Kukui nut oil (Aleurites moluccanus seed oil) promotes hair growth by activating the Nrf2/ARE-AKR1C family-PGF2α signaling axis

Hair plays an essential role in protecting the eyes and skin, and hair loss can cause psychological distress. Kukui nut oil (Aleurites moluccanus seed (AMS) oil) has been traditionally used to promote hair growth. While it is now widely used as a cosmetic ingredient, its mechanism for promoting hair growth has remained unknown. In this study, we investigated the hair growth-promoting mechanism of AMS oil, primarily focusing on prostaglandin F2α (PGF2α) production. Ex vivo culture of human hair follicles treated with AMS oil demonstrated a significant hair-growth effect. AMS oil elevated PGF2α levels and increased the expression of AKR1C family members, which are key enzymes involved in PGF2α synthesis. In addition, proliferation markers, including Ki67 and cyclins B1, D1, and E1, were upregulated. Transcriptional analysis revealed that AMS oil activates Nrf2 signaling, which leads to AKR1C family gene regulation via antioxidant response elements. Furthermore, a randomized, double-blind, left-right comparison human testing confirmed the efficacy of AMS oil in promoting eyelash growth. These findings suggest that AMS oil holds promise for applications not only in promoting hair and eyelash growth but also in improving health through its antioxidant effects.