Abstract:

Li Qilin, Lu Xiaojuan, Niu Mu. Department of Dermatology, Fourth Affiliated Hospital of Jinan University, Guangzhou Red Cross Hospital, Guangzhou 510220, China Corresponding author: Li Qilin, Email: qlli_cn@163.com 【Abstract】 Objective To explore the effect of curcumin on the activity and migration of as well as c-kit mRNA expression in melanocytes. Methods Human epidermal melanocytes were isolated from the prepuce in adolescents and subjected to primary culture. To estimate the effect of curcumin on the proliferative activity of melanocytes, some melanocytes were randomly divided into several groups to be cultured in the MelM-2 medium with or without the presence of 5, 10, 20 or 30 μmol/L curcumin, the MelM-2 medium containing curcumin of 5 － 30 μmol/L served as the drug control groups, and the MelM-2 medium without curcumin served as the blank control group. After 24 and 48 hours of culture, MTS assay was performed to evaluate the proliferative activity of melanocytes. Some cultured melanocytes were randomly divided into 4 groups to be cultured in the MelM-2 medium with 0, 5, 10 and 20 μmol/L curcumin respectively for 48 hours. Then, wound scratch assay was conducted to estimate the migratory activity of melanocytes, and real-time fluorescence-based quantitative PCR to quantify the mRNA expression of c-kit in melanocytes. Statistical analysis was carried out by factorial design analysis of variance （ANOVA）, one-way ANOVA and least significant difference （LSD）-t test. Results The proliferative activity of melanocytes was significantly decreased at 24 and 48 hours in the 30-μmol/L curcumin group compared with the negative control group （0.783 ± 0.053 vs. 1.000 ± 0.018 at 24 hours, 0.637 ± 0.015 vs. 0.993 ± 0.064 at 48 hours, both P < 0.05）, while no significant differences were observed between the other curcumin groups and the negative control group （all P > 0.05）. The 48-hour treatment with curcumin could significantly inhibit the migration of melanocytes in the 5-, 10- and 20-μmol/L curcumin groups compared with the control group （all P < 0.05）. The mRNA expression level of c-kit was also significantly reduced at 48 hours in the 5-, 10- and 20-μmol/L curcumin groups compared with the control group （1.799 ± 0.372, 1.539 ± 0.224 and 1.026 ± 0.038 vs. 3.371 ± 0.352, all P < 0.05）. Conclusion Curcumin at low concentrations （≤ 20 μmol/L） has no obvious cytotoxicity against melanocytes, but can inhibit the migration of and c-kit mRNA expression in melanocytes, while curcumin at 30 μmol/L can promote the apoptosis of melanocytes.