Hesperidin from Chenpi Ameliorates Skin Photoaging by Targeting HSPA1L to Stabilize GPX4 and Suppress Ferroptosis.

Photoaging is an extrinsic skin aging process caused by chronic ultraviolet (UV) radiation. A core pathological feature of photoaging is excessive oxidative stress, which can further induce ferroptosis. The HSP70 family plays a critical role in this stress response by protecting the key antioxidant enzyme GPX4. In this study, we established UV-induced photoaging models in cultured cells and 3D skin organoids. UPLC-MS/MS analysis of Chenpi transdermal permeate (prepared by in vitro transdermal penetration of Chenpi extract through mouse skin) identified hesperidin as the primary bioactive compound of Chenpi (dried peel of the plant Citrus reticulata Blanco after the aging process). The efficacy of hesperidin was validated in human keratinocytes (HaCaTs), fibroblasts (HSFs), and skin organoids. Mechanistically, transcriptomic and metabolomics analysis indicated that ferroptosis is a key pathway through which hesperidin ameliorates photoaging. Limited proteolysis mass spectrometry (LiP-MS), transcriptomics, and molecular dynamics simulation results demonstrated that hesperidin directly binds to the molecular chaperone HSPA1L. By upregulating HSPA1L expression, hesperidin enhanced the stability of GPX4 and suppressed UV-triggered ferroptosis. Our findings identify the HSPA1L/GPX4 axis as a critical redox regulatory pathway targeted by hesperidin, providing a mechanistic foundation for anti-photoaging therapies.