Immunoregulatory effects of traditional Chinese medicine and its ingredients on psoriasis.

Psoriasis is an immune-mediated inflammatory skin disease involving the activation and regulation of various immune cells. A proportion of psoriasis patients remain unresponsive to conventional therapies or targeted drugs, highlighting the urgent need for novel therapeutic strategies. In addition, although many conventional immunosuppressants are effective in the treatment of psoriasis, they may cause various side effects. Traditional Chinese Medicine (TCM) represents a potential drug candidate, with a rich history of traditional use and a vast array of pharmacological options. In particular, TCM may serve as an alternative or complementary therapy of psoriasis with potentially less side effects. In this review, we focus on immune cells, including dendritic cells, neutrophils, macrophages, myeloid-derived suppressor cells, Th17, regulatory T (Treg) cells, and γδ T cells. We provide an overview of the roles for these immune cells in the pathogenesis of psoriasis and regulatory effects of TCM and its ingredients on them. Additionally, we briefly summarize the clinical research involving treatment of psoriasis with TCM and discuss the existing challenges and limitations in this field.