chrysin and acetyl-aspartyl-glutamyl-valyl-aspartal

The antitumor activity of 7-piperazinethylchrysin (7-PEC) was investigated in HCT-116 human colon cancer cells. MTT assay revealed that the IC50 of 7-PEC in HCT-116 cells was 1.5 µM after 72 h of treatment, much lower than that of chrysin (>100 µM). The data showed that 7-PEC was able to inhibit the growth of HCT-116 cells in a concentration- and time-dependent manner. Topical morphological changes of apoptotic body formation after 7-PEC treatment were observed by Hoechst 33258 staining. 7-PEC reduced mitochondrial membrane potential (∆Ψm) of cells in a concentration-dependent manner and increased the production of intracellular reactive oxygen species (ROS). After treatment with 7-PEC, a significant increase of Bax protein expression and decrease of Bcl-2 protein expression were observed at the same time. These events paralleled with activation of p53, caspase-3 and -9 and the release of cytochrome c (cyt‑c), as well as poly(ADP-ribose) polymerase-1 (PARP1) cleavage and downregulation of p-Akt. However, the apoptosis induced by 7-PEC was blocked by Ac-DEVD-CHO, a caspase-3 inhibitor. These results demonstrate that 7-PEC-induced mitochondrial dysfunction in HCT-116 human colon cancer cells triggers events responsible for caspase-dependent apoptosis pathways, and the elevated ratio of Bax/Bcl-2 is likely involved in this effect.

Topics: Antineoplastic Agents; Apoptosis; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Caspase 3; Caspase 9; Caspase Inhibitors; Cell Survival; Colorectal Neoplasms; Cytochromes c; Down-Regulation; Flavonoids; HCT116 Cells; Humans; Membrane Potential, Mitochondrial; Mitochondria; Oligopeptides; Piperazines; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Tumor Suppressor Protein p53