Biomonitoring of pharmacists and nurses at occupational risk from handling antineoplastic agents

OBJECTIVE

The objective of this study was to evaluate the frequency of genetic lesions in pharmacists and nurses who prepare and/or handle antineoplastic agents and to evaluate whether there are traces of contaminants in the urine of these professionals.

METHODS

A total of 59 professionals participated in the study, of which 10 were non-exposed professionals (controls), 25 were pharmacists, and 24 were nurses.

KEY FINDINGS

There was a significant increase in genetic damage in lymphocytes and cells of the oral mucosa in both pharmacists and nurses. The levels of cyclophosphamide and ifosfamide were also increased in the urine samples from those individuals.

CONCLUSIONS

These results demonstrate the growing need for genetic biomonitoring and biomonitoring of trace antineoplastic agents in the urine of health professionals who prepare and/or handle antineoplastic agents.

Anti-hyperlipidemic effects of Campomanesia xanthocarpa aqueous extract and its modulation on oxidative stress and genomic instability in Wistar rats

The use of natural products from herbs may be a therapeutic option in dyslipidemia treatment. Campomanesia xanthocarpa (Mart.) O. Berg (Myrtaceae) leaves have been used to decrease cholesterol levels. However, studies to determine activities of this plant on triglycerides metabolism have received little attention. The aim of this study was to examine anti-hyperlipidemic effects of a C. xanthocarpa aqueous leaf extract (CxAE) and assess protective actions against oxidative stress and DNA damage. The tyloxapol-induced hyperlipidemia model was used in Wistar rats. Rats were treated orally with CxAE either 250 or 500 mg/kg/day for 7 days prior to tyloxapol administration. Biochemical parameters, oxidative stress levels, and genomic instability were assessed in several tissues. CxAE decreased cholesterol and triglyceride levels in serum and hepatic and renal DNA damage in tyloxapol-treated rats. There was no marked effect on the micronucleus frequency in bone marrow. The extract increased catalase activity and decreased glutathione S-transferase activity in kidney tissue. CxAE showed anti-hyperlipidemic effects, improved oxidative parameters, and protected DNA against damage induced by tyloxapol-induced hyperlipidemia, suggesting C. xanthocarpa leaves may be useful in preventing dyslipidemias.Abbreviations: ALP: Alkaline phosphatase; ALT: Aspartate aminotransferase; ANOVA: Analysis of variance; AST: Aspartate aminotransferase; Ator: Atorvastatin; CAT: Catalase; Chol: Cholesterol; CxAE: Campomanesia xanthocarpa aqueous extract; GST: Glutathione S-transferase; HDL: High density cholesterol; i.p.: Intraperitoneal; NCE: Normochromatic erythrocyte; PBS: Phosphate buffer solution; PCE: Polychromatic erythrocyte; ROS: Reactive oxygen species; SD: Standard deviation; SOD: Superoxide dismutase; T: Tyloxapol; TBARS: Thiobarbituric acid reacting substances; TG: Triglyceride.

Experimental modeling of the acute toxicity and cytogenotoxic fate of composite mixtures of chromate, copper and arsenate oxides associated with CCA preservative using Clarias gariepinus (Burchell 1822)

Concurrent occurrence of chromium (Cr), copper (Cu) and arsenic (As) from chromated copper arsenate (CCA) wood preservative in aquatic ecosystems demands that their joint-actions in eliciting toxic effects be assessed for adequate understanding of the health risk they may pose to biota. Clarias gariepinus was exposed to As₂O₃ , CrO₃ and CuO and their composite mixtures (1:1 and 1:1:1) at various concentrations (0 – 600 mg/L) for 96-h to determine the acute toxicity using OECD (1992) protocol. C. gariepinus was then exposed to sub-lethal concentrations corresponding to 6.25, 12.5, 25.0, 50.0 and 100% of the 96-h LC₅₀ for 7 days to assess the cytogenotoxic effects using piscine micronucleus (MN) test. The 96-h LC₅₀ showed that the metals/metalloid demonstrated differential interactions in a concentration dependent pattern. The 96-h LC₅₀ showed that Cr was the most toxic while Cu and As:Cu were indeterminate (Cr > Cr:Cu > As:Cr > As > As:Cr:Cu > Cu = As:Cu indeterminate). Isobologram and synergistic ratio (SR) models predicted antagonistic interaction between Cu:Cr and As:Cr and synergism between As:Cu in the causation of morbidity and mortality of C. gariepinus. Interaction factor model predicted antagonism as common interactive mechanism among the metal/metalloid mixtures in the induction of MN and abnormal nuclear erythrocytes in C. gariepinus. Predicted interactions among the three metals/ metalloid were largely antagonism and synergism towards the induction of acute toxicity and cytogenotoxicity. The models employed herein may be useful in establishing environmental safe limits for mixtures of metals/metalloids against the induction of acute toxicity and DNA damage in lower aquatic vertebrates.

Antigenotoxic and antimutagenic effects of Myrciaria dubia juice in mice submitted to ethanol 28-day treatment

Myrciaria dubia is a native plant from the Amazon region which produces red-purplish fruit rich in antioxidant compounds such as ascorbic acid, carotenoids, and phenolic. M. dubia fruit is used to prepare juices considered to possess high nutritional content providing health benefits. The aim of this study was to examine the ability of M. dubia juice to protect DNA against genomic instability induced by sub-acute ethanol consumption attributed to oxidative stress. Mice were treated for 28 days with juice at 25% and 50% diluted in distilled water or with the diluted combination juice plus ethanol (5 g/kg). The genotoxic/antigenotoxic and mutagenic/antimutagenic effects were assessed using comet assay in blood, liver, and kidney and micronucleus (MN) test with bone marrow. In addition, the mutagenicity was also evaluated using Salmonella/microsome assay. Phytochemical compounds were determined using HPLC/PDA/MS/MS. The juice did not induce genotoxic effects in blood, kidney, and liver cells at both doses. In combination with ethanol, the juice reduced the alcohol-mediated DNA damage in all tissues analyzed. Further, the juice did not produce mutagenic effects and decreased mutagenicity induced by ethanol in the bone marrow. The anthocyanins were major compounds detected by HPLC/PDA/MS/MS, which modulated genotoxic and mutagenic effects initiated by ethanol and at least in part appeared responsible for the observed antigenotoxic and antimutagenic effects of M. dubia juice.

Evaluation of cell and DNA damage induced by panoramic radiography

Background

X-rays are potential mutagenic agents that can cause both the gene mutations and chromosomal aberrations.

Aims

In this study, the micronucleus (MN) test and the comet assay methods are implemented in order to observe the damage that can occur in the cell nucleus and in the structure of DNA of the patients who underwent a panoramic examination.

Methods and Materials

In our study, buccal mucosa swabs were obtained just before the radiography and 2 weeks after the radiography from 30 volunteer patients who had to take radiographs due to dental diagnosis. Changes in the nuclei of 1,000 cells of each swab sample had been counted under a light microscope and recorded. Besides, 100 cells of each other swab samples were analyzed by the comet assay. Comet assay parameters namely tail length and percentage of DNA in tail, which indicate the level of DNA damage were analyzed and compared in both groups. Statistical analysis was performed by using the Statistical Package for the Social Sciences (Version 21).

Results

In our study, the results of percentage of DNA in tail and tail length before and after X-ray exposure were statistically significant (P < 0.001). Likewise, increase in the MN frequency observed in buccal mucosa cells after X-ray exposure was found significant (P < 0.001).

Conclusions

As a result, panoramic radiographs taken during dental diagnosis and treatment cause cytotoxicity and DNA damage in oral mucosal cells. Panoramic radiographs should be applied only when necessary, using an accurate radiographic technique and radioprotection criteria.

Antioxidant and Cytoprotective Effect of Piper aduncum L. against Sodium Fluoride (NaF)-Induced Toxicity in Albino Mice

Piper aduncum, commonly known as matico, is a plant that grows in the mountainous and coastal regions of Peru, and is studied for its antimicrobial properties and various ethnopharmacological uses. The main objective of this study was to determine the cytoprotective and antioxidant effects of the methanolic extract of Piper aduncum leaves in Mus musculus previously administered with sodium fluoride (NaF) using the Micronucleus test and the Comet assay. The extract was administrated orally in four different concentrations: 150, 300, 600, and 1200 mg/Kg for ten days. At the 11th day, a single dose of NaF was administrated via intraperitoneal at 20 mg/Kg. The genotoxicity study was performed with mice from the strain BALB/c, using the Micronucleus test on bone marrow and the Comet assay on peripheral blood according to OECD guidelines 474 and 489, respectively. The statistical analysis was performed by median analysis with ANOVA. Significant differences were found in Micronucleus frequency between the highest concentrations of Piper aduncum and NaF. The Comet assay showed significant reduction of NaF-induced damage on erythrocytes depending on the different concentrations of the extract which were evaluated in this study. It is concluded that the methanolic extract of P. aduncum leaves has cytoprotective and antioxidant activity against sodium fluoride.

Genomic Instability and Cytotoxicity in Buccal Mucosal Cells of Workers in Banana Farming Evaluated by Micronucleus Test

BACKGROUND/AIM

Studies have demonstrated the biological consequences of environmental contamination caused by human pesticide exposure following banana production. The aim of this study was to evaluate genomic instability and cytotoxicity in buccal mucosal cells of workers in banana farming.

MATERIALS AND METHODS

For this purpose, a total of 21 male workers in banana farming in the Ribeira Valley were included in the experimental group. A total of 20 individuals, not occupationally exposed to pesticides, were included in the control group.

RESULTS

The frequency of micronuclei was significantly increased (p<0.05) in buccal mucosa cells from workers of banana farming when compared to the control group. Furthermore, a high frequency of karyolysis was detected in buccal mucosaI cells in these individuals. No significant differences were found in pyknosis or karryorhexis when compared to controls.

CONCLUSION

Taken together, our results indicate that workers in banana farming represent a group in high risk for carcinogenesis since chromosomal damage and cellular death are increased in these individuals.

Genotoxic effects induced by beta-myrcene following metabolism by liver HepG2/C3A human cells

Beta-myrcene [or myrcene (1,6-Octadiene, 7-methyl-3-methylene-)] and the essential oils containing this monoterpene have been widely used in cosmetics, detergents, and soaps, and as flavoring additives for food and beverages. Due to the potentially high level of human exposure to beta-myrcene, and absence of studies involving its genotoxicity in human cells, the aim of this study was to investigate the cytotoxic and genotoxic potential of this terpenoid in non-metabolizing cells (leukocytes) and liver metabolizing cells (HepG2/C3A cells). Prior to the genotoxic assessment by the comet and micronucleus (MN) assays, a range of beta-myrcene concentrations was tested in a preliminary MTT assay. Regarding the MTT assay, the results showed cytotoxic effects for leukocytes at 250 µg/ml and higher concentrations, while for HepG2/C3A cells, absence of cytotoxicity was noted relative to all tested concentrations (after 24 hr exposure). Thus, the concentrations of 2.5, 10, 25, 50, and 100 µg/ml for leukocytes, and 2.5, 100, and 1000 µg/ml for HepG2/C3A cells were selected for subsequent assays. Genotoxicity evaluation demonstrated significant DNA damage in the comet assay and significant chromosomal abnormalities including nucleoplasmic bridges and nuclear buds in HepG2/C3A cells at beta-myrcene concentrations of 100 and 1000 µg/ml. Under our experimental conditions, caution is recommended in the use of beta-myrcene, since this compound produced genotoxic effects especially after metabolic activation using human HepG2/C3A cells, which may be associated with carcinogenic and teratogenic effects previously reported in the literature.

Are Our Farm Workers in Danger? Genetic Damage in Farmers Exposed to Pesticides

Modern agriculture, practiced after the "green revolution" worldwide, aims to maximize production in order to provide food for the growing world population. Thus, farmers are required to modernize their practices through the mechanization of land use and, above all, the use of chemical pesticides to control agricultural pests. However, in addition to combating the target pest, chemical pesticides indirectly affect a wide range of species, including humans, leading to health damage. Among the main problems caused by the use of pesticides is the genotoxicity caused by chronic exposure. The present study aims to verify the occurrence of genetic damage in farmers who are occupationally exposed to agrochemicals compared to people of other professions that do not use toxic substances (control group). The research was conducted with 36 male participants (18 farmers and 18 control group, ages 24⁻71 for the farmer group and 22⁻61 for the control group). The comet assay and micronucleus test results revealed a higher rate of genetic damage in the group of farmers than in the control group. A questionnaire answered by the farmers showed that the Personal Protect Equipment (PPE) is used incorrectly or not used. In summary, our results indicate that farmers are exposed to occupational hazards. To mitigate this risk, we conducted awareness campaigns to notify the farmers of the risks and highlight the importance of using PPE correctly. Intensive efforts and training are thus required to build an awareness of safety practices and change the attitudes of farm workers in the hope of preventing harmful environmental and anthropogenic effects.

A Comparative Study for Selectivity of Micronuclei in Cervical Exfoliated Cells on Chronic Boron Effects

Background:

Cervical cancer is one of the most frequent malignancies in women. Micronucleus (MN) testing has gained popularity as a biomarker in early diagnosis of many types of cancer.

Aims:

This study aims to investigate the role of MN testing on early detection of cervical cancer and the effect of boron exposure on cervical cells.

Settings and Design:

The study population comprised women who were diagnosed to be human papillomavirus (HPV)-positive and had atypical squamous cells of undetermined significance (ASCUS) as cervical cytology in a cervical screening project. A total of 15 HPV-positive and 36 ASCUS patients were identified. Randomly selected 20 women were selected from boron-rich region (n = 10) and nonboron region (n = 10).

Materials and Methods:

Cervical swab specimens were dyed using Papanicolaou (PAP) and May–Grünwalds–Giemsa (MGG) techniques, and MN count in 1000 cells was performed. The results were statistically evaluated.

Statistical Analysis Used:

Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 13. Quantitative data were presented as mean ± standard deviation. MN test scoring was compared using Mann–Whitney U-test.

Results:

Boron content of urine was measured to be 3.02 ± 1.45 and 0.98 ± 0.42 mg/day in boron-rich and nonboron regions, respectively. When MN counts were compared according to PAP and MGG staining in HPV- and ASCUS-positive women, there was statistically no significant difference (P > 0.05). Disregarding regions, HPV/control and HPV/ASCUS cases stained with PAP and MGG had statistically significant difference in MN count (P < 0.05).

Conclusion:

These findings suggest that MGG and PAP staining gives similar results with regard to MN count. On the other hand, it has been shown again that HPV induces MN and causes genomic instability.

The Dependence of the Mutagenic Effect on the Dose of X-Ray Irradiation in an In Vivo Experiment on Female (CBA×C57Bl/6)F1 Mice

We studied the mutagenic effect of X-ray irradiation in doses of 0.5, 1, and 1.5 Gy on female (CBA×C57Bl/6)F1 mice. The mutagenic effect (assessed by the parameter "frequency of bone marrow polychromatophilic erythrocytes with micronuclei") linearly depended on the dose of X-ray irradiation in the range of up to 1 Gy and reached the plateau at 1.5 Gy. The fraction of polychromatophilic erythrocytes was 45, 45, and 46% under control conditions (without exposure) and exposure to the irradiation in the doses of 0.5 and 1 Gy, respectively. Irradiation in a dose of 1.5 Gy induced a slight inhibition of erythropoiesis. These data confirm the hypothesis on possible death of highly aberrant erythrocyte precursors after irradiation in high doses.

Chronic exposure to quinalphos shows biochemical changes and genotoxicty in erythrocytes of silver barb, Barbonymus gonionotus

An in vivo study was carried out on the freshwater fish Barbonymus gonionotus to evaluate the genotoxic effects of the organophosphate quinalphos. The fish were exposed to sub-lethal doses of quinalphos (0%, 10%, 25%, and 50% of LC₅₀) for a period of 30 days. Analysis of biochemical characteristics (protein and lipid contents of different organs), nuclear abnormalities of erythrocytes (NAE) and morphological abnormalities of erythrocytes (MAE) were performed on peripheral erythrocytes sampled at post-treatment intervals of 0 and 30 days. The biochemical results revealed a significant dose-dependent decline in protein and lipid contents and increase in the frequencies of NAE as well as MAE. Our findings also confirmed that the morphological deformations of erythrocytes in addition to NAE on fish erythrocytes in vivo are effective tools in determining the potential genotoxicity of organophosphates.

Genomic Instability in Buccal Mucosal Cells of Municipal Street Sweepers as Evaluated by Micronucleus Test

BACKGROUND/AIM

Since street sweepers comprises a group of workers who are in daily contact with rubbish, dust and air pollution, the aim of this study was to evaluate potential cytotoxic and mutagenic effects in buccal mucosa cells of street sweepers.

MATERIALS AND METHODS

A total of 20 male street sweepers aged from 22 to 56 years were included in the experimental group. A total of 20 men matched by age were used as the control group. Cytotoxicity and mutagenicity were analyzed by micronucleus test in buccal mucosal cells.

RESULTS

Statistically significant differences (p<0.05) in the frequency of micronuclei was detected in the street sweepers when compared to the control group. No remarkable differences were found to other metanuclear alterations indicative for cytotoxicity such as pyknosis, karyolysis, and karryorhexis when compared to matched controls.

CONCLUSION

Taken together, our results indicate that street sweepers comprise an at-risk group as a result of increased mutagenicity found to buccal mucosa cells.

In vitro evaluation of the genotoxicity of CeO2 nanoparticles in human peripheral blood lymphocytes using cytokinesis-block micronucleus test, comet assay, and gamma H2AX

Engineered nanoparticles (ENPs) are used in a wide range of applications because of their unique properties. Cerium dioxide nanoparticles (CeO₂ NPs) are one of the important ENPs, and they can cause negative health effects, such as genotoxicity, in humans and other living organisms. The aim of this work was to analyze the genotoxic effects of short-term (3-24 h) CeO₂ NPs exposure to cultured human blood lymphocytes. Three genotoxicity systems "cytokinesis-block micronucleus test, comet assay, and gamma H2AX test" were used to show the genotoxic potential of CeO₂ NPs (particle size <25 nm, concentrations: 6, 12, and 18 µg/mL). Hydrogen peroxide was selected as the positive-control genotoxic agent. Our results indicate that CeO₂ NPs have genotoxic potential on human peripheral blood lymphocytes cells even at 3-24 h exposure under in vitro conditions.

The genotoxic effects of fruit extract of Crataegus oxyacantha (hawthorn) in mice

Crataegus oxyacantha L. (Rosaceae) is a medicinal plant with a long history of use in European, Chinese, and American. The majority of pharmacological activities associated with fruit extracts of C. oxyacantha L. are related to cardio-stimulant properties utilized in the treatment of atherosclerosis, hypertension with myocardic insufficiency, angina pectoris, cardiac rhythm alterations, and heart failure. Some other therapeutic uses for renal calculi, dyspnea, as well as a diuretic, sedative, and anxiolytic were also reported. Due to the beneficial potential of C. oxyacantha fruits extract but evidence in vitro of genetic toxicity, the aim of the present study was to examine the genotoxic potential of plant extract in vivo in mice. The extract was administered orally, daily by gavage at doses of 50, 100, and 200 mg/kg body weight for seven days. Data demonstrated that C. oxyacantha extract did not markedly induce DNA damage in leukocytes and bone marrow cells by the comet assay; however, the extract produced a significant rise in micronucleated polychromatic erythrocytes (PCE) at all tested doses in a non-dose dependent manner as evidenced by the micronucleus test. The PCE/normochromatic erythrocytes (NCE) ratio indicated no significant cytotoxicity. Under our experimental conditions, C. oxyacantha fruits extract exhibited weak clastogenic and/or aneugenic effects in bone marrow cells of male mice, confirming our previous in vitro findings that this plant extract induced genotoxicity suggesting that prolonged or high dose use needs to be undertaken with caution.

Antigenotoxicity properties of Copaifera multijuga oleoresin and its chemical marker, the diterpene (-)-copalic acid

In view of the biological activities and growing therapeutic interest in oleoresin obtained from Copaifera multijuga, this study aimed to determine the genotoxic and antigenotoxic potential of this oleoresin (CMO) and its chemical marker, diterpene (-)-copalic acid (CA). The micronucleus (MN) assay in V79 cell cultures and the Ames test were used for in vitro analyses, as well as MN and comet assays in Swiss mice for in vivo analyses. The in vitro genotoxicity/mutagenicity results showed that either CMO (30, 60, or 120 µg/ml-MN assay; 0.39-3.12 mg/plate-Ames test) or CA (2.42; 4.84, or 9.7 µg/ml-MN assay; 0.39-3.12 mg/plate-Ames test) did not induce a significant effect on the frequency of MN and number of revertants, demonstrating an absence of genotoxic and mutagenic activities, respectively, in vitro. In contrast, these natural products significantly reduced the frequency of MN induced by methyl methanesulfonate (MMS), and exerted a marked inhibitory effect against indirect-acting mutagens in the Ames test. In the in vivo test system, animals treated with CMO (6.25 mg/kg b.w.) exhibited a significant decrease in rate of MN occurrence compared to those treated only with MMS. An antigenotoxic effect of CA was noted in the MN test (1 and 2 mg/kg b.w.) and the comet assay (0.5 mg/kg b.w.). Data suggest that the chemical marker of the genus Copaifera, CA, may partially be responsible for the observed chemopreventive effect attributed to CMO exposure.

ABBREVIATIONS

2-AA, 2-anthramine; 2-AF, 2-aminofluorene; AFB₁, aflatoxin B₁; B[a]P, benzo[a]pyrene; BOD, biological oxygen demand; BPDE, benzo[a]pyrene-7,8-diol-9,10-epoxide; CA, (-)-copalic acid; CMO, oleoresin of Copaifera multijuga, DMEM, Dulbecco`s Modified Eagles`s Medium; DMSO, dimethylsulfoxide; EMBRAPA, Brazilian agricultural research corporation; GC-MS, gas chromatography-mass spectrometry; HAM-F10, nutrient mixture F-10 Ham; HPLC, high performance liquid chromatography; LC-MS, liquid chromatography-mass spectrometry; MI, mutagenic index; MMC, mitomycin C; MMS, methyl methanesulfonate; MN, micronucleus; MNPCE, micronucleated polychromatic erythrocyte; NCE, normochromatic erythrocyte; NDI, nuclear division index; NMR, nuclear magnetic resonance; NPD, 4-nitro-o-phenylenediamine; PBS, phosphate-buffered saline; PCE, polychromatic erythrocyte; SA, sodium azide; V79, Chinese hamster lung fibroblast.

Clarification of some aspects related to genotoxicity assessment

The European Commission requested EFSA to provide advice on the following: (1) the suitability of the unscheduled DNA synthesis (UDS) in vivo assay to follow‐up positive results in in vitro gene mutation tests; (2) the adequacy to demonstrate target tissue exposure in in vivo studies, particularly in the mammalian erythrocyte micronucleus test; (3) the use of data in a weight‐of‐evidence approach to conclude on the genotoxic potential of substances and the consequent setting of health‐based guidance values. The Scientific Committee concluded that the first question should be addressed in both a retrospective and a prospective way: for future assessments, it is recommended no longer performing the UDS test. For re‐assessments, if the outcome of the UDS is negative, the reliability and significance of results should be carefully evaluated in a weight‐of‐evidence approach, before deciding whether more sensitive tests such as transgenic assay or in vivo comet assay would be needed to complete the assessment. Regarding the second question, the Scientific Committee concluded that it should be addressed in lines of evidence of bone marrow exposure: toxicity to the bone marrow in itself provides sufficient evidence to allow concluding on the validity of a negative outcome of a study. All other lines of evidence of target tissue exposure should be assessed within a weight‐of‐evidence approach. Regarding the third question, the Scientific Committee concluded that any available data that may assist in reducing the uncertainty in the assessment of the genotoxic potential of a substance should be taken into consideration. If the overall evaluation leaves no concerns for genotoxicity, health‐based guidance values may be established. However, if concerns for genotoxicity remain, establishing health‐based guidance values is not considered appropriate.

Evidence of genotoxicity and cytotoxicity of X-rays in the oral mucosa epithelium of adults subjected to cone beam CT

OBJECTIVES

To assess cytological evidence of genotoxicity and cytotoxicity of X-rays in oral exfoliated cells of adults subjected to partial and total cone beam CT (CBCT) (stitching module) by means of micronuclei frequency, associated with counting of degenerative nuclear alterations (pyknosis, karyolysis, karyorrhexis, buds and broken eggs), besides comparing the partial and total CBCT (stitching module) in search of possible differences in the nature and/or intensity of the effects.

METHODS

29 adults who were referred to total or partial CBCT were selected. All CBCT were performed with a Carestream CS 9000 3D scanner (Carestream Health Inc., Rochester, NY). Material collection was done immediately before CBCT and 10 days later, by scraping the left and right cheek mucosa with a plastic spatula. Statistical analysis was performed using the Wilcoxon test (paired data), at a significance level of 5%.

RESULTS

The statistically significant difference was noted in the frequency of micronucleated cells for both partial and total acquisition (p = 0.008 and p < 0.001, respectively). Regarding to cytotoxicity, there was a statistically significant difference for both partial and total acquisition (p < 0.001 and p < 0.001, respectively).

CONCLUSIONS

The partial and total CBCT seems to offer risks of inducing genetic damage. In addition both forms of CBCT acquisition have promoted the induction of cytotoxic nuclear alterations.

[Genotoxicity assessment of 2-ethylhexyl acrylate using an in vivo Pig-a gene mutation assay integrated system]

OBJECTIVE

To verify the mutagenicity of 2-ethylhexyl acrylate( 2-EHA)using in vivo Pig-a gene mutation assay integrated system.

METHODS

The SPF-grade male SD rats( n = 30) were randomized to six treatment groups, i. e. 4 treatment groups( 100, 200, 400 and 800 mg/kg), a control group( vegetable oil) and a positive groups( Nethyl-N-nitrosourea, 10 mg/kg). All treatments were administrated by gavage for continuous 28 days. Tail vein blood specimens for Pig-a gene mutation assay were collected on days 0, 15 and 29. The number of mutant erythrocytes and reticulocytes was acquired by flow cytometer. Tail vein blood for comet assay was collected at 6 h after the final administration, followed by the bone marrow micronucleus test after animal sacrifice.

RESULTS

Later in the study, signs of mild poisoning were observed in the animals treated with 400 and 800 mg/kg BW 2-EHA. There was no significant difference among the groups in mutant cell frequency of erythrocytes and reticulocytes at all 3 timepoint in Piga gene mutation assay, and no significant difference among the groups in tail length and Olive tail moment in comet assay. There was likewise no significant difference among groups in micronucleus test.

CONCLUSION

In present experiment conditions, 2-EHA did not show genotoxicity in Pig-a gene mutation assay, comet assay and micronucleus test, which indicated that 2-EHA probably is not mutagenic in vivo.

Hypogymnia tubulosa extracts: chemical profile and biological activities

This study reports for the first time in the chemical composition of acetone, ether, ethyl acetate and dichloromethane extracts of Hypogymnia tubulosa determined by HPLC-UV, GC-FID and GC-MS as well as effect of H. tubulosa acetone extract on micronucleus distribution on human lymphocytes and on cholinesterase activity. Additionally, antioxidant (estimated via DPPH, ABTS, TRP, CUPRAC and TPC assays) and antibacterial activity against two Gram-positive and three Gram-negative bacteria were also determined. The HPLC-UV analysis revealed the presence of depsidones, 3-hydroxyphysodic, 4-O-methyl physodic acid, physodic and physodalic acid together with two depsides, atranorin and chloroatranorin. GC-FID and GC-MS analyses enabled the identification of atranol, chloroatranol, atraric acid, olivetol, olivetonide and 3-hydroxyolivetonide as the main components. The results of present study show that H. tubulosa acetone extract is a promising candidate for in vivo experiments considering antioxidant activity.

Acute toxicity of commercial atrazine in Piaractus mesopotamicus: Histopathological, ultrastructural, molecular, and genotoxic evaluation

Aim:

The aim of this work was to evaluate the sensitivity of Pacu fingerlings (Piaractus mesopotamicus) by measuring the effects of median lethal concentration (LC₅₀) of atrazine (ATZ - 28.58 mg/L) after acute exposure (up to 96 h).

Materials and Methods:

The fish were exposed to the LC₅₀ of ATZ for 96 h (28.58 mg/L) in a static system. During the experiment, the fingerlings were randomly distributed in four glass tanks (50 L) containing dechlorinated water. Four glass tanks were for the control group, and four were for the ATZ-exposed group (n=4 per glass tank), given a total number of 16 animals tested per group. The genotoxicity was evaluated by micronucleus (MN) test in erythrocytes from peripheral blood. Qualitative and semi-quantitative histopathological analyses, and also ultrastructural study, were applied in liver and kidney samples. Finally, the content of heat shock protein (Hsp70) in the liver was evaluated by the western blotting method.

Results:

The morphological alterations in the liver, which was associated with increased expression of Hsp70, included nuclear and cytoplasmic vacuolization, cytoplasmic hyaline inclusions, and necrosis. The kidney presented edema and tubular cell degeneration with cytoplasmic hyaline inclusion. The semi-quantitative histopathological analyses indicated that the liver was more sensitive than kidney to ATZ-induced damage. Ultrastructural analysis showed that ATZ caused membrane alterations in several organelles and increased the number of lysosomes in hepatocytes and kidney proximal tubular cells. Nevertheless, no significant difference was observed in MN frequency in erythrocytes comparing treated and control groups.,

Conclusion:

These results indicated that ATZ-induced damage to the kidney and liver function, ATZ at the concentration tested did not induce a significant difference in MN frequency in Pacu erythrocytes comparing treated and control groups, and also that Pacu fingerlings may be a good bioindicator for testing freshwater contamination.

Combinations of genotoxic tests for the evaluation of group 1 IARC carcinogens

Many of the known human carcinogens are potent genotoxins that are efficiently detected as carcinogens in human populations but certain types of compounds such as immunosuppressants, sex hormones, etc. act via non-genotoxic mechanism. The absence of genotoxicity and the diversity of modes of action of non-genotoxic carcinogens make predicting their carcinogenic potential extremely challenging. There is evidence that combinations of different short-term tests provide a better and efficient prediction of human genotoxic and non-genotoxic carcinogens. The purpose of this study is to summarize the in vivo and in vitro comet assay (CMT) results of group 1 carcinogens selected from the International Agency for Research on Cancer and to discuss the utility of the comet assay along with other genotoxic assays such as Ames, in vivo micronucleus (MN), and in vivo chromosomal aberration (CA) test. Of the 62 agents for which valid genotoxic data were available, 38 of 61 (62.3%) were Ames test positive, 42 of 60 (70%) were in vivo MN test positive and 36 of 45 (80%) were positive for the in vivo CA test. Higher sensitivity was seen in in vivo CMT (90%) and in vitro CMT (86.9%) assay. Combination of two tests has greater sensitivity than individual tests: in vivo MN + in vivo CA (88.6%); in vivo MN + in vivo CMT (92.5%); and in vivo MN + in vitro CMT (95.6%). Combinations of in vivo or in vitro CMT with other tests provided better sensitivity. In vivo CMT in combination with in vivo CA provided the highest sensitivity (96.7%).

Cobalt chloride exposure dose-dependently induced hepatotoxicity through enhancement of cyclooxygenase-2 (COX-2)/B-cell associated protein X (BAX) signaling and genotoxicity in Wistar rats

Cobalt chloride (CoCl₂ ) is one of the many environmental contaminants, used in numerous industrial sectors. It is a pollutant with deadly toxicological consequences both in developing and developed countries. We investigated toxicological impact of CoCl₂ on hepatic antioxidant status, apoptosis, and genotoxicity. Forty Wistar rats were divided into four groups, 10 rats per group: Group 1 served as control and received clean tap water orally; Group 2 received CoCl₂ solution (150 mg/L); Group 3 received CoCl₂ solution (300 mg/L); and Group 4 received CoCl₂ (600 mg/L) in drinking water for 7 days, respectively. Exposure of rats to CoCl₂ led to a significant decline in hepatic antioxidant enzymes together with significant increase in markers of oxidative stress. Immunohistochemistry revealed dose-dependent increase in cyclooxygenase-2 and BAX expressions together with increased frequency of Micronucleated Polychromatic Erythrocytes. Combining all, CoCl₂ administration led to hepatic damage through induction of oxidative stress, inflammation, and apoptosis.

Anti-Genotoxicity Evaluation of Cratoxylum Formosum Dyer Leaves by Comet Assay and Micronucleus Test

Cratoxylum formosum Dyer is the Thai vegetable which commonly consumed a fresh leaves. In this study, we extracted Cratoxylum formosum with water and tested the extract for genotoxicity and anti-genotoxicity effects. We carried out the experiment using micronucleus test and comet assay in TK6 cells. In micronucleus experiment, we used cytokinesis-block proliferation technique to stop cell division which produced a cell at binucleated (BNC) stage. The comet assay was carried out after pre-treatment the cell with C. formosum for 18 h. The results revealed not increased the micronucleus frequency of C. formosum at concentration ranging from 50-150 μg/ml. In contract, it showed that the combination between C. formosum at various concentrations (25, 50, 75, 100, 150 and 200 μg/ml) and mitomycin C could decrease significantly in frequency of micronuclei. The mean of micronucleus frequency in the sample were 23.17 ±3.33, 23.33 ±4.72, 21.00 ±3.61, 11.33 ±3.21, 16.67 ±2.08, and 23.33±1.53 MN/ 1,000 BNC, respectively whereas the MMC-treated group was 33.67 ± 8.96 MN/ 1,000 BNC. The comet assay result showed that pre-treatment with Cratoxylum formosum (25, 50, 100, 200 μg/ml) could inhibit the hydrogen peroxide induced DNA damage by 6.95, 12.99, 17.61, and 26.39 respectively.

Ramalina capitata (Ach.) Nyl. acetone extract: HPLC analysis, genotoxicity, cholinesterase, antioxidant and antibacterial activity

In the present investigation, effects of Ramalina capitata acetone extract on micronucleus distribution on human lymphocytes, on cholinesterase activity and antioxidant activity (by the CUPRAC method) were examined, for the first time as well as its HPLC profile. Additionally, total phenolic compounds (TPC), antioxidant properties (estimated via DPPH, ABTS and TRP assays) and antibacterial activity were determined. The predominant phenolic compounds in this extract were evernic, everninic and obtusatic acids. Acetone extract of R. capitata at concentration of 2 μg mL^-1 decreased a frequency of micronuclei (MN) for 14.8 %. The extract reduces the concentration of DPPH and ABTS radicals for 21.2 and 36.1 % (respectively). Values for total reducing power (TRP) and cupric reducing capacity (CUPRAC) were 0.4624 ± 0.1064 μg ascorbic acid equivalents (AAE) per mg of dry extract, and 6.1176 ± 0.2964 μg Trolox equivalents (TE) per mg of dry extract, respectively. The total phenol content was 670.6376 ± 66.554 μg galic acid equivalents (GAE) per mg of dry extract. Tested extract at concentration of 2 mg mL^-1 exhibited inhibition effect (5.2 %) on pooled human serum cholinesterase. The antimicrobial assay showed that acetone extract had inhibition effect towards Gram-positive strains. The results of manifested antioxidant activity, reducing the number of micronuclei in human lymphocytes, and antibacterial activity recommends R. capitata extract for further in vivo studies.

Cytogenetic Biomonitoring in Buccal Mucosal Cells from Municipal Solid Waste Collectors

Waste collectors collect, transport, and process the garbage produced by people living in the city. Nowadays, this activity requires special attention due to the environmental impact of garbage and its potential consequences on human health. The aim of this study was to evaluate potential cytotoxic and mutagenic effects of garbage collection on waste collectors. For this purpose, a total of 47 male waste collectors aged from 24 to 53 years were included in the experimental group. A total of 30 men matched by age were used as the control group. Cytotoxicity and mutagenicity were analyzed by micronucleus test in buccal mucosaI cells. No statistically significant difference (p>0.05) in the frequency of micronuclei was detected in the waste collectors when compared to controls. Nevertheless, higher frequencies of karyolysis and pyknosis (p<0.05) were detected in buccal mucosaI cells from waste collectors when compared to matched controls. Taken together, our results indicate that waste collectors comprise an at-risk group as a result of increased cytotoxicity apparent from buccal mucosa cells.

Toxic effects of mercury on the cell nucleus of Dictyostelium discoideum

Governmental agencies (www.epa.gov/mercury) and the scientific community have reported on the high toxicity due to mercury. Indeed, exposure to mercury can cause severe injury to the central nervous system and kidney in humans. Beyond its recognized toxicity, little is known regarding the molecular mechanisms involved in the actions of this heavy metal. Mercury has been also observed to form insoluble fibrous protein aggregates in the cell nucleus. We used D. discoideum to evaluate micronuclei formation and, since mercury is able to induce oxidative stress that could bring to protein aggregation, we assessed nuclear protein carbonylation by Western Blot. We observed a significant increase in micronuclei formation and 14 carbonylated proteins were identified. Moreover, we used isotope-coded protein label (ICPL) and mass spectrometry analysis of proteins obtained by lysis of purified nuclei, before of tryptic digestion to quantify nuclear proteins affected by mercury. In particular, we examined the effects of mercury that associate a classical genotoxic assay to proteomic effects into the nucleus. The data present direct evidences for mercury genotoxicity, nuclear protein carbonylation, quantitative change in core histones, and the involvement of pseudouridine synthase in mercury toxicity. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 417-425, 2017.

Oxidative Stress and Genotoxicity of Long-Term Occupational Exposure to Low Levels of BTEX in Gas Station Workers

Atmospheric benzene, toluene, ethylbenzene, and xylenes (BTEX) can lead to multiple health injuries. However, what remains uncertain is the effect of long-term exposure to low levels of BTEX. Thus, we determined the BTEX levels in the air from the refueling and office areas in gas stations. Then we collected workers’ (200 refueling vs. 52 office workers) peripheral blood samples to analyze the serum total-superoxide dismutase (T-SOD), glutathione (GSH), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) levels. DNA damage was analyzed by the comet assay and micronucleus test in buccal epithelial cells. We found that the levels of BTEX in refueling areas were significantly higher than those in office areas (p < 0.001). The serum T-SOD and GSH of refueling workers were significantly lower than those in office workers (p < 0.001). By contrast, the serum MDA and 8-OHdG of refueling workers were significantly higher than those of office workers (p < 0.001, MDA; p = 0.025, 8-OHdG). Furthermore, tail and Olive tail moments in refueling workers were longer (p = 0.004, tail moment; p = 0.001, Olive tail moment), and the micronucleus rate was higher (p < 0.001) than those in office workers. Taken together, long-term exposure to low levels of BTEX may reduce the antioxidant ability and increase the risk of DNA damage in refueling workers of gas stations.

The effect of particle size on the genotoxicity of gold nanoparticles

Despite the increasing biomedical applications of gold nanoparticles (AuNPs), their toxicological effects need to be thoroughly understood. In the present study, the genotoxic potential of commercially available AuNPs with varying size (5, 20, and 50 nm) were assessed using a battery of in vitro and in vivo genotoxicity assays. In the comet assay, 20 and 50 nm AuNPs did not induce obvious DNA damage in HepG2 cells at the tested concentrations, whereas 5 nm NPs induced a dose-dependent increment in DNA damage after 24-h exposure. Furthermore, 5 nm AuNPs induced cell cycle arrest in G1 phase in response to DNA damage, and promoted the production of reactive oxygen species (ROS). In the chromosomal aberration test, AuNPs exposure did not increase in the frequency of chromosomal aberrations in Chinese hamster lung (CHL) cells. In the standard in vivo micronucleus test, no obvious increase in the frequency of micronucleus formation was found in mice after 4 day exposure of AuNPs. However, when the exposure period was extended to 14 days, 5 nm AuNPs presented significant clastogenic damage, with a dose-dependent increase of micronuclei frequencies. This finding suggests that particle size plays an important role in determining the genotoxicity of AuNPs. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 710-719, 2017.

Cytotoxic and Chemopreventive Effects of Gemin D Against Different Mutagens Using In Vitro and In Vivo Assays

BACKGROUND

Gemin D (GD) is an ellagitannin found in several plant species rich in phenolic compounds. Its many beneficial properties include antioxidant and antitumoral.

OBJECTIVE

The present study assessed the genotoxicity, cytotoxicity, antigenotoxicity, and anticytotoxicity of GD by in vitro and in vivo assays.

METHOD

The Ames mutagenicity assay in Salmonella typhimurium, Micronucleus and Comet tests in mice were used to evaluate the biological activities mentioned above. To assess the GD's protective effects against DNA damage induced by different mutagens we performed co-, pre- and/or post-treatment in these assays.

RESULTS

There was no genotoxic effect of GD via Ames and Micronucleus tests, but in the Comet assay the highest dose induced DNA damage. This same highest dose presented a significant cytotoxicity in mice. In the antigenotoxicity, GD protected DNA against the action of 4-nitroquinoline-1-oxide and sodium azide by Ames test, and also against the harmful action of cyclophosphamide in pre- and co-treatment by Micronucleus and Comet tests, but it did not protect DNA in post-treatment. Regarding to anticytotoxicity, GD provoked an anticytotoxic effect only during pre-treatment.

CONCLUSION

Therefore, GD showed relevant antigenotoxic, anticytotoxic and cytotoxic effects, which indicate that it may be a probable candidate for chemoprevention or for the development of new cancer therapies.

FR-900098, an antimalarial development candidate that inhibits the non-mevalonate isoprenoid biosynthesis pathway, shows no evidence of acute toxicity and genotoxicity

FR-900098 is an inhibitor of 1-deoxy-d-xylulose-5-phosphate (DXP) reductoisomerase, the second enzyme in the non-mevalonate isoprenoid biosynthesis pathway. In previous studies, FR-900098 was shown to possess potent antimalarial activity in vitro and in a murine malaria model. In order to provide a basis for further preclinical and clinical development, we studied the acute toxicity and genotoxicity of FR-900098. We observed no acute toxicity in rats, i.e. there were no clinical signs of toxicity and no substance-related deaths after the administration of a single dose of 3000 mg/kg body weight orally or 400 mg/kg body weight intravenously. No mutagenic potential was detected in the Salmonella typhimurium reverse mutation assay (Ames test) or an in vitro mammalian cell gene mutation test using mouse lymphoma L5178Y/TK(+/-) cells (clone 3.7.2C), both with and without metabolic activation. In addition, FR-900098 demonstrated no clastogenic or aneugenic capability or significant adverse effects on blood formation in an in vivo micronucleus test with bone marrow erythrocytes from NMRI mice. We conclude that FR-900098 lacks acute toxicity and genotoxicity, supporting its further development as an antimalarial drug.

Study of the genotoxic and cytotoxic effects of the α-, β-, and γ- Hexachlorocyclohexane isomers in human lymphocyte cells using the cytokinesis-block micronucleus assay

The genotoxic potential of hexachlorocyclohexane (HCH) isomers (α-, β-, and γ-) which are organochlorine pesticides was tested in peripheral blood lymphocyte cultures from two donors by using the cytokinesis-block micronucleus assay. Micronucleus (MN) frequency, binucleated cells with micronucleus (BNMN), and cytokinesis-blocked proliferation index (CBPI) were determined as genotoxic and cytotoxic endpoints. At the concentration ranges tested (12.5-100 μg.L ^-1), all HCH isomers induced dose-dependent cytotoxic effects, γ-HCH being the most toxic. This isomer was also able to induce significant increase in MN frequency and BNMN cells indicating a genotoxic potential at 50 and 100 μg.L ^-1. The genotoxic test of β-HCH showed a positive induction of MN and BNMN cells at the highest concentration of 100 μg.L ^-1 and a significant cytotoxicity at 50 μg.L ^-1. Under the experimental condition used, α-HCH was unable to induce any significant increase in MN frequency confirming that α-HCH is a non-genotoxic agent.

Cytogenetic Biomonitoring in Buccal Mucosa Cells from Women Submitted to Chemotherapy After Mastectomy for Breast Cancer

In addition to surgery, one of the most widely applied treatments for breast cancer is chemotherapy. Chemotherapy is currently considered efficient in curing this disease; however, the therapy may induce damage to the patient's genetic material. Thus, the aim of this study was to evaluate putative cytotoxic and mutagenic effects induced by chemotherapy in women diagnosed with breast cancer. For this purpose, a cross-sectional study was carried out in 42 women, aged 18 to 70 years, allocated according to the diagnosis and stage of breast cancer treatment: control group (healthy) (n=15), chemotherapy group (n=11) and post-chemotherapy group (n=16). Cytotoxicity and mutagenicity were analyzed by the micronucleus test in buccal mucosa cells. A higher frequency (p<0.05) of micronucleated cells was detected in the chemotherapy and post-chemotherapy groups when compared to the control. A higher frequency (p<0.05) of karyorrhexis and pyknosis in the chemotherapy group was also noted. Taken together, our results indicate that chemotherapy induces mutagenicity and cytotoxicity in buccal mucosa cells of women diagnosed with breast cancer, being persistent after finishing their treatment.

[Age features of cytogenetic effects of spring-summer encephalitis among residents of northern western Siberia in connection with polymorphism for genes of glutathione-S-transferase]

The aim of this work was a comparative study of the effects of spring diseases cytogenetic years of tick-borne encephalitis in elderly and young age due to differences in genes of glutathione-S-transferase. Surveyed by routine cytogenetics 120 patients with tick-borne encephalitis residents North of Tomsk region. We have taken in the study persons aged 20-35 years (Group 1) and 65-85 years old (Group 2). Material for study (buccal epithelium) was taken from each subject 3-5 times: 1st-2nd day after hospitalization, in 1 week, 1, 3 and 6 months. Tick-borne encephalitis infection causes a significantly large changes in cytogenetic regimens using buccal epithelium in the elderly than in younger patients. Restoring cytogenetic norms observed in a group of young in 3 months after hospitalization, in the elderly - in 6 months. When comparing cytogenetic effects of encephalitis shows: the young patients tick-borne encephalitis level by routine cytogenetics abnormal cells was significantly higher in carriers of inactive forms of gene GSTM1 (0)/GSTT1 (0) than containing active homozygous variants of these genes. Such patterns have not been noted in a group of elderly patients.

Genotoxic effect of Lythrum salicaria extract determined by the mussel micronucleus test

A wide range of aquatic plants have been proven to release allelochemicals, of them phenolics and tannin are considered rather widely distributed. Tannins, however, have been demonstrated to have genotoxic capacity. In our study genotoxic potential of Lythrum salicaria L. (Purple Loosestrife, family Lythraceae) was assessed by the mussel micronucleus test, using Unio pictorum. In parallel, total and hydrolysable tannin contents were determined. Results clearly show that the extract had a high hydrolysable tannin content and significant mutagenic effect. As L. salicaria has been long used in traditional medicine for chronic diarrhoea, dysentery, leucorrhoea and blood-spitting, genotoxic potential of the plant should be evaluated not only with regard to potential effects in the aquatic ecosystem, but also assessing its safe use as a medicinal herb.

An in vivo cytogenetic analysis of human oral squamous cell carcinoma

BACKGROUND

Oral cancer ranks in the top three of all cancers in India, which accounts for over 30% of all cancers reported in the country. The micronucleus test (MNT) is one of the most widely applied short term tests used in genetic toxicology to evaluate the mutagenicity and carcinogenicity.

AIMS

The present study aims at an in vivo cytogenetic analysis of human oral squamous cell carcinoma and to assess the applicability of MNT in diagnosing early detection of oral carcinoma.

MATERIALS AND METHODS

Exfoliated scrape smears were collected from the clinically diagnosed 136 patients suffering from oral precancerous and cancerous lesions. The wet fixed smears were stained by adopting Papanicolaou's staining protocol and counter-stained with Giemsa's solution.

RESULTS

The frequency of micronucleated cells has been observed to be in increasing order with the increase of the age-groups and from control to precancerous to cancerous cases significantly in both sexes.

CONCLUSION

Micronucleus formation in the oral mucosa could be a biomarker of genetic damage and also a potential onco-indicator in the long run of oral carcinogenesis. Therefore, MNT can be applied for the early detection of oral carcinoma in the human being.

An evaluation of 25 selected ToxCast chemicals in medium-throughput assays to detect genotoxicity

ToxCast is a multiyear effort to develop a cost-effective approach for the US EPA to prioritize chemicals for toxicity testing. Initial evaluation of more than 500 high-throughput (HT) microwell-based assays without metabolic activation showed that most lacked high specificity and sensitivity for detecting genotoxicants. Thus, EPA initiated a pilot project to investigate the use of standard genotoxicity endpoints using medium-throughput genotoxicity (MTG) assays in the context of a large testing program. Twenty-five chemicals were selected from the ToxCast program based in part on their known genotoxicity. The two MTG assays used were the Ames II(™) assay and 96-well In Vitro MicroFlow(®) Micronucleus (MN) assay. The Ames II assay showed a reasonable correlation with published Ames test data and industry submissions, though specificity was much better than sensitivity due to restraints on top concentrations as prescribed by ToxCast. Overall concordance was 73% both with and without metabolic activation. The flow MN assay had concordances of 71% and 58% with and without metabolic activation, respectively, when compared to published data and submissions. Importantly, a comparison of results without S9 from the MTG assays to an HT ToxCast p53 activation assay showed a fairly good degree of concordance (67%). The results reported here indicate that assays for genotoxicity endpoints can be conducted in a MT format and have the potential to add to the interpretation of results from large-scale testing programs such as EPA's ToxCast program. Inherent limitations such as the top concentrations used in large scale testing programs are discussed. Environ. Mol. Mutagen. 56:468-476, 2015. © 2014 Wiley Periodicals, Inc.

Earthworm biomarker responses on exposure to commercial cypermethrin

Cypermethrin is a synthetic pyrethroid insecticide used worldwide in agriculture, home pest control, disease vector control, and food safety. It accumulates in soil. Therefore, traces of cypermethrin may frequently appear in vegetables grown in contaminated soil. There is a push now to develop biomarkers as early warning indicators of environmental pollution. In this study, DNA damage (tail DNA%, tail length, and olive tail moment), the micronucleus, neutral red retention (NRR) time, and pinocytic adherence ability of coelomocytes were investigated in Pheretima peguana earthworms exposed to cypermethrin in filter paper tests. The NRR time of earthworm coelomocytes decreased significantly at a concentration of 3.5 × 10(-3) µg · cm(-2) (1/100 LC50 ) after 48 h exposure, with a highly negative correlation with cypermethrin concentration. Pinocytic adherence ability of coelomocytes also declined significantly at a cypermethrin concentration of 3.5 × 10(-2) µg · cm(-2) (1/10 LC50 ). The DNA damage to earthworm coelomocytes (tail DNA%, tail length, and olive tail moment) increased considerably at the highest concentration (3.5 × 10(-1) µg · cm(-2) ) although the correlation between tail DNA% and cypermethrin concentration was low. Thus, physiological biomarkers were more sensitive than the genotoxic effects in earthworms exposed to commercial cypermethrin. Although a suite of earthworm biomarkers could be used to evaluate cypermethrin terrestrial pollution, the NRR test is easier to conduct and a more sensitive indicator.

Induction of micronuclei and nuclear lesions in Channa punctatus following exposure to carbosulfan, glyphosate and atrazine

The genotoxic effects of commonly used agricultural pesticides viz., carbosulfan, glyphosate, and atrazine, were evaluated in Channa punctatus (Pisces, Perciformes) using micronucleus (MN) test and induction of nuclear lesions (NL). The 96 h LC50 value were estimated by probit analysis as 0.27, 32.0 and 42.0 mg L(-1), respectively, for carbosulfan, glyphosate, and atrazine using semi-static bioassays. Based on these values, three sublethal test concentrations of carbosulfan (0.07, 0.13, 0.20 mg L(-1)), glyphosate (8.1, 16.3, 24.4 mg L(-1)) and atrazine (10.6, 21.2, 31.8 mg L(-1)) corresponding to ¼, ½ and ¾ of the LC50 of the pesticides respectively, were selected for exposure for 96 h. Peripheral blood samplings were taken at intervals of 24 h for assessment of MN and NL frequencies. Considerably higher genotoxic damage was induced by carbosulfan as compared to glyphosate and atrazine. There were significant effects (p < 0.01) of concentrations in all the treated groups. The induction of MN and NL was highest at 96 h pesticide exposure at all test concentrations. The nuclear abnormalities recorded in this study, such as blebbed-, lobed-, notched- and bi-nuclei, other than micronuclei, are indicators of genotoxic damage.

Soy isoflavones have antimutagenic activity on DNA damage induced by the antileishmanial Glucantime (meglumine antimoniate)

Isoflavones are phytoestrogens reported to be potent antioxidant agents. In contrast, the antileishmanial meglumine antimoniate has mutagenic activities. This study evaluated the ability of soy isoflavones to reduce DNA damage induced by meglumine antimoniate. Antimutagenic effects (by micronucleus test) were tested using Swiss mice divided into seven groups treated with meglumine antimoniate (425 mg/kg bw pentavalent antimony); cyclophosphamide (50 mg/kg bw); water (negative control); single isoflavones dose (1.6 mg/kg bw), and three groups received one dose of isoflavones via gavage (0.4 mg/kg bw, 0.8 mg/kg bw or 1.6 mg/kg bw) plus meglumine antimoniate via intraperitoneal, simultaneously. To evaluate antigenotoxicity (by Comet assay), each group with 10 animals received the above-mentioned control doses; single dose of isoflavones 0.8 mg/kg bw, and three groups received isoflavones (0.8 mg/kg bw) by gavage along with intraperitoneal meglumine antimoniate, which were treated with isoflavones 24 h before or after receiving meglumine antimoniate (pre-treatment and post-treatment, respectively) or simultaneously. Cells were harvested 24 h after the treatment, and the data were evaluated by ANOVA followed by Tukey's test (p < 0.05). The data from the simultaneous treatment by micronucleus test revealed that isoflavones (0.4 and 0.8 mg/kg) were able to reverse the mutagenic effect of Glucantime. Moreover, all regimes of the treatment with 0.8 mg/kg bw dose were able to reduce the genotoxicity caused by meglumine antimoniate. It is suggested that the protective effect of isoflavones against DNA damage is related to their ability to reduce oxidative stress caused by the trivalent Sb(III) metabolite of meglumine antimoniate.

Cytogenetic biomonitoring in mucopolyssacharosis I, II and IV patients treated with enzyme replacement therapy

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate genotoxicity and mutagenicity in peripheral blood and buccal mucosal cells in mucopolysaccharidosis (MPS) I, II or VI patients.

METHODS

A total of 12 patients with MPS type I, II and VI attended at the Institute of Genetics and Inborn Errors of Metabolism treated with enzyme replacement therapy (ERT) and 10 healthy control volunteers were included in this study. Mechanically exfoliated cells from cheek mucosa (left and right side) were used to micronucleus test and single cell gel (comet) assay in peripheral blood cells.

RESULTS

The results of this study detected the presence of genetic damage in peripheral blood for all individuals with MPS treated with ERT, regardless of type of MPS as depicted by tail moment results. In addition, an increased number of micronucleated cells were found in buccal cells of MPS type II patients. It was also observed an increase of other nuclear alterations closely related to cytotoxicity as depicted by the frequency of pyknosis, karyolysis and karyorrhexis in buccal mucosa cells of MPS VI patients (p < 0.05).

CONCLUSION

Taken together, such results demonstrate that metabolic alterations induced by the enzymatic deficiency characteristic of MPS associated with ERT therapy can induce genotoxicity and mutagenicity in peripheral blood and buccal mucosa cells, respectively. This effect appears to be more pronounced to MPS II.

Concurrent evaluation of general, immune, and genetic toxicity endpoints as part of an integrated testing strategy

Integrated testing strategies involve the assessment of multiple endpoints within a single toxicity study and represent an important approach for reducing animal use and streamlining testing. The present study evaluated the ability to combine general, immune, and genetic toxicity endpoints into a single study. Specifically, this study evaluated the impact of sheep red blood cell (SRBC) immunization, as part of the T-cell dependent antibody response (TDAR) assay, on organ weights, micronuclei (MN) formation (bone marrow and peripheral blood), and the Comet assay response in the liver of female F344/DuCrl rats treated with cyclophosphamide (CP) a known immunosuppressive chemical and genotoxicant. For the TDAR assay, treatment with CP resulted in a dose-dependent decrease in the antibody response with a suppression of greater than 95% at the high dose. Injection with SRBC had no impact on evaluated organ weights, histopathology, hematology, and clinical chemistry parameters. Analysis of MN formation in bone marrow and peripheral blood revealed a dose-dependent increase in response to CP treatment. Injection with SRBC had no impact on the level of MN in control animals and did not alter the dose response of CP. There was a slight increase in liver DNA damage in response to CP as measured by the Comet assay; however, injection with SRBCs did not alter this endpoint. Overall these data provide strong support for the concurrent assessment of general, immune, and genetic toxicology endpoints within a single study as part of an integrated testing strategy approach.

Evaluation of the toxic activity of anorectic diethylpropion in Chinese hamster ovary cells

Diethylpropion has been available in the market for treating obesity for over 50 years. Refined studies are lacking to fully elucidate its action spectrum. The aim of our study was to evaluate possible toxic effects of anorectic diethylpropion in Chinese hamster ovary (CHO) cells. Comet assay (detects breaks in the DNA strand), micronucleus test (detects clastogenic/aneugenic damage), and cell survival test (detects cytotoxic damage) were used to evaluate the toxic effects. In comet assay, we found that the damage scores with diethylpropion treatments at the concentrations of 20 and 40 μg/mL were more significant ( p < 0.05) than that of the negative control. When assessing the possible aneugenic and/or clastogenic damage caused by the drug in CHO cells, we found no difference ( p > 0.05) in the values of micronucleated cells when comparing different diethylpropion treatments and the negative control. Regarding the cell viability, for all the diethylpropion concentrations tested, higher values ( p < 0.05) of apoptosis were found compared with those of the negative control. In relation to the number of necrotic cells, no difference ( p > 0.05) was noted between the means of the three concentrations of diethylpropion evaluated and the negative control. In the experimental conditions, we conclude that diethylpropion has weak genotoxic and cytotoxic activities.

Sublethal toxicity of esbiothrin relationship with total antioxidant status and in vivo genotoxicity assessment in fish (Cyprinus carpio L., 1758) using the micronucleus test and comet assay

Esbiothrin, synthetic pyrethroid with quick activity against insects, is widely used against household pests and in public health. Despite widespread use, data on ecotoxicity and genotoxic effects are extremely scarce. The aim of the present study is to evaluate the genotoxic potential of esbiothrin on a model fish species Cyprinus carpio L., 1758 (Pisces: Cyprinidae, koi) using the micronucleus test and comet assay in peripheral blood erythrocytes. Effects of two sublethal exposure concentrations on plasma total antioxidant status (TAS mmol/L), and Hct values were examined. On the basis of the 96 h LC50 data from U.S. EPA ecotox database (32 μg/L) two sublethal exposure concentrations (5 and 10 μg/L) were used together with ethyl methanesulfonate (EMS) (5 mg/L) as positive control. Five fish were used for each dose/duration group (24, 48, and 72 h) under controlled laboratory conditions. The fish showed behavioral changes at the higher dose. Plasma TAS (mmol/L) levels decreased in 24 h; an increase was observed slightly for 48 and obviously for 72 h in both exposure doses. Similarly, hematocrit (Hct) values differed between exposure duration but no significant differences in mean values were found between groups of the same exposure time. The general trend was a rise after 48 h, which decreased afterwards. Our results revealed significant increases in the frequencies of micronuclei and levels of DNA strand breaks and thus demonstrated the genotoxic potential of this pesticide on fish, a nontarget organism of the aquatic ecosystem. To our knowledge this is the first study to report observable genotoxic effects of esbiothrin on fish.

The relationship of cytotoxic and genotoxic damage with blood aluminum levels and oxidative stress induced by this metal in common carp (Cyprinus carpio) erythrocytes

Aluminum is one of the most abundant elements in nature and is used in diverse industrial processes. As a result, it contaminates aquatic ecosystems, inducing damage on associated biota. In fish, it has been observed to induce hypoxia, hypercapnia, metabolic acidosis and respiratory arrest. Although there is little information on Al-induced cytotoxicity and DNA damage, this type of studies are essential in order to identify the mechanisms of action of this metal. The cytotoxic and genotoxic effects induced by Al on common carp (Cyprinus carpio) erythrocytes were determined in specimens exposed to 0.05, 120 and 239mgAlL(-1) in static exposure systems. Blood samples were taken at 12, 24, 48, 72 and 96h, erythrocytes were separated, and the following were evaluated: frequency of micronuclei and frequency of terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells, blood Al levels, lipid peroxidation, protein carbonyl content, and activity of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase. The results show that tested aluminum concentrations produces oxidative stress (increase in lipid peroxidation degree and oxidized proteins content, as well as decrease in antioxidant enzymes activity) and induced higher frequencies of micronuclei and TUNEL-positive cells, so this metal can be considered as a cytotoxic and genotoxic agent for erythrocytes of common carp.

Genotoxic effect of two bleaching agents on oral mucosa

AIM

To analyze the genotoxic effect of two hydrogen peroxide-containing bleaching products on oral mucosal cells.

MATERIALS AND METHODS

The research was conducted on 22 individuals divided into two groups. Group 1 used ZOOM2 and group 2 the Opalescence BOOST bleaching agent. Specimens of the gingival and the upper lip mucosa were obtained before, immediately after, and 72 h after the bleaching procedure and were analyzed using a micronucleus test.

RESULTS

Seventy-two hours after bleaching treatment with BOOST, samples collected from the oral mucosa exhibited a statistically significant increase of all genotoxicity markers, with large effect sizes (Cohen's d>0.8) observed in the total number of micronuclei (MN), number of cells with 3+ MN, karyolysis and bi-nuclear cells. ZOOM2 treatment showed a significant increase, with medium-to-large effect sizes, in the number of cells with 1 MN, karyolysis, nuclear buds and bi-nuclear cells.

CONCLUSION

Both preparations demonstrated potential genotoxic effects.

Assessment of the genotoxic potential of azidothymidine in the comet, micronucleus, and Pig-a assay

The genotoxic potential of azidothymidine (Zidovudine, AZT), chosen as a model compound for nucleotide analogs, was comprehensively assessed in vivo for gene mutation, clastogenicity, and DNA breakage endpoints. Male Wistar rats were treated by oral gavage over 7 days with AZT at dose levels of 2×0 (control), 2×250, 2×500, and 2×1000mg/kg/day with a final single dose given on day 8. DNA damage was then evaluated with the comet assay in liver, stomach, and peripheral blood and with the micronucleus test in bone marrow and peripheral blood (by flow cytometry) in the same animals. After a treatment-free period of upto 42 days, the Pig-a gene mutation assay was performed in peripheral blood of the high-dose animals. In the comet assay as well as the micronucleus test, AZT caused a considerable dose-dependent increase in DNA damage in all tissues evaluated and was highly cytotoxic to bone marrow and peripheral blood cells. These data are well in line with published results. Surprisingly, AZT did not significantly increase the number of Pig-a mutant cells. We speculate that two factors likely contributed to this negative result: a predominance of large deletions caused by AZT, and the relatively low statistical power of the first-generation scoring method used for this study.

Genotoxicity profile of azidothymidine in vitro

Azidothymidine (Zidovudine, AZT) is part of the standard care of treatment for acquired immunodeficiency syndrome since many years. A great number of studies on the genotoxic potential of AZT have been published, but no comprehensive hypothesis yet explains all observations. We investigated a multitude of genotoxic endpoints, both in vitro and in vivo, with the goal to complete the picture. The mutagenic potential of AZT in bacteria was found to be restricted to strains with an "ochre" target sequence and could be abrogated both by thymidine supplementation and rat liver S9 mix. Single-strand breaks in mammalian cells were detected in the comet assay after short-term treatment (3h) with AZT, which did not induce micronuclei. The latter were mainly seen after prolonged exposure (24 and 48h) and are probably not directly related to AZT incorporation into DNA. Our data demonstrate that short-term exposure to low AZT concentrations does not induce biologically relevant micronucleation. Only treatment with high concentrations of AZT for prolonged time periods manifests in substantial micronucleus induction. Furthermore, we found that high concentrations of thymidine have no effect in the comet assay but increase micronucleus frequency in a manner very similar to AZT. These results lead us to the following hypothesis: AZT is triphosphorylated and then incorporated into DNA strands, leading to mutations and cytotoxicity. Cellular attempts to repair these DNA lesions as well as stalled replication forks due to chain termination are detectable with the comet assay. Increased micronucleus frequency is likely related to nucleotide pool imbalance.

Genotoxicity of Nicotiana tabacum leaves on Helix aspersa

Tobacco farmers are routinely exposed to complex mixtures of inorganic and organic chemicals present in tobacco leaves. In this study, we examined the genotoxicity of tobacco leaves in the snail Helix aspersa as a measure of the risk to human health. DNA damage was evaluated using the micronucleus test and the Comet assay and the concentration of cytochrome P450 enzymes was estimated. Two groups of snails were studied: one fed on tobacco leaves and one fed on lettuce (Lactuca sativa L) leaves (control group). All of the snails received leaves (tobacco and lettuce leaves were the only food provided) and water ad libitum. Hemolymph cells were collected after 0, 24, 48 and 72 h. The Comet assay and micronucleus test showed that exposure to tobacco leaves for different periods of time caused significant DNA damage. Inhibition of cytochrome P450 enzymes occurred only in the tobacco group. Chemical analysis indicated the presence of the alkaloid nicotine, coumarins, saponins, flavonoids and various metals. These results show that tobacco leaves are genotoxic in H. aspersa and inhibit cytochrome P450 activity, probably through the action of the complex chemical mixture present in the plant.

Exposure to lambda-cyhalothrin, a synthetic pyrethroid, increases reactive oxygen species production and induces genotoxicity in rat peripheral blood

Lambda-cyhalothrin (LTC) is a synthetic pyrethroid with a broad spectrum of insecticidal and acaricidal activities used to control a wide range of insect pests in a variety of applications. However, there is little known about its adverse effects, in particular those related to its genotoxicity in humans. To elucidate the genotoxicity mechanisms of LTC, the micronuclei (MN) frequencies, the levels of reactive oxygen species (ROS), erythrocyte osmotic fragility, nitrite (NO) formation, protein carbonyl (PCO) levels and malondialdehyde (MDA) production were evaluated for a period of 7, 14 and 21 days. Our results show that exposure rat to LTC (1/10DL50 = 6.23 mg/kg) for a period of 7, 14 and 21 days induced a noticeable genotoxic effect in rat peripheral blood evidenced by a significant increase in the frequency of MN only at day 21 of treatment. Significant differences between the two groups were observed in erythrocyte osmotic fragility. Further, a significant (p < 0.01) increase in ROS contents, NO formation, PCO levels and lipid peroxidation in erythrocytes were observed at different times of treatments, suggesting the implication of oxidative stress in its toxicity. These results confirm the genotoxic and the pro-oxidant effects of LTC in rat peripheral blood.