Fenben lab fenbendazol, a member of the benzimidazole class of anthelmintics, is an established treatment for intestinal helminths in a wide variety of animal species. It is also effective against praziquantel-resistant schistosomiasis in humans by injection. It is available as tablets, a feed additive, and injectable formulations for domestic animals. In addition, fenbendazole is effective against pulmonary helminths such as lungworms in dogs and cat flukes, as well as nematodes such as girdling cysts in sheep.

In a previous study (10), we found that high concentrations of fenbendazole reduced the clonogenicity of EMT6 tumor cells in vitro and accelerated radiation-induced cell death in vivo when used for 24-h periods. The cytostatic and cytotoxic effects of fenbendazole were observed in both normal and tumor cells, with a larger effect on tumor cells in the presence of severe hypoxia.

To test the effect of fenbendazole in vivo, SCID mice bearing EMT6 mammary tumors were randomly assigned at an initial tumor volume of 100 mm3 to serve as untreated controls or receive three daily i.p. injections of fenbendazole followed by local tumor irradiation with 10 Gy. Tumor growth and radiation response were rigorously compared by determining the time to four-fold tumor volume, with both unirradiated and irradiated groups being measured for this parameter.

The fenbendazole groups showed a lessening of tumor growth relative to the control group, but this was not statistically significant (p=0.058). Terminal total white cell and neutrophil counts were lower in the fenbendazole groups, while lymphocyte numbers were higher. fenben lab fenbendazol