Genistein protects against ultraviolet B–induced wrinkling and photoinflammation in in vitro and in vivo models

BACKGROUND: Chronic exposure to ultraviolet (UV) rays causes severe skin damage by inducing oxidative stress and inflammation. Identifying a safe and natural substance for skin protection is a crucial research goal. OBJECTIVE: The aim of this study was to clarify the effects of genistein on skin inflammation and photoaging by using 3 models (humans: skin parameters; animals: wrinkle formation; and cells: anti-inflammatory effects). METHODS: Food frequency questionnaire data and serum and skin parameter data from 120 volunteers (a group with a genistein-rich diet [RG group] and a control group). Human keratinocytes were pretreated with genistein before ultraviolet B (UVB) irradiation. Genistein was topically applied to the dorsal skin of rats. RESULTS: The blood samples of the RG group had lower serum uric acid levels and blood urea nitrogen levels. The dynamic elasticity level in the RG group was higher than that in the controls. Genistein pretreatment suppressed the expression of proinflammatory cytokines (CXCL1, IL-1, MIF, and PLANH1) and the proteins released by UVB-treated keratinocytes. Topical application of genistein to the dorsal skin of rats reduced the severity of UVB-induced wrinkling. Both intake and topical application of genistein combated UVB-induced inflammation and aging. CONCLUSIONS: Genistein could be used as a safe and natural compound for use in novel anti-inflammatory agents for topical application. GRAPHICAL ABSTRACT: The experimental design procedure, including the skin parameter and blood serum measurements of 137 participants. Genistein-rich compounds provide protection against UVB-induced inflammation, as determined using in vitro and in vivo animal model experiments. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12263-022-00706-x.