Mutagenicity of a novel 2-phenylbenzotriazole (non-chlorinated 2-phenylbenzotriazole-9) in mice.

Dinitrophenylazo dyes can form 2-phenylbenzotriazoles (PBTAs) in the textile dyeing process upon the addition of chemical reducing agents. Some dinitrophenylazo dyes, as well as their respective reduced (non-chlorinated) and chlorinated PBTAs, are now found in rivers owing to wastewater from textile plants. This study aimed to investigate the genotoxicity of a new PBTA derived from C.I. Disperse Violet 93 azo dye, namely non-Cl PBTA-9. Primary DNA damage in the blood, liver, and colon cells, micronucleated cells in the bone marrow, and gene expression (NAT2, CYP1A1, TRP53, and CDKN1A) in liver cells were observed in mice, at acute oral exposure (gavage) doses of 5, 50, and 500 µg/kg body weight (b.w.). The non-chlorinated PBTA-9 caused DNA damage in the blood and liver (at 500 µg/kg b.w.) and in colon cells (at 5, 50, and 500 µg/kg), and increased the frequency of micronucleated cells in the bone marrow (at 5 and 50 µg/kg). No histological alterations or gene expression changes were observed. In conclusion, in vivo exposure to non-chlorinated PBTA-9 induced genetic damage in various rodent tissues, corroborating results previously obtained from the Ames test. Because this compound has been detected in rivers, exposure to humans and biota is a major concern.

Selenium supplementation prevents DNA damage in ram spermatozoa / Suplementação com selênio previne danos ao DNA espermático de ovinos

In the present study, we aimed to evaluate the effects of different concentrations of selenium (Se) ovine nutritional supplementation on spermatozoa DNA integrity. Thirty male ovines (age: 10 months) were used. They were fed with hay and ram food in an intensive system, which was divided into stalls (5 m long and 3 m wide) with feeding troughs, and had ad libitum access to food and water. Ovines in group 1 (G1, the negative control) received mineral salt supplementation without Se; ovines in G2 received the same mineral salt mixed with 5 mg Se (as sodium selenite)/kg mineral supplement;ovines in G3 received 10 mg Se/kg mineral supplement; ovines in G4 received 15 mg Se/kg mineral supplement; and ovines in G5 received 20 mg Se/kg mineral supplement. Ovines in all groups remained untreated for 14 days, followed by a treatment period of 56 days. Semen samples were obtained by electroejaculation. The DNA damage in semen samples was evaluated using the comet assay. The experimental design was implemented using a 5 × 5 Latin Square, i.e., five treatments and five experimental periods. The mean differences were compared using Tukeys test at a significance level of 5%. The control group (G1) showed a high percentage of DNA damage compared to the Se-treated groups (G2-G5). Therefore, Se supplementation could decrease the basal level of DNA damage in sperm cells, suggesting that Se might exert protective effects on sperm DNA.(AU)

O presente estudo teve por objetivo avaliar os efeitos da suplementação mineral com diferentes concentrações de selênio (Se) sobre a integridade de DNA espermático de ovinos. Utilizaram-se 30 machos, com 10 meses de idade. Eles foram mantidos em sistema intensivo, sendo alimentados com feno e ração própria para ovinos, divididos em baias (5 m x 3 m), com cochos e água ad libitum. Os ovinos do grupo 1 (G1=controle negativo) receberam suplementação de sal mineral sem a adição de Se, os animais do G2 receberam a mesma mistura mineral, porém com 5 mg de Se (selenito de sódio)/kg mistura mineral, os ovinos do G3 receberam 10 mg Se/kg mistura, os animais do G4 receberam 15 mg Se/kg mistura, os do G5 receberam 20 mg Se/kg mistura. Os ovinos de todos os grupos passaram por um período de adaptação de 14 dias, seguido por um período de tratamento de 56 dias. O sêmen foi colhido por meio de eletroejaculação. A integridade do DNA espermático foi avaliada por meio do teste de cometa. O modelo experimental utilizado foi Quadrado Latino 5 x 5, com cinco grupos e cinco períodos experimentais. A diferença entre as médias foi analisada pelo teste de Tukey, com 5% de nível de significância. O grupo controle (G1) apresentou elevada porcentagem de danos quando comparada aos demais grupos de tratamentos (G2 a G5). Portanto, a suplementação de Se diminui o nível de danos ao DNA espermáticos, sugerindo que o Se pode exercer efeitos protetores sobre o DNA dos espermatozoides de ovinos.(AU)

Selenium supplementation prevents DNA damage in ram spermatozoa / Suplementação com selênio previne danos ao DNA espermático de ovinos

ABSTRACT: In the present study, we aimed to evaluate the effects of different concentrations of selenium (Se) ovine nutritional supplementation on spermatozoa DNA integrity. Thirty male ovines (age: 10 months) were used. They were fed with hay and ram food in an intensive system, which was divided into stalls (5 m long and 3 m wide) with feeding troughs, and had ad libitum access to food and water. Ovines in group 1 (G1, the negative control) received mineral salt supplementation without Se; ovines in G2 received the same mineral salt mixed with 5 mg Se (as sodium selenite)/kg mineral supplement;ovines in G3 received 10 mg Se/kg mineral supplement; ovines in G4 received 15 mg Se/kg mineral supplement; and ovines in G5 received 20 mg Se/kg mineral supplement. Ovines in all groups remained untreated for 14 days, followed by a treatment period of 56 days. Semen samples were obtained by electroejaculation. The DNA damage in semen samples was evaluated using the comet assay. The experimental design was implemented using a 5 × 5 Latin Square, i.e., five treatments and five experimental periods. The mean differences were compared using Tukey's test at a significance level of 5%. The control group (G1) showed a high percentage of DNA damage compared to the Se-treated groups (G2-G5). Therefore, Se supplementation could decrease the basal level of DNA damage in sperm cells, suggesting that Se might exert protective effects on sperm DNA.

RESUMO: O presente estudo teve por objetivo avaliar os efeitos da suplementação mineral com diferentes concentrações de selênio (Se) sobre a integridade de DNA espermático de ovinos. Utilizaram-se 30 machos, com 10 meses de idade. Eles foram mantidos em sistema intensivo, sendo alimentados com feno e ração própria para ovinos, divididos em baias (5 m x 3 m), com cochos e água ad libitum. Os ovinos do grupo 1 (G1=controle negativo) receberam suplementação de sal mineral sem a adição de Se, os animais do G2 receberam a mesma mistura mineral, porém com 5 mg de Se (selenito de sódio)/kg mistura mineral, os ovinos do G3 receberam 10 mg Se/kg mistura, os animais do G4 receberam 15 mg Se/kg mistura, os do G5 receberam 20 mg Se/kg mistura. Os ovinos de todos os grupos passaram por um período de adaptação de 14 dias, seguido por um período de tratamento de 56 dias. O sêmen foi colhido por meio de eletroejaculação. A integridade do DNA espermático foi avaliada por meio do teste de cometa. O modelo experimental utilizado foi Quadrado Latino 5 x 5, com cinco grupos e cinco períodos experimentais. A diferença entre as médias foi analisada pelo teste de Tukey, com 5% de nível de significância. O grupo controle (G1) apresentou elevada porcentagem de danos quando comparada aos demais grupos de tratamentos (G2 a G5). Portanto, a suplementação de Se diminui o nível de danos ao DNA espermáticos, sugerindo que o Se pode exercer efeitos protetores sobre o DNA dos espermatozoides de ovinos.

Lipid damage is the best marker of oxidative injury during the cardiac remodeling process induced by tobacco smoke.

BACKGROUND: Oxidative stress is one potential mechanism that explain the direct effects of smoking on cardiac remodeling process. However, no study has compared different myocardial products of macromolecule oxidation after tobacco smoke exposure. Thus, the aim of this study was to investigate the lipid hydroperoxide (LH) levels, protein carbonyl concentrations and DNA damage in cardiac tissue of rats exposed to tobacco smoke. METHODS: Male Wistar rats were divided into two groups: group C (control, n = 14) composed of animals not exposed to cigarette smoke; group ETS (exposed to tobacco smoke, n = 14) composed by animals exposed to cigarette smoke. The animals were exposed to 2 month of ETS and morphological, biochemical and functional analyses were performed. RESULTS: Cardiac cotinine levels were elevated in the ETS group. In addition, the myocyte cross-sectional area was higher in the ETS group. (C = 266.6 ± 23.2 µm2 and ETS = 347.5 ± 15.1 µm2, p <  0.001). Cardiac LH was higher in the ETS group than in group C (C = 196.4 ± 51.5 nmol/g and ETS = 331.9 ± 52.9 nmol/g, p <  0.001). However, there were no between-group differences in cardiac protein carbonyl concentration or DNA damage. CONCLUSIONS: Therefore, our results suggest that, in this model, lipid damage is a good marker of oxidative damage during the cardiac remodeling process induced by 2 months of exposure to tobacco smoke.

In Vivo genotoxicity of a commercial C.I. Disperse Red 1 dye.

Color Index (C.I.) Disperse Red 1 (DR1) is a widely used textile azo dye found in rivers. As it may not be completely removed by conventional treatments, humans can be exposed through drinking water. Studies have supported in vitro toxicity and mutagenicity of commercial DR1. This study aimed to investigate the mutagenic and toxicogenomic effects of commercial DR1 in multiple tissues/organs of Swiss male mice. For that, animals were orally exposed to the dye (by gavage), at single doses of 0.0005, 0.005, 0.5, 50, or 500 mg/kg bw. The two lowest doses were equivalent to the ones found in two Brazilian rivers receiving influx of textile discharges. Cytotoxicity, micronucleated cell frequencies (for all doses tested), primary DNA damage (comet assay), and gene expression profiling of (0.0005 and 0.005 mg/kg of bw) were investigated 24 hr after animal exposure to commercial DR1. Data showed increased frequencies of micronucleated polychromatic erythrocytes in bone marrow cells after treatment with 0.5 and 50 mg/kg bw. At 0.005 mg/kg bw, commercial DR1 induced an increase of primary DNA damage in liver, but not in kidney cells. Additionally, upregulation of genes involved in the inflammatory process (IL1B) (0.0005 and 0.005 mg/kg bw) and cell-cycle control (CDKN1A) in liver cells, and apoptosis (BCL2 and BAX) in leukocytes (0.005 mg/kg bw) were also detected. In conclusion, the commercial DR1 was genotoxic (chromosome aberrations and primary DNA damage) and modulated gene expression in mice, and such effects were dependent on the doses and tissues analyzed. Environ. Mol. Mutagen. 59:822-828, 2018. © 2018 Wiley Periodicals, Inc.

Melatonin protective role in mouse cauda epipidymal spermatozoa damage induced by sodium arsenite / Rol protector de la melatonina en el daño de espermatozoides de cauda epididimaria en ratón producido por arsenito de sodio

We evaluated the sperm parameters such as cauda epididymis weight, sperm count, sperm morphology and sperm DNA stability of adult CF-1 male mice treated daily (oral exposure) with the toxic sodium arsenite (As, 7.0 mg/kg/body weight); Melatonin (Me, 10.0 mg/kg/bw), Me (10.0 mg/kg/bw) plus As (7.0 mg/kg/bw) and Negative Control (NaCl 0.9 percent) to assess acute (8.3 days), chronic (33.2 days) and recovery of testicular damage (66.4 days). Arsenic decreases the number of sperm from chronic treatment (33.2 days) and this effect continued until 66.4 days of treatment. The toxic effect of As also altered the morphology of spermatozoa in all treatment periods when compared to the negative control group. However, Metalonin induced protective effects in periods of 33.2 and 66.4 days of treatment. Additionally, the stability of DNA was significantly affected by arsenic in all periods, but the chronic treatment (33.2 days) in the AsMe revealed increased stability compared to the group treated with arsenic only. Melatonin partially protects sperm toxicity caused by Arsenic, especially during periods of 33.2 and 66.4 days.

Se evaluaron los parámetros espermáticos como peso de la cola del epidídimo, conteo de espermatozoides, morfología de los espermatozoides y estabilidad del ADN de espermatozoides de ratones machos adultos CF-1 tratados diariamente (exposición oral) con el tóxico arsenito de sodio (As, 7,0 mg/kg/peso corporal), melatonina (Me, 10,0 mg/kg/pc, Me (10,0 mg/kg/pc) más As (7,0 mg/kg/pc) y el Control Negativo (NaCl 0,9 por ciento) en evaluación aguda (8,3 días), crónica (33,2 días) y recuperación del daño testicular (66.4 días). El arsénico reduce el número de espermatozoides en el tratamiento crónico (33,2 días) y este efecto continuó hasta 66,4 días. El efecto tóxico de As también altero la morfología de los espermatozoides en todos los períodos de tratamiento cuando se compara con el grupo control negativo. Sin embargo, metalonina indujo efectos protectores en períodos de 33,2 y 66,4 días de tratamiento. La estabilidad del ADN se vio afectada significativamente por el arsénico en todos los periodos, pero en el tratamiento crónico (33,2 días) con AsMe se observa un aumento de la estabilidad em comparación com el grupo tratado con arsénico. Sin embargo, la melatonina protege parcialmente a los espermatozoides del daño causado por arsénico, especialmente durante los períodos de 33,2 y 66,4 días.

Protective role of melatonin in mouse spermatogenesis induced by sodium arsenite / Rol protector de la melatonina en el daño de la espermatogénesis en ratón producido por arsenito de sodio

Arsenic is a testicular environmental toxic. Melatonin (Me), being a potent antioxidant, may reduce the damage caused by arsenic in male fertility. The effects of daily oral exposure of Sodium Arsenite (As; 7.0 mg/kg/bw); Melatonin (Me, 10.0 mg/kg/bw); Me (10.0 mg/kg/bw) plus As (7.0 mg/kg/bw), and Negative Control (NaCl 0.9 percent) in male CF-1 adult mice were assessed in acute (8.3 days), chronic (33.2 days) and recovery (66,4 days) of testicular damage. We evaluated changes in testicular weight and histopathological, morphometric measurements, expression of COX-2 and Androgen Receptor (AR) antigens and lipid peroxidation levels. Treatment resulted in decreased tubular diameter and AR expression, and increased: interstitial area, luminal diameter, COX-2 expression levels and of lipid peroxidation. Co-administration of As and Me partially decreased germ cell degeneration and AR expression levels, improving testicular histopathological parameters. These results indicate that As causes toxicity and testicular germ cell degeneration by induction of oxidative stress. Me partially protects from this damage in mouse testis, acting as scavenger of oxygen radical species.

El arsénico es un tóxico testicular ambiental. La melatonina (Me), que es un potente antioxidante, puede reducir el daño causado por el arsénico en la fertilidad masculina. Se evaluaron los efectos de la exposición oral diaria de arsenito de sodio (As; 7,0 mg/kg/peso corporal), melatonina (Me, 10,0 mg/kg/p.c.); Me (10,0 mg/kg/p.c.) más As (7,0 mg/kg/pc) y el Control Negativo (NaCl 0,9 por ciento) en ratones adultos CF-1 machos, a los 8,3 días (exposición aguda), 33,2 días (crónica) y 66,4 días (recuperación) del daño testicular. Se evaluaron los cambios en el peso testicular y mediciones morfométricas, histopatológicas, expresión de COX-2, del receptor de andrógeno (AR) y los niveles de peroxidación de lípidos. El tratamiento con As resultó en disminución del diámetro tubular y la expresión de AR, y el aumento de: área intersticial, diámetro luminal, los niveles de expresión de COX-2 y peroxidación lipídica. La co-administración de As y Me disminuyó parcialmente la degeneración de células germinales, el aumento de los niveles de expresión de AR y hubo mejoría de los parámetros histopatológicos testiculares. Estos resultados indican que As es tóxico y causa degeneración de células germinales por inducción de estrés oxidativo. Me protege parcialmente este daño en los testículos de ratones, actuando como eliminador de especies radicalarias del oxígeno.