Caffeic Acid Phenethyl Ester Inhibits Nuclear Factor-κB and Protein Kinase B Signalling Pathways and Induces Caspase-3 Expression in Primary Human CD4+ T Cells
Clinical & Experimental Immunology, Published Online: 6 Jan 2010
Caffeic acid phenethyl ester (CAPE), an active component in propolis, is known to have anti-tumour, anti-inflammatory and anti-oxidant properties.
In this study, the effects of CAPE on the functions of primary human CD4+ T cells were evaluated in vitro.
CAPE significantly suppressed interferon (IFN)-γ and interleukin (IL)-5 production and proliferation of CD4+ T cells stimulated by soluble anti-CD3 and anti-CD28 monoclonal antibodies in both healthy subjects and asthmatic patients.
CAPE inhibited nuclear factor (NF)-κB activation and protein kinase B (Akt) phosphorylation, but not p38 mitogen-activated protein kinase (MAPK) phosphorylation in T cells. CAPE also induced active caspase-3 expression in CD4+ T cells; CCR4+CD4+ T cells were more sensitive to CAPE induction than CXCR3+CD4+ T cells.
Together, these results indicate that CAPE inhibits cytokine production and proliferation of T cells, which might be related to the NF-κB and Akt signalling pathways, and that CCR4+CD4+ T cells are more sensitive to CAPE inhibition.
This study provides a new insight into the mechanisms of CAPE for immune regulation and a rationale for the use of propolis for the treatment of allergic disorders.