Formulated extract from multiple citrus peels impairs dendritic cell functions and attenuates allergic contact hypersensitivity

- Effect of Gold lotion (GL) on the activation of LPS-stimulated murine bone marrow-derived DCs was investigated.
- GL-treated DCs showed a decreased ability to stimulate antigen specific T cell proliferationl.
- Oral administration of GL could prevent 2,4- dinitro-1-fluorobenzene -induced contact hypersensitivity in vivo.
- Blocking the LPS-induced activation of MAPK- JNK, p38 and NF-κB may contribute to the inhibitory effect of GL on DC activation.

It has been reported that gold lotion (GL), a formulated product made from the peels of six citrus fruits, has many pharmacological properties, such as anti-tumor, antioxidant, and anti-inflammatory activities. In this study, we investigated the immunomodulatory effect of GL on lipopolysaccharide (LPS) stimulated mouse bone marrow-derived DC maturation and function. Our experimental results have shown that GL significantly impaired the pro-inflammatory cytokine and chemokine secretion, suppressed the expression of major histocompatibility complex class I/II and costimulatory molecules (CD40, CD80 and CD86), increased phagocytic capacity, and reduced propensity to stimulate the autologous CD4+ and CD8+ T cell proliferation of LPS-induced DCs. Furthermore, we found that oral administration of GL attenuated the 2,4-Dinitro-1-fluorobenzene induced contact hypersensitivity (CHS) in animal models. Subsequently, our molecular mechanism studies showed that GL interfered with LPS-induced MAPK-JNK, p38 phosphorylation and nuclear translocation of NF-κB p65. In an essence, these findings are the first report to provide new insight in the immunopharmacological role of GL in terms of its effects on DC.