Avaliação do potencial antioxidante de derivados triazólicos inibidores da acetilcolinesterase em células de Saccharomyces cerevisiae

Abstract

Alzheimer's Disease (AD) is a progressive neurodegenerative disease known for memory loss and difficulty with language. It is formed by pathological factors, among which the cholinergic deficit and oxidative stress stand out. Oxidative stress is characterized by the imbalance between the generation of free radicals and/or non-radical reactive species and the action of antioxidant defense systems. Currently, the primary treatment for Alzheimer's disease is the use of inhibitors of cholinesterase enzymes. However, due to the multifactorial nature of the disease and the fact that many drug candidates have not been successful, a new approach has emerged, the so-called “multi-target” compounds. Therefore, this work evaluated the antioxidant protection of four new compounds containing the core 3-amino-1,2,4-triazole-N-1,5-trisubstituted cholinesterase inhibitors in two strains of Saccharomyces cerevisiae (BY4741 and ∆gsh1) with oxidative stress induced by hydrogen peroxide. The toxicity of the compounds was initially analyzed through the semi-qualitative assay with resazurin and cell growth curves. Antioxidant assays were TBARS and intracellular oxidation by 2,7'- dichlorofluorescein. In the resazurin assay, there was no toxicity of the compounds in the two strains at concentrations below 250 μM. The growth curves confirmed this non-toxicity in the concentration of 20 μM of the compounds for 24h. In strain BY4741 all compounds reduced MDA levels between 30-40%, however in strain ∆gsh1 only compounds containing phenolic substituents were active (25%). In the evaluation of protection to the intracellular environment, only in the ∆gsh1 strain in the fermentative phase of growth, there was a significant reduction of oxidant species promoted by the compounds, with emphasis on the compound with nitro substituent (27%). In the oxygen consumption test, it was not possible to conclude the mitochondrial protection capacity of the substances, as there was no statistical difference between treatments, in both strains. The results demonstrated that triazoles were not toxic and provided antioxidant protection even in the absence of glutathione in S. cerevisiae cells.