Monocrotaline induces acutely cerebrovascular lesions, astrogliosis and neuronal degeneration associated with behavior changes in rats: A model of vascular damage in perspective.

Pyrrolizidine alkaloids (PAs) are secondary plant metabolites playing an important role as phytotoxins in the plant defense mechanisms and can be present as contaminant in the food of humans and animals. The PA monocrotaline (MCT), one of the major plant derived toxin that affect humans and animals, is present in a high concentration in Crotalaria spp. (Leguminosae) seeds and can induce toxicity after consumption, characterized mainly by hepatotoxicity and pneumotoxicity. However, the effects of the ingestion of MCT in the central nervous system (CNS) are still poorly elucidated. Here we investigated the effects of MCT oral acute administration on the behavior and CNS toxicity in rats. Male adult Wistar were treated with MCT (109 mg/Kg, oral gavage) and three days later the Elevated Pluz Maze test demonstrated that MCT induced an anxiolytic-like effect, without changes in novelty habituation and in operational and spatial memory profiles. Histopathology revealed that the brain of MCT-intoxicated animals presented hyperemic vascular structures in the hippocampus, parahippocampal cortex and neocortex, mild perivascular edema in the neocortex, hemorrhagic focal area in the brain stem, hemorrhage and edema in the thalamus. MCT also induced neurotoxicity in the cortex and hippocampus, as revealed by Fluoro Jade-B and Cresyl Violet staining, as well astrocyte reactivity, revealed by immunocytochemistry for glial fibrillary acidic protein. Additionally, it was demonstrated by RT-qPCR that MCT induced up-regulation on mRNA expression of neuroinflammatory mediator, especially IL1ß and CCL2 in the hippocampus and cortex, and down-regulation on mRNA expression of neurotrophins HGDF and BDNF in the cortex. Together, these results demonstrate that the ingestion of MCT induces cerebrovascular lesions and toxicity to neurons that are associated to astroglial cell response and neuroinflammation in the cortex and hippocampus of rats, highlighting CNS damages after acute intoxication, also putting in perspective it uses as a model for cerebrovascular damage.

Amburana cearensis seed extracts protect PC-12 cells against toxicity induced by glutamate

ABSTRACT Amburana cearensis (Allemão) A.C. Sm., Fabaceae, has been widely studied for its medicinal activities. Many neurodegenerative disorders are caused by oxidative stress, mitochondrial dysfunction, excitotoxicity induced by glutamate and ultimately cell death. This study describes the chemical profile of the ethanolic, hexane, dichloromethane, and ethyl acetate extracts obtained from seeds of A. cearensis. The objective of this study was to investigate the chemical profile of extracts obtained from seeds of A. cearensis, as well as their cytotoxicity and neuroprotective effects in cultures of neural PC12 cells. Metabolite profile was performed by GC–MS. PC12 cells were treated with increasing concentrations of the extracts (0.01–2000 µg/ml) and the cell viability was analyzed after 24 and 72 h using an MTT test. For the excitotoxicity assay, PC12 cells were pre-treated with glutamate (1 mM) for 6 h and treated with increasing concentrations (0.1–1000 µg/ml) of the extracts. The chromatographic analysis of the extracts detected various compounds with antioxidant properties, with the majority of peaks corresponding to the isoflavone coumarin. Only the hexane extract showed toxicity after 72 h exposure at the highest concentration (1000 µg/ml). By contrast, all extracts increased the cellular viability of PC12 cells against the toxicity caused by glutamate. Therefore, the extracts from the seeds of A. cearensis showed no toxicity and have neuroprotective potential against neuronal damage induced by glutamate, which may be related to their antioxidant properties.