Antimelanogenesis of quercetin-related compounds in B16 melanoma cells: the difference moieties of C-3 position and its effect on H2O2

Abstract Quercetin (compound 2), isolated from the dried skin of Allium cepa, and 3-prenyl luteolin (compound 6), derived from the wood of Artocarpus heterophyllus, are polyphenolic compounds with demonstrated potential in regulating melanogenesis. This study investigated their anti-melanogenic activity and reactive oxygen species (ROS) scavenging effects, particularly against hydrogen peroxide (H₂O₂), in B16 melanoma cells. Both compounds significantly suppressed melanin synthesis, indicating potential as natural depigmenting agents. Quercetin (2) exhibited a half-maximal inhibitory concentration (IC₅₀) of 8.0 µg/mL, while 3-prenyl luteolin (6) showed an IC₅₀ of 20.1 µg/mL. For comparison, compound 1 displayed the strongest activity with an IC₅₀ of 3.0 µg/mL, whereas compounds 3–5 demonstrated no appreciable inhibitory effects. Additionally, both compounds reduced intracellular H₂O₂ levels, supporting their antioxidative role in mitigating oxidative stress-induced melanogenesis. These findings highlight the potential application of quercetin and 3-prenyl luteolin as novel active ingredients in skin-whitening formulations through dual mechanisms of melanin synthesis inhibition and ROS reduction.