Protective Effects of Donkey Milk-Derived Exosomes Against UVB-Induced Skin Photoaging via Regulation of DNA Damage and Aging-Related Pathways.

Prolonged exposure to UVB radiation accelerates skin photoaging by inducing DNA damage, promoting collagen degradation, and triggering cellular senescence. There is a growing interest in identifying effective natural interventions to prevent or mitigate these adverse effects. This study investigated the protective role and underlying mechanisms of donkey milk-derived exosomes (DM-Exos) against UVB-induced skin aging using both in vitro skin cell models and in vivo mouse models. The results demonstrated that DM-Exos significantly reduced UVB-induced cellular senescence, as evidenced by decreased β-galactosidase activity and downregulation of senescence-associated genes. DM-Exos also attenuated intracellular ROS production and reduced DNA damage markers (γ-H2AX and 8-OHdG) both in vitro and in vivo. Transcriptomic analysis further revealed that DM-Exos mitigated UVB-induced alterations in pathways related to cellular senescence, DNA damage, cell proliferation, and response to UV radiation, which were corroborated by qPCR validation of key aging-related genes. These findings underscore the potential of DM-Exos as a promising natural agent for protecting against UVB-induced skin aging and maintaining overall skin health.