Benzimidazoles Containing Piperazine Skeleton at C-2 Position as Promising Tubulin Modulators with Anthelmintic and Antineoplastic Activity

Benzimidazole anthelmintic drugs hold promise for repurposing as cancer treatmentsdue to their interference with tubulin polymerization and depolymerization, manifesting anticancerproperties. We explored the potential of benzimidazole compounds with a piperazine fragment atC-2 as tubulin-targeting agents. In particular, we assessed their anthelmintic activity against isolatedTrichinella spiralis muscle larvae and their effects on glioblastoma (U-87 MG) and breast cancer (MDAMB-231) cell lines. Compound 7c demonstrated exceptional anthelmintic efficacy, achieving a 92.7%reduction in parasite activity at 100 g/mL after 48 hours. In vitro cytotoxicity analysis of MDA-MB231 and U87 MG cell lines showed that derivatives 7b, 7d, and 7c displayed lower IC50 valuescompared to albendazole (ABZ), the control. These piperazine benzimidazoles effectively reducedcell migration in both cell lines, with compound 7c exhibiting the most significant reduction, makingit a promising candidate for further study. The binding mode of the most promising compound 7c,was determined using the induced fit docking-molecular dynamics (IFD-MD) approach. Regulardocking and IFD were also employed for comparison. The IFD-MD analysis revealed that 7c bindsto tubulin in a unique binding cavity near that of ABZ, but the benzimidazole ring was fitted muchdeeper into the binding pocket. Finally, the absolute free energy of perturbation technique wasapplied to evaluate the 7c binding affinity, further confirming the observed binding mode.