Cytotoxic effects of new synthesized bisbenzimidazole derivatives on different tumour cell lines

Since there is a constant need for new, more effective and less harmful potential anticancer drugs we tested antiproliferative activity of three novel benzimidazoyl hydrochloride analogues on different cancer cell lines. The cytotoxic effects of tested compounds were tested by colorometric MTT assay. A panel of 5 leukaemia (K562, RAJI, JURKAT, HL-60 and MOLT-4) and 6 carcinoma cell lines (AGS, HEp2, Caco-2, HeLa, HT-29, MiaPaca) were used. Investigated compounds showed a great variation in antiproliferative effect on tumour cell lines, depending on the cell line as well as on the dose applied. Analogues 2, 5-bis[5-(N-isopropylamidino)benzimidazo-2-yl)]-3, 4-ethylenedioxythiophene dihydrochloride (MB12) and 2, 5-bis[5-(2-imidazolino)benzimidazo-2-yl]-3, 4-ethylenedioxythiophene dihydrochloride (MB13) strongly inhibited the growth of leukemia cells, K562, RAJI and MOLT-4, for 50 - 80% at concentration of 10-4 and 10-5 M, but had no influence on JURKAT and HL-60 cells. At the same concentration 2, 5-Bis[2-(5-amidinobenzimidazoyl)]-3, 4-ethylenedioxythiophene dihydrochloride (MB11) inhibited proliferation of JURKAT and HL-60 cells for 30 - 40%. Lower concentration (10-6 and 10-7 M) of all tested compounds had no effects on proliferation of leukaemia cells. The best inhibitory effects against carcinoma HeLa and HEp-2 cells at relatively low concentration of 10-6 M displayed MB12 compound. MB11 and MB13 were less effective on these cell lines. MiaPaca cell line was sensitive on MB11 and MB12 compounds at concentration of 10-5 M. Investigated compounds had no effect on Caco-2 and AGS cells. According to obtained results we can conclude that cytotoxic efficiency of tested benzimidazoyl hydrochloride analogues is more pronounced on solid tumours cell lines compared to effects on leukaemia cells.