Researchers from Panjab University have found that fenbendazole (methyl N-(6-phenylsulfanyl-1H-benzimidazol-2-yl)carbamate) a broad-spectrum anti-parasitic drug used in veterinary medicine, could be effective against cancers. Their findings were published in Scientific Reports.
The drug is not currently available for treating cancer, as it hasn’t undergone clinical trials. It is a parasitic drug used to treat pinworm infections in dogs.
Microtubule Interference
Researchers have discovered that fenbendazole (methyl N-(6-phenylsulfanyl-1H-benzimidazol-2-yl) carbamate) is an effective antitumor drug, causing preferential elimination of cancer cells in vitro and in vivo. It acts by disrupting microtubule dynamics, resulting in mitosis-specific cell death as well as triggering several cell cycle-independent apoptosis mechanisms.
The team screened human non-small cell lung cancer cell lines and found that fenbendazole caused partial disruption of the microtubule network in cancer cells. This led to an increase in the amount of cyclin B and a decrease in p53 protein expression. Moreover, the drug also interfered with glucose metabolism in cancer cells, leading to a significant reduction in their proliferation.
To test if fenbendazole could also stop tumour growth in vivo, the team transplanted human lung adenocarcinoma tumour cells into athymic nu/nu mice. When fenbendazole was given orally at 1 mg/mouse every second day for 12 days, tumours shrunk and tumour weight dropped significantly.
To further assess the effectiveness of fenbendazole, the team compared it to three different drugs that were used in combination with radiation therapy to treat EMT6 mammary carcinoma tumors in BALB/cRw mice. Febendazole reduced tumour volume and did not alter the dose-response curves of the chemotherapeutic agents. It also enhanced the cytotoxic effects of radiation on tumours, suggesting that it may be an effective agent in the treatment of solid tumours.
p53 Stabilization
p53 is one of the most important genes in cancer treatment. It is responsible for controlling cell growth, preventing the formation of tumors, and suppressing cell mutations that may contribute to cancer development. However, if the p53 gene is mutated, it can no longer function properly. Mutations in the p53 gene are commonly found in human cancers. The p53 gene is also responsible for determining whether a tumor will respond to chemotherapy.
Researchers have found that fenbendazole stabilizes the wild-type (WT) p53 protein and provides moderate microtubule disruption, both of which have been linked to preferential elimination of cancer cells in vivo and in vitro. The drug also inhibits glucose uptake by cancer cells and thereby blocks the production of energy that they need for survival.
These results suggest that fenbendazole is an effective treatment for a variety of cancers. The drug could potentially be used in combination with other therapies, such as immunotherapy, to treat a wider range of cancers. Moreover, the drug’s ability to fix mutated p53 genes could prevent cancer from developing in the first place by correcting any broken ones before they cause problems. This research is ongoing, and randomized clinical trials will be needed to confirm these results. Until then, cancer patients should not attempt to self-treat with fenbendazole. One case of an 80-year-old lung cancer patient who received information about the antitumor effects of fenbendazole from social media and self-administered it orally to treat her disease resulted in severe liver injury.
Interference with Glucose Metabolism
Fenbendazole acts by interfering with the formation of microtubules, which are components of a protein scaffolding that gives cells their shape and structure. While textbook depictions of cells usually show them as amorphous bags of water, the cytoskeleton provides the cell with an internal framework to build upon and transport various organelles within. One of the critical functions of a cellular cytoskeleton is to ensure that chromosomes are evenly separated during cell division (mitosis). Drugs that interfere with this process can also inhibit cellular growth and activity.
In addition to the antimicrotubule effects of fenbendazole, this drug has also been shown to inhibit glucose uptake in cancer cells. This is important because tumor cells require large amounts of glucose for energy and to grow. A study conducted in vitro found that fenbendazole reduces the ability of human lung adenocarcinoma cells to uptake glucose.
However, there is insufficient evidence to support the claim that fenbendazole cures cancer. While studies in petri dishes and mice have shown that this drug can slow down cancer growth, there isn’t any data showing that it actually cures the disease. Moreover, there are other reasons Tippens may have gone into remission besides his alleged fenbendazole treatment, such as conventional cancer treatments he received in a clinical trial. As such, randomized trials involving large numbers of patients would need to be performed before this claim can be made with any confidence.
Anti-Cancer Effects
Some studies have found that fenbendazole can block cancer cell growth in laboratory experiments (in vitro).[1] However, researchers haven’t tested whether the drug can cure cancer in humans. It’s not the only anthelmintic drug to have been claimed to be an anticancer treatment. Mebendazole, another benzimidazole carbamate anthelmintic medication, has been shown to slow cancer progression in mice and human pancreatic cells.[2] The drug phenobarbital has also been shown to be effective against some cancers in animal studies.
The claims about fenbendazole being an anticancer drug have mostly appeared on social media platforms. They often come from people who say they have been diagnosed with cancer and are taking the drug. They claim the drug has cured their cancer and encourage others to do the same.
Several studies have reported that fenbendazole can suppress the proliferation of colorectal cancer cells.[2] In one study, fenbendazole was shown to block the ability of the cancer cells to take up glucose for energy.[3] It was also observed that the drug could cause the cancer cells to undergo apoptosis or cell cycle arrest.
But a specialist cancer information nurse tells Full Fact that fenbendazole won’t cure cancer. She says the drug hasn’t been tested in randomized clinical trials in humans and there is no evidence it works. Moreover, there are already other drugs that have been proven to be effective against various types of cancer in randomized clinical trials. fenbendazole for humans cancer