Two new coordination complexes were synthesized using the reaction of two organic salts with gallium(III) nitrate octahydrate. The salts were prepared and used as ligand from the reaction of 2- aminobenzimidazole with pyridine-2,6-dicarboxylic acid and 4-hydroxypyridine-2,6-dicarboxylic acid, respectively. All compounds were identified by spectroscopic methods and their crystal structures determined by single crystal X-ray diffraction. The investigations showed that the two complexes were isostructural. Moreover, thermal analysis was carried out to study the decomposition steps of the complexes. The inhibition properties of the compounds were studied in vitro using oxaliplatin as a standard against five cell lines including a human breast cancer, a prostate cancer, a human liver hepatocellular carcinoma, a colorectal carcinoma and a human foreskin fibroblast. The anti-proliferative activity of the complexes was found to be similar in the majority of cell lines except for the prostate cancer cells. The most remarkable cytotoxicity effect of both complexes appeared on the human breast cancer cells. Determination of mitochondrial membrane potential and reactive oxygen species in this cell line suggested that apoptosis may be the main pathway for the death of the cells.
