Estudo do potencial antioxidante do carvacrol em modelos experimentais in vitro

Abstract

Carvacrol has demonstrated, among several bioactive effects, antimicrobial, anti-inflammatory, antidepressive and antioxidant action. Moreover, carvacrol has been used as a food additive and is present in spices widely used in human food, such as oregano (Origanum vulgare), cumin (Carum carvi) and thyme (Thymus vulgaris), among others. H2O2 is a product generated physiologically in several reactions and acts as a signaler in mammalian cells. Increased H2O2 production induces redox dysfunction in animal cells, including neurons and glial cells in the central nervous system (CNS). The CNS presents increased susceptibility to pro-oxidants due to its high O2 consumption, low antioxidant defense and high lipid concentration. Thus, this study aimed to investigate the redox activity of carvacrol in a lipid system and in CNS cells. Two in vitro experimental models were applied, being a lipid system composed of egg yolk homogenate, in which the protection against lipid peroxidation induced by H2O2 was analyzed and a culture of dopaminergic cells SH-SY5Y, where the effects of pre-treatment with carvacrol against the action of H2O2 on cell viability, reactive oxygen species (ROS) production, lipid peroxidation and protein carbonylation were analyzed. In the lipid system, all concentrations of carvacrol tested, 10 μM, 100 μM, 500 μM and 1000 μM, were protective against the action of H2O2. But in cell culture only the concentration of 100 μM was able to attenuate oxidative stress and reduction of cell viability, whereas the concentration of 10 μM was not effective and the concentrations above 500 μM of carvacrol were cytotoxic even in the absence of H2O2. The results of the ROS production, lipid peroxidation and protein carbonylation tests with the 100 μM solution of carvacrol demonstrate that the increase in cell viability caused by this solution is related to the reduction of oxidative stress.