In vitroanti‐tubulin effects of mebendazole and fenbendazole on canine glioma cells

Benzimidazole anthelmintics have reported anti‐neoplastic effects bothin vitroandin vivo. The purpose of this study was to evaluate thein vitrochemosensitivity of three canine glioma cell lines to mebendazole and fenbendazole. The mean inhibitory concentration (IC50) (±SD) obtained from performing theMTT[3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide] assay after treatingJ3T,G06‐A, andSDT‐3Gcells for 72 h with mebendazole were 0.030 ± 0.003, 0.080 ± 0.015 and 0.030 ± 0.006μMrespectively, while those for fenbendazole were 0.550 ± 0.015, 1.530 ± 0.159 and 0.690 ± 0.095μM; treatment of primary canine fibroblasts for 72 h atIC50showed no significant effect. Immunofluorescence studies showed disruption of tubulin after treatment. Mebendazole and fenbendazole are cytotoxic in canine glioma cell linesin vitroand may be good candidates for treatment of canine gliomas. Furtherin vivostudies are required.