Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Vestitol is an isoflavonoid isolated from Brazilian red propolis with potential anti-inflammatory activity. This study investigated the mechanism of action of vestitol on the modulation of neutrophil migration in the inflammatory process. Pre-treatment with vestitol at 1, 3, or 10 mg/kg reduced LPS- or mBSA-induced neutrophil migration and the release of CXCL1/KC and CXCL2/MIP-2 in vivo. Likewise, pretreatment with vestitol at 1, 3, or 10 mu M reduced the levels of CXCL1/KC and CXCL2/MIP-2 in macrophage supernatants in vitro. Moreover, the administration of vestitol (10 mg/kg) reduced leukocyte rolling and adherence in the mesenteric microcirculation of mice. The pre-treatment with vestitol (10 mg/kg) in iNOS(-/-) mice did not block its activity concerning neutrophil migration. With regard to the activity of vestitol on neutrophils isolated from the bone marrow of mice, there was a reduction on the chemotaxis of CXCL2/MIP-2 or LTB4-induced neutrophils and on calcium influx after pre-treatment with the compound at 3 or 10 mu M. There was no change in CXCR2 expression by neutrophils treated with vestitol at 10 mu M. These findings demonstrate that vestitol is a promising novel anti-inflammatory agent.79 954960Sao Paulo Research Foundation (FAPESP) [2012/01365-0, 2012/22378-2, 2013/08216-2]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)