Hemp Seed-Derived Exosomes Protect Against Dihydrotestosterone-Induced Chicken Feather Growth Inhibition

Background/Objectives: Androgenetic alopecia suppresses hair follicle growth. This occurs via dihydrotestosterone (DHT), which inhibits key molecular pathways such as Wnt/β-catenin and Sonic Hedgehog (SHH) signaling. Exosomes derived from plant callus cultures are promising biomaterials for targeted delivery and regenerative medicine. This study aimed to investigate the protective effects of hemp seed callus-derived exosomes (E40) against DHT-induced inhibition of feather follicle development in a chicken embryo model. Methods: E40 exosomes were isolated and purified from the calli of germinated hemp seeds. A DHT-induced feather loss model was established by injecting chicken embryos on embryonic day 7 (E7) with DHT (50 ng/mL), with or without co-administration of E40 (40 µg/mL). On embryonic day 12 (E12), feather length, density, and expression of molecular markers were analyzed. The methods included FISH, Western blotting, and quantitative analysis of PTCH1, AR, SHH, SMO, GLI1, Wnt, β-catenin, BMP4, and Noggin. Results: DHT treatment significantly reduced feather length and density. It also downregulated SHH and Wnt/β-catenin markers, upregulating BMP4 and androgen receptor expression. Co-treatment with E40 restored feather length and density to levels comparable to controls and significantly recovered the expression of SHH, SMO, GLI1, Wnt, and β-catenin. E40 also suppressed DHT-induced BMP4 upregulation by approximately 30% and reduced androgen receptor expression. Conclusions: These results suggest that hemp seed-derived exosomes (E40) effectively mitigate DHT-induced feather follicle inhibition by modulating critical signaling pathways and immune-related markers, supporting their potential application as a nanocarrier-based therapeutic strategy for alopecia management.