A popular TikTok video has resurfaced of a cancer patient who was said to be completely cancer-free after taking the dog deworming drug fenbendazole. Researchers are now investigating the possibility of using anthelmintics as cancer treatments.
In vitro data demonstrated that high doses of fenbendazole significantly reduced EMT6 cell viability, measured by a colony formation assay. This was confirmed by results of experiments examining the effect of three injections of fenbendazole on unirradiated tumor growth and radiation response.
Antihelminthic activity
The antihelmintic drug fenbendazole is used to treat a variety of parasitic infections in many animals, including pinworms, giardiasis, and hookworms. It is also known to have potent anti-cancer activity in lab experiments. The anthelmintic effects of mebendazole are due to its binding to beta-tubulin subunits of microtubules, which are polymers that form the cytoskeleton and provide shape and structure to cells. This binding interferes with the polymerization of the tubulin molecule, thereby disrupting cell assembly.
The fenbendazole molecule is soluble in dimethyl sulfoxide. NMR analyses confirmed that the amount of fenbendazole in samples from two different brands was consistent with what was stated on the labels. HPLC and LC-MS were also used to determine the concentration of the active ingredient.
The effect of fenbendazole on EMT6 cancer cells was measured using a rigorous colony formation assay. 2 h of treatment with graded doses of fenbendazole significantly reduced the number of cells in these cultures, as measured by both the surviving fraction and yield-corrected surviving fraction. The same results were obtained when these cultures were incubated under severe hypoxia.
Cytotoxic activity
In addition to its antiparasitic activity, fenbendazole has been shown to have significant cytotoxic effects on tumor cells. These effects appear to be due to its pharmacological properties, which overlap with those of hypoxia-selective nitroheterocyclic cytotoxins/radiosensitizers and taxanes. It also appears to inhibit microtubule polymerization. This is a similar mechanism of action as that of vinca alkaloids and paclitaxel, which are also potent cancer chemotherapeutic agents.
In experiments comparing the effect of different treatments on EMT6 tumor growth and radiation response, 2-h and 24-h treatment with fenbendazole did not alter the survival of unirradiated or irradiated cultures (Table I). Survivals were measured using a colony formation assay and yield-corrected.
A video circulating on TikTok and Facebook claims that a dog deworming drug – fenbendazole – can cure advanced lung cancer in humans. However, the video does not contain any evidence to support its claims. The claims are based on unproven medical facts, and it is dangerous to rely on untrue information in a health crisis.
Hypoxia-selective activity
The anthelmintic fenbendazole has been demonstrated to exhibit hypoxia-selective activity, as well as potent cytotoxic and antitumor activities in cell culture. The compound also acts as a radiosensitizer and has synergistic interactions with other hypoxia-selective nitroheterocyclic chemotherapeutics. Its mechanism of action is related to microtubule polymerization inhibition and glucose uptake blockade. It also inhibits the formation of glycogen stores and decreases ATP production in cancer cells.
In a study conducted by researchers at the University of Toronto, fenbendazole was found to have significant cytotoxic and antitumor effects in cancer cells. Its effectiveness was confirmed in a series of experiments, including tests on solid tumors.
In a separate experiment, fenbendazole was tested against human colorectal carcinoma (CRC) cells. The results showed that it induced cell death in the sub-G1 phase of the cell cycle, but did not induce changes in markers of autophagy or other phases. This finding suggests that fenbendazole is a candidate for future clinical use.
Radiosensitizing activity
The proliferation assays showed that the fenbendazole samples were cytotoxic against several human cancer cells. The IC50 values obtained with the AlamarBlue assay were comparable to those of fenbendazole-alone treated samples. However, combining fenbendazole with x-rays enhanced the tumor growth inhibition in EMT6 tumors, as compared to irradiation alone.
The results of this study support the hypothesis that fenbendazole has radiosensitizing activity. It is known to inhibit cell proliferation by binding to the microtubules and disrupting their formation, resulting in the death of the parasite. This mechanism of action is similar to that of some anticancer drugs.
In the present study, fenbendazole analytical standard and commercial samples from two different brands (Brand P and Brand S) were tested using HPLC, LC-MS and NMR. The NMR experiments showed that the fenbendazole is soluble in dimethyl sulfoxide and contains the quantity mentioned on the product labels. Dissolution studies were also performed to simulate the ability of fenbendazole to dissolve in the fluids of the gastrointestinal tract and be absorbed in the blood.fenbendazole for cancer
