Melanin Regulation and Autophagy Modulation by Rosa centifolia L. Extract and Its Key Compounds (Astragalin and Ellagic Acid)

ABSTRACT Rosa centifolia , a widely used rose species, has been extensively studied for its antioxidant and anti‐inflammatory properties. However, little research has been conducted on its skin‐whitening properties. Therefore, this study investigated the application of R. centifolia for skin whitening in vitro. We conducted a flash extraction of R. centifolia (RCFE), quantified the total flavonoid and proanthocyanidin content, established the high‐performance liquid chromatography/diode array detection testing method, and analyzed the contents of three active ingredients: ellagic acid (ECA), astragalin (ASG), and isoquercitrin. A B16 cell model was established to screen three components for their activity. The results indicated that 3.00 µg/mL of ellagic acid and 6.00 µg/mL of astragalin were particularly effective in inhibiting melanogenesis and tyrosinase activity. We further investigated the whitening mechanism of RCFE, ECA, and ASG using enzyme‐linked immunosorbent assay and Western Blot methods. The RCFE, ASG, and ECA inhibited melanogenesis, suppressed tyrosinase activity, inhibited microphthalmia‐associated transcription factor expression, affected tyrosinase‐related protein 1 and 2 expression, and increased cellular autophagy, as evidenced by the elevation of the light chain 3 (LC3)‐II/LC3‐I ratio, the upregulation of Beclin‐1 expression, and the downregulation of p62 protein expression. These findings provide a theoretical basis for developing new pharmaceutical and skin care ingredients.