Safety assessment, biological effects, and mechanisms of Myrica rubra fruit extract for anti‐melanogenesis, anti‐oxidation, and free radical scavenging abilities on melanoma cells

Summary Objective Currently, the cosmetic and medical industries are paying considerable attention to solve or prevent skin damage or diseases, such as hyperpigmentation and oxidation and free radical damage. In this study, the effective compounds in Myrica rubra fruit were extracted and studied the biological effects of these M. rubra fruit extracts. Methods In this study, we extracted M. rubra fruit using solutions with various ratios of water to ethanol (100:0, 50:50, 5:95) and studied the anti‐melanogenesis, anti‐oxidation and radical scavenging effects of these M. rubra fruit extracts on two melanoma cell lines: mouse melanoma (B16‐F0) and human melanoma (A2058). The cytotoxicity, melanin synthesis, mushroom and cellular tyrosinase activities, enzyme kinetics, melanogenesis‐related gene expression, melanogenesis‐related protein secretion, radical DPPH scavenging activity and ROS inhibition after treatment with M. rubra fruit extracts were determined. Results The results showed that the water extract of M. rubra fruit was less cytotoxic to the melanoma cell lines, effectively inhibited melanin synthesis and tyrosinase activity and down‐regulated the gene expression and protein secretion of MITF and TRP ‐1. In addition, the M. rubra fruit extracts also showed the abilities to scavenge DPPH free radicals and suppress ROS production. Finally, the effective compounds in the water extract were Myricetin‐ O ‐deoxyhexoside, Quercetin‐ O ‐deoxyhexoside, and Kaempferol‐ O ‐hexoside determined by LC / MS / MS assay. Conclusion Overall, the water extract of M. rubra fruit is a safe and effective melanin inhibitor and anti‐oxidant and can be applied widely in the fields of cosmetics and medicine.