The immunoregulatory effects of natural products on psoriasis via its action on Th17 cells versus regulatory T cells balance.

Psoriasis is an incurable, chronic inflammatory disease, which brings a substantial burden on individuals and society. Currently, the treatment of psoriasis has entered the era of biologics, but its highly targeting of inflammatory mediators may enable the immune response to circumvent the blockade, leading to disease recurrence, or other clinical and immunological characteristics. Therefore, the discovery of new therapies that have the ability of multidirectional regulation on immunity and maintain the dynamic balance of immunity in psoriasis, may be the key to the treatment of the disease. Natural products extracted from herbal medicines have synergistic effects to alleviate psoriasis and its comorbidities because of their structural diversity and multiple active mechanisms. To date, the characteristics of natural products regulating T helper 17 (Th17) cells/regulatory T (Treg) cells balance in the treatment of psoriasis have attracted more and more attention from basic and clinical studies. In this review, we systematically introduced the natural products regulating the balance of Th17/Treg and their specific mechanism of action, finding Datura metel L, Grape seed proanthocyanidin extract (GSPE), Thymol, Kaempferol, Aloperine, Abietic acid (AA), Isogarcinol, Luteolin reduced the frequency and function of Th17 cells and simultaneously increased that of Treg cells. It is expected that our work can provide a reference for clinicians in drug use.