Induction of Apoptosis in SKOV3 and DNA Binding by Cobalt(III) Polypyridyl Complexes

Three new Co(III) polypyridyl complexes [Co(phen) 2 CIIP] 3+ {CIIP = 2-(5-chloro-3 a , H -isoindol-3-yl)-1 H -imidazo[4,5- f ][1,10]phenantholine} (phen = 1,10 phenanthroline), [Co(bpy) 2 CIIP] 3+ (bpy = 2,2′-bipyridine), and [Co(dmb) 2 CIIP] 3+ (dmb = 4,4′-dimethyl-2,2′-bipyridine) were synthesized and characterized by different spectral methods. The complexes interact with DNA in an intercalation mode as confirmed by spectroscopic titration and viscosity measurements. All three complexes cleaved the pBR322 DNA in photoactivated cleavage studies and exhibited good antimicrobial activity. Anticancer activity of these Co(III) complexes was evaluated on the SKOV3 cell line. Cytotoxicity by MTT assay showed growth inhibition in dose dependent manner. Cell cycle analysis by flow cytometry data showed increase in Sub G1 population. Annexin V FITC/PI staining confirmed that these complexes caused cell death by the induction of apoptosis.