Formononetin promotes apoptosis of colorectal cancer cells via activation of mitochondria-dependent MAPK pathway

Purpose: To investigate whether formononetin exhibits antitumor activity in colorectal cancer cell lines via the mitochondria-dependent mitogen-activated protein kinase (MAPK) pathway. Methods: Human colorectal cells were treated with various doses of formononetin for 24 h, followed by Cell Counting Kit-8 (CCK-8) assay and western blot. Human colorectal cells were incubated with equivalent vehicle (DMSO) or 100 mu M formononetin for 24 h, followed by nuclear staining with propidium iodide (PI) and diamidino-2-phenylindole (DAPI) for analyses of apoptosis. Human colorectal cells were incubated with equivalent vehicle or 100 mu M formononetin for 24 h followed by analysis of cell migration and invasion. Human colorectal cells were incubated with equivalent vehicle (DMSO) or 100 mu M formononetin for various duration (3, 6, 12, and 24 h), followed by detection of intracellular reactive oxygen species (ROS) level and measurement of mitochondria/ membrane potential (Lipm) to monitor mitochondria functionality. Results: In human colorectal cancer cell lines SW1463 and T84, formononetin (> 20 mu M) significantly inhibited cell growth (p < 0.05) in a dose-dependent manner, noticeably induced apoptosis, and suppressed cell migration and invasion. Western blot analysis revealed that formononetin treatment caused significantly increased levels of proapoptotic proteins, and suppression of cell proliferatio-nrelated protein and matrix metallopeptidases (MMP) levels. Formononetin also induced mitochondria/ depolarization and ROS generation in a time-dependent manner, indicating that formononetin mediates human colorectal cancer cell apoptosis via activation of MAPK pathway in a dose-dependent manner. Conclusion: Formononetin induces human colorectal cancer cell apoptosis via mitochondria-dependent MAPK pathway, thus lending experimental support for the clinical application of formononetin for colorectal cancer therapy.