RESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Achyrocline alata is a locally marketed (Mato Grosso do Sul/ Brazil) herb used in folk medicine as an anti-inflammatory and a sedative. Evaluate the anti-inflammatory properties of Achyrocline alata in both in vivo and in vitro models. MATERIALS AND METHODS: A hydroethanolic extract from inflorescences of Achyrocline alata (HEAa) was characterized by HPLC-DAD and compared to standards (chlorogenic acid; isoquercetrin; quercetin; 4,2',4'-trihydroxy-6'-methoxychalcone; gnaphalin; 3-O-methyl-quercetin; 3,5-dicaffeoyl-quinic acid and 4,5-dicaffeoyl-quinic acid). The in vivo anti-inflammatory properties of the HEAa (4, 20 and 100 mg/kg, per os) were evaluated using the following animal models: carrageenan-induced paw edema in rats, carrageenan-induced vascular permeability and peritonitis in mice and an acetic acid-induced writhing model to test antihyperalgesic activity in mice. In vitro assays were performed to study the effects of the HEAa (0.16, 0.8 and 4 mg/ml) on the cell viability, cell spreading and production of NO and H2O2 in stimulated macrophages. RESULTS: The A. alata extract inhibited the development of edema and vascular permeability, reduced polymorphonuclear cell recruitment in the acute peritonitis assay and decreased the amount of writhing induced by acetic acid. The HEAa did not increase NO/H2O2 production, while it did inhibit production when the macrophages were stimulated by LPS or PMA at all tested concentrations. In the presence of HEAa, macrophage spreading did not increase even after stimulation with LPS. Additionally, the HEAa was nontoxic to macrophages at all tested concentrations. CONCLUSIONS: The HEAa displayed anti-inflammatory and antihyperalgesic effects, which supports the use of this plant in folk medicine. These effects might be due to the flavonoids and phenylpropanoids derivatives present in the HEAa.