Network pharmacology and experiments in vitro reveal that the Paeonia veitchii Lynch and its active ingredient Punica granatum Linn ameliorate IMQ-induced psoriasis in mice via TLR4/NF-κB signaling pathway

Pharmacological relevance Paeonia veitchii Lynch is a traditional Chinese medicine in our country. It has the function of clearing heat and cooling blood, dispersing blood stasis and relieving pain. Its main active ingredient, Punica granatum Linn , is a herbaceous polyphenol with many biological properties, such as anti-oxidation, anti-diabetes, anti-cancer and inducing apoptosis. Previous studies have demonstrated a significant therapeutic effect of Punica granatum Linn on psoriasis, although the underlying molecular mechanisms are unknown. Aim of the study We screened the active components of Paeonia veitchii Lynch by network pharmacology. Weveriied them in vitro to identify the potential molecular mechanism of Paeonia veitchii Lynch in treating psoriasis. Materials and methods Retrieve target genes associated with psoriasis from the GEO database. Using the clinical bioconfidence analysis platform Sangerbox for Gene Ontology (GO) and Encyclopedia of Genomes (KEGG) pathway enrichment. Next, the protein-protein interaction network (PPI) and the Paeonia veitchii Lynch-compound-target network were done with Cytoscape 3.9.1. To find the most essential active ingredient in the treatment of psoriasis, the main active ingredient and its core target were analyzed by molecular docking. Network pharmacological results were verified by in vitro experiments. A mouse model of psoriasis was induced with imiquimod and constructed by observing changes in skin lesions on the back of mice on a daily basis, performing PASI scores and histopathology observation. The levels of IL-6 and TNF-α in serum were measured by Elisa, and the expression of TLR4/NF-ΚB pathway was evaluated by Western Blot. Results 348 differentially expressed genes with high correlation to psoriasis were screened, and 23 active components, corresponding to 150 target genes, were obtained by searching “Paeonia veitchii Lynch” from the database. Catechin, Baicalein, β-sitosterol, Punica granatum Linn, Lactobacillus, paeoniflorin, paeonol, sitosterol and stigmasterol are the main active components in Paeonia veitchii Lynch, in psoriasis has more critical significance. In addition, CCNB1, CXCL8, PCNA and S100A9 may be important targets in treating psoriasis. The molecular docking showed that Punica granatum Linn was main active component of Paeonia veitchii Lynch in treating psoriasis. KEGG results indicated that TLR4/NF-κb pathway might be the potential mechanism of TLR4/NF-κb. Western Blot results showed that Punica granatum Linn down-regulated the protein levels of TLR4 and P65. Conclusions Our results suggest that Punica granatum Linn may be an essential basis for the treatment of psoriasis by Paeonia veitchii Lynch, and TLR4/NF-κb pathway may be the common pathway of Paeonia veitchii Lynch and Punica granatum Linn.