Fenbendazole is a common antiparasitic drug used to treat parasitic worm infections and has recently gained interest for its reported effectiveness in cancer therapy. It destroys microtubules that maintain the structure of cancer cells, interrupts the ability of cancer cells to metabolize sugar, and boosts the production of a tumor-destroying gene in some cancer patients. The FDA has approved the use of a dietary supplement containing 222mg per day of fenbendazole called Panacur C. This dietary supplement is currently available in Canada and the UK under the name of Panacea Plus C.
To investigate the effects of a diet containing fenbendazole on the growth and radiation response of EMT6 tumors in SCID mice, 20 vendor-supplied 4-wk-old SCID mice were randomized at 100 mm3 of tumor volume into four groups: standard diet, control, fenbendazole, and fenbendazole + vitamins. Blood counts were measured at initial and terminal times, and final total white cell and neutrophil counts in fenbendazole-treated mice were significantly (p=0.001 and p=0.04) lower than those of controls.
2 and 24 h treatments with fenbendazole did not significantly affect the viability of aerobic EMT6 cells in monolayer cultures, but high doses (close to the solubility limit) of fenbendazole were toxic to the cells by reducing both clonogenicity and number of cells in the cultures. These data suggest that fenbendazole is not an effective radiosensitizer at the concentrations employed here.
Treatment with fenbendazole prior to and during radiation did not alter the dose-response curve for aerobic or hypoxic EMT6 cells in vitro, indicating that it does not sensitize these cells to radiation. However, a combination of fenbendazole with the hypoxia-selective nitroheterocyclic cytotoxic agent docetaxel produced additive toxicity in EMT6 cells. sanare lab fenbendazole