Pulsatilla saponin inhibits the proliferation of keratinocytes and ameliorates imiquimod-induced psoriasis through the NF-κB and STAT3 signaling pathways

Pulsatilla saponin (Ps) was isolated from Pulsatilla chinensis (Bunge) Regel, a traditional Chinese medicine, that has anti-proliferation, anti-inflammation, anti-tumor and immunomodulation activities. However, the anti-psoriasis activity of Ps and its underlying mechanisms have not been fully elucidated. This study aims to investigate the effect and potential mechanisms of Ps on psoriasis. Ps underwent quality control through HPLC and NMR analysis. Wound healing assay, MTT, clone assay, and EdU staining were used to detect HaCaT cells proliferation. Western blot and immunofluorescence were used to assess the expression of proteins. The th17 cells population was analyzed by flow cytometry. The levels of cytokines in the mice skin tissues were measured by RT-qPCR and ELISA. In vitro, Ps has an inhibition effect on the proliferation of M5-induced HaCaT cells. Ps inhibited proliferation by regulating NF-κB and JAK1/STAT3 pathways. Additionally, Ps decreased TNF-α, IL-1β, and IL-6 mRNA levels in M5-induced HaCaT cells. In vivo, Ps improved the pathological damage of Imiquimod (IMQ)-induced psoriasis BALB/c mice skin and reduced the Ki67 level in mice skin tissue. Further results showed that Ps decreased Th17 cells differentiation and IL-22, IL-17A, IL-6, IFN-γ, TNF-α, and IL-1β secretion. Ps could ameliorate the psoriatic symptoms, decrease M5-induced HaCaT cell proliferation, and decrease the differentiation of Th17 cells in IMQ-induced psoriasis mice. Ps suppressed the release of inflammation cytokines by regulating NF-κB and JAK1/STAT3 pathways. Those results indicate that Ps has promising therapeutic potential for psoriasis treatment.