Effects of Magnoliae Flos on Atopic Dermatitis-Like Inflammation Evaluated via Extracellular Signal-regulated Kinase or Signal Transducers and Activators of Transcription 1/3 Signalling Pathways

Atopic dermatitis is a chronic inflammatory skin disease. Skin is the largest organ and plays a pivotal role in protecting the body. Not only does the skin act as a physical barrier against the external environment, but it also has its own immune system. Atopic dermatitis is caused by prolonged excessive inflammatory responses that worsen under imbalanced cutaneous immune system skin conditions. Although the prevalence and burden of atopic dermatitis is increasing, the standard therapeutic agents remain unclear due to the complicated pathophysiology of the condition. The objective of this study is to examine the use of Magnoliae flos, the dried flower bud of Magnolia biondii or related plants. The effects and underlying mechanism of action of aqueous extract of the buds of Magnoliae flos (MF) were evaluated. Immortalized human keratinocytes (HaCaT) stimulated with tumour necrosis factor-α and interferon-γ mixture and NC/Nga mice stimulated with 2,4-dinitrochlorobenzene were used as atopic dermatitis models, in vitro and in vivo, respectively. The effects of MF were determined by measuring the suppression of pro-inflammatory signalling pathways, such as extracellular signal-regulated kinase or signal transducers and activators of transcription 1/3 and restoring skin barrier molecules. In conclusion, MF is a potential therapeutic alternative for the treatment of atopic dermatitis through repressing inflammatory pathways. SIGNIFICANCE The chronic inflammatory skin disease atopic dermatitis reduces patients’ quality of life due to severe effects of itch and frequent relapse. There is a need for therapeutic agents that will relieve the symptoms of atopic dermatitis in the long-term without side-effects. Magnoliae flos has been used for a long time to treat inflammatory diseases with safety and low toxicity for; therefore this study examined its potential in treating atopic dermatitis. MF showed repressive effects on cutaneous inflammatory responses and recovery on skin barrier molecules which were done regulating through ERK or STAT1/3 signalling pathways.