Hair Growth Effect and the Mechanisms of Rosa rugosa Extract in DHT-Induced Alopecia Mice Model

<i>Rosa rugosa</i> is a medicinal plant known for its potential anti-inflammatory, antioxidant, anti-cancer, and antimicrobial benefits. The pharmacological effects of <i>Rosa rugosa</i> extract on hair loss have not yet been documented. This research sought to assess the inhibitory effects and mechanisms of action of <i>Rosa rugosa</i> water extract (RWE) in a mouse model of dihydrotestosterone (DHT)-induced alopecia. The study was conducted using C57BL/6 mice, which were assigned to five groups: control, DHT-treated, <i>Rosa rugosa</i> water extract (RWE) at doses of 25 mg/kg and 100 mg/kg body weight, and bicalutamide-treated. To induce hair loss, dihydrotestosterone (1 mg/day per body weight) was administered via intraperitoneal injections, and dorsal hair removal was timed to align with the telogen phase. Each group received oral treatments for a period of 23 days. In this study, we assessed hair growth activity, examined histological changes, and performed immunoblot analysis. We noted improvements in hair length and thickness. Additionally, the protein expression of growth factors associated with hair growth, including vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and insulin-like growth factor-1 (IGF-1), showed significant increases in the group treated with RWE. Additionally, treatment with RWE suppressed the protein expression of hair growth inhibitory factors, including dickkopf WNT signaling pathway inhibitor 1 (DKK1) and interleukin (IL)-6. Moreover, hair growth regulatory pathway related factors, including ERK, AKT, and GSK-3β, were activated. These findings indicate that RWE could serve as a promising natural therapy for preventing hair loss by enhancing the production of factors that promote hair growth while inhibiting those that suppress it.