Protective Effects of Astragalin Against Acute Ultraviolet B-Induced Photodamage in HaCaT Cells and Mouse Skin.

Astragalin (AST), a natural flavonoid found in various plants, possesses antioxidant and anti-inflammatory properties. However, its protective efficacy against ultraviolet B (UVB)-induced cutaneous damage remains unclear. This study investigated the photoprotective effects of AST against UVB-induced photodamage using HaCaT keratinocytes and Kunming mice. In vitro, AST mitigated UVB-induced cytotoxicity and apoptosis in HaCaT cells. In vivo, topical application of AST attenuated UVB-induced erythema, epidermal hyperplasia, and collagen degradation in mouse skin. Additionally, AST reduced reactive oxygen species accumulation and enhanced antioxidant enzyme activity via activation of the Keap1/Nrf2 pathway. Furthermore, AST suppressed the expression of proinflammatory cytokines by inhibiting the TLR4/NF-κB signaling pathway. These findings demonstrate the photoprotective properties of AST and support its potential as a natural therapeutic agent for preventing UVB-induced skin damage.