TA98, TA100 and TA102 strains with or without metabolic activation system (S9) and Allium cepa root meristematic cells, respectively. Metolcarb was dissolved in DMSO in Ames/Salmonella test system. 0.1, 1 and 10 microg/plate doses of metolcarb were found to be mutagenic S. typhimurium TA98 without S9. In Allium root growth inhibition test, EC50 value was determined 200 ppm and 0.5xEC50, EC50 and 2xEC50 concentrations of metolcarb were introduced to onion tuber roots and distilled water used as a negative control. Mitotic index (MI), increased in all concentrations compared to control at each exposure time. While disturbed anaphase-telophase, chromosome laggards, stickiness and bridges were observed in anaphase-telophase cells, pro-metaphase, C-mitosis, polyploidy, binuclear cells and disturbed nucleus were observed in other cells. The results were also analyzed statistically by using SPSS for Windows, Mann-Whitney test and Duncan's multiple range tests were performed respectively.