RESUMO A Portulaca oleracea L. (Portulacaceae) é uma espécie cosmopolita com uma vasta gama de atividades biológicas, incluindo as ações antioxidante e neuroprotetora. No presente trabalho foram investigados os efeitos do tratamento com extratos de P. oleracea em modelo animal (aplicação de 6-hidroxidopamina) para estudo da doença de Parkinson, uma desordem debilitante para a qual não há tratamentos efetivos. Os perfis químicos do extrato aquoso e etanólico obtidos a partir de todas as partes da planta foram analisados por cromatografia em camada delgada e a atividade antioxidante foi avaliada pelo método de 2,2-difenil-1-picrilhidrazil (DPPH). Ratos Wistar machos receberam aplicação intraestrial de 6-hidroxidopamina e foram tratados com veículo ou com os extratos (por via oral, 200 e 400 mg/kg) diariamente durante duas semanas. O teste comportamental de campo aberto foi realizado nos dias 1 e 15. A análise imunohistoquímica foi realizada 4 semanas depois da cirurgia a fim de quantificar as células positivamente marcadas para a enzima tirosina-hidroxilase na substância negra compacta. Os extratos apresentaram atividade antioxidante em concentrações superiores a 300 µg/kg. A análise cromatográfica revelou a presença de levodopa, alcalóides, flavonóides, saponinas, taninos, terpenóides e polissacáridos. Ambos os extratos promoveram recuperação da função motora 15 dias após a lesão e protegeram contra a perda de neurônios positivos para a tirosina-hidroxilase depois de 4 semanas, mas estes efeitos foram mais evidentes para o extrato aquoso. Considerando a presença no precursor dopaminérgico e de compostos com ação antioxidante e neuroprotetora nos extratos, a P. oleracea pode representar uma potencial alternativa para o tratamento da doença de Parkinson.

ABSTRACT The Portulaca oleracea L. (Portulacaceae) is a cosmopolitan species with a wide range of biological activities, including antioxidant and neuroprotective actions. We investigated the effects of P. oleracea extracts in a 6-hydroxydopamine rat model of Parkinson's disease, a debilitating disorder without effective treatments. Chemical profiles of aqueous and ethanolic extracts of whole plant were analyzed by thin layer chromatography and the antioxidant activity was assessed by 2,2-diphenyl-1-picrilhidrazila method. Male Wistar rats received intrastriatal 6-hydroxydopamine and were treated with vehicle or extracts (oral, 200 and 400 mg/kg) daily for two weeks. The behavioral open field test was conducted at days 1 and 15. Immunohistochemical analysis was performed 4 weeks after surgery to quantify tyrosine-hydroxylase cell counts in the substantia nigra pars compacta. Extracts presented antioxidant activity in concentrations above 300 µg/kg. The chromatographic analysis revealed the presence of Levodopa, alkaloids, flavonoids, saponins, tannins, terpenoids and polysaccharides. Both extracts improved motor recovery 15 days after lesion and protected from tyrosine-hydroxylase cell loss after 4 weeks, but these effects were more evident for the aqueous extract. Because the dopamine precursor is present, in addition to antioxidant compounds and neuroprotective effects, P. oleracea can be considered as potential strategy for treating Parkinson's disease.

Lead is one of the heavy metals most used in industry. Poisoning due to long-term lead exposure is known as saturnism, and is an occupational illness that has been known for many years. Lead is highly toxic and can compromise the structural and functional patterns of organs and systems. The aim of this study was to examine the lungs and kidneys of fetuses from female Wistar rats exposed to lead acetate. In this study, the lungs and kidneys of 20 fetuses from female rats that had previously been treated with lead acetate were dissected, fixed, embedded in paraffin and stained with hematoxylin and eosin. Macroscopic changes to the shape, color and consistency of organs from fetuses treated with this heavy metal were observed, in comparison with organs from control fetuses. Microscopic lesions characterized by vascular sclerosis, cell atrophy or hyperplasia, progressive interstitial fibrosis, inclusion bodies containing lead acetate and glomerular sclerosis were found in the kidneys. The lesions found in the lungs consisted of destructuring of the parenchyma, impregnation with lead acetate, formation of fibrosis, extravasation of vascular fluids, reduction of the alveolar spaces and formation of alveolar edema. These changes were correlated with the level of lead acetate absorption, as determined using atomic spectrophotometry.

El plomo es un metal pesado utilizado en la industria. El envenenamiento debido a la exposición prolongada por plomo es una enfermedad profesional conocida por muchos años. La toxicidad del plomo es muy expresiva y puede poner en peligro el modelo estructural y funcional de los órganos y sistemas. El objetivo de este estudio fue examinar los pulmones y riñones de fetos de ratas Wistar expuestos al acetato de plomo. En este estudio, 20 fetos de ratas Wistar previamente tratados con acetato de plomo durante la gestación, tuvieron sus órganos disecados, fijados, incluidos en parafina y teñidos con hematoxilina y eosina. Macroscópicamente, los órganos fetales tratados por este metal fueron comparados con los órganos de fetos controles en relación a forma, color y consistencia. Microscópicamente, se encontraron lesiones en el riñón que se caracterizaron por esclerosis vascular, atrofia o hiperplasia de células, fibrosis intersticial progresiva, presencia de cuerpos de inclusión que contenían acetato de plomo y esclerosis glomerular. En el pulmón se observó desorganización del parénquima impregnado con acetato de plomo, formación de fibrosis, líquido intersticial, reducción de los espacios alveolares y edema alveolar. Estos cambios se correlacionaron con el nivel de absorción de acetato de plomo, determinado por espectrometría atómica.