Hair Growth-Promoting Effects of Rosehip (Rosa canina L.) Seed Oil in C57BL/6 Mice.

Rosehip (Rosa canina L.) seeds, a by-product of the food processing industry, contain various bioactive compounds that have potential cosmetic and pharmacological applications. Rosehip seed oil (RHSO) has been shown to exert therapeutic effects in skin disorders, but its role in promoting hair growth remains unknown. In this study, we aimed to elucidate the hair growth-promoting activity of RHSO and the related mechanisms of action. The depleted dorsal skin of telogenic C57BL/6 mice was topically treated with RHSO for 21 days, and the extent of hair regrowth was assessed. The results indicated that RHSO stimulated hair growth by inducing the early transition of hair follicles from telogen to anagen phase. Histological analysis revealed significant increases in hair follicle density, hair bulb size, and skin thickness. RHSO treatment also upregulated the expression of hair growth-associated genes, including β-catenin, phospho-glycogen synthase kinase-3 beta, Sonic hedgehog, smoothened, cyclin D1, cyclin E, and insulin like growth factor 1. These findings suggest that RHSO stimulates hair growth and may show promise as a preventive and/or therapeutic agent for hair loss.