Protective effect of ginseng berry saponin conversion products on skin photodamage caused by UVB in vitro and in vivo

Ultraviolet (UV) B irradiation is closely related to skin aging and skin damage. Here, we report the photoprotective mechanism of action of ginseng berry rare saponins (GFRS) on UVB-induced damage to human keratinocytes and mouse skin. Several UVB irradiation-induced cytotoxicity and oxidative stress responses were assessed. GFRS preconditioning significantly improved HaCaT cell survival and reduced the levels of the DNA damage markers histone H2AX and cyclobutane pyrimidine dimer. Under oxidative stress, GFRS could reduce the transformation and loss of the mitochondrial membrane potential to the monomer form; effectively clear the expression of lipid reactive oxygen species, malondialdehyde, and other peroxides, and restore total superoxide dismutase, glutathione peroxidase, and catalase levels. The occurrence of ferroptosis after UVB induction was also studied. Erastin exacerbated the induced cellular iron overload, whereas GFRS and Fer-1 reversed this response to varying degrees. Mechanistically, GFRS activated the Nrf2/HO-1/GPX4 pathway and inhibited the phenomenon of ferroptosis in cells. Our findings were confirmed using a mouse model of UV induced skin injury. GFRS not only mitigated lipid peroxides and iron overload in tissues but also prevented skin barrier damage and collagen loss. Therefore, GFRS shows potential as a novel functional product as it protects the skin from UVB light-induced damage.