Essential Oil of Alleviate Psoriatic-Like Skin Inflammation by Inhibiting PI3K/Akt/mTOR and p38MAPK Signaling Pathway.

Background: The traditional L. has been used to treat dermatitis for thousands of years. Due to emerging trends in alternative medicine, patients prefer natural remedies to relieve their symptoms. Therefore, finding safe and effective plant medicines for topical applications on the skin is an important treatment strategy for dermatologists. German chamomile ( L.) from the Compositae family is a famous medicinal plant, often known as the "star of medicinal species."However, the function of essential oil on skin inflammation has not been thoroughly examined in earlier research.

Methods: GC-MS analyzed the components of MCEO, and this study explored the anti-inflammation effects of MCEO on psoriasis with network pharmacological pathway prediction. Following this, we used clinical samples of psoriasis patients to confirm the secretory characteristic of relative inflammatory markers. The therapeutic effect of MCEO on skin inflammation was detected by examination of human keratinocytes HaCaT. At the same time, we prepared imiquimod-induced psoriatic-like skin inflammation in mice to investigate thoroughly the potential inhibition functions of MCEO on psoriatic skin injury and inflammation.

Results: MCEO significantly reduced interleukin-22/tumor necrosis factor α/lipopolysaccharide-stimulated elevation of HaCaT cell inflammation, which was correlated with downregulating PI3K/Akt/mTOR and p38MAPK pathways activation mediated by MCEO in HaCaT cells treated with IL-22/TNF-α/LPS. Skin inflammation was evaluated based on the PASI score, HE staining, and relative inflammatory cytokine levels. The results showed that MCEO could significantly contribute to inflammatory skin disease treatment.

Conclusion: MCEO inhibited inflammation in HaCaT keratinocytes induced by IL-22/TNF-α/LPS, the potential mechanisms associated with inhibiting excessive activation and crosstalk between PI3K/Akt/mTOR and p38MAPK pathways. MCEO ameliorated skin injury in IMQ-induced psoriatic-like skin inflammation of mice by downregulating the levels of inflammatory cytokines but not IL-17A. Thus, anti-inflammatory plant drugs with different targets with combined applications were a potential therapeutic strategy in psoriasis.