Dietary supplementation with α-ionone alleviates chronic UVB exposure-induced skin photoaging in mice

Photoaging is widely regarded as the most significant contributor to skin aging damage. It is triggered by prolonged exposure to ultraviolet (UV) light and typically manifests as dryness and the formation of wrinkles. Nutritional intervention is a viable strategy for preventing and treating skin photoaging. In previous studies, we demonstrated that α-ionone had ameliorating effects on photoaging in both epidermal keratinocytes and dermal fibroblasts. Here, we investigated the potential anti-photoaging effects of dietary α-ionone using a UVB-irradiated male C57BL/6N mouse model. Our findings provided compelling evidence that dietary α-ionone alleviates wrinkle formation, skin dryness, and epidermal thickening in chronic UVB-exposed mice. α-Ionone accumulated in mouse skin after 14 weeks of dietary intake of α-ionone. α-Ionone increased collagen density and boosted the expression of collagen genes, while attenuating the UVB-induced increase of matrix metalloproteinase genes in the skin tissues. Furthermore, α-ionone suppressed the expression of senescence-associated secretory phenotypes and reduced the expression of the senescence marker p21 and DNA damage marker p53 in the skin of UVB-irradiated mice. Transcriptome sequencing results showed that α-ionone modifies gene expression profiles of skin. Multiple pathway enrichment analyses on both the differential genes and the entire genes revealed that α-ionone significantly affects multiple physiological processes and signaling pathways associated with skin health and diseases, of which the p53 signaling pathway may be the key signaling pathway. Taken together, our findings reveal that dietary α-ionone intervention holds promise in reducing the risks of skin photoaging, offering a potential strategy to address skin aging concerns.