Decursin in Angelica gigas Nakai (AGN) Enhances Doxorubicin Chemosensitivity in NCI/ADR-RES Ovarian Cancer Cells via Inhibition of P-glycoprotein Expression.

Angelica gigas Nakai (AGN, Korean Dang-gui) is traditionally used for the treatment of various diseases including cancer. Here, we investigated multidrug-resistant phenotype-reversal activities of AGN and its compounds (decursin, ferulic acid, and nodakenin) in doxorubicin-resistant NCI/ADR-RES ovarian cancer cells. Our results showed that a combination of doxorubicin with either AGN or decursin inhibited a proliferation of NCI/ADR-RES cells. These combinations increased the number of cells at sub-G1 phase when cells were stained with Annexin V-fluorescein isothiocyanate. We also found that these combinations activated caspase-9, caspase-8, and caspase-3 and increased cleaved PARP level. Moreover, an inhibition of P-glycoprotein expression by either AGN or decursin resulted in a reduction of its activity in NCI/ADR-RES cells. Therefore, our data demonstrate that decursin in AGN inhibits doxorubicin-resistant ovarian cancer cell proliferation and induces apoptosis in the presence of doxorubicin via blocking P-glycoprotein expression. Therefore, AGN would be a potentially novel treatment option for multidrug-resistant tumors by sensitizing to anticancer agents.