Bergapten (5-Methoxypsoralen), a psoralen, inhibits cell replication.

5-Methoxypsoralen (5-MOP) is dissolved in DMSO and stored, and then diluted with appropriate medium (final DMSO <0.1%) before use[1]. The human colon adenocarcinoma cell line (COLO 205, from a 70-year-old male Caucasian) sre placed into 75-cm2 tissue culture flasks and grown in RPMI1640 medium, supplemented with 10% fetal bovine serum, containing penicillin and streptomycin (100 Ig/mL) and 1 mM glutamine, at 37°C in a humidified atmosphere of 5% CO2 and 95% O2. The human stomach adenocarcinoma cell line are placed into 75-cm2 tissue culture flasks and grown in RPMI 1640 medium, supplemented with 10% fetal bovine serum, containing penicillin and streptomycin (100 Ig/mL) and 1 mM glutamine, at 37°C in a humidified atmosphere of 5% CO2 and 95% O2. SC-M1 and COLO 205 cells are treated with different concentrations of 5-MOP (0.05, 0.5, 5, 10, 25 and 50 mM) and incubated for 72 h for the dose-effect study of 5-MOP on NAT activity. To determine the time-course effect of 0.5 mM 5-MOP on NAT activity, the cells are incubated at 37AC and harvested at 12, 24, 48 and 72 h, respectively. 5-MOP is dissolved in DMSO and the final concentration of vehicle is <0.1%. Only DMSO (solvent) is added for the control regimen[1].