Abstract: BACKGROUND: Excessive melanin production is a primary cause of skin pigmentation and the formation of age spots. This process is intricately regulated by various enzymes and cellular signaling pathways. Angelica dahurica, a traditional Chinese medicinal herb, has long been recognized for its potential benefits in skin whitening and anti-inflammatory effects. However, the role of its extracellular vesicles in inhibiting melanogenesis remains largely unexplored.
OBJECTIVE: To investigate the effects of Angelica dahurica extracellular vesicles on melanin production and their underlying mechanisms.
METHODS: Extracellular vesicles were first isolated and purified from Angelica dahurica using ultracentrifugation. The morphology and size distribution of these vesicles were characterized using transmission electron microscopy and nanoparticle tracking analysis. Through network pharmacology analysis, we identified nine active components in Angelica dahurica and predicted their interactions with genes involved in melanogenesis. Finally, different concentrations of Angelica dahurica extracellular vesicles were applied to a wild-type AB zebrafish model to assess their anti-melanogenesis effects by observing changes in surface pigmentation and measuring tyrosinase activity. 
RESULTS AND CONCLUSION: Angelica dahurica extracellular vesicles exhibited typical vesicular morphology with a size distribution ranging from 30 to 150 nm. Network pharmacology analysis suggested that several active components in Angelica dahurica, such as ethyl linoleate and byakangelicin, may interact with melanogenesis-related genes like GSK3β and MITF. In the zebrafish model, treatment with Angelica dahurica extracellular vesicles significantly reduced surface pigmentation. Moreover, these Angelica dahurica extracellular vesicles notably decreased tyrosinase activity in zebrafish, with a reduction of approximately 30% at a concentration of 1×108 particles/mL. These findings indicate that Angelica dahurica extracellular vesicles possess significant anti-melanogenesis effects, likely through the regulation of melanogenesis-related genes and enzymes. Therefore, Angelica dahurica extracellular vesicles hold great potential as active ingredients in whitening cosmetics, offering new insights and approaches for addressing skin pigmentation issues. 

Key words: anti-melanogenesis, Angelica dahurica extracellular vesicles, network pharmacology, zebrafish model, tyrosinase, pigmentation