Abstract

Psoriasis is a chronic immune-mediated inflammatory skin disease in which gamma delta T cells play an important role. Chinese herbal medicine Jia Wei Jing Xie Yin has its origin in Jing Xie Yin, a medicine created by the traditional Chinese medicine doctor Wu Jun. Previous studies have shown that Jia Wei Jing Xie Yin has good clinical efficacy for patients with blood-heat type psoriasis by inhibiting the interleukin-23/T-helper 17 immune inflammation axis. This study aims to determine the immunoregulatory effects and the underlying mechanisms of Jia Wei Jing Xie Yin in psoriasis-related inflammatory responses. Bagg albino mice with imiquimod-induced psoriasis-like dermatitis were treated with saline (Model), methotrexate that serves as a positive control, or low, medium and high doses of Jia Wei Jing Xie Yin intragastrically. The pathological changes, inflammatory cell infiltration, the expression of inflammatory cytokines, and Janus tyrosine kinase 3/signal transducers and activators of transcription pathway related proteins in the skin lesion were examined. The abundance of Vγ4+ T cells in lymph nodes and spleen was determined by flow cytometry. Jia Wei Jing Xie Yin ameliorated psoriasis area and severity index scores, reduced the infiltration of inflammatory cells and interleukin-17 producing gamma delta T cells, inhibited the messenger ribonucleic acid expression of interleukin-17, interleukin-22, interleukin-6, tumour necrosis factor alpha and matrix metalloproteinase-9, reduced inflammatory cell infiltration and pathological damage. Nevertheless, the expression of the Janus tyrosine kinase 3/signal transducers and activators of transcription signaling pathway was not significantly changed in the MTX and Jia Wei Jing Xie Yin groups. Our work demonstrates that Chinese herbal medicine Jia Wei Jing Xie Yin alleviates Imiquimod-induced inflammation in psoriasis. We have found a good regulatory effect of Jia Wei Jing Xie Yin on gamma delta T cells.