Psoralen (Ficusin) is a furocoumarin that intercalates with DNA, inhibiting DNA synthesis and cell division.

Psoralen inhibits the proliferation of MCF-7/ADR cells as shown by G0/G1 phase arrest rather than encouraging apoptosis. Psoralen reverses MDR(multidrug resistance) through inhibiting ATPase activity rather than reducing P-gp expression. Psoralen inhibits the migration abilities of MCF-7/ADR cells by repressing EMT possibly through inhibiting the activation of NF-κB. Psoralens are photoactive compounds that readily alkylate DNA when activated by longwave ultraviolet light. Proliferation has been significantly promoted in MCF-7/ADR cells treated with low concentration of psoralen (<10.75 μM) and inhibited with high concentration(>21.5 μM). Psoralen can inhibit metastasis of breast cancer. Psoralen mediates a variety of cell processes including cell death, proliferation, inflammation and migration[1].

Psoralen has been characterized as a tumor suppressor in various tumors[1]. Psoralen ameliorates sex hormone deficiency-induced osteoporosis in female and male mice. It has antiosteoporosis effect in ovariectomy-induced osteoporotic rats via stimulating osteoblastic differentiation from bone mesenchymal stem cells[2].

The effects of psoralen on cell proliferation are measured by MTT assay. MCF-10A and MCF-7/ADR cells are cultured in 96-well plates at a cell density of 2×104 cells per well for 48 h. The medium is then removed and replaced by fresh medium containing different concentrations of psoralen (0, 21.5, 43.0, 64.5, 86.0, 107.5 μM) for 48 h. Cells in the negative control group are incubated with RPMI-1640 culture medium supplemented with 0.1% dimethyl sulfoxide (DMSO). Cells are incubated with 10 µL MTT (5 mg/mL) for 4 h, and then discarded the medium and added 200 µL DMSO. The spectrophotometric absorbance is measured at 490 nm with enzyme-labeling instrument after the crystals were fully dissolved. (Only for Reference)