RESUMO
Agathisflavone, purified from Cenostigma pyramidale (Tul.) has been shown to be neuroprotective in in vitro models of glutamate-induced excitotoxicity and inflammatory damage. However, the potential role of microglial regulation by agathisflavone in these neuroprotective effects is unclear. Here we investigated the effects of agathisflavone in microglia submitted to inflammatory stimulus in view of elucidating mechanisms of neuroprotection. Microglia isolated from cortices of newborn Wistar rats were exposed to Escherichia coli lipopolysaccharide (LPS, 1 µg/mL) and treated or not with agathisflavone (1 µM). Neuronal PC12 cells were exposed to a conditioned medium from microglia (MCM) treated or not with agathisflavone. We observed that LPS induced microglia to assume an activated inflammatory state (increased CD68, more rounded/amoeboid phenotype). However, most microglia exposed to LPS and agathisflavone, presented an anti-inflammatory profile (increased CD206 and branched-phenotype), associated with the reduction in NO, GSH mRNA for NRLP3 inflammasome, IL1-ß, IL-6, IL-18, TNF, CCL5, and CCL2. Molecular docking also showed that agathisflavone bound at the NLRP3 NACTH inhibitory domain. Moreover, in PC12 cell cultures exposed to the MCM previously treated with the flavonoid most cells preserved neurites and increased expression of ß-tubulin III. Thus, these data reinforce the anti-inflammatory activity and the neuroprotective effect of agathisflavone, effects associated with the control of NLRP3 inflammasome, standing out it as a promising molecule for the treatment or prevention of neurodegenerative diseases.
RESUMO
Corn silk has been widely used as a nutritional and medicinal supplement due to its pharmacological properties, but there is a lack of studies that correlate the extracts' chemical composition with their biological activities. Herein, we performed the large-scale chemical characterization of corn silk extracts and used chemometrics to correlate the chemical composition with the biological activities of the extracts. Twenty-two metabolites were identified by High-Performance Liquid Chromatography coupled to Mass Spectrometry (HPLC-MS), whereas twelve were identified by Gas Chromatography coupled to Mass Spectrometry (GC-MS). Chemometrics allowed us to discriminate extracts obtained in different organic solvents from in natura and commercial product samples and to pinpoint potential candidate metabolites for the antioxidant and anti-glioma activities. Two flavone glycosides (7 and 8), along with a O-methylated anthocyanidin (26) seems to be the main contributors for the biological activities of the corn silk extracts.
Assuntos
Extratos Vegetais , Zea mays , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Metabolômica , SedaRESUMO
Astrocytic tumour cells derived from human (GL-15) and rat (C6) gliomas, as well as non-tumoural astrocytic cells, were exposed to the saponin-rich fraction (SF) from Agave sisalana waste and the cytotoxic effects were evaluated. Cytotoxicity assays revealed a reduction of cell viability that was more intensive in glioma than in non-tumoural cells. The SF induced morphological changes in C6 cells. They were characterised by cytoplasmic vacuole formation associated with increase in the formation of acidic lysosomes. The SF was subjected to purification on Sephadex LH-20, which characterised three probable steroidal saponins (sisalins) by electrospray ionisation mass spectrometry multistage (ESI-MSn). Sisalins from sisal may be responsible for the cytotoxicity, which involves cytoplasmatic vacuole formation and selective action for glioma cells.