The anthelmintic, fenben, has been used to treat several diseases in cattle and other animals. It has been marketed as a cancer cure by unlicensed veterinarians on social media platforms like Facebook and TikTok. However, a recent case study on a patient with advanced NSCLC who self-administered the drug suggests that fenben is not effective against tumors.

The author and other authors do not have any financial interest in the drug or company. This article is based on a research project funded by the University of Saskatchewan.

Cells were treated with 0.5 and 5.0 mM fenbendazole (Sigma, St Louis, MO, USA) for 2 h in hypoxic conditions by sealing the glass culture bottles with rubber gaskets, inserting needles for the influx and efflux of gases, and gassing with a humidified mixture of 95% nitrogen/5% carbon dioxide containing 1 ppm oxygen before treatment (25, 26). Fenbendazole treatment induced autophagy via Beclin-1 in SNU-C5 and SNU-C5/5-FUR cells, as indicated by increased expression of LC3-I and Atg7. However, apoptosis was not affected by fenbendazole in both CRC cells.

In addition, fenbendazole did not alter the radiation dose-response curves of aerobic or hypoxic EMT6 cells and inhibited neither p53-induced apoptosis nor ferroptosis-augmented apoptosis in these cells. This finding indicates that the benzimidazole-induced cell death is mainly triggered by p53-mediated apoptosis and not through necroptosis, which requires the phosphorylation of MLKL. The low expression of SLC7A11 and GPX4 is also suggested to contribute to the observed ferroptosis.