Quercetagetin, a component of premature Citrus unshiu (Swingle) Marcow., suppress the chemokines related with atopic dermatitis by regulating STAT1 signal

Atopic dermatitis (AD) is an ithchy and relapsing inflammatory skin disease. It was known that a predominant systemic Th2 dysbalance with increased IgE levels and eosinophilia is widely accepted in the pathogenesis of AD [1]. 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 [2, 3]. Citrus unshiu (CU) contains various flavonoids that have various bioactive effects [4]. In present study, we investigated the effect of a component of premature CU, quercetagetin, 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. These results suggest that quercetagetin, a component of premature CU, may have an anti-atopic activity by inhibiting the inflammatory chemokines (TARC and MDC) via the STAT1 pathway.

Keywords: quercetagetin, Citrus unshiu, Atopic dermatitis, TARC/CCL17, MDC/CCL22, Jak-STAT pathway

References: 1. Bieber T (2010) Ann Dermatol 22 (2): 125–137.

2. Hijnen D et al. (2004)J Allergy Clin Immunol 113 (2): 334–340.

3. Leung TF et al. (2003) Pediatr Allergy Immunol 14 (4): 296–301.

4. Kim YD et al. (2009) Korean J Nutr 42(3): 278–290.