Fructus Sophorae Extract Generated Using the Natural Deep Eutectic Solvent ChCl Urea Activates Wnt/β Catenin and cAMP/MITF Signaling to Stimulate Hair Growth and Pigmentation

Androgenetic alopecia remains challenging to treat, with limited FDA-approved therapies. Natural products, such as the fruit of Sophora japonica L. (Fructus Sophorae), could be alternatives. This study developed a green extraction method using natural deep eutectic solvents (NADESs) coupled with ultrasonic assistance to recover active phytochemicals from Fructus Sophorae and evaluated the extract for promoting hair growth and melanogenic activities. Among ten NADES formulations, ChCl-Urea (1:2) with 40% water content, named CU-40, generated the highest yield of sophoricoside (8.79 mg/g), surpassing that of 70% ethanol by ~25%. In dermal papilla cells, this extract activated Wnt/β-catenin signaling, upregulated downstream targets, such as β-catenin, AXIN2, LEF-1, ALP, and IGF-1, and induced GSK3β phosphorylation. In B16 melanoma, the extract of Fructus Sophorae stimulated cAMP signaling, enhanced MITF promoter activity, and increased melanin production. In an ex vivo mouse vibrissae hair follicle culture, the extract promoted mouse vibrissae hair follicle growth. These findings establish CU-40 as a sustainable, efficient NADES solvent for Fructus Sophorae that yields a bioactive extract promoting hair growth and pigmentation via the Wnt/β-catenin and cAMP/MITF pathways.