Postbiotic Effects of Pediococcus acidophilus LS for Anti-Melanogenesis, Photoprotection, and Wound Repair

Skin health is significantly impacted by factors such as melanin production, UV-induced photodamage, and wound healing. Excessive melanin leads to hyperpigmentation, while UVA radiation accelerates skin aging and oxidative stress. This study investigated the multi-functional dermatological potential of <i>S</i> strain LS-derived cell-free supernatant (CFS-LS) to address these concerns. Our findings demonstrate that CFS-LS effectively inhibits melanogenesis in B16F10 cells. It significantly reduced α-MSH-induced melanin synthesis, comparable to arbutin, by downregulating key melanogenic enzymes (tyrosinase, TRP-1, and TRP-2) and regulatory proteins (p-CREB, MITF, SOX9, and SOX10). Mechanistically, CFS-LS suppressed the phosphorylation of MEK, ERK, p38, and JNK, indicating a dual inhibitory effect on both PKA/CREB and MAPK pathways. Furthermore, CFS-LS mitigated UVA-induced photodamage in HaCaT cells by significantly reducing intracellular reactive oxygen species and suppressing the downstream phosphorylation of p53 and α-MSH levels. It also restored UVA-suppressed Nrf-2 and HO-1 expression, enhancing cellular antioxidant defenses. Lastly, CFS-LS promoted skin wound healing by significantly enhancing HaCaT cell migration in a scratch assay, associated with increased p-MEK1/2 and p-ERK1/2 levels, and notably elevated collagen type I synthesis. Collectively, these results highlight CFS-LS as a potent multi-functional agent for skin protection and repair, with significant potential for cosmetic and therapeutic applications. The active components of CFS-LS warrant further investigation.