Reynoutria japonica consisted of emodin-8-β-D-glucoside ameliorates Dermatophagoides farinae extract-induced atopic dermatitis-like skin inflammation in mice by inhibiting JAK/STAT signaling.

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by skin barrier dysfunction and chronic inflammatory responses. Reynoutria japonica , known as Huzhang in traditional Chinese Medicine, can enhance blood circulation to eliminate wind pathogens and terminate coughing. Despite pharmacological evidence supporting the efficacy of R. japonica in suppressing edema-induced skin inflammation or connective tissue diseases, its pharmaceutical potential for treating AD-like skin inflammation remains unexplored. This study investigated the possible effects of R. japonica ethanol extract (RJE) on Dermatophagoides farinae extract (DfE)-induced AD-like skin inflammation in NC/Nga mice. To elucidate the underlying mechanisms by which RJE inhibits skin inflammation, we examined the effect of RJE on IFN-γ/TNF-α-induced signal transducer and activator of transcription (STAT) signaling in human epidermal keratinocytes (HEKs) and human dermal fibroblasts (HDFs). Our findings revealed that RJE mitigates DfE-induced AD-like symptoms and skin barrier disruptions in mouse skin lesions. Moreover, RJE attenuated DfE-induced mast cell infiltration and serum levels of inflammatory cytokines (IL-1α, IL-1β, IL-6, IL-23, IFN-γ, TNF-α, and GM-CSF). RJE also inhibited IFN-γ/TNF-α-induced chemokine levels and STAT3 phosphorylation in HEKs and HDFs. Virtual binding analysis of the RJE components suggested that emodin-8-β-D-glucoside binds to Janus kinase (JAK) 1/2, thereby suppressing STAT signaling, which was confirmed by Western blot analysis. In conclusion, our results suggest that RJE may alleviate DfE-induced skin barrier dysfunction by inhibiting JAK/STAT signaling and the proinflammatory immune response through the suppression of inflammatory mediators in AD-like skin disease. These findings suggest that RJE has potential as an effective therapy for AD management. [Display omitted] • Reynoutria japonica extract (RJE) ameliorates Dermatophagoides farinae extract (DfE)-induced atopic dermatitis (AD) in NC/Nga mice. • RJE maintains the level of skin barrier proteins on DfE-treated NC/Nga mice. • Emodin-8-β-D-glucoside, a major component of RJE, could contribute to reduce DfE-induced skin inflammation by inhibiting JAK/STAT signaling. • RJE may have potential as therapeutic treatment for skin inflammatory diseases. [ABSTRACT FROM AUTHOR]