The effect of different polyphenols against neurotoxicity induced by quinolinic acid in U87-MG glial cells

Abstract

Neurodegenerative disorders (ND) are very debilitating aging-related diseases and mitochondrial dysfunction, oxidative stress and nitrosative stress (ONS) have been demonstrated to be associated with its clinical manifestations. Mitochondria stand out as crucial organelles in the interplay between neurodegeneration and neuroinflammation, and polyphenols are promising mitochondria-targeting medicine. Phenolic compounds can regulate mitochondria by means of controlling their redox state, function and apoptosis system. In this work, it was investigated the neuroprotective potential of Araucaria angustifolia (AAE) and Camellia sinensis (GT) extracts and six isolated compounds (resveratrol, gallic acid, ellagic acid, catechin, epicatechin and proanthocyanidins) in a neurodegeneration model using quinolinic acid (QA). U87-MG glial cells were pre-treated with AAE or GT or one of the phenolic compounds for 1 hour and then, exposed to QA for 24 hours. Cells exposed to QA presented decreased viability, exacerbated reactive oxygen species (ROS) generation, reduced the mitochondrial membrane potential, and increased inflammatory response. Despite the similar results found with both GT and AAE, the last one was capable to prevent all the parameters tested in this work. In conclusion, we suggest that AAE could be a potential agent to prevent ND related to mitochondrial dysfunction associated with ONS. [resumo fornecido pelo autor]