Herbal medicine for psoriasis and their molecular targets: A systematic review

Psoriasis is an incurable, chronic, recurrent immune-mediated inflammatory dermatosis characterized by epidermal hyperplasia and excessive infiltration of inflammatory cells into the dermis and neovascularization. The study aimed to provide a systematic review on the in vitro, in vivo, and clinical studies to support traditional uses of herbal medicine for psoriasis treatment. The systematic review was performed by combining three databases, that is, PubMed, ScienceDirect, and Scopus, using the search terms “Psoriasis” AND “Herbal medicine” AND/OR “Traditional medicine.” Full-text articles included after the screening were further evaluated by applying the predefined eligibility criteria. One hundred and twenty research articles were included in the analysis. The included articles involve 94 herbs used as a single herbal extract (n=58 plants) or isolated compounds (n=54 compounds) or as compositions in traditional medicine formulas (n=24 formulas). Most were related to plants or recipes used in Traditional Chinese Medicine (TCM) (63 articles and 207 plants). Research targeting inflammatory and proliferative processes in disease pathogenesis, development, and progression has been an extensive area. The antipsoriasis activity of most plants was mainly through the effects on inflammatory molecules and signaling pathways and immune cells (T-cells, dendritic cells, monocytes, neutrophils, and macrophages), as well as apoptotic molecules and signaling pathways. Plants targeting other signaling molecules should be further investigated.