RESUMO
Hexavalent chromium [Cr(VI)] compounds are extremely toxic and carcinogenic. Despite the vast quantity of reports about Cr(VI) toxicity, the information regarding its effects when it is intraperitoneally (i.p.) administered is still limited. In contrast, it has been shown that curcumin prevents hepatotoxicity induced by a single intraperitoneal injection of 15 mg/kg body weight (b.w.) of potassium dichromate (K2Cr2O7). This study aims to evaluate oxidative stress markers, the activity of antioxidant enzymes, and the potential histological injury in brain, heart, lung, kidney, spleen, pancreas, stomach, and intestine from rats treated with a hepatotoxic dose of K2Cr2O7 (15 mg/kg b.w.), and the effect of curcumin pretreatment. Rats were divided into four groups: control, curcumin, K2Cr2O7, and curcumin+K2Cr2O7. At the end of the treatment, plasma and ascites fluid were collected and target organs were dissected out for biochemical and histological analysis. K2Cr2O7 induced hepatotoxicity but failed to induce in all the other studied organs either oxidative or histological injury, since levels of malondialdehyde (MDA), glutathione (GSH), and the activity of superoxide dismutase (SOD), catalase (CAT), and related GSH enzymes were unchanged. As expected, curcumin was safe. Lack of K2Cr2O7-induced toxicity in those target organs could be due to the following: (1) route of administration, (2) absorption through the portal circulation, (3) lower dose than needed, (4) short time of exposure, or (5) repeated doses are required to produce damage. Thus, the intraperitoneal injection of 15 mg/kg of K2Cr2O7, that is able to induce hepatotoxicity, was unable to induce histological and oxidative damage in other target organs.
Assuntos
Biomarcadores/metabolismo , Curcumina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Dicromato de Potássio/toxicidade , Análise de Variância , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Biomarcadores/sangue , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Catalase/metabolismo , Relação Dose-Resposta a Droga , Mucosa Gástrica/metabolismo , Injeções Intraperitoneais , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Intestinos/patologia , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Malondialdeído/sangue , Malondialdeído/metabolismo , Miocárdio/metabolismo , Miocárdio/patologia , Tamanho do Órgão/efeitos dos fármacos , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Pâncreas/patologia , Dicromato de Potássio/administração & dosagem , Ratos Wistar , Baço/efeitos dos fármacos , Baço/metabolismo , Baço/patologia , Estômago/efeitos dos fármacos , Estômago/patologia , Superóxido Dismutase/metabolismoRESUMO
Se evaluó la capacidad fermentativa de levaduras nativas de la zona costanera del departamento de Córdoba, Colombia, para la obtención de etanol a partir de la pulpa de excedentes de plátano Musa (AAB Simmonds), con el objetivo de encontrar cepas eficientes. Los microorganismos utilizados correspondieron a las especies: Kloeckera sp, Candida guillliermondii 14AD, Candida albicans y Candida guillliermondii 13AD (nativas), y una cepa comercial de referencia, Saccharomyces cerevisiae T73. La fermentación se realizó a diferentes concentraciones de sustrato, siendo la concentración del 40% la mejor; se evaluó la producción de etanol mediante el método colorimétrico del dicromato de potasio utilizando un equipo espectrofotómetro Lambda 11. Se observó que la levadura Candida guilliermondii 14AD nativa fue la más eficiente con una producción promedio de 3,45% v/v de etanol a las 72 horas de fermentación; no se encontraron diferencias estadísticamente significativas con la producción de etanol a partir de la cepa de referencia, la cual produjo 3,59% v/v. Estos resultados sugieren la existencia de levaduras nativas con capacidad para ser utilizadas en la obtención de etanol a partir de material residuo de plátano.
Native yeasts (Cordoba, Colombia) fermentation ability for producing ethanol from plantain (Musa AAB Simmonds) surplus pulp was evaluated; the object was to find efficient yeasts. The microorganisms used here came from the Kloeckera sp, Candida guillliermondii (14AD), Candida albicans and Candida guilllier-mondii 13AD strains (native) and Saccharomyces cerevisiae T73 (a commercial reference yeast). Fermentation was carried out on different substrate concentrations, the 40% one giving the best result; ethanol production was evaluated by the potassium dichromate colorimetric method using a Lambda 11 spectrophotometer. It was observed that the Candida guilliermondii 14AD native yeast was the most efficient, having an average 3.45% v/v ethanol production after 72 hoursâ fermentation. There were no statistically significant differences compared to reference yeast strain ethanol production (3.59% v/v). These results suggest that native yeasts can be used in obtaining ethanol from residual plantain matter.
Assuntos
Dicromato de Potássio/administração & dosagem , Dicromato de Potássio/toxicidade , Leveduras/classificação , Leveduras/enzimologia , Leveduras/química , Nutriente para LevedurasRESUMO
Potassium dichromate was given to female Swiss mice (25 mg/kg per day) orally in water for 1-3 days. Brain homogenates were prepared to evaluate the occurrence of oxidative stress in this organ through the measurement of the antioxidant defense levels. and the extent of lipid peroxidation. In addition, mitochondrial fractions were isolated from brain homogenates to determine the production of reactive oxygen species in this subcellular fraction. The administration of potassium dichromate for 3 days caused increases of 72 and 74% in superoxide dismutase and catalase activities, respectively, in the homogenates. The treatment with this metal for 3 days increased brain homogenate chemiluminescence and thiobarbituric acid-reactive substances by 34 and 29%, respectively. The brain contents of the non-enzymatic antioxidants alpha-tocopherol and sulfhydryl groups decreased by 35 and 32%, respectively. Ascorbic acid levels were not modified by the administration of potassium dichromate. Finally, there was a significant increment in the mitochondrial production of oxidants in the brain of treated mice as compared with controls. These results suggest that chromium(VI) produces an increased formation of reactive oxygen species and brain lipid peroxidation. The increase in the antioxidant enzyme activities reflects an adaptive response against oxidative stress, while the reduction in the levels of non-enzymatic antioxidants might be due to their reaction with reactive oxygen species generated during the metabolism of chromium(VI).