Synergistic Antioxidant and Skin-whitening Effects of Co-extracts of Rubus coreanus, Lycium chinense, and Epimedium koreanum

Background: This study investigates the synergistic antioxidant and skin-whitening effects of Rubus coreanus, Lycium chinense, and Epimedium koreanum co-extracts to develop functional cosmetic ingredients. Methods and Results: Single extracts and co-extracts at various ratios were analyzed for antioxidant compounds using HPLC-DAD and LC-MS/MS. Skin-whitening efficacy was evaluated using tyrosinase inhibition and melanin synthesis assays in B16F10 melanoma cells. The 3:1 co-extract of R. coreanus and L. chinense exhibited the highest synergistic increase in total polyphenols and ellagic acid. Furthermore, this specific combination demonstrated maximum tyrosinase inhibition (100%) and significantly reduced cellular melanin synthesis (71.1%) without inducing cytotoxicity. Conclusion: The 3:1 mixture of R. coreanus and L. chinense was the most effective combination, demonstrating the strongest synergistic effect on both antioxidant and skin-whitening activities.