Apigenin treatment induces dose-dependent apoptosis in T24 human bladder cancer cells. (A) Dose-dependent apoptosis induced by treatment with apigenin in T24 bladder cancer cells. Cells treated with various concentrations of apigenin were double-stained with annexin V and PI and analyzed by flow cytometry. The gate setting distinguished between living (bottom left), necrotic (top left), early apoptotic (bottom right), and late apoptotic (top right) cells. (B) The percent of total apoptotic cells was quantified from three independent experiments. * P < 0.05, ** P < 0.01 versus untreated control. (C) Apigenin treatment activates caspase-3 and PARP in T24 human bladder cancer cells. The expression of proteins in treated cells was analyzed by Western blotting as detailed in Methods. A representative blot is shown from three independent experiments with identical results.