Abstract
Thymus and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22) are related with AD and are elevated in serum and lesional skin of AD patients. Citrus unshiu (CU) contains various flavonoids and the content is high at premature fruits rather than mature fruits. In present study, we investigated the effect of quercetagetin, a component of premature CU, on the production of TARC and MDC in HaCaT human keratinocytes. As results, quercetagetin showed inhibitory activity on the protein production and mRNA expression of TARC and MDC in IFN-γ and TNF-α-stimulated HaCaT human keratinocytes. Also, quercetagetin inhibited the phosphorylation of STAT1, key transcription factor initiating IFN-γ signaling pathway, in a time- and dose-dependent manner. Moreover, quercetagetin augmented the mRNA expression of TGF-β1 that down-regulates the expression of TARC and MDC. These results suggest that quercetagetin may have an anti-atopic activity by inhibiting the inflammatory chemokines (TARC and MDC) via the regulation of STAT1 and TGF-β1.
Key words : Quercetagetin, Citrus unshiu, Atopic dermatitis, TARC/CCL17, MDC/CCL22, Jak-STAT pathway, TGF-β1
