Extract from Black Soybean Cultivar A63 Extract Ameliorates Atopic Dermatitis-like Skin Inflammation in an Oxazolone-Induced Murine Model

Black soybean has been used in traditional medicine to treat inflammatory diseases, cancer, and diabetes and as a nutritional source since ancient times. We found that Korean black soybean cultivar A63 has more cyanidin-3-O-glucoside, (C3G), procyanidin B2 (PB2), and epicatechin (EPC) contents than other cultivars and has beneficial effects on cell viability and anti-oxidation. Given the higher concentration of anthocyanidins and their strong anti-oxidant activity, we predicted that A63 extract could relieve inflammatory disease symptoms, including those of atopic dermatitis (AD). Here, we evaluated the anti-AD activity of A63 extract in an oxazolone (OXA)-induced mouse model. A63 extract treatment significantly reduced epidermal thickness and inflammatory cell infiltration, downregulated the expression of AD gene markers, including Interleukin (IL)-4 and IL-5, and restored damaged skin barrier tissues. Furthermore, A63 extract influenced the activation of the signal transducer and activator of transcription (STAT) 3 and STAT6, extracellular regulatory kinase (ERK), and c-Jun N-terminal kinase (JNK) signaling pathways, which play a crucial role in the development of AD. Altogether, our results suggest that A63 can ameliorate AD-like skin inflammation by inhibiting inflammatory cytokine production and STAT3/6 and Mitogen-activated protein kinase (MAPK) signaling and restoring skin barrier function.