Conferone, a coumarin from Ferula flabelliloba, induced toxic effects on adult T-cell leukemia/lymphoma cells.

Background: Adult T-cell leukemia/lymphoma (ATL) is a lymphoid malignancy caused by HTLV-1 infection, with distinct geographical distribution. Despite advances in cancer treatment, the average survival rate of ATL is low. Conferone is a natural coumarin extracted from Ferula species with a wide range of pharmaceutical effects. In search for a novel chemotherapeutic agent, we investigated the cytotoxicity of conferone on ATL cells.

Methods: To obtain conferone, the methanolic extract of the roots of F. flabelliloba was subjected to silica gel column chromatography, followed by ¹H- and ¹³C-NMR to confirm its structure. For cytotoxicity assay, MT-2 cells were treated with different concentrations of conferone (2.5, 5, 10, 20, and 40 µM) for 24, 48, and 72 h, and viability was evaluated by a colorimetric assay using alamarBlue. Cell cycle was analyzed by PI staining and flow cytometry, and qPCR was used to study the expression of candidate genes.

Results and conclusion: Obtained findings indicated that conferone induced considerable cytotoxic effects on MT-2 cells in a time- and dose-dependent manner. In addition, accumulation of cells in the sub-G₁ phase of the cell cycle was detected upon conferone administration. Moreover, conferone reduced the expression of CDK6, c-MYC, CFLIP_L, and NF-κB (Rel-A) in MT-2 cells. Accordingly, conferone could be considered as a potent agent against ATL, although complementary investigations are required to define more precisely its mechanism of action.