Fenbendazole is an orally administered benzimidazole anthelmintic used in dogs (as a dewormer for Giardia), cats, horses, goats, sheep, cattle, fish, reptiles, and freshwater shrimp tanks as a planaria and hydra treatment. It is also used to treat gastrointestinal parasites in ferrets and rabbits. In addition to its broad spectrum anthelmintic activity, fenbendazole has been shown to have anti-cancer effects in cancer cells and in vivo in animal models.
The drug has a unique mode of action, binding to the host cell’s b-tubulin and inhibiting the function of the microtubule network around the nucleus, thus causing the dissociation of host proteins and apoptosis. It has been shown to induce apoptosis in 5-FU-sensitive colorectal cancer cells and in 5-FU-resistant CRC cells through both p53-dependent and -independent pathways.
It has also been shown to have anti-tumor activities in vivo, showing efficacy against the nematodes Heterobilharzia americana and Crenosoma procyonis; against the cestodes Dipylidium caninum and Taenia spp.; and against the trematodes Heterobilharzia leonina and Nanophyetus salmincola. It is also effective as a preventative against infestations caused by the cysticercus flea beetle in guinea pigs.
To determine the effect of fenbendazole on radiation response, tumor-bearing mice were randomized to receive either three daily injections of 50 mg/kg/day fenbendazole (fenb) or fenb plus 10 Gy of X-rays, resulting in 3 groups of 8 animals per group. Upon x-ray analysis, there were no significant differences in tumor size between the fenb/fenb + X-rays treated and control groups. fenbendazole capsules