Solvent extracts of Carpinus tschonoskii suppress the expression of atopic inflammatory cytokines and chemokines in RAW264.7 macrophages and HaCaT keratinocytes

Atopic dermatitis (AD) is a common, chronic relapsing, inflammatory skin disease characterized by pruritus and inflammation and accompanied by cutaneous physiological dysfunction through chemokine-mediated infiltration of numerous mononuclear cells in lesional skin [1]. TARC (thymus and activation-regulated chemokine/CCL17) and MDC (macrophage-derived chemokine/CCL22) that bind to the chemokine receptor CCR4 which is highly expressed on T-helper 2 cells lead to preferential influx of Th2-type lymphocytes to the lesianal skin in AD [2]. Furthermore, cytokines are another triggers of AD and the expressions of inflammatory cytokines (TNF-α, IL-1β and IL-6) increase in lesional skin macrophages of AD patients [3]. In present study, we investigated the anti-inflammatory effects of Carpinus tschonoskii Maxim. in RAW264.7 murine macrophage and HaCaT human keratinocytes. As results, the CHCl3 sub-fractions (C-4, -5, and -6 fr.) dose-dependently inhibited the production of TNF-α, IL-1β and IL-6 in the LPS-stimulated RAW264.7 murine macrophage. Also, they inhibited the mRNA expression and protein level of TARC and MDC via suppressing the phosphorylation of STAT1 protein in IFN-γ-stimulated HaCaT human keratinocytes. These results suggest that C. tschonoskii may be an effective source for improving atopic dermatitis by inhibiting the inflammatory cytokines and chemokines.

Keywords: Carpinus tschonoskii, Atopic dermatitis, TARC/CCL17, MDC/CCL22, RAW264.7 macrophages, HaCaT keratinocytes

References: 1. Bieber T (2008) N Engl J Med 358:1483–94.

2. Sekiya T et al. (2000)J Immunol 165:2205–2213.

3. Grossman RM et al. (1989) Proc Natl Acad Sci USA 86: 6367–71.