Multifunctional cosmetic potential of extracellular vesicle‑like nanoparticles derived from the stem of <i>Cannabis sativa</i> in treating pigmentation disorders

While natural products and synthetic chemicals are used in functional cosmetics, their potential side effects remain a concern. This has driven the need for safer and more effective agents to treat skin disorders. This has driven the need safer and more effective agents to treat skin disorders. Therefore, the present study aimed to explore the functional properties of Cannabis sativa stem‑derived nanoparticles (CSS‑NPs) and evaluate their potential as a cosmetic ingredient. Using nanoparticle analysis, CSS‑NPs, with a mean diameter of ~120 nm exhibited notable resistance to external stress conditions, including pH fluctuation and enzymatic degradation by DNase, RNase and proteinase K. They also contained 48 distinct biochemical components. <i>In vitro</i> assays revealed that CSS‑NPs significantly downregulated the expression of genes and proteins associated with melanin synthesis in mouse B16F10 melanoma cells under α‑melanocyte stimulating hormone (α‑MSH)‑induced hyperpigmentation. These inhibitory effects were mediated by the activation of ERK and Akt signaling pathways. Furthermore, CSS‑NPs improved the viability of α‑MSH‑treated B16F10 cells; this was accompanied by the upregulation of antioxidant‑associated enzymes and a decrease in α‑MSH‑induced reactive oxygen species levels. Collectively, these findings suggested that CSS‑NPs carry out a key role in mitigating skin pigmentation and enhancing antioxidant defenses by modulating the ERK/Akt axis during excessive melanin synthesis. Thus, CSS‑NPs represent a promising multifunctional cosmetic ingredient with potential in treating pigmentation disorders and protecting skin cells.