Toxicity and oxidative stress of canine mesenchymal stromal cells from adipose tissue in different culture passages / Toxicidade e estresse oxidativo das células mesenquimais estromais do tecido adiposo de cão em diferentes passagens de cultura

Stem cells in regenerative therapy have received attention from researchers in recent decades. The culture of these cells allows studies about their behavior and metabolism. Thus, cell culture is the basis for cell therapy and tissue engineering researches. A major concern regarding the use of cultivated stem cell in human or veterinary clinical routine is the risk of carcinogenesis. Cellular activities require a balanced redox state. However, when there is an imbalance in this state, oxidative stress occurs. Oxidative stress contributes to cytotoxicity, which may result in cell death or genomic alterations, favoring the development of cancer cells. The aim of this study was to determine whether there are differences in the behavior of cultured mesenchymal stem cells from canine adipose tissue according to its site of collection (omentum and subcutaneous) evaluating the rate of proliferation, viability, level of oxidative stress and cytotoxicity over six passages. For this experiment, two samples of adipose tissue from subcutaneous and omentum where taken from a female dog corpse, 13 years old, Pitbull. The results showed greater levels of oxidative stress in the first and last passages of both groups, favoring cytotoxicity and cell death.(AU)

O uso de células-tronco como terapia regenerativa tem recebido atenção de pesquisadores nas últimas décadas. A possibilidade de cultivá-las permite o estudo de seu comportamento e metabolismo. Assim, o cultivo celular representa a base para pesquisas de terapia celular e engenharia de tecidos. Uma das principais preocupações relativa ao uso de células-tronco cultivas na rotina clínica humana ou veterinária é a reprogramação dessas células em tumores benignos ou malignos. As atividades celulares necessitam de um estado redox balanceado e quando há algum desequilíbrio nessas reações ocorre o estresse oxidativo. O quadro de estresse oxidativo contribui pra a citotoxicidade podendo resultar em morte celular e até mesmo em alterações genômicas e ocorrência de células cancerígenas. O objetivo deste trabalho foi verificar se há diferenças no comportamento de células-tronco mesenquimais estromais de tecido adiposo de cão de acordo com o seu tecido de coleta (omento e subcutâneo) avaliando o cultivo dessas células quanto a sua taxa de proliferação, viabilidade, estresse oxidativo e citotoxicidade ao longo de seis passagens. Para a execução deste experimento foram utilizadas duas amostras de tecido adiposo coletas do subcutâneo e omento do cadáver de um cão, fêmea, 13 anos de idade, da raça Pitbull. O cadáver era oriundo do Hospital Veterinário Universitário e sofreu eutanásia devido a complicações no seu quadro de cardiomiopatia. As duas amostras foram encaminhadas para o isolamento e cultura celular. Os resultados mostraram que a primeira e última passagem em ambos os grupos são as passagens mais submetidas ao estresse oxidativo ficando mais sujeitas à citotoxicidade.(AU)

Influencia del hábito de fumar sobre las concentraciones séricas de zinc, cobre y selenio en adultos jóvenes / Influence of smoking on serum concentrations of zinc, copper and selenium in young adults

Zinc, cobre y selenio son cofactores de enzimas antioxidantes, por lo que una disminución de sus niveles séricos, compromete su papel preventivo de enfermedades degenerativas. En este estudio se planteó evaluar la influencia del hábito de fumar cigarrillo sobre las concentraciones séricas de estos cofactores en adultos jóvenes. La muestra estuvo conformada por 40 individuos sanos del sexo masculino, con edades entre 18 y 25 años, índice de masa corporal normal y consumo de nutrientes acorde con sus requerimientos nutricionales, divididos en grupo control (n=20) y grupo de fumadores crónicos (n=20), a los cuales se les cuantificó los niveles séricos de zinc, cobre, selenio y se les estimó la ingesta de nutrientes a través del recordatorio de 24 horas y la frecuencia de consumo de alimentos. En los fumadores los niveles séricos de zinc se mostraron severamente disminuidos (0,36 + 0,10 mg/L) y significativamente inferiores a los encontrados en los controles (0,71 + 0,09 mg/L), mientras que los niveles sérico de cobre y selenio no mostraron diferencia significativa. Los resultados indican que aún cuando el consumo de minerales en los fumadores fue adecuado, la dieta habitual no logró mantener la concentración sérica de zinc en los rangos normales, haciéndolos más susceptibles al estrés oxidativo.

Relationship between Pulmonary Surfactant Protein and Lipid Peroxidation in Lung Injury due to Paraquat Intoxication in Rats

BACKGROUND: Pulmonary damage resulting from lipid peroxidation is a principal effect of paraquat intoxication. The host-defense functions of surfactant are known to be mediated by the surfactant proteins A and D (SP-A and SP-D, respectively). The primary objective of this study was to evaluate the variations over time in levels of surfactant protein and lipid peroxidation (LPO) in lung tissue following free-radical-induced injury. METHODS: 42 adult, male, Sprague-Dawley rats were administered intraperitoneal injections of paraquat (35 mg/kg body weight). SP-A and SP-D levels were determined via Western blot. LPO in the left lung homogenate was measured via analyses of the levels of thiobarbituric acid-reactive substances. RESULTS: LPO levels peaked at 6 hours, with no associated histological changes. SP-D levels increased until hour 12 and declined until hour 48; SP-D levels subsequently began to increase again, peaking at hour 72. SP-A levels peaked at hour 6, declining thereafter. CONCLUSIONS: We suggest that in the early phase of paraquat injury, SP-D levels reflect alveolar damage and that de novo synthesis of SP-D takes 72 hours. Levels of SP-A, on the other hand, reflect abnormalities in the surfactant system in the late stage of paraquat intoxication. Surfactant proteins may play a role in protecting the lungs from reactive oxygen injury. A time-dependent variation has been observed in the levels of surfactant proteins A and D following paraquat injury, and it has been suggested that these proteins play a role in the protection of lung tissue against ROS-induced injuries.

Antimutagenic and antioxidant/prooxidant activity of quercetin.

The present study has been performed to evaluate the antimutagenic activity of quercetin, ascorbic acid and their combination against an oxidative mutagen. An effort was also made to correlate this activity to the in vitro antioxidant activity of these agents. Antimutagenicity testing was done in Ames Salmonella Assay system using Salmonella typhimurium TA102 against t-butylhydroperoxide as an oxidative mutagen. In vitro antioxidant scavenging activity was tested for DPPH free radical, superoxide anion, hydrogen peroxide and hydroxyl radical in their specific test systems. Quercetin (0.5-8 nmole/plate) and ascorbic acid (0.1-100 micromole/plate) showed significant effect. Quercetin (4 and 8 nmole/plate) when combined with ascorbic acid (500 nmole/plate) showed an increase in the antimutagenic activity. In vitro antioxidant activity of quercetin was better than ascorbic acid in all the test systems used. The study indicated that the antimutagenic activity of quercetin was not solely accountable by its antioxidant nature. However, in vitro free radical scavenging activity of quercetin correlated well with the antimutagenic activity.

Efecto oxidativo de la sobrecarga hepática de cobre / Oxidative effect of hepatic copper overload

A efectos de evaluar la citoxicidad de la excesiva producción de radicales libres en hígado, se estudió la lipoperoxidación en estructuras subcelulares y el estado de algunos componentes de los sistemas antioxidantes. Con tal fin se indujo la generación de radicales libres mediante la sobrecarga hepática de cobre y se determinaron los niveles de compuestos reactivos al ácido tiobarbitúrico en homogenatos y fracciones subcelulares de hepatocitos, la actividad de la enzima Cu-Zn superoxido dismutase (Cu-Zn-SOD) y la concentración de glutatión reducido (GSH). Ratas Wistar hembras, fueron dosificados con 0,2 por ciento de CuSO4 en el agua a fin de inducir la sobrecarga hepática de cobre. En suero se determinaron los niveles de cobre y la actividad de la fosfatasa ácida. En la semana doce de iniciado el ensayo, seis ratas dosificadas con CuSO4 fueron sacrificadas, junto con tres controles. Otras seis ratas del grupo dosificado fueron sacrificadas en la semana 16, momento de incremento de la actividad sérica de la fosfatase ácida, junto con tres ratas del grupo control. Se observó un alto contenido de cobre en los hígados provenientes de las ratas tratadas y evidencia de peroxidación de lfpidos en homogenatos y fracciones subcelulares. Esto fue vinculado con un incremento en la actividad de la Cu-Zn-SOD y con disminución de los niveles de GSH. Puede ser argumentado que los altos niveles de cobre inducirfan a un incremento en la actividad de la Cu-Zn-SOD y a una disminución de la concentración de GSH. Adicionalmente, en este trabajo ha sido evidenciado que la sobrecarga hepática de cobre promueve la peroxidación de lípidos.

study of free radical injury to vital organs

The study of toxicities which are caused by free radical inducing chemicals [e.g., carbon tetrachloride], helps to determine the mode of action of those important drugs which act by inhibiting free radicals. Evaluation of toxicities induced by carbon tetrachlonde and phenobarbitone administration was carried out in seventy healthy male rabbits. Each animal received CCL4 0.25-0.5 mL/kg body weight, intraperitoneally, twice weekly for eleven doses. During this period, the only water which was provided for drinking to these animals contained 0.25 g/L pentobarbitone. Examination of these animals revealed that carbon tetrachloride produced severe liver and kidney injuries which could be assessed by physical parameters, liver and kidney function tests, and microscopic examinations of the vital organs of these animals