Phycodris Fimbriata Extract Attenuates UVA-Induced Photoaging in Dermal Fibroblasts by Modulating Antioxidant Enzymes and ERK1/2 Pathway

This study investigated the photoprotective effects of the Phycodris fimbriata extract against ultraviolet A (UVA)-induced photoaging in normal human dermal fibroblasts (NHDFs). The effects of the extract on the mRNA expression of COL1A1, COL3A1, MMP1, SODs, CAT, and GPXs, as well as on the protein levels of type I collagen and MMP1, were evaluated. Real-time quantitative RT-PCR analysis revealed that P. fimbriata treatment upregulated the mRNA expression levels of COL1A1, COL3A1, SOD2, and SOD3. Furthermore, the extract effectively restored type I collagen protein levels in UVA-irradiated NHDFs while concomitantly attenuating both MMP1 transcription and MMP1 protein secretion. Beyond extracellular matrix (ECM) remodeling, P. fimbriata exhibited potent free radical scavenging activity, effectively reducing intracellular H2O2 accumulation. GPX1 and GPX7 were identified as the primary antioxidant enzymes mediating this intracellular H2O2 clearance. UVA exposure drives cellular senescence via reactive oxygen species generation and the subsequent activation of ERK1/2 and NF-κB signaling pathways. Interestingly, P. fimbriata extract significantly suppressed the UVA-induced phosphorylation of ERK1/2, thereby rescuing COL1A1 expression and decreasing MMP1 expression. Collectively, these findings demonstrate that P. fimbriata extract exerts significant anti-aging and antioxidative effects in NHDFs.