Gold lotion from citrus peel extract ameliorates imiquimod-induced psoriasis-like dermatitis in murine.

BACKGROUND: Gold lotion (GL), a natural mixed product made from the peels of six citrus fruits, has recently been identified as possessing anti-oxidative, anti-inflammatory, and immunomodulatory effects. GL has been used to protect skin against UV-induced damage, but its activity against psoriasis, a chronic autoimmune skin disease caused by dysregulation between immune cells and keratinocytes, is not known. We therefore evaluated the effect of GL on imiquimod (IMQ)-induced psoriasis-like inflammation in mice. RESULTS: GL treatment significantly attenuated IMQ-induced psoriasis-like symptoms in mice. The inflammatory cytokines upregulated by IMQ in skin lesions were also inhibited by feeding GL. In addition, GL treatment reduced the infiltration of CD4+ T cells/neutrophils in skin lesions and the percentage of IL-17-/IL-22-producing T cells in lymph nodes. Furthermore, GL impaired IMQ-induced type I interferon production by plasmacytoid dendritic cells (pDCs) in vitro. CONCLUSION: Our results indicate GL can act to suppress the initiation of psoriasis and strongly suggest that GL may have potential to be applied to the treatment of psoriasis. © 2018 Society of Chemical Industry.