The anthelmintic drug fenben (also known as Pancur and Safe-Guard) is typically prescribed by veterinarians to treat parasites and worms in pets. However, it is also commonly used by humans as part of a treatment protocol known as the Joe Tippens protocol for cancer.
To better understand the mechanism of action of fenben against cancer, we treated 5-fluorouracil-resistant SNU-C5 and SNU-C5/5-FUR colorectal cancer cells with fenbendazole. Cell viability, apoptosis, and cell cycle analysis were evaluated by flow cytometry. The results showed that fenbendazole significantly induces apoptosis and arrests the G2/M phase in SNU-C5 cells, while promoting autophagy and ferroptosis in SNU-C5/5-FUR cells. It is likely that fenbendazole triggers apoptosis by p53-p21 pathway in SNU-C5 cells and autophagy-mediated apoptosis through Beclin-1 and LC3-I in SNU-C5/5-FUR cancer cells. Moreover, it was found that fenbendazole inhibits necroptosis through decreased expression of GPX4 in SNU-C5/5-FUR tumor cells.
This study demonstrates that information about fenben has been widely disseminated on social media and internet. Physicians should inform patients that there is no scientific evidence about the effectiveness of fenben as an alternative medicine and should help them to acquire accurate medical information by suggesting the sources that are verified. Physicians should also enquire whether patients are self-administering dietary supplements or other non-FDA-approved products and check the quality of information. In particular, physicians should carefully evaluate the source and validity of information obtained from YouTube as well as other websites.