ABSTRACT
Whole plants of Eichhornia crassipes and Pistia stratiotes were exposed to various concentrations (0, 0.1, 0.3, 0.5, 1.0, 3.0 and 5.0 mM) of 8 heavy metals (Ag, Cd, Cr, Cu, Hg, Ni, Pb and Zn) hydroponically for 21 days. Spectrometric assays for the total activity of catalase, peroxidase, and superoxide dismutase in the leaves were studied. At the end of the experimental period, data referred to metal treated plants were compared to data of untreated ones (control). Heavy metals increased the activity of catalase, peroxidase and superoxide dismutase in both species and there was differential inducement among metals. Overall, Zn had the least inducement of antioxidant enzymes in both species while Hg had the highest inducement. The increase in antioxidant enzymes in relation to the control plants was more in E. crassipes than P. stratiotes. The results showed that E. crassipes tolerated higher metal concentrations in a greater number of metals than P. stratiotes. Rev. Biol. Trop. 55 (3-4): 815-823. Epub 2007 December, 28.
Plantas completas de Eichhornia crassipes y Pistia stratiotes fueron expuestas a varias concentraciones (0, 0.1, 0.3, 0.5, 1.0, 3.0 and 5.0 mM) de metales pesados (Ag, Cd, Cr, Cu, Hg, Ni, Pb and Zn) utilizando hidroponía, por 21 días. Se realizaron análisis espectrométricos en las hojas para determinar la actividad total de la catalasa, peroxidasa y dismutasa superóxida. Al final del periodo experimental, se comparó con plantas no tratadas (control). Los metales pesados incrementan la actividad de la catalasa, peroxidasa y la dismutasa superóxida para ambas especies y hay diferencias entre los metales. El Zn produce el menor estímulo para enzimas antioxidantes en ambas especies; Hg produce el mayor estímulo. El incremento de las enzimas antioxidantes en relación con las plantas control fue mayor en E. crassipes que P. stratiotes. E. crassipes tolera altas concentraciones de metal en un gran número de ellos, mientras que la tolerancia en P. stratiotes es menor.
Subject(s)
Araceae/drug effects , Eichhornia/drug effects , Metals, Heavy/pharmacology , Oxidoreductases/drug effects , Araceae/enzymology , Catalase/drug effects , Eichhornia/enzymology , Peroxidase/drug effects , Plant Leaves/drug effects , Plant Leaves/enzymology , Superoxide Dismutase/drug effectsABSTRACT
En el presente trabajo se estudió el efecto de la administración intramuscular de 30.000, 50.000 y 100.000 UI de palmitato de vitamina A/día, durante 7 días, respectivamente, sobre la actividad enzimática hepática en 45 ratas Wistar machos, de 12 semanas de edad, con pesos entre 180 y 200 gramos. El grupo control estuvo integrado por 15 ratas Wistar sanas, con género, edad y peso similares a los animales tratados. El consumo de alimentos y de agua, y el peso de las ratas se determinó al finalizar el período experimental. Las ratas se examinaron en busca de manifestaciones clínicas de toxicidad. Al final el estudio, las ratas se sacrificaron bajo anestesia con éter y se tomaron muestras de tejido hepático para la determinación de la actividad enzimática. La administración de vitamina A en exceso incrementó de manera significativa (p menor que 0,05) el contenido hepático del retinol, determinó diversos y variados signos clínicos (tales como: anorexia, pérdida de peso, alopecia, conjuntivitis, hemorragias internas y externas, alteraciones cutáneas y muerte de los animales) e incrementó (p menor que 0,05) la actividad de las siguientes enzimas: alanina aminotransferasa, aspartato aminotransferasa, maltasa ácida (alfa-1,4-glucosidasa ácida), proteasas ácidas, lactato dehidrogenasa y fosfatasa alcalina mientras que las actividades de la glucosa-6-fosfatasa, glucógeno fosforilasa, alfa-amilasa, colinesterasa y arginasa disminuyeron (p menor que 0,05) al comparar con los controles no tratados. Estos cambios son proporcionales a las dosis inyectadas de vitamina A. En conclusión, nuestros resultados proporcionan evidencias que la administración de dosis altas de vitamina A a corto plazo determina diversos y variados signos clínicos y produce una marcada alteración de la actividad enzimática hepática.
In the present work the effect of intramuscular administration of 30.000, 50.000 and 100.000 IU of vitamin A palmitate daily for seven days, respectively, on the liver enzyme activity in 45 white male Wistar rats, aged 12 weeks and weighing 180-200 g, have been studied. The group control was integrated by 15 healthy rats with similar characteristics (strain, gender, age and weight) to treated animals. Food and water consumption and body weights were recorded at the end of the experimental period. Rats were observed for clinical signs of toxicity. At the end of the study, rats were sacrificed under ether anesthesia. Liver samples were taken for the determination of enzyme activity. Administration of excess of vitamin A produced a significant (p menor 0.05) increase in the content of liver vitamin A, determined diverse and variable clinical signs (such as, anorexia, loss of body weight, alopecia, conjunctivitis, external and internal hemorrhages, skin abnormalities and death) and increased (p menor que 0.05) the activity of the following enzymes: alanine aminotransferase, aspartate aminotransferase, acid maltase (acid alfa-1,4-glucosidase), acid proteases, lactate dehydrogenase and alkaline phosphatase while glucose-6-phosphatase, glycogen phosphorylase, alfa-amylase, cholinesterase and arginase decreased (p menor que 0.05) as compared with untreated controls. These changes depend on the doses given of vitamin A. In conclusion, our results provide evidence that short-term administration of high doses of vitamin A determined diverse and variable clinical signs and produces a marked alteration of activity of liver enzymes.
Subject(s)
Animals , Male , Rats , Antioxidants/administration & dosage , Hydrolases/drug effects , Hypervitaminosis A/enzymology , Liver/enzymology , Oxidoreductases/drug effects , Transferases/drug effects , Vitamin A/administration & dosage , Vitamin A/analogs & derivatives , Acute Disease , Antioxidants/pharmacology , Hydrolases/analysis , Injections, Intramuscular , Liver/drug effects , Oxidoreductases/analysis , Rats, Wistar , Transferases/analysis , Vitamin A/pharmacologyABSTRACT
The schistosomicidal properties of Nigella sativaseeds were tested in vitro against Schistosoma mansoni miracidia, cercariae, and adult worms. Results indicate its strong biocidal effects against all stages of the parasite and also showed an inhibitory effect on egg-laying of adult female worms. In the present work we also studied the effects of crushed seeds on some antioxidant enzymes; which have a role in protection of adult worms against host oxidant killing; as well as some enzymes of glucose metabolism; which have a crucial role in the survival of adult worms inside their hosts. The data revealed that the used drug induce an oxidative stress against adult worms which indicated by a decrease in the activities of both antioxidant enzymes, superoxide dismutase, glutathione peroxidase, and glutathione reductase and enzymes of glucose metabolism, hexokinase and glucose-6-phosphate dehydrogenase. Disturbing of such enzymes of adult worms using N. sativa seeds could in turn render the parasite vulnerable to damage by the host and may play a role in the antischistosomal potency of the used drug.
Subject(s)
Animals , Female , Nigella , Oxidoreductases/drug effects , Seeds , Schistosoma mansoni/drug effects , Schistosomicides/pharmacology , Schistosoma mansoni/enzymology , Schistosoma mansoni/growth & developmentABSTRACT
El surgimiento de resistencia en poblaciones de insectos es uno de los efectos indeseables asociados al uso de insecticidas, y es un buen ejemplo del modo en que ocurren los procesos microevolutivos. En 1908 se documentó por primera vez la existencia de insectos resistentes a insecticidas. Ahora se conocen casos de resistencia en más de 500 especies de artrópodos. Los principales mecanismos que confieren resistencia a insecticidas son penetración cuticular reducida, metabolismo degradativo aumentado y reducción en la susceptibilidad de los sitios de acción. Los métodos de la biología molecular permiten identificar las bases moleculares de esos mecanismos. El propósito de este artículo es reseñar el conocimiento disponible acerca de la biología molecular de la resistencia a insecticidas: mutaciones puntuales en genes de acetilcolinesterasa (Drosophila melanogaster) y del receptor de GABA (varias especies), inserciones en genes de transferasas (D. melanogaster) y del citocromo P450 (D. melanogaster), amplificación de genes de esterasas (Myzus persicae y Culex pipiens / quinquefasciatus complex), cambios que afectan la expresión del gen del citocromo P450 (Musca domestica), y una mutación ligada al gen del canal de sodio dependiente de voltaje (M. domestica)
Subject(s)
Insecticide Resistance/genetics , Insecticides/adverse effects , Insecta/drug effects , Pest Control/standards , Acetylcholinesterase/drug effects , Acetylcholinesterase/genetics , Aedes/drug effects , Culicidae/drug effects , Cytochrome P-450 Enzyme System/drug effects , Cytochrome P-450 Enzyme System/genetics , Drosophila melanogaster/drug effects , Esterases/drug effects , Esterases/genetics , Insect Control/standards , Insect Control/trends , Insecticides/classification , Houseflies , Oxidoreductases/drug effects , Oxidoreductases/genetics , Receptors, GABA/drug effects , Receptors, GABA/genetics , Transferases/drug effects , Transferases/geneticsABSTRACT
The effect of alpha-tocopherol pretreatment on lipid peroxidation and antioxidant status in isoproterenol induced myocardial infarction was studied in rats. Isoproterenol administered rats showed a significant increase in lipid peroxides in serum, heart and aorta. A significant increase in serum iron level with a significant decrease in iron binding capacity was also observed. The levels of antioxidants such as ceruloplasmin, glutathione and the activities of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase decreased significantly in isoproterenol administered rats when compared to control. The activity of Na+K+ATPase decreased significantly and the activity of Ca2+ATPase increased significantly in heart and aorta of isoproterenol administered rats. alpha-tocopherol pretreated rats maintained the levels of antioxidants, membrane bound enzymes and activities of antioxidant enzymes near normal, on isoproterenol administration, thus establishing its effect as an antioxidant.