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Background: Propolis, an ancient herbal medicine, has been reported the beneficial effect both in asthma patients and murine model of asthma, but the mechanism was not clearly understood. In this study, the effect of caffeic acid phenethyl ester (CAPE), the most extensively studied components in propolis, on the functions of human monocyte-derived dendritic cells (MoDCs) was investigated., Results: CAPE significantly inhibited IL-12 p40, IL-12 p70, IL-10 protein expression in mature healthy human MoDCs stimulated by lipopolysaccharides (LPS) and IL-12 p40, IL-10, IP-10 stimulated by crude mite extract. CAPE significantly inhibited IL-10 and IP-10 but not IL-12 expression in allergic patients' MoDCs stimulated by crude mite extract. In contrast, the upregulation of costimulatory molecules in mature MoDCs was not suppressed by CAPE. Further, the antigen presenting ability of DCs was not inhibited by CAPE. CAPE inhibited IkappaBalpha phosphorylation and NF-kappaB activation but not mitogen-activated protein kinase (MAPK) family phosphorylation in human MoDCs., Conclusion: These results indicated that CAPE inhibited cytokine and chemokine production by MoDCs which might be related to the NF-kappaB signaling pathway. This study provided a new insight into the mechanism of CAPE in immune response and the rationale for propolis in the treatment of asthma and other allergic disorders.

Introduction: The purpose of this study was to determine if oral administration of the interleukin (IL) 12/IL-23 inhibitor, STA-5326, is effective in experimental autoimmune uveoretinitis (EAU)., Methods: C57BL/6J mice were immunised with human interphotoreceptor retinoid binding protein peptide (IRBP 1-20). STA-5326 at a dose of either 5 mg/kg or 20 mg/kg, or vehicle alone, was orally administered once a day for six days a week from day 0 to day 14. Fundus examination was performed on day 14 and day 18 after immunisation. Mice were euthanased on day 18 and the eyes were enucleated for histopathological examination. In vivo-primed draining lymph node cells were stimulated with IRBP 1-20 and culture supernatant was harvested for assay of interferon (IFN)-gamma and IL-17 by ELISA. Intracellular expression of IFN-gamma and IL-17 in CD4+ T cells of cultured draining lymph node cells was assessed by flow cytometry. The level of IL-12 p40 in serum was examined in STA-5326-treated or vehicle-treated mice receiving immunisation., Results: The level of IL-12 p40 in serum was decreased in mice treated with STA-5326. Oral administration of either 5 mg/kg or 20 mg/kg STA-5326 reduced the severity of EAU on day 14 and 18. In addition, mice treated with 20 mg/kg STA-5326 showed significantly decreased severity of EAU by histopathological analysis. Although IFN-gamma production of draining lymph node cells was increased in STA-5326-treated mice by ELISA analysis, the proportion of IFN-gamma-producing cells was not significantly altered. However, IL-17 production and the proportion of IL-17-producing cells were significantly reduced in STA-5326-treated mice. Furthermore, oral administration of STA-5326 during the effector phase reduced the severity of EAU., Conclusions: These results indicate that oral administration of the IL-12/IL-23 inhibitor STA-5326 is effective in suppressing inflammation in the EAU model, and reduces the expansion of IL-17-producing cells. STA-5326 may represent a new therapeutic modality for human refractory uveitis.