Vincristine is the generic name of a chemotherapy drug used for the treatment of certain cancer types, including leukemia, lymphoma, various childhood cancers, and mesothelioma. Laboratory development was based on the earlier use of certain medicinal plants, particularly the Madagascar periwinkle. It is in a class of drugs known as vinca alkaloid, and works as an inhibitor of cancer cell division. Cells have what is known as a cytoskeleton, which along with the mitotic spindle is made up of microtubules. The protein tubulin is necessary for the formation of microtubules, but the administering of vincristine disrupts the formation of these structures during metaphase, which partly or completely prevents proper cell division. The drug therefore destroys many of the cancer cells that are attempting division, reducing the number of these cells in the affected area.
How It Works
Catharanthus roseus, or periwinkle, is a flowering plant that for centuries was used as a folk remedy. It contains over 70 alkaloids that modern medicine has analyzed and shown to be greatly effective for a number of health conditions because of its ability to inhibit cell division. Cancer cells grow and divide more rapidly than normal healthy cells, and the use of chemotherapies such as vincristine targets these cells and destroys a percentage of them. There are a number of other cells in the body that are affected by this type of chemotherapy, especially hair cells and those involved with the immune system.
Initial studies with catharanthus roseus indicated a decreased amount of blood cell formation in the bone marrow, which led to the discovery of how these chemical compounds operate. Vincristine is administered exclusively through intravenous injection. Side effects of vinca alkaloids such as vincristine include constipation, hair loss, nausea and diarrhea. The drug is often used in combination with other chemotherapy treatments for certain individuals.
Asbestos is a natural substance that has been used extensively as an insulating compound and fire retardant. Commonly made into tiles, wraps for hot plumbing pipes, and protective clothing, asbestos fibers are quite tiny and can be inhaled if they become airborne. These fibers become embedded in the pleural lining of the lungs and may remain there for the duration of a person’s life. After years or even decades asbestos can begin to act as a carcinogen, resulting in malignant growths that are life-threatening. Mesothelioma is one such condition, largely caused by long-term exposure to asbestos. Research has suggested that vinca alkaloids such as vincristine will act as an inhibitor of mesothelioma cancer cell division; however, the drug is not a cure for mesothelioma. The U.S. Food and Drug Administration approved the use of vincristine as of 1984.