Which chemotherapy agent is known for causing cell cycle phase arrest?

Plant alkaloids are known for their ability to cause cell cycle phase arrest, particularly in the M phase (metaphase) of the cell cycle. These agents, such as vincristine and paclitaxel, disrupt the normal function of the mitotic spindle during cell division, hindering the cell's ability to properly segregate chromosomes. This results in apoptosis or programmed cell death, as cells are unable to complete mitosis effectively.

In contrast, hormonal agents primarily work by influencing hormonal pathways rather than directly affecting the cell cycle phases. Alkylating agents and antimetabolites have their respective mechanisms focused on DNA damage and interfering with DNA synthesis, but they may not specifically target particular phases of the cell cycle in the way that plant alkaloids do, making plant alkaloids distinct in their cell cycle phase arrest capabilities.