Tyrosinase Inhibitory Activity of Rosmarinic Acid on Human Skin Melanoma Cells Treated with Hydrogen Peroxide

• Published in: Laboratory animal research Vol. 25; no. 2; pp. 95 - 100
• Main Authors: Kang, J.R., Konkuk University, Seoul, Republic of Korea, Yoo, S.M., Dongkang College, Gwangju, Republic of Korea
• Format: Journal Article
• Language: Korean
• Published: 한국실험동물학회 01.06.2009
• Subjects: HYDROGEN PEROXIDE; microscopic; MTT; PEROXIDO DE HIDROGENO; PEROXYDE D'HYDROGENE; Rosmarinic acid; tyrosinase inhibitory activity; 수의학; Rosmarinic acid; tyrosinase inhibitory activity; microscopic; MTT
• ISSN: 1738-6055; 2233-7660

The purpose of this study was to evaluate the tyrosinase inhibitory activity of rosmarinic acid on the cultured human skin melanoma cells damaged by reactive oxygen species (ROS). The cytotoxicity effect was analyzed by MTT assay for cell viability, tyrosinase inhibitory activity after treating the cells with or without hydrogen peroxide (H₂O₂) for 1-10 hours. Light microscopic study was also carried out for morphological changes of the cells and tyrosinase activities. H₂O₂ decreased the cell viability in the cultured human melanoma cells in a dose- and time-dependent manner after cells had been treated with 20-80 μM of H₂O₂ for 7 hours. IC∧50 value of H₂O₂ by the MTT assay was 80 μM. Rosmarinic acid increases cell viability, inhibitory activity of tyrosinase. In light microscopic study, the number of human skin melanoma cells treated with H₂O₂ was decreased compared with control, and H2O2 activated tyrosinase activity, which was observed through darkened cell color (mid-activity, +++). However, colors of cells treated with Rosmarinic acid changed from white to brown in cell staining due to tyrosinase activity (moderate-activity, ++). The treatment of the cells with H₂O₂ shows highly toxic effects on cultured human skin melanoma cells. Rosmarinic acid increases cell viability and tyrosinase inhibitory activity in the cells treated with H₂O₂. It is considered that Rosmarinic acid shows tyrosinase inhibitory effect on ROS such as H₂O₂.