Inhibitory Effects of Carnosic Acid on Melanin Synthesis

Purpose: This research was carried out to ascertain the whitening effects of carnosic acid on a B16F1 mouse melanoma cell line.Methods: It involved quantitative assessments based on cell viability and assays of gene expression, tyrosinase enzyme activity, and melanin contents. The effects of carnosic acid on tyrosinase (TYR)/microphthalmia-associated transcription factor (MITF)/ tyrosinase-related protein 1 (TYRP1)/TYRP2 messenger ribonucleic acid expression levels and melanin content were determined.Results: Real-time quantitative reverse transcription polymerase chain reaction (real-time qRT-PCR) showed that carnosic acid decreased the expression levels of TYR/MITF/TYRP1/TYRP2 and melanin content compared to alpha-melanocite-stimulating hormone-treated B16F1 cells. The tyrosinase activity assay also revealed that carnosic acid decreased melanin production in B16F1 cells.Conclusion: These data indicate that carnosic acid increases the whitening effects on the B16F1 cells. Therefore, carnosic acid is a potential ingredient that can be used for skin whitening. Additionally, further research on the mechanisms of the action of carnosic acid should be conducted for the development of functional foods, cosmetics, and medicines.