Many modern drugs are derived from purified and concentrated plant compounds (although compared to 20 years ago, few drug companies expend time and money looking at medicinal plant chemistry these days). Rosy periwinkle (Catharanthus roseus), for example, a perennial plant native to Madagascar, is the basis for a number of commonly used cancer drugs that have been in use since the 1960s.1
Of the 70 different alkaloids found in periwinkle, the two primary compounds used in anticancer drugs are the powerful vinca alkaloids2 vinblastine and vincristine.3Alkaloids are nitrogen-containing compounds shown to be very important for human health. Within the family of alkaloids, there are those with antiparasitic, antidiabetic, anticancer, antihypertensive and/or antiasthma properties, just to name a few. Others benefit your mood.
Even the humble daffodil contains a valuable alkaloid with anticancer properties called haemanthamine. This alkaloid inhibits the protein production cancer cells depend on to grow and flourish. Berberine is yet another powerful alkaloid found in plants such as goldenseal, goldthread, Oregon grape root and barberry. These plants have traditionally been used in the treatment of Type 2 diabetes, gastrointestinal infections, liver problems and a number of other health conditions.
Berberine is particularly beneficial for mitochondrial function and is a powerful activator of AMPK, a metabolic master switch. Interestingly, glyphosate — the most widely used herbicide in the world — robs the plant of the ability to make these important medicinal compounds.
Vinca Alkaloids Are Powerful Cancer Fighters
Aside from vinblastine and vincristine, two others known for their cancer-fighting powers are vinorelbine and vindesine.4 All but vindesine have been approved for use in the U.S., and vincristine and vinblastine are included in the World Health Organization's list of essential medicines.5
A synthetic vinca alkaloid called vinflunine, developed in 2008, has since been approved in Europe for the treatment of certain types of bladder cancer. It's also being investigated for the use against other malignancies. Other medicinal applications include the treatment of diabetes and hypertension (high blood pressure). Their cytotoxic effects have gained the greatest attention, however. As explained in a 2013 paper in the International Journal of Preventive Medicine:6
"The main mechanisms of vinca alkaloid cytotoxicity is due to their interactions with tubulin and disruption of microtubule function … directly causing metaphase arrest … [T]he vinca alkaloids and other antimicrotubule agents also have an effect on both nonmalignant and malignant cells in the non-mitotic cell cycle, because microtubules are involved in many non-mitotic functions …
The vinca alkaloids and other microtubule disrupting agents have power to inhibit malignant angiogenesis in vitro. For example, [vinblastine] with concentrations range from 0.1 to 1.0 pmol/L blocked endothelial proliferation, chemotaxis and spreading on fibronectin, all essential steps in angiogenesis, but other normal fibroblasts and lymphoid tumors were unaffected at these minute concentrations.
In combination with antibodies against vascular endothelial growth factor, low doses of [vinblastine] increased antitumor response considerably, even in tumors resistant to direct cytotoxic effects of the drug. Vinca alkaloids inhibit cell proliferation by binding to microtubules, which can cause a mitotic block and apoptosis …
Side effects of [vinblastine] consist of toxicity to white blood cells, nausea, vomiting, constipation, dyspnea, chest or tumor pain, wheezing and fever. It is also rarely associated with antidiuretic hormone secretion."
Vinca alkaloids are the second most-used class of cancer drugs today. They've also been used the longest. Vinca alkaloids were originally discovered by two Canadian scientists, Robert Noble and Charles Beer, in the 1950s.7
During that time, Gordon Svoboda, a medical researcher at Eli Lilly, also added periwinkle to his list of research subjects, having heard reports of its use for diabetes during World War II. In 1958, Gordon discovered extract from the plant also performed remarkably well in anticancer tests.
That same year, Noble and Beer presented their own anticancer findings at a research symposium at the New York Academy of Sciences. Notably, the two teams (Eli Lilly and Noble/Beer) concluded that since periwinkle extract lowered white blood cell counts, it might be useful against leukemia — a disease characterized by white blood cell proliferation.
Beer was responsible for isolating vinblastine, which he named. Eventually, Eli Lilly and Noble/Beer established a joint research collaboration, which led to the development of two chemotherapy drugs. Vincristine gained approval as a chemotherapeutic agent by the U.S. Food and Drug Administration (FDA) in 1961. Vinblastine gained FDA approval in 1963. Many other countries around the world approved the two drugs shortly thereafter.