毛髪の白髪化に対するプロテオグリカンベースの局所治療薬：in vitroでの抗酸化作用およびメラニン生成促進作用

Hair greying (canities) is a common and impactful feature of hair aging, primarily driven by oxidative stress, mitochondrial dysfunction, and progressive impairment of melanocyte function. Reactive oxygen species disrupt key melanogenic pathways, including Wnt/β-catenin signaling and microphthalmia-associated transcription factor (MITF) activity. Given the central role of oxidative and inflammatory processes in pigment loss, antioxidant and melanocyte-stimulating strategies represent promising approaches to delay hair greying.

The present study evaluated the in vitro antioxidant, anti-inflammatory, and pro-melanogenic effects of PP-PTKL (Pilopeptan^® Woman Proteokel), a proteoglycan-based topical formulation. Total antioxidant capacity was assessed using a copper reduction assay. Pro-melanogenic activity was evaluated in Normal Human Epidermal Melanocytes (NHEM) under Wnt/β-catenin inhibition induced by FH535. Anti-inflammatory effects were assessed through histamine release in mast cells and by measuring IL-1Ra and S100A8/9 levels using ELISA.

PP-PTKL significantly restored MITF expression in a dose-dependent manner in human melanocytes subjected to Wnt/β-catenin pathway inhibition, with increases of 43.1% at 1% and a 3.7-fold increase at 5%. The formulation exhibited strong synergistic antioxidant activity, with total antioxidant capacity nearly four times higher than the sum of its individual components. In addition, histamine release was significantly reduced in mast cells, while IL-1Ra and S100A8/9 levels were significantly decreased compared with placebo, indicating attenuation of inflammation-associated oxidative stress.

PP-PTKL demonstrates combined pro-melanogenic, antioxidant, and anti-inflammatory activity in vitro, supporting its potential as a preventive or therapeutic strategy for hair greying. Further in vivo and clinical studies are warranted to confirm these findings.