Fenbendazole, the broad-spectrum benzimidazole anthelmintic drug used to treat parasitic worms in animals, may also kill cancer cells. This was revealed in a study published in the journal Scientific Reports on February 20, 2023, by McMaster University scientist Sheila Singh. Singh is the director of McMaster’s Centre for Discovery in Cancer Research. Fenbendazole is currently approved by Health Canada for veterinary use to treat parasitic helminths in dogs, cats, horses, and pigs. It is also an ingredient in some over-the-counter antihelminthic pet medications. The anthelmintic class of drugs is also being studied as potential cancer treatments for humans.
The cellular activity of fenbendazole causes it to bind to tubulin and disrupt its microtubule equilibrium. The disruption prevents tubulin from polymerizing into its normal state, blocking cell division. It also blocks glucose uptake by inhibiting GLUT 4 (glucose transporter isoform 4) expression, thereby starving cancer cells of their energy source. The researchers found that both a 2-h treatment and a 24-h treatment of EMT6 cells with high concentrations of fenbendazole significantly reduced the number of cells in monolayer cultures, as well as their clonogenicity. In vivo, they found that in a mouse model of EMT6 lung tumorigenesis, three daily injections of fenbendazole, either in the diet or given by intraperitoneal injection, significantly reduced tumor volume and increased the percentage of mice alive at four-times the initial tumor size when compared to untreated controls. These effects were not observed in irradiated tumors, although in these mice, the fenbendazole treatment also reduced lung metastasis.
In addition to these cytostatic effects, fenbendazole is known to kill helminthes by disrupting their cell membrane and preventing them from absorbing nutrients. It is thought that the sensitivity of helminthes to fenbendazole results from differences in its binding to tubulin and its inhibition of polymerization in different organisms, as well as the low absorption of fenbendazole through the gut wall.
Despite the lack of scientific data on human patients, many people have taken fenbendazole for cancer, and claim to have experienced positive results. A search of the European Medicine Agency’s public database reveals that a single dose of up to 2,000 mg per person for ten days appears to be well tolerated by the body, with only minor side effects reported.
However, some supplements can interact with fenbendazole and reduce its effectiveness. For this reason, it is recommended that anyone taking fenbendazole for cancer consult a medical professional first. This is especially important for people who are already receiving chemotherapy or are taking certain other medications. fenbendazole for humans