Journal: The Open Plant Science Journal
Author(s): Y. Hirata, M. Tatsu, C. Amano, Y. Kawaratani, M. Hirata, Y. Ohmomo, Y. Nagaoka, M. Shibano, T. Sasaki, S. Uesato, M. Taniguchi
As was reported, gefitinib (Iressa®) showed a strong growth inhibitory effect on non-small-cell lung cancer PC-9 cells with mutant EGFR, but did not so much on A549 cells with wild-type EGFR.
We here demonstrated by isobolograms and combination index analyses that the paired combinations of gefitinib with flavonoids from Wogon (Scutellaria baicalensis root): wogonin, oroxylin A and chrysin exerted synergistic anti-tumor effects against A549 cells.
The cell cycle analyses revealed that the combination of gefitinib and oroxylin A in A549 cells induced more apoptotic cells than other paired combinations as well as gefitinib alone. Thus, it is anticipated that oroxylin A could help to enhance the remission rate in the gefitinib therapy for the patients with non-small cell cancer cells with wild-type EGFR which provide a poor prognosis.
Since the Wogon flavonoids, wogonin, oroxylin A and chrysin, accelerated the acetylation of Lysine residues of histone proteins, it is suggested that they put forth anti-tumor activities through inhibition of histone deacetylases which mediated the post-translational modification of histones.