Tanshinol ameliorates imiquimod-induced psoriasis by inhibiting M1 macrophage polarization through suppression of the notch signaling pathway.

Background: Psoriasis is a common immune-related chronic inflammatory skin disease, often accompanied by significant itching, and once diseased, the course of the disease lasts for most of the lifetime. Tanshinol (TAN) is an active ingredient of Salvia miltiorrhiza, which possesses pharmacological effects such as anti-inflammatory and antioxidant properties. However, the effects of TAN on psoriasis have not been widely reported.