RESUMEN

We investigated the occurrence of extended-spectrum ß-lactamase (ESBL) and AmpC-type ß-lactamase (ACBL) producing quinolone-resistant Klebsiella pneumoniae (KP) in milk samples of apparently healthy buffaloes (n = 348) and buffaloes (n = 19) with evidence of subclinical mastitis from seven districts of West Bengal, India. In total, 12 ESBL producing KP were isolated with blaCTX-M-15 gene and 7 of them were ACBL producers, as well. The blaCTX-M-15 genes were carried by transposable element ISEcp1. The plasmid-mediated quinolone resistance genes-qnrS, qnrA, qnrB, qepA, and aac(6')-Ib-cr were detected in five, one, three, four, and one isolate (s), respectively. In addition, eight isolates carried mutation in gyrase (gyrA) and six in topoisomerase IV (parC). Resistance markers/genes for sulfonamide (sul1), tetracycline [tet(A) and tet(B)], and aminoglycoside (aacC2) were also detected in eight, four, and one isolate(s), respectively. The class I integrons identified in five isolates carried aad2/aad5 and dfrA12/dfrA17 gene cassettes. The enterobacterial repetitive intergenic consensus-PCR revealed that all the isolates were genetically diverse and comprised a heterogeneous population. Isolation of multidrug-resistant KP, a typical nosocomial pathogen from buffalo milk, reiterates the need to monitor farm animals for ESBL producing Enterobacteriaceae and emphasizes on judicious use of antibiotics in animal husbandry sector.

Asunto(s)

Proteínas Bacterianas/genética , Búfalos/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Fluoroquinolonas/farmacología , Klebsiella pneumoniae/genética , Leche/microbiología , beta-Lactamasas/genética , Animales , Antibacterianos/farmacología , Femenino , Genes Bacterianos/genética , India , Integrones/genética , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , Pruebas de Sensibilidad Microbiana/métodos , Plásmidos/genética , Quinolonas/farmacología

RESUMEN

The present investigation was carried out to study the vancomycin resistance pattern of Staphylococcus aureus isolates (n = 274) obtained from 352 milk samples of bovine (269) and caprine (63) clinical and subclinical mastitis from different districts of West Bengal, India. Of them, seven isolates (vancomycin-resistant S. aureus [VRSA] 1-7) exhibited resistance to vancomycin. Minimum inhibitory concentration of vancomycin (MICvan) for VRSA2 and VRSA3 was ≥16 µg/ml; thus categorized as VRSA. For rest of the isolates, MICvan was 8 µg/ml and they were grouped as vancomycin intermediate S. aureus (VISA). Even though all the isolates were resistant to cefoxitin and oxacillin and possessed mecA gene, none of them carried vancomycin resistance gene. Furthermore, all the seven isolates were subjected to Staphylococcal cassette chromosome mec (SCCmec) typing, Staphylococcal protein A (spa) typing, and enterobacterial repetitive intergenic consensus polymerase chain reaction. All the isolates except VRSA3 and VRSA4 from Kolkata district exhibited diverse genetic lineage, irrespective of their host and antibiotic resistance pattern. These two isolates showed clonal similarity (MRSA-SCCmec-V-spa t267) with methicillin-resistant S. aureus (MRSA) strains previously reported in human and animal infection. Isolation of VRSA and VISA could probably be due to intensive use of vancomycin in healthcare premises, which might have led to the development of glycopeptide-resistant strains and thereafter, further disseminated in the environment, including livestock farms. Detection of VRSA in milk is a serious concern as it may further cause health problems in the consumers. This is the first ever report of VRSA in food animals, even though the pathogen is otherwise prevalent in humans.

Asunto(s)

Regulación Bacteriana de la Expresión Génica , Mastitis Bovina/epidemiología , Staphylococcus aureus Resistente a Meticilina/genética , Leche/microbiología , Resistencia a las Penicilinas/genética , Infecciones Estafilocócicas/veterinaria , Resistencia a la Vancomicina/genética , Animales , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Bovinos , Cefoxitina/farmacología , Femenino , Cabras , India/epidemiología , Lactancia/fisiología , Mastitis Bovina/microbiología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/crecimiento & desarrollo , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Oxacilina/farmacología , Proteínas de Unión a las Penicilinas/genética , Proteínas de Unión a las Penicilinas/metabolismo , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología

RESUMEN

The present study was undertaken to determine the occurrence and characterization of extended spectrum beta-lactamase (ESBL) producing Escherichia coli isolated from cattle and poultry in Odisha, India. Of 316 E. coli isolated from 305 samples (170 fecal samples from poultry and 135 milk samples from cattle), a total of 18 E. coli isolates were confirmed as ESBL producers by combination disc method and ESBL E-test. The isolates were resistant to oxyimino cephalosporins and monobactam as revealed by disc diffusion assay and determination of minimum inhibitory concentration. Resistance against other antibiotics was frequently noted as well. Further, beta-lactamase genes viz., blaSHV, blaCTXM, blaTEM and blaampC were detected in 17, 13, 9 and 2 isolates, respectively in PCR. Of the 18 ESBL strains, 16 were positive for class I integron (int1), nine of them carried sulphonamide resistance gene (sul1) and one harbored quinolone resistance gene (qnrB). Virulence markers for extraintestinal pathogenic E. coli like astA, tsh and iucD were also present in 4, 3 and 3 isolates, respectively. All the PCR amplified products were cloned and subjected to sequencing for homology analysis and data were submitted to gene bank. Sequence analysis of the amplified variable regions of class 1 integron of four representative isolates revealed the presence of aadA2 and dfrA12 gene cassettes conferring resistance to aminoglycosides and trimethoprim, respectively. Most of the ESBL producing strains emerged as single lineage through phylogenetic analysis by RAPD and ERIC PCR. This is the first ever systemic study on multidrug resistant ESBL producing E. coli in food producing animals from India.

Asunto(s)

Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli/clasificación , Escherichia coli/genética , Heces/microbiología , Leche/microbiología , Enfermedades de las Aves de Corral/microbiología , Animales , Antibacterianos/farmacología , Bovinos , Enfermedades de los Bovinos/tratamiento farmacológico , Cefalosporinas/farmacología , Escherichia coli/efectos de los fármacos , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Monobactamas/farmacología , Filogenia , Aves de Corral , Enfermedades de las Aves de Corral/tratamiento farmacológico , Análisis de Secuencia de ADN , Resistencia betalactámica/efectos de los fármacos

RESUMEN

Emergence of antimicrobial resistance among bovine mastitis pathogens is the major cause of frequent therapeutic failure and a cause of concern for veterinary practitioners. This study describes intra-mammary infection of methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum ß-lactamase (ESBL) producing Escherichia coli in two Holstein Friesian crossbred cows with subclinical mastitis and one non-descript cow with clinical mastitis in two different districts of West Bengal, India. In total, three MRSE, one MRSA and three ESBL producing E. coli were isolated from these cases. Both the crossbreds were detected with MRSE (HFSE1 and HFSE2) and ESBL producing E. coli (HFEC1 and HFEC2), whereas, simultaneous infection of three pathogens viz. MRSA (NDSA1), MRSE (NDSE1) and ESBL producing E. coli (NDEC1) was found in the non-descript cow. The methicillin-resistant isolates possessed mecA gene and exhibited resistance to various antibiotics such as amikacin, tetracycline and glycopeptides. The ESBL producers were positive for blaCTX-M and blaTEM genes; in addition, HFEC1 and HFEC2 were positive for blaSHV and possessed the genes for class I integron (int1), sulphonamide resistance (sul1), quinolone resistance (qnrS) and other virulence factors (papC, iucD and ESTA1). All the ESBL producers exhibited resistance to a variety of antibiotics tested including third- and fourth-generation cephalosporins and were also intermediately resistant to carbapenems. This is the first ever report on simultaneous occurrence of MRSE, MRSA and ESBL producing E. coli in bovine mastitis indicating a major concern for dairy industry and public health as well.

Asunto(s)

Infecciones por Escherichia coli/veterinaria , Mastitis Bovina/microbiología , Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas/veterinaria , Staphylococcus epidermidis , Animales , Antibacterianos/farmacología , Bovinos , Coinfección , Farmacorresistencia Bacteriana Múltiple , Escherichia coli/enzimología , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/complicaciones , Infecciones por Escherichia coli/microbiología , Femenino , India , Mastitis Bovina/tratamiento farmacológico , Resistencia a la Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Infecciones Estafilocócicas/complicaciones , Infecciones Estafilocócicas/microbiología , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/aislamiento & purificación , beta-Lactamasas/aislamiento & purificación

RESUMEN

We present a data based statistical study on the effects of seasonal variations in the growth rates of the gastro-intestinal (GI) parasitic infection in livestock. The alluded growth rate is estimated through the variation in the number of eggs per gram (EPG) of faeces in animals. In accordance with earlier studies, our analysis too shows that rainfall is the dominant variable in determining EPG infection rates compared to other macro-parameters like temperature and humidity. Our statistical analysis clearly indicates an oscillatory dependence of EPG levels on rainfall fluctuations. Monsoon recorded the highest infection with a comparative increase of at least 2.5 times compared to the next most infected period (summer). A least square fit of the EPG versus rainfall data indicates an approach towards a super diffusive (i. e. root mean square displacement growing faster than the square root of the elapsed time as obtained for simple diffusion) infection growth pattern regime for low rainfall regimes (technically defined as zeroth level dependence) that gets remarkably augmented for large rainfall zones. Our analysis further indicates that for low fluctuations in temperature (true on the bulk data), EPG level saturates beyond a critical value of the rainfall, a threshold that is expected to indicate the onset of the nonlinear regime. The probability density functions (PDFs) of the EPG data show oscillatory behavior in the large rainfall regime (greater than 500 mm), the frequency of oscillation, once again, being determined by the ambient wetness (rainfall, and humidity). Data recorded over three pilot projects spanning three measures of rainfall and humidity bear testimony to the universality of this statistical argument.

RESUMEN

Natural contamination of arsenic in ground water is a major health problem throughout the World. It is one of the most hazardous substances in the environment known to cause toxicity in multiple organs via oxidative stress. The molecular basis for arsenic toxicity involves direct or indirect damage to protein, lipid and DNA. Various studies have focused on the possible toxic effects of arsenic on membrane components and its correlation with oxidative damage. The present study was aimed to mitigation of arsenic induced hepatic oxidative stress by dietary modulation using of mushroom lectin in rats. Animals were divided into four groups; the first group was used as control. Groups 2, 3 and 4 were arsenic (20 ppm) exposed through drinking water, arsenic exposed plus oral ascorbic acid (25 mg/kg body weight) and arsenic exposed plus oral mushroom lectin (150 mg/kg body weight) respectively for a period of 12 weeks. We observed significant alterations in the antioxidant enzymes, oxidative stress intermediates and SOD(2) gene expression profile on arsenic exposure. These alterations were restored by co-administration of Pleurotus florida lectin which was as potent as standard antioxidant viz. ascorbic acid. The findings of the experiment suggested that P. florida lectin has capability of modulating arsenic mediated toxic effects and could be helpful in ameliorating them.

Asunto(s)

Antioxidantes/farmacología , Arsenitos/toxicidad , Lectinas/farmacología , Hígado/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Pleurotus/química , Compuestos de Sodio/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Antioxidantes/aislamiento & purificación , Arsenitos/farmacocinética , Lectinas/aislamiento & purificación , Peróxidos Lipídicos/metabolismo , Hígado/enzimología , Hígado/metabolismo , Hígado/patología , Masculino , Óxido Nítrico/metabolismo , Tamaño de los Órganos/efectos de los fármacos , Carbonilación Proteica , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Compuestos de Sodio/farmacocinética , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Factores de Tiempo , Transcripción Genética , Contaminantes Químicos del Agua/farmacocinética

RESUMEN

Oyster mushroom, Pleurotus florida is regarded as one of the popular food with biopharmaceutical properties. Here, the study aimed to investigate the antioxidative effects of mushroom (Pleurotus florida) lectin against arsenic-induced nephrotoxicity in rats. Animals were divided into four groups; Group 1 was control. Groups 2, 3 and 4 were exposed to arsenic (20 parts per million [ppm] in drinking water), arsenic plus oral supplementation of ascorbic acid (25 mg/kg body weight) and arsenic plus oral supplementation of mushroom lectin (150 mg/kg body weight) respectively. Both ascorbic acid and mushroom lectin prevented the arsenic-mediated growth retardation and normalized the elevated kidney weight. Disrupted activities of superoxide dismutase (SOD) and catalase (CAT) and enhanced lipid peroxidation (LPO), protein carbonyl (PC) and nitric oxides (NO) production in kidney caused by arsenic could also be maintained towards normalcy by supplementation of mushroom lectin and ascorbic acid. These antioxidative effects were exhibited in a time-dependant manner. Further, arsenic-mediated down-regulation of messenger RNA (mRNA) expression of superoxide dismutase 2 (SOD(2)) gene was obstructed by these agents. Thus it was found that mushroom lectin reversed the effect of arsenic-mediated oxidative stress in a time-dependent manner.

Asunto(s)

Antioxidantes/uso terapéutico , Intoxicación por Arsénico/tratamiento farmacológico , Riñón/efectos de los fármacos , Lectinas/uso terapéutico , Pleurotus/química , Animales , Antioxidantes/aislamiento & purificación , Intoxicación por Arsénico/enzimología , Intoxicación por Arsénico/metabolismo , Intoxicación por Arsénico/patología , Peso Corporal/efectos de los fármacos , Catalasa/metabolismo , Regulación hacia Abajo , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Riñón/enzimología , Riñón/metabolismo , Riñón/patología , Lectinas/aislamiento & purificación , Peroxidación de Lípido/efectos de los fármacos , Masculino , Óxido Nítrico/metabolismo , Tamaño de los Órganos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Carbonilación Proteica , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Factores de Tiempo

RESUMEN

Acute and chronic arsenic exposure result in toxicity both in human and animal beings and cause many hepatic and renal manifestations. The present study stated that mushroom lectin prevents arsenic-induced apoptosis. Apoptosis was measured by morphological alterations, cell proliferation index (CPI), phagocytic activity (nitro blue tetrazolium index; NBT), nitric oxide (NO) production, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, DNA fragmentation and caspase-3 activity. Arsenic exposure at 5 µM in the form of sodium arsenite resulted in significant elevation of deformed cells, NO production, TUNEL stained nuclei of hepatocytes, DNA fragmentation and caspase-3 activity. But the CPI and NBT index were significantly declined in arsenic-treated hepatocytes. The beneficial effect of mushroom lectin at 10 µg/mL, 20 µg/mL and 50 µg/mL) showed increased CPI and phagocytic activity. Mushroom lectin at those concentrations reduced deformed cells, NO production, DNA fragmentation and caspase-3 activity of hepatocytes. But significant better protection was observed in 50 µg/mL mushroom lectin-treated hepatocytes. This finding may be of therapeutic benefit in people suffering from chronic arsenic exposure.

Asunto(s)

Arsenitos/toxicidad , Hepatocitos/efectos de los fármacos , Lectinas/farmacología , Pleurotus/química , Compuestos de Sodio/toxicidad , Animales , Apoptosis/efectos de los fármacos , Intoxicación por Arsénico/prevención & control , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Quimioprevención , Relación Dosis-Respuesta a Droga , Hepatocitos/metabolismo , Hepatocitos/patología , Masculino , Óxido Nítrico/metabolismo , Fagocitosis/efectos de los fármacos , Extractos Vegetales/farmacología , Ratas , Ratas Wistar

RESUMEN

Arsenic contamination of ground water in West Bengal, India, is a great concern for both human and livestock populations. Our study investigated and correlated the arsenic concentration in the drinking water, urinary excretion and deposition of total arsenic in hair of cattle at an arsenic contaminated zone in West Bengal. The results of our study indicated that the average concentration of arsenic in tube well water in contaminated villages ranged from 0.042 to 0.251 ppm and a statistical significant (p < 0.01) difference was seen when compared to samples from a non-contaminated zone. The arsenic concentration in urine and hair of cattle ranged between 0.245-0.691 ppm and 0.461-0.984 ppm, respectively. A close relationship was found between the total arsenic in drinking water urinary excretion (r² = 0.03664, p < 0.05) and the arsenic concentration in hair (r² = 0.03668, p < 0.05). Our findings indicate that quantification of arsenic concentration in cattle urine and hair can serve as biomarkers for both present and past exposure in cattle population.

Asunto(s)

Arsénico/análisis , Agua Dulce/química , Contaminantes Químicos del Agua/análisis , Abastecimiento de Agua/análisis , Animales , Arsénico/metabolismo , Arsénico/orina , Bovinos , Exposición a Riesgos Ambientales/análisis , Cabello/metabolismo , India , Medición de Riesgo , Contaminantes Químicos del Agua/metabolismo , Contaminantes Químicos del Agua/orina , Contaminación Química del Agua/estadística & datos numéricos

RESUMEN

This study aimed to determine the hemato-biochemical picture and blood oxidative stress in zebu cattle in an arsenic-contaminated zone. Significant decline in total erythrocyte count, packed cell volume, and total plasma protein was observed in cattle of that area in comparison to uncontaminated zone. There was significant elevation of plasma enzyme activities of both alanine aminotransaminase and aspertate aminotransaminase. Increased corpuscular osmotic fragility also proved to be a mechanism for deviation from normal functioning of erythrocytes. Cattle in the affected zone showed a significantly higher arsenic burden in blood. Those animals further showed decreased superoxide dismutase, catalase activities of erythrocytes, and plasma nitrite level, but increased lipid peroxidation and protein carbonyl level. Our finding concluded that cattle of the arsenic-contaminated zone is suffering from a subclinical form of arsenic toxicity, which is proved through altered hemato-biochemical indices and a certain extent of oxidative stress with higher arsenic concentration in blood.

Asunto(s)

Intoxicación por Arsénico/sangre , Arsénico/toxicidad , Enfermedades de los Bovinos/sangre , Estrés Oxidativo/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Alanina Transaminasa/sangre , Animales , Arsénico/análisis , Arsénico/sangre , Intoxicación por Arsénico/enzimología , Intoxicación por Arsénico/metabolismo , Intoxicación por Arsénico/veterinaria , Aspartato Aminotransferasas/sangre , Proteínas Sanguíneas/análisis , Bovinos , Enfermedades de los Bovinos/enzimología , Enfermedades de los Bovinos/metabolismo , Ingestión de Líquidos , Eritrocitos/enzimología , India , Peroxidación de Lípido/efectos de los fármacos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/sangre

RESUMEN

Oxidative stress due to arsenic toxicity and ameliorative potentiality of L-ascorbic acid was evaluated in an ex vivo system of rat hepatic tissue. The study revealed that arsenic increased the activity of superoxide dismutase (SOD) and catalase (CAT) and the level of lipid peroxidation (LPO), protein carbonyl (PC) and nitric oxide (NO) at 1 hour, 1.5 hours and 2 hours of incubation. Co-treatment with L-ascorbic acid was found effective to normalize the activity of SOD and CAT and the production of LPO, PC and NO in hepatic tissue. This ex vivo study suggested that ascorbic acid is helpful to ameliorate arsenic-induced oxidative stress. This may be one of the alternative screening systems to study the efficacy of antioxidant and hepatoprotective agent.

Asunto(s)

Antioxidantes/farmacología , Arsénico/toxicidad , Ácido Ascórbico/farmacología , Contaminantes Ambientales/toxicidad , Hígado/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Animales , Catalasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Hígado/enzimología , Hígado/metabolismo , Masculino , Óxido Nítrico/metabolismo , Técnicas de Cultivo de Órganos , Carbonilación Proteica/efectos de los fármacos , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo , Factores de Tiempo , Pruebas de Toxicidad

RESUMEN

Ascorbic acid is a sugar acid and an essential vital food nutrient found mainly in fruits and vegetables. The purpose of this study was to investigate the effects of ascorbic acid against arsenic induced oxidative stress in blood of rat. In rat, treatment with ascorbic acid prevented the increased serum enzymatic activity of AST, ALT, ALP, ACP and LDH. In addition, treatment with ascorbic acid prevented elevated production of LPO, PC and NO and restored the depletion of reduced SOD and CAT activities. Interestingly, ascorbic acid markedly upregulated lymphocytes relative mRNA expression of lymphocytes SOD2 gene corresponding to GAPDH, house keeping candidate gene in arsenic-treated rat, which might provide anti-oxidative activity in the blood.

Asunto(s)

Antioxidantes/farmacología , Intoxicación por Arsénico/prevención & control , Ácido Ascórbico/farmacología , Estrés Oxidativo/efectos de los fármacos , Animales , Intoxicación por Arsénico/metabolismo , Biomarcadores/sangre , Catalasa/metabolismo , Enfermedad Crónica , Modelos Animales de Enfermedad , Enzimas/sangre , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Linfocitos/química , Linfocitos/efectos de los fármacos , Masculino , Óxido Nítrico/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Regulación hacia Arriba/efectos de los fármacos

RESUMEN

Sodium arsenite-exposed hepatocytes of rat showed higher production of nitric oxide (NO) and increased lipid peroxidation (LPO) level vis-a-vis activity of superoxide dismutase (SOD) and catalase (CAT) were significantly lowered. Subsequently, the cell proliferation index (CPI) and cell viability were also reduced. Treatment with L-ascorbate was found effective in normalizing the arsenic-induced alteration of SOD and CAT activity and LPO level in rat hepatocytes. These observations indicated that L-ascorbate also has potent cytoprotective role as it could reduce the NO production and normalize the cell proliferation and viability of hepatocytes. Therefore, the in vitro study suggested that ascorbic acid is helpful to ameliorate the arsenic-induced cytotoxicity and oxidative stress of rat hepatocytes.

Asunto(s)

Antioxidantes/farmacología , Arsenitos/toxicidad , Ácido Ascórbico/farmacología , Catalasa/antagonistas & inhibidores , Inhibidores Enzimáticos/toxicidad , Estrés Oxidativo/efectos de los fármacos , Compuestos de Sodio/toxicidad , Superóxido Dismutasa/antagonistas & inhibidores , Animales , Intoxicación por Arsénico/tratamiento farmacológico , Catalasa/metabolismo , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Hepatocitos/efectos de los fármacos , Hepatocitos/enzimología , Hepatocitos/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Masculino , Nitritos/análisis , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo , Factores de Tiempo