Efeitos do ácido clorogênico sobre funções de neutrófilos: estudos in vitro

Abstract

BELINATI, K.D. Effects of chlorogenic acid on neutrophils functions: in vitro studies. 2010. 83 p. Dissertacao (M) [Faculdade de Ciencias Farmaceuticas da Universidade de Sao Paulo, Sao Paulo] Chlorogenic acid (CGA) is the term utilized to design a group of phenolic compounds from the sterification reaction between the hydroxycinnamic acids (p-coumaric, caffeic and ferulic acid) and the quinic acid. They are largely found in natural products and exert anti-oxidant, citoxic, anti-tumoral, anti-bactericidal, anti-fungicidal and anti-inflammatory activity. Besides the description of its anti-inflammatory effect in different experimental models, the literature is scarse regarding its specific actions in neutrophil inflammatory functions. Therefore, the aim of this present work was to investigate the CGA effects on neutrophils functions in vitro. Neutrophils were obtained from the peritoneal lavage of male Wistar rats four hours after a local injection of oyster glycogen 1% and were incubated, in the presence or absence of LPS, with CGA in the concentrations of 25, 50, 100 or 1000 μM. The cellular viability (trypan-blue exclusion), the cytokines secretions (enzyme-linked immunosorbend assay), production of nitric oxide (Greiss reaction); adhesion molecules expression (flow citometry), adherence and chemotaxis in vitro were assessed. The results shows that the CGA did not affect the secretion of the tumor necrosis factor-α , of nitric oxide and prostaglandin E2 and only the incubation with 50μM of CGA inhibited the secretion of Interleukin 1β after stimulation with LPS. Differently, the incubation with CGA inhibited the adherence of neutrophils on the primary culture of endothelial cell from the micro-circulation of rats and the chemotaxis in vitro against formylated peptide (fenyl-metyl-leucyl-alanin). This lasts effects might be associated with the action of CGA on the expression of adhesion molecules, hence this compound was capable of elevate the expression of L-selectin and reduce the expression of β2 integrin and PECAM-1. The data here obtained are not dependent of cellular viability alterations. In conjunct, the data here obtained shows that the CGA has direct effect on neutrophils functions responsible of the interaction with the micro vascular endothelium and the oriented migration in response to an inflammatory stimuli. These effects can contribute, at least in part, to the decreased neutrophil migration in the inflammatory focus in the presence of CGA treatment.