Imidazole and carbazole derivatives as potential anticancer agents: molecular docking studies and cytotoxic activity evaluation

Carbazoles and imidazole represent two important classes of heterocycles which exhibit diverse biological activities such as antitumor properties. In this study, imidazole (C1-C3) and carbazole (C4 and C5) derivatives were evaluated for their cytotoxic activity against three human cancer cell lines namely, MCF7 (human breast cancer), HT29 (human colon cancer), and HeLa (human cervical cancer). Carbazole derivatives (C4 and C5) with IC50 < 10 µM showed greater cytotoxic effect than imidazole derivatives (C1-C3). Furthermore, all compounds exhibited better anticancer activity against MCF-7 than other two cell lines (HT-29, HeLa) and compound C4 was the most potent compound with the IC50 values of 2.5, 5.4 and 4.0 µM, against MCF-7, Hela and HT-29 cell lines, respectively. Physicochemical properties of compounds were calculated and their correlation with the IC50 values on MCF-7 cell line investigated. Surface area and polarizability of compounds showed good correlation by R2 = 0.8396 and R2 = 0.834, respectively. Docking studies of these compounds were also performed on the DNA as proposed target to comprehend their binding interactions and binding energies. The docking energy of compounds ranged from - 11.32 to -13.48 kcal/mol. Compound C3 with energy of -13.48 kcal/mol had the highest docking energy. Docking results indicated that these compounds (C1-C5) had strong affinity in binding to the DNA.                     KEY WORDS: Imidazole, Carbazole, Molecular docking, Cancer, MTT assay   Bull. Chem. Soc. Ethiop. 2020, 34(2), 377-384 DOI: https://dx.doi.org/10.4314/bcse.v34i2.1