Efeito do tratamento com nanopartículas de ouro sobre o estresse oxidativo vascular induzido por diquat.

Abstract

Poisoning with pesticides or pesticides is extremely common and, depending on the type or time of exposure, can lead to death within a few hours. It is known that circulatory collapse is a common event resulting from poisoning with various pesticides. Most studies correlate vascular dysfunctions with organophosphate poisoning. In Brazil, a new pesticide, diquat, was approved by ANVISA to replace paraquat, both non-selective contact herbicides. Although much is known about the toxicity mechanisms of paraquat, little or nothing is known about the mechanisms of action of diquat in humans. Nor are there any known effective antidotes or therapies to reverse such effects. Nanotechnology has been identified as an important weapon for combating diseases whose basis is oxidative stress or inflammation. For these reasons, the present study aims to evaluate the effects of ex vivo and in vitro exposure of arteries and endothelial cells exposed to diquat (DQ), as well as the potential preventive benefits of treatment with gold nanoparticles (GNP). Our vascular reactivity data clearly showed that DQ induced vascular dysfunction characterized by increased contractile response to phenylephrine and reduced relaxing response to acetylcholine. The mechanism of vascular dysfunction involves increased production of reactive oxygen species (ROS), as measured by fluorescence microscopy in sections of aorta and endothelial cells, and possible production of peroxynitrite, as there is also increased production of NO. Treatment with GNP prevents vascular dysfunction caused by DQ, mainly by negatively regulating the production of ROS.