Corydalis Tuber Extract Alleviates Atopic Dermatitis: Transcriptomics-Based Mechanism Prediction and In Vitro/In Vivo Studies

Atopic dermatitis (AD) is a common inflammatory skin disease characterized by recurrent eczema and chronic itching, affecting a significant portion of the global population. This study investigated the effects of Corydalis Tuber 70% ethanol extract (CTE) on tumor necrosis factor-α- and interferon-γ (TI)-stimulated human keratinocytes (HaCaT) and a house dust mite-induced AD mouse model, elucidating its mechanism via transcriptome analysis. A total of 13 compounds, including columbamine, corydaline, dehydrocorydaline, and glaucine, were identified in CTE using ultra performance liquid chromatography-tandem mass spectrometry. CTE downregulated pathways related to cytokine signaling and chemokine receptors in TI-stimulated HaCaT cells. It significantly inhibited C-C motif chemokine ligand (CCL)5, CCL17, and CCL22 levels by blocking the Janus kinase-signal transducers and activators of transcription and nuclear factor kappa-light-chain-enhancer of activated B cells pathways. In the AD mouse model, topical CTE significantly decreased dermatitis scores, epidermal thickening, and inflammatory cell infiltration. Plasma levels of histamine, immunoglobulin E, CCL17, CCL22, corticosterone, and cortisol were reduced. Lesions showed decreased thymic stromal lymphopoietin, CD4⁺ T cells, interleukin-4, and intercellular adhesion molecule-1 expression. The findings demonstrate that CTE alleviates AD by modulating inflammatory mediators, cytokines, and chemokines, reducing inflammatory cell infiltration, and alleviating stress-related factors.