Pro-inflammatory activity of Astronium fraxinifolium Schott on Lipopolysaccharide-stimulated RAW 264.7 cells

ABSTRACT

This study aimed to investigate the antioxidant and immunomodulating activities of ethanolic extract from the sapwood of Astronium fraxinifolium (EEAF) on Lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The constituents of the EEAF were analyzed by high-performance liquid chromatography (HPLC). Antioxidant activity of EEAF was evaluated by its capacity of inhibiting the production of free radical 2,2'-diphenyl-1-picrylhydrazyl and 2,2-azino-bis3-ethylbenzothiazoline-6-sulfonic acid. For the analysis of its immunomodulatory properties, Nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and transforming growth factor beta (TGF-β) levels were determined in supernatants from LPS-stimulated RAW 264.7 cells after treatment with the EEAF at different concentrations. Expression for mRNA of Cyclooxygenase-2 (COX-2) and Inducible nitric oxide synthase (iNOS), and detection of COX-2 protein were also analyzed. Caffeic acid, quercetin, followed by orientin and ρ-coumaric acid, were identified in the extract by the HPLC technique. The EEAF showed poor antioxidant activity when compared to the reference standard. NO, expression of COX-2 mRNA and COX-2 protein were found in high levels when LPS-stimulated cells were treated with the EEAF. Moreover, increased levels of TNF-α and low secretion of TGF-β were demonstrated in supernatants from LPS-stimulated cells treated with EEAF at different concentrations. In opposition to many different types of medicinal plants, the EEAF demonstrated a powerful pro-inflammatory capacity