31: The effects of Brazilian propolis on NF-κB transcription factor activation and LPS-induced cytokine production by human dendritic cells

Abstract

Introduction Dendritic cells (DC) are professional antigen presenting cells (APCs) and play an essential role in the initiation and modulation of immune responses. DC may generate either immunity or tolerance by expressing costimulatory molecules and producing pro- or anti-inflammatory cytokines. Propolis is a resinous product made by honeybees from various plant parts, and has attracted the attention of researchers because of its biological properties, highlighting its immunomodulatory effects. Aims this work aimed to investigate propolis effects in vitro, evaluating cell viability, the activation of NF- κ B transcription factor and TNF- α , IL-6 and IL-10 production by human DC. Methods: Human monocytes were obtained from healthy donors and incubated with IL-4 and GM-CSF for 7 days for DC differentiation. Then DC were incubated with different concentrations of propolis (5, 10, 20, 40 μg/mL) and LPS (10 μg/mL) for 24 h. A possible cytotoxicity was assessed by the MTT assay, and NF- κ B and LPS-induced cytokine production were determined by ELISA. Significant differences were determined by analysis of variance (ANOVA), followed by Dunnett’s test ( p Results Data showed that cell viability was not affected after DC incubation with propolis and LPS. Propolis maintained the LPS-induced activation of NF- κ B transcription factor, and the production of TNF- α and IL-6 by DC, whereas propolis at low concentrations increased IL-10 release. Conclusions One may conclude that propolis displayed an immunomodulatory profile in human DC.