Effect of sauchinone on gene expression in UVB-induced photoaging of dermal fibroblasts

Sauchinone, a phenolic lignan derived from Saururus chinensis, possesses potent antioxidant and anti-inflammatory activities. Ultraviolet B (UVB) irradiation is a major environmental factor contributing to skin photoaging, primarily through the induction of oxidative stress and disruption of redox homeostasis in dermal fibroblasts. However, the transcriptional mechanisms underlying the protective effects of sauchinone against UVB-induced damage remain unclear. Human foreskin fibroblasts (HFFs) were treated with UVB irradiation in the presence or absence of sauchinone to investigate transcriptional changes, followed by RNA sequencing (RNA-seq) to analyze genome-wide gene expression profiles. We found that sauchinone treatment significantly reshaped the transcriptional landscape of UVB-exposed fibroblasts. KEGG pathway enrichment analysis revealed that differentially expressed genes were prominently enriched in signaling pathways related to inflammation, cellular stress responses, and extracellular signaling, including cytokine–cytokine receptor interaction, MAPK signaling pathway, and neuroactive ligand–receptor interaction. In addition, pathways associated with metabolic regulation and cellular communication were also affected. Notably, several genes involved in antioxidant defense and redox regulation, including downstream targets of the Nrf2 pathway, were upregulated under UVB + sauchinone conditions. These findings suggest that sauchinone exerts protective effects against UVB-induced oxidative stress at the transcriptional level and highlight its potential as a candidate antioxidant compound for mitigating photoaging-related cellular damage.