Effect of cobalt(II) chloride hexahydrate on some human cancer cell lines

The present study investigates the anti-proliferative and apoptosis inducing mechanism of CoCl 2 ·6H 2 O in PC-3 cancer cell line. Preliminary, three different forms of cobalt i.e., cobaltous (CoCl 2 ·6H 2 O), macro-Co(II,III) oxide and nano-Co(II,III) oxide were screened for antiproliferative activity in PC-3 cell line. The CoCl 2 ·6H 2 O being the most effective antiproliferative agent, hence it was further tested against lung (A549), prostrate (PC-3) and brain (IMR-32) cell lines. Human embryonic kidney cell line (293T) was used as a normal cell line to compare the toxicity of CoCl 2 ·6H 2 O. The CoCl 2 ·6H 2 O induced morphological and anatomical changes in PC-3 cancer cell which were studied using light, confocal and scanning electron microscopy. The lactate dehydrogenase was estimated which showed mild necrotic mode of cell death. The Annexin/PI staining confirmed the apoptotic mode of cell death in PC-3 cells. Further, production of reaction of reactive oxygen species and changes in mitochondrial membrane potential was also assessed spectrofluorimetrically. The cell cycle arrest was also investigated using flow cytometery. Finally, the caspase activity was estimated in CoCl 2 ·6H 2 O treated PC-3 cancer cell line. Interestingly, it was found that CoCl 2 ·6H 2 O induces more cell death in cancerous cells as compared to normal non-cancerous cells. These findings presented CoCl 2 ·6H 2 O as potential antiproliferative agent.