Examination of various biomarkers measuring genotoxic endpoints from Barcelona airport personnel

In vitro Safety Assessment of Extracts and Compounds From Plants as Sunscreen Ingredients

This work investigated the safety of extracts obtained from plants growing in Colombia, which have previously shown UV-filter/antigenotoxic properties. The compounds in plant extracts obtained by the supercritical fluid (CO2) extraction method were identified using gas chromatography coupled to mass spectrometry (GC/MS) analysis. Cytotoxicity measured as cytotoxic concentration 50% (CC50) and genotoxicity of the plant extracts and some compounds were studied in human fibroblasts using the trypan blue exclusion assay and the Comet assay, respectively. The extracts from Pipper eriopodon and Salvia aratocensis species and the compound trans-β-caryophyllene were clearly cytotoxic to human fibroblasts. Conversely, Achyrocline satureioides, Chromolaena pellia, and Lippia origanoides extracts were relatively less cytotoxic with CC50 values of 173, 184, and 89 μg/mL, respectively. The C. pellia and L. origanoides extracts produced some degree of DNA breaks at cytotoxic concentrations. The cytotoxicity of the studied compounds was as follows, with lower CC50 values representing the most cytotoxic compounds: resveratrol (91 μM) > pinocembrin (144 μM) > quercetin (222 μM) > titanium dioxide (704 μM). Quercetin was unique among the compounds assayed in being genotoxic to human fibroblasts. Our work indicates that phytochemicals can be cytotoxic and genotoxic, demonstrating the need to establish safe concentrations of these extracts for their potential use in cosmetics.

Measurement of chromosomal instability and level of DNA damage in peripheral blood mononuclear cells of endometrial cancer patients

Endometrial cancer is one of the most common invasive gynecologic malignancies in developed countries. The aim of this study was to evaluate chromosomal instability and level of DNA damage in peripheral blood mononuclear cells (PBMCs) of newly diagnosed endometrial cancer patients in relation to health status (diagnosis), age, histological grade of cancer, residence, smoking, number of pregnancies, miscarriages, and abortions. The analyzed sample consisted of 60 individuals, 30 endometrial cancer patients with an average age of 64.37 ± 7.08, and 30 healthy control women with an average age of 60.23 ± 11.55. Chromosomal instability was evaluated by the cytokinesis-block micronucleus (CBMN) assay, and the level of DNA damage by the single-cell gel electrophoresis (comet) assay in PBMCs. The average frequencies of micronuclei (MNi), nucleoplasmic bridges (NPBs) as well as nuclear buds (NBUDs) were significantly higher in cancer patients compared to controls (P < .0005). There was no difference in the nuclear division index (NDI) among the analyzed samples. The comet assay showed that the patients had a significantly increased genetic damage index (GDI) compared with controls (P < .0005). Using linear regression analysis, we found that health status (diagnosis) had the strongest influence on the MN frequency as well as GDI (P < .0005). Our results indicated that there is a high level of genetic damage in both the level of DNA and the level of chromosomes in the PBMCs of newly diagnosed patients with endometrial cancer, where the frequency and level of damage were significantly affected by health status, grade of cancer, residence, number of pregnancies, miscarriages, and abortions.

The toxicity assessment of phosmet on development, reproduction, and gene expression in Daphnia magna

The use of pesticides to control pests, weeds, and diseases or to regulate plant growth is indispensable in agricultural production. However, the excessive use of these chemicals has led to significant concern about their potential negative impacts on health and the environment. Phosmet is one such pesticide that is commonly used on plants and animals against cold moth, aphids, mites, suckers, and fruit flies. Here, we investigated the effects of phosmet on a model organism, Daphnia magna using acute and chronic toxicity endpoints such as lethality, mobility, genotoxicity, reproduction, and gene expression. We performed survival experiments in six-well plates at seven different concentrations (0.01, 0.1, 1, 10, 25, 50, 100 μM) as well as the control in three replicates. We observed statistically significant mortality rates at 25 µM and above upon 24 h of exposure, and at 1 µM and above following 48 h of exposure. Genotoxicity analysis, reproduction assay and qPCR analysis were carried out at concentrations of 0.01 and 0.1 μM phosmet as these concentrations did not show any lethality. Comet assay showed that exposure to phosmet resulted in significant DNA damage in the cells. Interestingly, 0.1 μM phosmet produced more offspring per adult compared to the control group indicating a hormetic response. Gene expression profiles demonstrated several genes involved in different physiological pathways, including oxidative stress, detoxification, immune system, hypoxia and iron homeostasis. Taken together, our results indicate that phosmet has negative effects on Daphnia magna in a dose- and time-dependent manner and could also induce lethal and physiological toxicities to other aquatic organisms.

Do environmentally relevant concentrations of the neonicotinoid insecticide imidacloprid induce DNA damage and oxidative stress on Cnesterodon decemmaculatus (Jenyns, 1842)?

Lethal and sublethal effects of imidacloprid (IMI) were assessed on Cnesterodon decemmaculatus (Pisces: Poeciliidae) by acute exposure to environmentally relevant concentrations of the commercial formulation Punto 35® (Gleba S.A.) under laboratory conditions. Specimens were exposed for 96 h to 1, 10, 20, 25, 35, 75, 100, 125, 150 and 175 mg IMI L^-1 from which an LC₅₀ 96 h value of 35.59 mg IMI L^-1 was calculated. Moreover, sublethal concentrations 0.175, 0.35 and 1 mg IMI L^-1 for 96 h were employed for the evaluation of the comet assay and the variation of activities of catalase (CAT) and glutathione content (GSH). Result demonstrated an increased genetic damage index and activity of CAT was observed. Conversely, no significant variation was observed in GSH activity. Total protein content decreased in treated organisms. These results represent the first report of acute effects induced by IMI on C. decemmaculatus exposed under laboratory conditions.

Investigation of incidence and geographic distribution of gliomas in Canada from 1992 to 2010: a national population-based study highlighting the importance of exposure to airport operations

Background

Gliomas account for over two-thirds of all malignant brain tumors and have few established risk factors beyond family history and exposure to ionizing radiation. Importantly, recent studies highlighted the exposure to ultrafine particles (UFP) as a putative risk factor for malignant brain tumors.

Methods

Clinical and geographic data encompassing all provinces and territories from 1992 to 2010 was obtained from the Canadian Cancer Registry and Le Registre Québécois du Cancer. Linear regression and joinpoint analyses were performed to assess incidence trends. Significantly higher and lower incidence postal codes were then interrogated using Standard Industrial Classification codes to detect significant industrial activity.

Results

In Canada, between 1992 and 2010, there were ~32,360 cases of glioma. Of these, 17,115 (52.9%) were glioblastoma. The overall crude incidence rates of 5.45 and 2.87 cases per 100,000 individuals per year for gliomas and glioblastomas, respectively, were identified. Our findings further revealed increasing crude incidence of gliomas/glioblastomas over time. A male predominance was observed. Provinces leading in glioma incidence included Quebec, Nova Scotia, and New Brunswick. Significantly lower crude incidence of glioma was found in Nunavut, Northwest Territories, Ontario, and Alberta. A putative regional clustering of gliomas was observed, with higher incidence rates in postal code areas correlating with industrial activity related to airport operations.

Conclusion

This study describes the geographic distribution of the glioma disease burden and, potentially, identifies industrial activity related to airport operations as potentially being associated with higher incidence of this cancer.

Realistic scenarios of pesticide exposure alters multiple biomarkers in BOANA PULCHELLA (ANURA) Adult Frogs

Imazethapyr, a post-emergent herbicide used in worldwide soybean and corn crops, induces genetic and biochemical alterations in aquatic vertebrates. This study examined the relationship between biomarkers at different organization levels and imazethapyr real-life route exposure in Boana pulchella adults. Frogs were exposed to imazethapyr-based formulation Pivot^® H (10.59%) at concentrations representing possible acute routes: field runoff (S1:10 mg.L^-1), exposure after direct foliar application (S2:100 mg.L^-1) and during direct foliar application (S3:1000 mg.L^-1). Post-exposure, endpoints levels were evaluated: organism alterations, biochemical activities and cytogenetic assays. Forty-eight hours post-exposure, antioxidant enzymes decrease, micronuclei induction and DNA damage were observed in all scenarios, while cholinesterase activity increase and body condition reduction were observed in frog-exposed to S3. Ninety-six hours post-exposure, frogs showed glutathione-S-transferase inhibition in S1, micronuclei induction in S2 and S3, and DNA-damage increase in S3. Herbicides routes of exposures in real-life could indicate that authorized applications have a risk to amphibian populations.

Bioaccumulation of trace metals and genotoxicity responses in Liza aurata as an indicator of industrial pollution

Heavy metal contamination in the coastal and marine ecosystems is becoming a serious risk to aquatic organisms and humans. This study reports the effects, including genetic damage, of accumulations of trace metals on Liza aurata, which is used as a bio-indicator species, in the Payas coast of Iskenderun Bay, north-eastern Mediterranean by COMET Assay. L. aurata were seasonally collected from a sampling site and a reference site for one year. Physicochemical parameters in water and trace metals in the tissues of fish collected from these sites were determined by electrochemical techniques. High DNA damage frequency in L. aurata was observed along the Payas coast of Iskenderun Bay compared to the reference site because of pollutants. The detected high levels of Cd, Pb, Fe and Cu accumulation in L. aurata exceed the maximum levels allowed by the national and international limit values. Significant positive correlations between Cd, Pb, Hg, Cr, Fe, Zn, and Cu accumulations and DNA damage parameters were observed in the present study. Additionally, we first reported the successful use of the electrochemical technique in the determination of trace metal concentrations in mullet. Moreover, L. aurata constitutes a key tool as a sentinel organism for biomonitoring of coastal ecosystems.

Flower Extracts from Ornamental Plants as Sources of Sunscreen Ingredients: Determination by In Vitro Methods of Photoprotective Efficacy, Antigenotoxicity and Safety

Plants are sources of sunscreen ingredients that prevent cellular mutations involved in skin cancer and aging. This study investigated the sunscreen properties of the extracts from some ornamental plants growing in Colombia. The UV filter capability of the flower extracts obtained from Rosa centifolia L., Posoqueria latifolia (Rudge) Schult, and Ipomoea horsfalliae Hook. was examined. Photoprotection efficacies were evaluated using in vitro indices such as sun protection factor and critical wavelength. UVB antigenotoxicity estimates measured with the SOS Chromotest were also obtained. Extract cytotoxicity and genotoxicity were studied in human fibroblasts using the trypan blue exclusion and Comet assays, respectively. Major compounds of the promising flower extracts were identified by UHPLC-ESI+-Orbitrap-MS. The studied extracts showed high photoprotection efficacy and antigenotoxicity against UVB radiation, but only the P. latifolia extract showed broad-spectrum photoprotection at non-cytotoxic concentrations. The P. latifolia extract appeared to be safer for human fibroblast cells and the R. centifolia extract was shown to be moderately cytotoxic and genotoxic at the highest assayed concentrations. The I. horsfalliae extract was unequivocally cytotoxic and genotoxic. The major constituents of the promising extracts were as follows: chlorogenic acid, ecdysterone 20E, rhamnetin-rutinoside, cis-resveratrol-diglucoside, trans-resveratrol-diglucoside in P. latifolia; quercetin, quercetin-glucoside, quercetin-3-rhamnoside, kaempferol, kaempferol-3-glucoside, and kaempferol-rhamnoside in R. centifolia. The potential of the ornamental plants as sources of sunscreen ingredients was discussed.

Tissue distribution and sublethal effects of imidacloprid in the South American grayish baywing (Agelaioides badius)

The neonicotinoids are globally used insecticides, which have been shown to cause negative impacts on birds. The current study aimed to evaluate the distribution of the neonicotinoid imidacloprid (IMI) in the tissues of a songbird and identify related physiological effects. Adults of the grayish baywing (Agelaioides baduis) were administered with a single dose of 35 mg IMI/kg, and the IMI concentration was evaluated in liver, kidney and plasma at 4, 12, 24, and 48 h after dosing. At the same time points, effects on hematological, genetic and enzymatic parameters were assessed. Results showed that IMI was absorbed before 4 h, and eliminated at 48 h, in every tissue, and the highest concentrations were detected in plasma. Baywings showed intoxication signs and reduced mobility within the first 5 min post-dosing. Hematological parameters: red blood cells, packed cell volume, hemoglobin, and their derived indices exhibited a transient elevation 24 h after dosing, which coincided with maximum concentrations of IMI in the tissues. No effects were observed on the genotoxicity parameters evaluated: micronuclei and comet assay. Treated birds exhibited an alteration of cholinesterases activity in the muscle and plasma, and of glutathione-S-transferase (GST) activity in the plasma, brain, liver, and muscle. Based on the results obtained, the combined detection of IMI and inhibition of GST activity in the plasma is suggested as a non-lethal biomarker of IMI exposure in wild birds. As efficient field monitoring depends on the availability of proven biomarkers, the current study provides valuable tools for bird conservation in agroecosystems.

Assessment of cytotoxicity in gills of fish Labeo rohita reared in untreated and treated sewage water

The unregulated discharge of untreated municipal sewage water to the natural water bodies is a major threat to the aquatic ecosystems. In the present study, the fingerlings of Labeo rohita were exposed to treated sewage water and 1/10^th of LC₅₀ and 1/20^th of LC₅₀ of untreated sewage water (UT) obtained from sewage water treatment plant, Ludhiana, India. After determining 96-h LC₅₀ value of UT, fingerlings were divided into four groups: control, treated, 1/10^th of LC₅₀ UT and 1/20^th of LC₅₀ UT and exposed for a period of 2 months. Our study revealed that 1/10^th LC₅₀ UT and 1/20^th LC₅₀ UT groups had significant reduction in body weight, total body length, standard body length and gills somatic index in comparison with the control and treated groups. Histopathological alterations in cellular structure of gills such as ruptured primary lamellae, broken secondary lamellae, distorted chloride cells and goblet cells, missing lamellae and disintegrated lamellar epithelium were also observed in 1/10^th LC₅₀ UT and 1/20^th LC₅₀ UT groups. A significantly high frequency of micronucleated (MN) cells was observed in 1/10^th LC₅₀ UT and 1/20^th LC₅₀ UT groups along with the presence of binucleated cells (BN), elongated nuclei (EN) and nuclear buds in gill cells. Genotoxic nature of UT was further confirmed from significantly high values of genetic damage index (GDI) and percentage (%) DNA damage in gill cells of fingerlings exposed to sub-lethal concentrations of UT. The study concluded that untreated sewage water has potential to induce anatomical and physiological defects in gills cells and the severity of toxicity increases with the increase in duration of exposure.

In vitro cytogenotoxic and mutagenic effects of Commiphora myrrha essential oil

Commiphora myrrha, located in the tropical zone, is a widely used tree for medicinal purposes in the Arabian Peninsula and a large part of Africa. In this research, cytogenotoxic effects of the commercially available Commiphora myrrha essential oil (myrrh) were studied using micronucleus (MN), comet, and total oxidant (TOS), and total antioxidant (TAS) assays on human peripheral lymphocytes under in vitro conditions. In addition, pure pBR322 plasmid DNA was used to investigate DNA damaging/protecting activity of the essential oil. Finally, a bacterial reversion (Ames) test was performed using Salmonella typhimurium mutant strains TA98 and TA100 to determine the potential effect of the agent in the induction of gene mutations. The high concentration of Commiphora myrrha (0.125 µL/mL) induced MN formation significantly compared to the untreated control in both treatment times (24 or 48 h). Only at the highest concentration, nuclear division index (NDI) values were found lower than the controls. In the Comet test performed on healthy lymphocytes, only the highest concentration of myrrh caused significant increases in the percentage of damaged cells and genetic damage index (GDI) values. Myrrh oil showed no significant mutagenic effect on mutant Salmonella strains. In addition, the substance did not directly damage plasmid DNA but also protected DNA against damaging factors such as H₂O₂ and UV. Finally, in the TAS and TOS assays, no significant differences on the oxidative stress parameters were found in cell culture compared to the control. The results of this study showed that myrrh oil exerts cytogenotoxic risk only at higher concentrations.

Occupational exposure and markers of genetic damage, systemic inflammation and lung function: a Danish cross-sectional study among air force personnel

Air force ground crew personnel are potentially exposed to fuels and lubricants, as raw materials, vapours and combustion exhaust emissions, during operation and maintenance of aircrafts. This study investigated exposure levels and biomarkers of effects for employees at a Danish air force military base. We enrolled self-reported healthy and non-smoking employees (n = 79) and grouped them by exposure based on job function, considered to be potentially exposed (aircraft engineers, crew chiefs, fuel operators and munition specialists) or as reference group with minimal occupational exposure (avionics and office workers). We measured exposure levels to polycyclic aromatic hydrocarbons (PAHs) and organophosphate esters (OPEs) by silicone bands and skin wipes (PAHs only) as well as urinary excretion of PAH metabolites (OH-PAHs). Additionally, we assessed exposure levels of ultrafine particles (UFPs) in the breathing zone for specific job functions. As biomarkers of effect, we assessed lung function, plasma levels of acute phase inflammatory markers, and genetic damage levels in peripheral blood cells. Exposure levels of total PAHs, OPEs and OH-PAHs did not differ between exposure groups or job functions, with low correlations between PAHs in different matrices. Among the measured job functions, the UFP levels were higher for the crew chiefs. The exposure level of the PAH fluorene was significantly higher for the exposed group than the reference group (15.9 ± 23.7 ng/g per 24 h vs 5.28 ± 7.87 ng/g per 24 h, p = 0.007), as was the OPE triphenyl phosphate (305 ± 606 vs 19.7 ± 33.8 ng/g per 24 h, p = 0.011). The OPE tris(1,3-dichlor-2-propyl)phosphate had a higher mean in the exposed group (60.7 ± 135 ng/g per 24 h) compared to the reference group (8.89 ± 15.7 ng/g per 24 h) but did not reach significance. No evidence of effects for biomarkers of systemic inflammation, genetic damage or lung function was found. Overall, our biomonitoring study show limited evidence of occupational exposure of air force ground crew personnel to UFPs, PAHs and OPEs. Furthermore, the OH-PAHs and the assessed biomarkers of early biological effects did not differ between exposed and reference groups.

Histopathological, genotoxic, and behavioral damages induced by manganese (II) in adult zebrafish

Manganese is a metal often found as an environmental pollutant and very associated with neurological disorders when in high concentrations. However, little is known about the effects that this contaminant can cause when in environmentally relevant concentrations and occurrence, that is, much lower than those commonly studied. So, the aim of the study was to evaluate the effects that environmentally relevant concentrations of this metal would cause in different zebrafish organs (brain, liver, and blood). Acute 96-h and chronic 30-day exposures were performed using the manganese chloride salt as a pollutant. Behavioral alterations of anxiogenic type were observed in the animals after chronic exposures to 4.0 mg L^-1 MnCl₂, which traveled a greater distance at the bottom of the aquarium. This may be associated with neuronal damages in the telencephalic region responsible for motor and cognitive activity of the fish, observed in animals from the same exposure. In addition, hepatic histopathological damage as vacuolization of hepatocytes and genotoxic damage, identified by comet assay and micronucleus test, was also observed after acute and chronic exposure, especially at the highest pollutant concentrations (8.0 and 16.0 mg L^-1 in acute exposure, and 4.0 mg L^-1 in chronic exposure. The study reinforces the risk that environmental pollutants pose to the ecosystem, even in low concentrations.

Genotoxicity of mixtures of glyphosate with 2,4-dichlorophenoxyacetic acid chemical forms towards Cnesterodon decemmaculatus (Pisces, Poeciliidae)

Acute genotoxicity of commercial glyphosate (GLY) (Credit®)-, 2,4-D-acid (2,4-D) (Dedalo Elite)-, 2,4-D-amine (2,4-D DMA) (Weedar Full®)- and 2,4-D-ester (2,4-D BE) (Herbifen Super®)-based herbicide formulations alone and their combinations were analysed in Cnesterodon decemmaculatus. Mortality was evaluated as a lethal end-point and the single cell gel electrophoresis (SCGE) bioassay was used as a sublethal end-point. LC5096h values for Dedalo Elite was 0.46 mg/L and Herbifen Super® was 2.67 mg/L based on 2,4-D and 2,4-D BE, respectively. Results reveal a higher toxicity exerted on C. decemmaculatus after exposure to 2,4-D- rather than 2,4-D BE-based herbicide formulations. Overall, results demonstrated an enhancement in the genetic damage index committed to an enhancement of damaged erythrocytes of C. decemmaculatus when exposed to Credit®, Dedalo Elite, Weedar Full® and Herbifen Super® at 5% and 10% of LC5096h values alone as well as in their combinations. Overall, the combination of GLY plus 2,4-D or GLY plus 2,4-D DMA showed a synergistic pattern whereas the combination of GLY plus 2,4-D BE was antagonic. Furthermore, this research is pioneer in the assessment of lethality and genotoxicity induced by 2,4-D-, 2,4-D DMA- and 2,4-D BE-based formulations when combined with GLY-based formulated herbicides in fish after they are acutely exposed.

An imazethapyr-based herbicide formulation induces genotoxic, biochemical, and individual organizational effects in Leptodactylus latinasus tadpoles (Anura: Leptodactylidae)

Genotoxic, biochemical, and individual organizational effects on Leptodactylus latinasus tadpoles were evaluated after exposure to an imazethapyr (IMZT)-based commercial herbicide formulation, Pivot® H (10.59% IMZT). A determination of the value of the lethal concentration (LC50) was determined as a toxicological endpoint. Alterations in animal behavior and morphological abnormalities as well as cholinesterase (ChE), catalase (CAT), and glutathione S-transferase (GST) activities were employed as individual sublethal endpoints. Micronuclei frequencies (MNs), binucleated cells (BNs), blebbed nuclei (BLs), lobed nuclei (LBs), notched nuclei (NTs), erythroplastids (EPs), and evaluation of DNA strand breaks were employed as genotoxic endpoints. All biomarkers were evaluated after 48 and 96 h of exposure to concentrations of IMZT within 0.07-4.89 mg/L. LC50_96h values of 1.01 and 0.29 mg/L IMZT were obtained for Gosner stages 25 and 36, respectively. Irregular swimming, diamond body shape, and decreased frequency of keratodonts were detected at both sampling times. Results showed that IMZT increased GST activity and MN frequency at 48 and 96 h of exposure. Other nuclear abnormalities were also observed in the circulating erythrocytes of tadpoles, i.e., NT and BL values after 48 h, and LN, BL, and EP values after 96 h. Finally, results showed that IMZT within 0.07-0.22 mg/L increased the genetic damage index in tadpoles exposed for both exposure times (48 and 96 h). This study is the first to report the sublethal biochemical effects of IMZT in anurans and is also the first report using L. latinasus tadpoles as a bioindicator for ecotoxicological studies.

The Wing-Spot and the Comet Tests as Useful Assays for Detecting Genotoxicity in Drosophila

In spite of its pioneer use in detecting mutational processes, Drosophila still plays an important role in those studies aiming to detect and quantify the induction of DNA damage. Here we describe two assays, one detecting primary damage (the Comet assay) and the other detecting somatic mutation and recombination effects (wing-spot test). It is important to emphasize that somatic recombination is a key event in cancer development and no assays exist at present to detect and quantify somatic recombination processes, other than the spot tests developed in Drosophila.

Auxinic herbicides induce oxidative stress on Cnesterodon decemmaculatus (Pisces: Poeciliidae)

Pesticides might increase the production of reactive oxygen species (ROS). Dicamba (DIC) and 2,4-dichlorophenoxyacetic acid (2,4-D) are auxinic herbicides commonly applied in agroecosystems to control unwanted weeds. We analysed the oxidative damage exerted on the fish Cnesterodon decemmaculatus by an acute exposure to DIC- and 2,4-D-based herbicides formulations Banvel® and DMA®, respectively. The Endo III- and Fpg-modified alkaline comet assay was employed for detecting DNA damage caused by oxidative stress, whereas enzymatic and non-enzymatic biomarkers such as the activities of catalase (CAT), glutathione-S-transferase (GST), acetylcholinesterase (AChE), and glutathione content (GSH) were used to assess antioxidant response to these two herbicides. At the DNA level, results demonstrate that both auxinic herbicides induce oxidative damage at purines level. An increase on CAT and GST activities were detected in 48 h- and 96 h-treated specimens with both auxinics. GSH content decreased in fish exposed to DIC during 48 h and to 2,4-D after 96 h of exposure. Additionally, a diminished AChE activity in specimens treated with DIC and 2,4-D was observed only after 96 h. Total protein content decreased in fish exposed to both auxinics during 96 h. These results represent the first evaluation of oxidative damage related to DIC and 2,4-D exposure on a fish species as the Neotropical freshwater teleost C. decemmaculatus.

DNA damage exerted by mixtures of commercial formulations of glyphosate and imazethapyr herbicides in Rhinella arenarum (Anura, Bufonidae) tadpoles

Glyphosate (GLY) and imazethapyr (IMZT) are two herbicides commonly used worldwide, either alone or in mixtures. They represent key pesticides in modern agricultural management. The toxicity that results when employed as mixtures has not been characterized so far. Acute toxicity of the 48% GLY-based herbicide (GBH) Credit® and the 10.59% IMZT-based herbicide (IBH) Pivot® H alone and their binary combinations was analyzed in Rhinella arenarum tadpoles exposed in a semi-static renewal test. Lethal effects were determined using mortality as the end-point, whereas sublethal effects were determined employing the single-cell gel electrophoresis (SCGE) bioassay. Based on mortality experiments, results revealed LC5096 h values of 78.18 mg/L GBH and 0.99 mg/L IBH for Credit® and Pivot® H, respectively. An increase in the genetic damage index (GDI) was found after exposure to Credit® or Pivot® H at 5 and 10% of LC5096 h values. The combinations of 5% Credit®-5% Pivot® H LC5096 h and 10% Credit®-10% Pivot® H LC5096 h concentrations significantly enhanced the GDI in comparison with tadpoles exposed only to Credit® or Pivot® H. Thus, the effect of interaction between GBH and IBH inducing DNA damage in R. arenarum blood cells can be considered to be synergistic.

Photoprotective and Antigenotoxic Effects of the Flavonoids Apigenin, Naringenin and Pinocembrin

This work evaluated the photoprotective and antigenotoxic effects against ultraviolet B (UVB) radiation of flavonoid compounds apigenin, naringenin and pinocembrin. The photoprotective efficacy of these compounds was estimated using in vitro photoprotection indices, and the antigenotoxicity against UVB radiation was evaluated using the SOS chromotest and an enzymatic (proteinase K/T4 endonuclease V enzyme) comet assay in UV-treated Escherichia coli and human (HEK-293) cells, respectively. Naringenin and pinocembrin showed maximum UV-absorption peak in UVC and UVB zones, while apigenin showed UV-absorption capability from UVC to UVA range. These compounds acted as UV filters reducing UV-induced genotoxicity, both in bacteria and in human cells. The enzymatic comet assay resulted highly sensitive for detection of UVB-induced DNA damage in HEK-293 cells. In this work, the photoprotective potential of these flavonoids was widely discussed.

Genotoxicity by long-term exposure to the auxinic herbicides 2,4-dichlorophenoxyacetic acid and dicamba on Cnesterodon decemmaculatus (Pisces: Poeciliidae)

Long-term genotoxic effects of two auxinic herbicide formulations, namely, the 58.4% 2,4-dichlorophenoxyacetic acid (2,4-D)-based DMA^® and the 57.7% dicamba (DIC)-based Banvel^® were evaluated on Cnesterodon decemmaculatus. Primary DNA lesions were analyzed by the single-cell gel electrophoresis methodology. Two sublethal concentrations were tested for each herbicide corresponding to 2.5% and 5% of the LC50_96h values. Accordingly, fish were exposed to 25.2 and 50.4 mg/L or 41 and 82 mg/L for 2,4-D and DIC, respectively. Fish were continuously exposed for 28 days with replacement of test solutions every 3 days. Genotoxicity was evaluated in ten individuals from each experimental point at the beginning of the exposure period (0 day) and at 7, 14, 21 and 28 days thereafter. Results demonstrated for first time that 2,4-D-based formulation DMA^® induced primary DNA strand breaks after 7-28 days exposure on C. decemmaculatus regardless its concentration. On the other hand, DIC-based formulation Banvel^® exerted its genotoxic effect after exposure during 7-14 days and 7 days of 2.5 and 5% LC50_96h, respectively. The present study represents the first evidence of primary DNA lesions induced by two widely employed auxinic herbicides on C. decemmaculatus, namely 2,4-D and DIC, following long-term exposure.

Monitoring the Genotoxic and Cytotoxic Potential and the Presence of Pesticides and Hydrocarbons in Water of the Sinos River Basin, Southern Brazil

The Sinos River is one of the most polluted rivers in Brazil. The purpose of this work was to monitor the presence of some pesticides and hydrocarbons as well as the genotoxic and cytotoxic potential on HEp-2 cells from water samples collected at seven sites in the Sinos River Basin (SRB), southern Brazil. Nine samples were taken from the three main rivers in the SRB and used as a solution to dilute the HEp-2 cell culture medium after microfiltration. Twenty-four pesticides and 19 hydrocarbons were measured. Cytotoxicity was assessed by methyl thiazolyl tetrazolium (MTT) and neutral red (NR) assays, in which cells were exposed to different concentrations of the water samples for 24 h. Genotoxicity of the microfiltrated raw water samples was assessed by comet assay after 6 and 24 h of exposure. Among the chemicals analyzed, only the 2,4-D, dichloromethane, tetrachloroethene, chloroform, bromodichloromethane, styrene, and toluene were detected, but they were all lower than the limit established by Brazilian regulations. Twenty samples from a total of 60 had a cytotoxic effect in the MTT assay and 30 in the NR assay. The comet assay indicated the presence of genotoxic substances in the water at the seven locations monitored. Temporal and spatial variation was observed in the cytotoxicity and genotoxicity assays. Results indicated that the water in all stretches of the SRB is contaminated and it can cause harmful effects to humans and to the aquatic biota. This HEp-2 cell-line approach can be an additional tool for environmental monitoring.

Evaluation of genetic toxicity caused by acid mine drainage of coal mines on fish fauna of Simsang River, Garohills, Meghalaya, India

Fishery ecology of the Simsang River, Meghalaya is being threatened by large scale environmental degradation due to acid mine drainage (AMD) of coal mines. In the present paper, effort has been made to evaluate the genotoxicity caused due to AMD of coal mines on Channa punctata under laboratory condition through comet assay, micronucleus and chromosome aberration tests. Water samples were collected seasonally from affected and unaffected sites of the River and physico-chemical quality of water indicated low pH (4.6), high concentration of sulphates (270mgL(-1)) and iron (7.2mgL(-1)) beyond permissible limits. Polycyclic aromatic hydrocarbon (PAH) showed highest concentration of 4-ring PAH and Benzo[a]anthracene was the most important pollutant in the water collected from affected sites. The highest and the lowest mean concentrations of PAHs were estimated in monsoon and winter season, respectively. The index of DNA damage assessed by comet assay, micronucleus and chromosome aberration tests demonstrated significant differences season wise in different sampling sites. Frequency of DNA-damaged cells was found highest in the water samples collected from affected site in monsoon season.

Applicability of the comet assay in evaluation of DNA damage in healthcare providers' working with antineoplastic drugs: a systematic review and meta-analysis

BACKGROUND

Unintended occupational exposure to antineoplastic drugs (ANDs) may occur in medical personnel. Some ANDs are known human carcinogens and exposure can be monitored by genotoxic biomarkers.

OBJECTIVE

To evaluate the obstacles to obtaining conclusive results from a comet assay test to determine DNA damage among AND exposed healthcare workers.

METHODS

We systematically reviewed studies that used alkaline comet assay to determine the magnitude and significance of DNA damage among health care workers with potential AND exposure. Fifteen studies were eligible for review and 14 studies were used in the meta-analysis.

RESULTS

Under random effect assumption, the estimated standardized mean difference (SMD) in the DNA damage of health care workers was 1.93 (95% CI: 1.15-2.71, p < 0.0001). The resulting SMD was reduced to 1.756 (95% CI: 0.992-2.52, p < 0.0001) when the analysis only included nurses. In subgroup analyses based on gender and smoking, heterogeneity was observed. Only for studies reporting comet moment, I2 test results, as a measure of heterogeneity, dropped to zero. Heterogeneity analysis showed that date of study publication was a possible source of heterogeneity (B = -0.14; p < 0.0001).

CONCLUSIONS

A mixture of personal parameters, comet assay methodological variables, and exposure characteristics may be responsible for heterogenic data from comet assay studies and interfere with obtaining conclusive results. Lack of quantitative environmental exposure measures and variation in comet assay protocols across studies are important obstacles in generalization of results.

Treatment of cosmetic effluent in different configurations of ceramic UF membrane based bioreactor: Toxicity evaluation of the untreated and treated wastewater using catfish (Heteropneustes fossilis)

Extensive usage of pharmaceutical and personal care products (PPCPs) and their discharge through domestic sewage have been recently recognized as a new generation environmental concern which deserves more scientific attention over the classical environmental pollutants. The major issues of this type of effluent addressed in this study were its colour, triclosan and anionic surfactant (SDS) content. Samples of cosmetic effluent were collected from different beauty treatment salons and spas in and around Kolkata, India and treated in bioreactors containing a bacterial consortium isolated from activated sludge samples collected from a common effluent treatment plant. Members of the consortium were isolated and identified as Klebsiella sp., Pseudomonas sp., Salmonella sp. and Comamonas sp. The biotreated effluent was subjected to ultrafiltration (UF) involving indigenously prepared ceramic membranes in both side-stream and submerged mode. Analysis of the MBR treated effluent revealed 99.22%, 98.56% and 99.74% removal of colour, triclosan and surfactant respectively. Investigation of probable acute and chronic cyto-genotoxic potential of the untreated and treated effluents along with their possible participation in triggering oxidative stress was carried out with Heteropneustes fossilis (Bloch). Comet formation recorded in both liver and gill cells and micronucleus count in peripheral erythrocytes of individuals exposed to untreated effluent increased with duration of exposure and was significantly higher than those treated with UF permeates which in turn neared control levels. Results of this study revealed successful application of the isolated bacterial consortium in MBR process for efficient detoxification of cosmetic effluent thereby conferring the same suitable for discharge and/or reuse.

Assessment of DNA damage in floriculturists in southern Brazil

The aim of this study was to assess possible genotoxic effects on floriculturists in a region of the state of Rio Grande do Sul, in the south of Brazil, using the micronucleus test (MN) and comet assay. Thirty-seven floriculturists and 37 individuals not exposed to pesticides participated in the study. The micronucleus test was performed with epithelial cells of the oral mucosa. In the microscopic analysis, 2000 cells were evaluated per subject, verifying the frequency of MN and the frequency of other nuclear abnormalities (nuclear buds, binucleated cells, and karyorrhexis). For the comet assay in the peripheral blood lymphocytes, 100 cells were classified in five classes, according to the migration of DNA fragments, thereby generating the frequency of damaged cells and the damage index. There was no difference between the exposed and control groups in the frequencies of MN and other nuclear abnormalities in the epithelial cells of the oral mucosa. However, the comet assay showed that both the frequency of DNA damaged cells and the damage index were significantly greater in the exposed group. The results therefore indicate that floriculturists are exposed to mixtures of pesticides with genotoxic potential.

Evaluation of genotoxicity and cytotoxicity of water samples from the Sinos River Basin, southern Brazil

<p>Some water bodies in the Sinos River Basin (SRB) have been suffering the effects of pollution by residential, industrial and agroindustrial wastewater. The presence of cytotoxic and genotoxic compounds could compromise the water quality and the balance of these ecosystems. In this context, the research aimed to evaluate the genotoxicity and cytotoxicity of the water at four sites along the SRB (in the cities of Santo Antônio da Patrulha, Parobé, Campo Bom and Esteio), using bioassays in fish and cell culture. Samples of surface water were collected and evaluated <italic>in vitro</italic> using the <italic>Astyanax jacuhiensis</italic> fish species (micronucleus test and comet assay) and the Vero lineage of cells (comet assay and cytotoxicity tests, neutral red - NR and tetrazolium MTT). The micronucleus test in fish showed no significant differences between the sampling sites, and neither did the comet assay and the MTT and NR tests in Vero cells. The comet assay showed an increase in genetic damage in the fish exposed to water samples collected in the middle and lower sections of the basin (Parobé, Campo Bom and Esteio) when compared to the upper section of the basin (Santo Antônio da Patrulha). The results indicate contamination by genotoxic substances starting in the middle section of the SRB.</p>

Cytotoxicity, oxidative stress and genotoxicity induced by glass fibers on human alveolar epithelial cell line A549

Man-made vitreous fibers have been widely used as insulation material as asbestos substitutes; however their morphology and composition raises concerns. In 1988 the International Agency for Research on Cancer classified fiberglass, rock wool, slag wool, and ceramic fibers as Group 2B, i.e. possibly carcinogenic to humans. In 2002 it reassigned fiberglass, rock and slag wool, and continuous glass filaments to Group 3, not classifiable as carcinogenic to humans. The aim of this study was to verify the cytotoxic and genotoxic effects and oxidative stress production induced by in vitro exposure of human alveolar epithelial cells A549 to glass fibers with a predominant diameter <3 μm (97%) and length >5 μm (93%). A549 cells were incubated with 5, 50, or 100 μg/ml (2.1, 21, and 42 μg/cm(2), respectively) of glass fibers for 72 h. Cytotoxicity and DNA damage were tested by the MTT and the Comet assay, respectively. Oxidative stress was determined by measuring inducible nitric oxide synthase (iNOS) expression by Western blotting, production of nitric oxide (NO) with Griess reagent, and concentration of reactive oxygen species by fluorescent quantitative analysis with 2',7'-dichlorofluorescein-diacetate (DCFH-DA). The results showed that glass fiber exposure significantly reduced cell viability and increased DNA damage and oxidative stress production in a concentration-dependent manner, demonstrating that glass fibers exert cytotoxic and genotoxic effects related to increased oxidative stress on the human alveolar cell line A549.

Effects of fullerenol nanoparticles on acetamiprid induced cytoxicity and genotoxicity in cultured human lung fibroblasts

The aim of this study was to investigate the effects of water soluble fullerene (fullerenol) nanoparticles on the in vitro genotoxicity induced by the insecticide acetamiprid. Healthy human lung cells (IMR-90) were treated with fullerenol C60(OH)n (n: 18-22) alone and in combination with acetamiprid for 24h. The micronucleus test, comet assay and γ-H2AX foci formation assays were used as genotoxicity endpoints. Cytotoxicity was evaluated using the clonogenic assay. The maximum tested concentration of fullerenol (1.600 μg/ml) induced 77% survival where as the lowest concentration (25 μg/ml) was not cytotoxic where as acetamiprid was cytotoxic. Fullerenol did not induce genotoxicity at tested concentrations (50-1600 μg/L). On the other hand, acetamiprid (>50 μM) significantly induced formation of micronuclei, and double and single stranded DNA breaks in IMR-90 cells. For simultaneous exposure studies, two non-cytotoxic concentrations (50 and 200 μg/ml) of fullerenol and three cytotoxic concentrations of acetamiprid (100, 200 and 400 μM) were selected. As a result, we observed that co-exposure with fullerenol significantly reduced the cytotoxicity and genotoxicity of acetamiprid in IMR-90 cells. Our results indicated the protective effect of water soluble fullerene particles on herbicide induced genotoxicity.

Application of isolated bacterial consortium in UMBR for detoxification of textile effluent: comparative analysis of resultant oxidative stress and genotoxicity in catfish (Heteropneustes fossilis) exposed to raw and treated effluents

A bacterial consortium isolated from activated sludge was identified to be Bacillus sp., Pseudomonas sp., Shigella sp. and E. coli. and was found capable of 98.62 % decolourization of highly toxic textile effluent, when applied in an ultrafiltration (UF) membrane bioreactor (UMBR). Ceramic capillary UF membranes prepared over low cost support proved to be highly efficient in adverse experimental conditions. The UMBR permeate and untreated textile effluent (40 % (v/v)) was then used to treat Heteropneustes fossilis for a comparative assessment of their toxicity. Micronucleus count in peripheral blood erythrocytes and comet assay carried out in liver and gill cells showed significantly lower nuclear and tissue specific DNA damage respectively in organisms exposed to membrane permeate and was further supported by considerably lower oxidative stress response enzyme activities in comparison to raw effluent treated individuals. The results indicate efficient detoxification of textile effluent by the UMBR treatment using the isolated bacterial consortium.

The genotoxic effects of the imidacloprid-based insecticide formulation Glacoxan Imida on Montevideo tree frog Hypsiboas pulchellus tadpoles (Anura, Hylidae)

The neonicotinoid insecticide imidacloprid (IMI) affects the insect central nervous system and is successfully applied to control pests for a variety of agricultural crops. In the current study, acute toxicity and genotoxicity of the IMI-containing commercial formulation insecticide Glacoxan Imida (35 percent IMI) was evaluated on Hypsiboas pulchellus (Anura: Hylidae) tadpoles exposed under laboratory conditions. A lethal effect was evaluated as the end point for lethality, whereas micronucleus (MN) frequency and DNA single-strand breaks evaluated by the single cell gel electrophoresis (SCGE) assay were employed as end points for genotoxicity. Sublethal end points were assayed within the 12.5-37.5mg/L IMI concentration range. Experiments were performed on tadpoles at stage 36 (range, 35-37) according to the classification proposed by Gosner. Lethality studies revealed an LC50 96h value of 52.622mg/L IMI. Increased frequency of MNs was only observed when 25.0mg/L was assayed for 96h, whereas no other nuclear abnormalities were induced. Increase of the genetic damage index was observed at 48h of treatment within the 12.5-37.5mg/L concentration range, whereas an increased frequency of DNA damage was observed only in tadpoles treated with 37.5mg/L IMI for 96h. This study represents the first evidence of the acute lethal and genotoxic effects exerted by IMI on tadpoles of an amphibian species native to Argentina under laboratory conditions.

The wing-spot and the comet tests as useful assays detecting genotoxicity in Drosophila

In spite of its pioneer use in detecting mutational processes, Drosophila has yet an important role in studies aiming to detect and quantify the induction of DNA damage. Here we describe two assays, one detecting primary damage (the Comet assay) and the other detecting somatic mutation and recombination effects (wing-spot test). It is important to emphasize that somatic recombination is a key event in cancer and no assays exist to detect and quantify somatic recombination processes, other than the spot tests developed in Drosophila.

DNA damage in Wistar rats exposed to dithiocarbamate pesticide mancozeb

Pesticides are used in large amounts in agriculture and the evaluation of their toxic effects is of major concern to public and environmental health. The aim of the present study was to investigate the genotoxic potential of a commercial formulation of the fungicide mancozeb by the micronucleus test in bone marrow and the comet assay in total blood of Wistar rats. Adult male Wistar rats were treated with a solution of mancozeb at a concentration of 40 mg/kg/day, administered intraperitoneally for 18 consecutive days, and compared to a control group. The results indicate that mancozeb induced significantly higher DNA damage as detected by the comet assay and increased the frequency of micronuclei. The results show that mancozeb is genotoxic and may adversely affect the DNA integrity of exposed organisms.

Single-cell gel electrophoresis assay in the ten spotted live-bearer fish, Cnesterodon decemmaculatus (Jenyns, 1842), as bioassay for agrochemical-induced genotoxicity

The ability of two 48 percent chlorpyrifos-based insecticides (Lorsban* 48E® and CPF Zamba®), two 50 percent pirimicarb-based insecticides (Aficida® and Patton Flow®), and two 48 percent glyphosate-based herbicides (Panzer® and Credit®) to induce DNA single-strand breaks in peripheral blood erythrocytes of Cnesterodon decemmaculatus (Jenyns, 1842) (Pisces, Poeciliidae) exposed under laboratory conditions was evaluated by the single-cell gel electrophoresis (SCGE) assay. In those fish exposed to Lorsban* 48E®, CPF Zamba®, Aficida®, Patton Flow®, Credit®, and Panzer®, a significant increase of the genetic damage was observed for all formulations regardless of the harvesting time. This genotoxic effect was achieved by an enhancement of Type II-IV comets and a concomitant decrease of Type 0-I comets over control values. A regression analysis revealed that the damage varied as a negative function of the exposure time in those Lorsban* 48E®- and Aficida®-treated fish. On the other hand, a positive correlation between damage increase and exposure time was achieved after Patton Flow® and Credit® treatment. Finally, no correlation was observed between increase in the genetic damage and exposure time after treatment with CPF Zamba® or Panzer®. These results highlight that all agrochemicals inflict primary genotoxic damage at the DNA level at sublethal concentrations, regardless of the exposure time of the aquatic organisms under study, at least within a period of 96 h of treatment.

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.

Genotoxic potential and physicochemical parameters of Sinos River, southern Brazil

The present study aimed to evaluate the physicochemical parameters and the genotoxic potential of water samples collected in the upper, middle, and lower courses of the Sinos River, southern Brazil. The comet assay was performed in the peripheral blood of fish Hyphessobrycon luetkenii exposed under laboratory conditions to water samples collected in summer and winter in three sampling sites of Sinos River. Water quality analysis demonstrated values above those described in Brazilian legislation in Parobé and Sapucaia do Sul sites, located in the middle and in the lower courses of the Sinos River, respectively. The Caraá site, located in the upper river reach, presented all the physicochemical parameters in accordance with the allowed limits in both sampling periods. Comet assay in fish revealed genotoxicity in water samples collected in the middle course site in summer and in the three sites in winter when compared to control group. Thus, the physicochemical parameters indicated that the water quality of the upper course complies with the limits set by the national guidelines, and the ecotoxicological assessment, however, indicated the presence of genotoxic agents. The present study highlights the importance of combining water physicochemical analysis and bioassays to river monitoring.

Toxic, cytotoxic, and genotoxic effects of a glyphosate formulation (Roundup®SL-Cosmoflux®411F) in the direct-developing frog Eleutherodactylus johnstonei

The aerial spraying of glyphosate formulations in Colombia to eradicate illegal crops has generated great concern about its possible impact on nontarget organisms, particularly amphibians. This study evaluated the toxic, cytotoxic, and genotoxic effects of a glyphosate formulation (Roundup®SL-Cosmoflux®411F) in the direct-developing frog Eleutherodactylus johnstonei by estimating the median lethal application rate (LC50 ), median hemolytic application rate (HD50 ), and extent of DNA damage using the in vitro and in vivo Comet assays. Toxicity results indicated that the application rate [37.4 µg acid equivalent (a.e.)/cm(2) ] equivalent to that used in aerial spraying (3.74 kg a.e./ha) is not lethal in male and female adult frogs, whereas neonates are highly sensitive. Glyphosate formulation at application rates above 5.4 µg a.e./cm(2) (in vivo) and concentrations above 95 µg a.e./mL (in vitro) showed clear evidence of cytotoxicity. In vivo and in vitro exposure of E. johnstonei erythrocytes to the glyphosate formulation induced DNA breaks in a dose-dependent manner with statistically significant values (P < 0.05) at all doses tested. DNA damage initially increased with the duration of exposure and then decreased, suggesting that DNA repair events were occurring during in vivo and in vitro exposures. These results are discussed from the perspective of possible ecotoxicological risks to anuran species from exposure to glyphosate formulation.

In vivo genotoxicity evaluation of atrazine and atrazine-based herbicide on fish Carassius auratus using the micronucleus test and the comet assay

Atrazine is a selective triazine herbicide used to control broadleaf and grassy weeds mainly in corn, sorghum, sugarcane, pineapple, and other crops, and in conifer reforestation planting fields. It has been showed that atrazine is one of the most frequently detected pesticides in agricultural streams and rivers, over the past two decades. Although the toxic properties of atrazine are well known, the data on the genotoxic effects of atrazine on aquatic organisms are rather scarce. Thus, in the present study we aimed to evaluate the genotoxic effects of atrazine and an atrazine-based herbicide (Gesaprim®) on a model fish species Carassius auratus L., 1758, (Pisces: Cyprinidae) using the micronucleus test and the comet assay in peripheral blood erythrocytes. Fish were exposed to 5, 10 and 15 μg/L atrazine and to its commercial formulation for 2, 4 and 6 days. Ethyl methane sulfonate (EMS) at a single dose of 5 mg/L was used as positive control. Our results revealed significant increases in the frequencies of micronuclei and DNA strand breaks in erythrocytes of C. auratus, following exposure to commercial formulation of atrazine and thus demonstrated the genotoxic potential of this pesticide on fish.

Evaluation of Sinos River water genotoxicity using the comet assay in fish

The Sinos River, in southern Brazil, is polluted by industrial discharges and untreated urban wastes. Fish genotoxicity biomarkers are valuable parameters for environmental risk assessment. In this study, we used the comet assay to detect genotoxicity due to multiple sources of pollution in the peripheral blood of a native fish species (Hyphessobrycon luetkenii). In addition, we analysed possible DNA damage from aluminum, lead, chromium, copper, nickel, iron and zinc contamination. Water samples were collected seasonally from three sampling sites and the fish were assessed under laboratory conditions. Water chemical analysis showed an increased level of aluminum and iron in most of the samples at sites 2 and 3, located in the middle and lower river course, respectively. The index of DNA damage assessed by the comet assay demonstrated no significant differences in different seasons or at the different sampling sites, while the frequency of cells with DNA damage was higher in water samples collected at sites 1 and 2 during the spring season. None of the metals studied seems to be associated with the increase in the frequency of cells with DNA damage observed during the spring season. The results of this study indicate that the Sinos River is contaminated with substances that are genotoxic to fish, including the waters near the river spring.

A multibiomarker approach in rats to assess the impact of pollution on Sinos River, Southern Brazil

The aim of this study was to determine the feasibility of combining water quality analysis with different biomarkers to characterise the relationship between anthropogenic contamination and biotic response in the Sinos River, southern Brazil. Wistar rats were studied using three biomarkers combined with physical, chemical and microbiological analysis to assess the effects of pollution at four sampling sites. The induction of oxidative stress was quantified by MDA levels in peripheral blood, lymphocyte DNA damage was determined using the comet assay, and histopathological changes were analysed in the liver. After sampling, animals were allowed to drink the river water during a 48 hours period. No increase in oxidative stress and DNA damage was observed. However, liver damage was observed in the animals exposed to water samples, indicating that the Sinos River is contaminated with hepatotoxic substances. Water analyses confirmed that water quality decreased downriver.

Evaluation of a suitable DNA damage biomarker for human biomonitoring of exposed workers

The objective of this study was to identify a sensitive and noninvasive biomarker of early genotoxic effects, for health risk assessment of workers exposed to mixtures of low doses of xenobiotics. We studied 30 workers exposed to antineoplastic drugs, 57 workers exposed to different mixtures of polycyclic aromatic hydrocarbons (PAHs) (41 airport workers and 16 paving workers) and 76 controls. Comet and micronucleus (MN) tests were performed on lymphocytes and exfoliated buccal cells. The MN assay on lymphocytes did not show significant differences between exposed and controls, while the MN assay on exfoliated buccal cells showed higher values in workers exposed to antineoplastics as compared with controls (0.85 vs. 0.48, P = 0.042). The comet assay on lymphocytes showed a higher comet percentage value (18.11 vs. 11.24 in controls, P = 0.001) and mean tail moment (TM) value (21.84 vs. 16.72 in controls, P = 0.003) in individuals exposed to PAHs as compared with controls; no significant differences were found in exposed to antineoplastics. The comet assay on exfoliated buccal cells did not show significant differences between exposed and control groups for comet percentages, whereas the TM value was higher in workers exposed to PAHs (55.1 vs. 32.31 for controls, P < 0.001). These results show that exfoliated buccal cells, obtained by a noninvasive procedure, represent robust target cells to assess the occupational exposure to inhalable mixture of chemicals at low doses. The comet assay seems to be suitable to promptly evaluate the genotoxic effects of PAHs mixtures that also contain volatile substances. The MN test is suitable to evaluate the effects of antineoplastics. Inc.

Detection of cytogenetic and DNA damage in peripheral erythrocytes of goldfish (Carassius auratus) exposed to a glyphosate formulation using the micronucleus test and the comet assay

Glyphosate is a widely used broad-spectrum weed control agent. In the present study, an in vivo study on the genotoxic effects of a technical herbicide (Roundup) containing isopropylamine salt of glyphosate was carried out on freshwater goldfish Carassius auratus. The fish were exposed to three doses of glyphosate formulation (5, 10 and 15 ppm). Cyclophosphamide at a single dose of 5 mg/l was used as positive control. Analysis of micronuclei, nuclear abnormalities and DNA damage were performed on peripheral erythrocytes sampled at intervals of 48, 96 and 144 h posttreatment. Our results revealed significant dose-dependent increases in the frequencies of micronuclei, nuclear abnormalities as well as DNA strand breaks. Our findings also confirmed that the alkaline comet assay and nuclear deformations in addition to micronucleus test on fish erythrocytes in vivo are useful tools in determining the potential genotoxicity of commercial herbicides.

[Increased DNA damage of lymphocytes in Korean male smokers]

OBJECTIVE

The purpose of this study was to evaluate the levels of DNA damage in human lymphocytes caused by smoking and other lifestyle factors.

METHODS

The study population consisted of 173 normal healthy male adults from 21 to 59 years old. The demographic and lifestyle variables were obtained from administered questionnaires. The level of lymphocytic DNA damage in the peripheral blood was evaluated by the Comet assay. Statistical analyses were done by general linear model analysis and Dunnett's multiple comparison.

RESULTS

The difference in DNA damage between smokers and non-smokers was statistically significant. The means for the Tail%DNA were found to be 10.48 in the current smokers and 9.60 in the non-smokers (p < 0.05). The tail moment means were 1.58 and 1.45 (p < 0.05) for the current smokers and non-smokers, respectively. The number of cigarettes smoked per day did not result in a significant difference in the level of DNA damage among the smokers. Other lifestyle factors such as age, and drinking and exercise habits were not related to DNA damage.

CONCLUSIONS

The DNA damage in the lymphocytes of smokers was found to be significantly higher than that for non-smokers. However, the number of cigarettes smoked per day was not related to DNA damage. Further study is needed to evaluate the relationship between the amount of smoking and level of damage to DNA. In addition, the status of DNA repair activities should be assessed.

Micronucleus studies in the peripheral blood and bone marrow of mice treated with jet fuels, JP-8 and Jet-A

The potential adverse effects of dermal and inhalation exposure of jet fuels are important for health hazard evaluation in humans. The genotoxic potential of jet fuels, JP-8 and Jet-A, was investigated in an animal model. Mice were treated dermally with either a single or multiple applications of these jet fuels. Peripheral blood and bone marrow smears were prepared to examine the incidence of micronuclei (MN) in polychromatic erythrocytes (PCEs). In all experiments, using several different exposure regimens, no statistically significant increase in the incidence of MN was observed in the bone marrow and/or peripheral blood of mice treated with JP-8 or Jet-A when compared with those of untreated control animals. The data in mice treated with a single dose of JP-8 or Jet-A did not confirm the small but statistically significant increase in micronuclei reported in our previous study.