Triglochin maritima Extracts Exert Anti-Melanogenic Properties via the CREB/MAPK Pathway in B16F10 Cells

<i>Triglochin maritima</i>, a salt-tolerant plant, has demonstrated antioxidant effects, the ability to prevent prostate enlargement, antifungal properties, and skin moisturizing benefits. This study aimed to explore the anti-melanogenic potential of the 70% ethanol extract of <i>T. maritima</i> (TME) along with its ethyl acetate (TME-EA) and water (TME-A) fractions. TME (10-200 µg/mL), TME-EA (1-15 µg/mL), and TME-A (100-1000 µg/mL) were prepared and applied to B16F10 cells with or without α-MSH for 72 h. MTT assays were used to assess cytotoxicity, and anti-melanogenesis activity was determined by measuring melanin content, conducting a tyrosinase activity assay, and evaluating the expression of melanogenesis-related genes and proteins via RT-PCR and Western blotting. HPLC-PDA was used to analyze TME and TME-EA. The IC₂₀ cytotoxicity values of TME, TME-A, and TME-EA without α-MSH, were 198.426 μg/mL, 1000 μg/mL, and 18.403 μg/mL, respectively. TME and TME-EA significantly decreased melanin and tyrosinase activity in α-MSH-stimulated B16F10 cells, with TME-EA showing comparable effects to arbutin, while TME-A showed no influence. TME-EA down-regulated melanogenesis genes (<i>Tyr</i>, <i>Trp1</i>, <i>Dct</i>, <i>Mitf</i>, <i>Mc1r</i>) and reduced CREB, p-38, and JNK phosphorylation while increasing ERK phosphorylation, suggesting the CREB/MAPK pathway's role in the anti-melanogenic effect. Luteolin was identified as a potential active ingredient. TME-EA may serve as an effective cosmeceutical for hyperpigmentation improvement due to its anti-melanogenic properties.