Study on the Mechanism of Anti-atopic Dermatitis by Herba Siegesbeckiae Based on System Pharmacology

Background Atopic dermatitis (AD) is a common but complex chronic inflammatory skin condition characterised by intense pruritus, severely impacting patients’ quality of life. At present, there is no specific drug for AD. Herba Siegesbeckiae (HS) had a therapeutic effect on AD, but its mechanism has not been completely elucidated. Purpose We aimed to understand the mechanism of HS in the treatment of AD in this study. Materials and Methods To investigate the mechanism of HS for AD, including active components, key targets and pathway analyses, systemic pharmacology was used. Molecular docking was conducted to validate the interactions between the key components and their targets. Afterwards, an AD-like animal model was established, skin pathology was observed and immunohistochemical staining was used to confirm the key targets. Results Six vital active components (daucosterol, d-mannitol, hythiemoside B, 15,16-di- O-acetyldarutoside, 19-acetoxy-15-hydroperoxy-12-oxo-13,14E-dehydro-10,11,14,15-tetrahydr-ogeranylnerol and 17- O-acetyldarutoside) highly correlated with potential targets and the key targets (TNF-α, VEGFA, TLR4, STAT3, TLR2, STAT1, MMP9, IL-6, TRPV1 and PPARG) highly correlated with disease processes were identified, pathway enrichment analysis revealed that the toll-like receptor, PI3K-Akt and HIF-1 signalling pathways were significantly enriched with key targets, suggesting their involvement in the anti-Alzheimer’s disease mechanism of HS. As a result of animal experiments, AD-like mice from the model group showed epidermal thickening and inflammatory cell infiltration; TNF-α, VEGFA, TLR4, STAT3, TLR2, STAT1, MMP9, IL-6, TRPV1 levels are significantly up-regulated and PPARG levels were significantly down-regulated; those of which could be reversed by 3.0 g/kg. Conclusion HS might exert its anti-AD effects by up-regulating PPARG and down-regulating TNF-α, VEGFA, TLR4, STAT3, TLR2, STAT1, MMP9, IL-6 and TRPV1. This study laid a foundation for understanding HS’s bioactive components and mechanism against AD.