Fenben is a broad-spectrum anthelmintic that has been in use for decades. It is a member of the benzimidazole carbamate family of drugs (I coined this group Benz) and it has a good track record in animals. There are several other drugs in this class that have entered the clinical trial stage as cancer treatments but it is a long road to turn these results into an approved drug. A McMaster University researcher has found similarities between parasitic behavior and some types of cancer but there is no evidence to date that animal anthelmintics can cure human cancer.
The fenben cancer treatment has gained traction online after some anecdotal reports of patients whose cancer went into remission. The protocol calls for the use of a dog deworming medication called fenbendazole (Panacur C) as well as other supplements and lifestyle changes. The claims have gone viral on social media platforms like Facebook and TikTok.
A broad-spectrum anthelmintic drug, fenbendazole, also known as 5-(methylsulfanyl)-1H-benzimidazol-2-yl] carbamate, is able to kill parasites by binding to beta-tubulin and disrupting the formation of microtubules in parasitic cells. This mechanism of action is similar to that of some anticancer drugs.
Fenbendazole is used to treat a variety of parasitic diseases in humans and animals including pinworms, tapeworms, and hookworms. Some research has found that fenbendazole may inhibit the growth of tumors in cell cultures and mice. However, there is no evidence that fenbendazole cures cancer in people.
This article aims to evaluate the cytotoxic effects of fenbendazole and its commercial formulation, which has been formulated for human consumption, against a panel of cancer cell lines. The chemistry of the drug, which belongs to the class of antiparasitics, shows some similarities to certain anticancer drugs and it has been shown to exhibit some cytotoxic activity in animal studies.
To determine the toxicity of fenbendazole, two commercial samples of the drug were purchased: Brand P (panacur) and Brand S (safe-guard). The chemical composition of the drugs was determined using a USP Apparatus 2, Model RCZ-8B Type Medicine Dissolving Instrument. Both formulations were subjected to quantitative and qualitative dissolution tests in methanol for LC-MS analysis.
In vitro experiments analyzed the effects of graded doses of fenbendazole on the viability of exponentially growing EMT6 cells in cell culture, both at aerobic and hypoxic conditions. Results show that fenbendazole exhibits a concentration-dependent toxicity with cell numbers decreasing rapidly at low drug concentrations and reaching a plateau at higher doses. Severe hypoxia significantly increased the toxicity of 2-h treatments of cells with fenbendazole.