Table of Contents
Fenbendazole for humans cancer has received a lot of attention after a series of videos by a Canadian veterinarian were posted on TikTok and Facebook. These videos promoted a deworming medication called fenbendazole as a cure for cancer.
The drug works by collapsing the tubulin microtubule balance in helminthes and starving them of nutrients. It also has cytotoxic effects in tumor cells.
Antiparasitic activity
Originally used as an antiparasitic agent against gastrointestinal parasites such as pinworms, roundworms, hookworms, and Taenia solium, fenbendazole (methyl N-(6-phenylsulfanyl-1H-benzimidazol-2-yl) carbamate) works by binding to b-tubulin microtubule subunits and disrupting their polymerization. These structures are both the skeleton of the cell and a highway for transporting nutrients within the cell. By collapsing these structures, fenbendazole starves cancer cells of the energy they need to grow and survive.
Cellular growth was measured by the AlamarBlue assay, while mitosis was monitored by flow cytometry. The results showed that fenbendazole inhibited the proliferation of all four human cancer cells tested, except for MCF7.
To test the effects of hypoxia on fenbendazole toxicity, cultures were made hypoxic by sealing culture bottles with rubber gaskets, inserting needles for the inflow and outflow of gases, and gassing them with a mixture of 95% nitrogen/5% carbon dioxide with 1 ppm oxygen for 2 h before treatment. Survival curves in cultures treated under hypoxia and those in air showed that a lower drug concentration was required to achieve similar results.
Cytotoxic activity
The anthelmintic fenbendazole has cytotoxic and cytostatic activities in cell cultures. These effects have been linked to its ability to inhibit microtubule growth in cancer cells, thereby blocking their proper function. These cells need microtubules to maintain their structure and support other cellular processes. The drug also stops the formation of new mitochondria, which helps to kill them.
Using the in vitro AlamarBlue assay, commercial samples of fenbendazole analytical standard and Brand P and Brand S all exhibited similar activity against most human cancer cells, with the exception of COLO699N lung adenocarcinoma and HuNS1 multiple myeloma. However, commercial Brand S showed greater cytotoxicity than the analytical sample.
NMR experiments also confirmed the presence of fenbendazole in all three commercial samples and showed that it is well soluble in dimethyl sulfoxide. This information was used to develop a quick, robust HPLC method that can accurately measure fenbendazole in samples from different batches of the two commercial brands.
Toxicity
Indian scientists have found that fenbendazole, a broad-spectrum antiparasitic drug used in the veterinary sector, can be useful against human cancer. In a study published in Scientific Reports, they found that fenbendazole can kill cancer cells by inhibiting their glucose uptake. This is a crucial step in preventing the proliferation of cancerous cells, as it prevents the formation of new glucose-rich DNA.
Fenbendazole is a benzimidazole that acts by interfering with the formation of microtubules, a protein scaffold in cells. This process is responsible for establishing the shape and structure of cells. While textbook depictions of cells appear to be amorphous bags of water, they establish their structure and movement through the cytoskeleton, which is composed of microtubules.
Treatment with fenbendazole caused a significant decrease in the viability of colorectal cancer cells, including those resistant to 5-fluorouracil. It also induced necroptosis in these cells. This effect was accompanied by decreased expression of p53 and decreased autophagy and ferroptosis.
Safety
Fenbendazole is a broad-spectrum anthelmintic used to treat gastrointestinal parasites (pinworms, giardia, tapeworms, hookworms, and Taenia solium) in humans, dogs, cats, horses, cattle, sheep, and rabbits [3]. This drug acts by binding to beta-tubulin and disrupting the formation of microtubules, which provides structure and shape to cells. This is a similar mechanism of action to some anticancer drugs, including vinca alkaloids (vinblastine, vincristine, and vinorelbine) and taxanes (paclitaxel and docetaxel).
For HPLC and LC-MS analysis, the analytical standard fenbendazole, as well as samples from two different LOT numbers of commercial Brand P and Brand S powders, were dissolved in hydrochloric methanol (0.4% w/v). Samples were collected at the indicated times, and the solution was then filtered with 0.45-m PTFE filters.
Although Tippens’ anecdotal experience may be valid, there is no sufficient evidence that fenbendazole cures cancer in humans. Moreover, there are several established treatments for cancer that work differently and are more likely to lead to a cure.