First-row transition metal compounds containing benzimidazole ligands: An overview of their anticancer and antitumor activity

•First-row transition metal compounds with benzimidazole offer an alternative to Pt-based drugs.•Benzimidazole ligands enhance the biological activity of their coordination compounds.•The trend observed in the anticancer and antitumor activity was Cu > Co ≥ Zn > Ni.•Some metals like Mn and V have received less attention but their results are promising.•Assay types and incubation times need to be standardized to facilitate research.