Estudo do efeito do galato de metila na atividade de neutrófilos in vivo e in vitro

Abstract

Neutrophils are polymorphonuclear cells of myeloid origin that are extremely important for the effectiveness of innate immunity. They are the most abundant leukocytes in the blood circulation and, in inflamed tissue, produce reactive oxygen species (ROS), neutrophil extracellular traps (NETs), and granules rich in enzymes, which can be either pro-inflammatory or pro-resolving. In this context, approaches that regulate the accumulation and activity of these cells are relevant. Methyl gallate (MG), a phenolic acid derivative found in plant species, has anti-inflammatory activity. Therefore, this study evaluated the effect of methyl gallate on human neutrophil activity in vitro and on inflammation in an animal model. Human neutrophils were analyzed regarding migration and chemotaxis, the release of ROS and extracellular traps, and the process of apoptosis. The expression of the adhesion molecule CD11b and the accumulation of circulating leukocytes in the thoracic cavity of mice after induction of pleurisy with LPS were also evaluated. Our results showed that MG inhibited migration and chemotaxis in neutrophils stimulated with IL-8 and fMLP, as well as inhibiting the polymerization of actin filaments in neutrophils stimulated with IL-8. MG reduced ROS production in neutrophils stimulated with PMA and LPS and dose-dependently reduced the release of extracellular traps from neutrophils stimulated with PMA. In LPS-induced pleurisy, pre-treatment with MG inhibited the accumulation of neutrophils in the thoracic cavity, as well as reducing circulating neutrophils and the expression of the adhesion molecule CD11b. We conclude from this study that MG modulates neutrophil activity both in vitro and in vivo.