Fermented Platycodon grandiflorum extract alleviates TNF-α/IFN-γ-induced inflammatory response in HaCaT cells and modulates immune balance on 1-chloro-2,4-dinitrobenzene-induced atopic dermatitis in NC/Nga mice

The bioactive compounds of Platycodon grandiflorum have been studied with saponin, including platycodin D (PD) and platycoside E (PE), but functional enhancement studies through bioconversion as fermentation are insufficient. In this study, we determined the potential therapeutic effects of fermented Platycodon grandiflorum extracts (FPE) on the atopic dermatitis-induced HaCaT cell line and NC/Nga mice. Atopic dermatitis was induced by TNF-α (10 ng/mL)/IFN-γ (10 ng/mL) in HaCaT cells and topical application of 0.2% 1-chloro-2,4-dinitrobenzene (DNCB) in NC/Nga mice. FPE regulated TNF-α/IFN-γ-induced the production of inflammation-related cytokines, chemokines and expression of transcription factors in HaCaT cells. Oral administration of FPE and PD/PE ameliorated DNCB-induced atopic dermatitis symptoms and reduced the number of T cells, immunoglobulin E-producing B cells, eosinophils in the dorsal skin. Taken together, our results indicate that FPE can modulate the Th1/Th2 immune balance and has potential as a functional food supplement that can prevent skin diseases.