Atividade anti-inflamatória de novos compostos sintéticos da classe dos Nitroestirenos

Abstract

Inflammation is a physiological process that begins in response to infection or tissue damage. It is a mechanism focusing on tissue repair after injury and consists of a cascade of cellular and microvascular events that aims to remove damaged tissue and generation of new ones. In this cascade is observed an increasing in microvascular permeability, followed by adhesion and cell infiltration at the site of injury, apoptosis, and growth of new tissue and blood vessels. The nitrostyrene is a group of compounds consisting of an aromatic ring linked to a chain of the nitro group (NO2). It has been studied by having various biological activities such as anti-apoptotic, anti-platelet or anti-microbial, although few studies have been made for the anti-inflammatory activity of these compounds. The aim of this study was to evaluate anti-inflammatory activity of four new compounds from the class of nitrostyrene (NPA, 7B, 7D and 7E) in in vitro/in vivo assays. Initially, the compounds were submitted to in vitro testing in a murine macrophages model activated by lipopolysaccharide (LPS) and MRC5 human lung fibroblast in order to assess the cytotoxic potential of such compounds. Shortly thereafter, they were evaluated for inhibition of nitric oxide (NO·), for dosage of the cytokine TNF-α and evaluation of the expression of proteins involved in the inflammatory process. To evaluate the acute inflammatory process in vivo was performed edema induction by carrageenan tests on zebrafish model of LPS-induced pleurisy in mice. The four new compounds tested showed cytotoxic activity on J774A.1 and MRC5 cell when tested in the concentrations (3.12-25 μg/ml). For THP-1 cytotoxic activity was starting concentration of 10 μg/ml. All compounds inhibited nitric oxide production by macrophages activated by LPS but only the NPA showed a possibly significant concentration-response at the concentrations of 10 and 20 μg/ml. This same compound also reduced TNF-α, NF-B and ERK 1/2 levels in THP-1 cells. The NPA possibly also inhibited the carrageenan-induced edema in Zebrafish fish and leukocyte migration into the pleural cavity of mice by inhibiting the intracellular signaling pathways NF-B and ERK 1/2 in in vivo assays. In conclusion, compounds tested in this study not only presented significant cytotoxic activity, as also showed an excellent in vitro/in vivo anti-inflammatory potential, most likely by acting in the inhibition of NF-B and ERK 1/2 pathways. Data were important to explore the biological activity of these novel compounds and their possible application in the treatment of inflammatory diseases.