Remarkable visible light-triggered cytotoxicity of mitochondria targeting mixed-ligand cobalt(iii) complexes of curcumin and phenanthroline bases binding to human serum albumin

Abstract

Co(iii) complexes of curcumin and phenanthroline bases show remarkable visible-light induced cytotoxicity in HeLa cells but are much less toxic in dark and to normal cells. The complexes bind to HSA with significant affinity.

Enhanced photocytotoxicity of curcumin delivered by solid lipid nanoparticles

“…37 As shown in Figure 4, treating A549 cells with Cur and Cur-SLNs in the dark did not alter the cell cycle, compared with the untreated control group. In contrast, after they were exposed to the excitation light at 430 nm, A549 cells treated with Cur-SLNs showed 49.26% arrest in G2/M phase of cell cycle leading to cell death and the cells treated with Cur showed 25.29% arrest in G2/M phase.…”

“…40 It is well known that Cur exposed to 430 nm light could generate a large amount of ROS, inducing the apoptosis of cancer cells. 32,37,41 Cytotoxic intracellular ROS can cause damage to mitochondria in cells, resulting in cell death. Our results demonstrated that SLN was a good drug delivery system for Cur, which enhanced its intracellular uptake and slowed down its hydrolysis in PDT.…”

Visible light-induced cytotoxicity of a dinuclear iron(III) complex of curcumin with low-micromolar IC50 value in cancer cells

“…The electronic absorption spectra of the complexes in aqueous DMF showed a common ligand-based band around 270 nm. In addition, complex 2 showed a strong curcumin-based π → π* visible absorption band within 400˗500 nm in 5% aqueous DMF [31]. were observed.…”

“…These values are considerably less than the spin-only value of 5.92 µ B /Fe suggesting antiferromagnetic interaction between the two iron(III) centres via the µ-oxo bridge [51]. The electrospray ionization mass spectrometry (ESI-MS) of the complexes in methanol displayed a single peak corresponding to [M˗2ClO 4 -] 2+ species [31]. The electronic absorption spectra of the complexes in aqueous DMF showed a common ligand-based band around 270 nm.…”

“…Thus, we envisaged that the combination of curcumin and iron(III) would produce a system with enhanced stability and photocytotoxicity. Recently, we have reported a series of cobalt(III) complexes of curcumin showing photocytotoxicity in HeLa cells in visible light [31]. Furthermore, the intrinsic green fluorescence of curcumin can be conveniently exploited to study the localization of the curcumin-bound complex in cancer cells [20][21][22][23].…”