To explore the potential mechanisms of germacrone induced cell
cycle arrest and toxicity, the expression of several proteins related to cell
cycle regulation and apoptosis was determined by Western blotting.
Germacrone induced a signifi cant decrease of phospho-ATR (Ser428)
(Fig. 3E1), phospho-cdc2 (Tyr15) (Fig. 3E2), phospho-Rb (Ser795)
(Fig. 3E3), and cdc2 (Fig. 3E4) protein expressions in a dose-dependent
manner. Compared with untreated cells, germacrone treatment did not
result in a significant alteration of Bcl-2, Bcl-xL, Bax, and Bim protein
expressions. However, the expression of Bok was dramatically upregulated in a dose-dependent manner