Fenbendazole (Fenben Lab)
Fenbendazole (Fenben lab) is an anthelmintic used in several animal species to treat parasites and worms. It is a broad-spectrum benzimidazole and exerts microtubule depolymerization activity similar to cytotoxic anticancer agents.
We investigated its effect on tumor growth in mice by administering it via three daily i.p. injections. Tumor volume was measured weekly, and the time to reach four times the initial tumor volume was determined.
ANTHELMINTIC
Fenbendazole is a broad spectrum benzimidazole class anthelmintic that has been used worldwide since 1974. It is very effective in treating intestinal helminth parasites, such as Giardia and the tapeworm genus Taenia (but not Dipylidium caninum, the common dog tapeworm).
In addition to its anthelmintic activity, fenbendazole also has anti-parasitic properties. It works by blocking the synthesis of microtubules in parasitic cells. This can inhibit cell mitosis and prevent them from dividing. It can also be combined with other cancer-fighting drugs to increase their effectiveness.
A woman with stage 4 melanoma was taking oral fenbendazole and Doxycycline for herxing. She experienced a significant reduction in her CEA levels and an improved prognosis. However, she was still unable to get rid of all the squamous cells in her skin. Despite this, she is optimistic about her future. She will continue her treatment and hopes to be able to live a normal life in the near future.
ANTI-INFECTIVE
The benzimidazole compound fenbendazole (methyl N-(6-phenylsulfanyl-1H-benzimidazol-2-yl) carbamate) has broad antiparasitic activity in numerous animal species. It exerts its anthelmintic effect by binding to b-tubulin microtubule subunits and disrupting polymerization. Recent studies indicate that fenbendazole also exhibits moderate microtubule depolymerizing and antitumor activities in human cancer cells.
An 80-year-old woman with advanced nonsmall cell lung cancer experienced severe liver dysfunction after starting pembrolizumab monotherapy. During an interview with the patient and her family, it was determined that she had been self-administering fenbendazole for a month based on information from social media reports suggesting its effectiveness against cancer.
When fenbendazole was administered to mice with transplanted A549) human lung adenocarcinoma, the tumors significantly decreased in volume after treatment. Furthermore, fenbendazole significantly suppressed RAS-related signaling pathway expression in A549) human lung adenocarcinoma cells with a KRAS mutation. It was also found that fenbendazole significantly inhibited the growth of established human fibrosarcoma in vivo. These results suggest that fenbendazole may be a useful antitumor agent in humans by combining it with other agents to target multiple pathways involved in tumorigenesis.
ANTI-HIPPERMIC
Fenbendazole (FZ) is a broad-spectrum benzimidazole anthelmintic approved for use in numerous animal species.7 Repurposing veterinary drugs that show promise for human uses could reduce the time and cost required to develop new therapies.
In vitro and in vivo studies indicate that fenbendazole has antitumor activity by inhibiting microtubule depolymerization, suppressing RAS-related signaling pathways, and promoting cell death via multiple mechanisms.
In our study, mice bearing EMT6 mammary tumors were randomized to receive either three daily i.p. injections of fenbendazole, local tumor irradiation (10 Gy), or a combination of both treatments. After the tumors reached a volume of 1000 mm3, mice were euthanized and necropsied. Neither the number of pulmonary metastases nor the number of liver metastases was significantly reduced in fenbendazole-treated mice compared to control mice. Also, fenbendazole did not alter the radiation dose-response curve or increase the antineoplastic effects of the combined regimen. This suggests that fenbendazole acts as an antitumor agent and may be useful in combination therapy with hypoxia-selective nitroheterocyclic cytotoxins/radiosensitizers and taxanes.
ANTI-HIPOXIC
Fenbendazole is a member of the broad-spectrum benzimidazole carbamate family of drugs (I coined this group “BZ”) that has been safely used as an animal anthelmintic for six decades. It is effective against ascarids, whipworms and hookworms, as well as one species of tapeworm (Taenia pisiformis).
In vivo, fenbendazole reduces inflammation in an ovalbumin-induced asthma model. It decreases the number of eosinophils in bronchoalveolar lavage fluid and inhibits activation of CD4+ T cells. It also inhibits inflammatory mediators of allergic airway response, including Th2-derived cytokines and mast cell degranulation.
The anthelmintic effect of fenbendazole has inspired speculation that it could treat cancer in humans. However, there is no evidence that it could cure cancer or even slow tumor growth. Moreover, fenbendazole can interfere with the cellular response to other anti-cancer agents, such as paclitaxel. In the lab, it has been shown to interfere with the binding of paclitaxel to -tubulin microtubules. This can lead to an increase in the clearance of paclitaxel and reduce the efficacy of this chemotherapy drug.fenben lab fenbendazol