Photorelease and Cellular Delivery of Mitocurcumin from Its Cytotoxic Cobalt(III) Complex in Visible Light
| Autor: | Samya Banerjee, Bhabatosh Banik, Aditya Garai, Ila Pant, Paturu Kondaiah, Akhil R. Chakravarty |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Curcumin
Light chemistry.chemical_element Apoptosis 010402 general chemistry Photochemistry 01 natural sciences Redox Medicinal chemistry Inorganic Chemistry Metal chemistry.chemical_compound Coordination Complexes Humans Curcuminoid Physical and Theoretical Chemistry 010405 organic chemistry Chemistry Ligand Cobalt 0104 chemical sciences Photochemotherapy Octahedron visual_art MCF-7 Cells visual_art.visual_art_medium Derivative (chemistry) |
| Zdroj: | Inorganic Chemistry. 55:6027-6035 |
| ISSN: | 1520-510X 0020-1669 |
| Popis: | Ternary cobalt(III) complexes of curcumin (Hcur) and mitocurcumin [Hmitocur, a dicationic bis(triphenylphosphonium) derivative of curcumin] having a tetradentate phenolate-based ligand (H2L), namely, [Co(cur)(L)] (1) and [Co(mitocur)(L)]Cl2 (2), were prepared and structurally characterized, and their photoinduced cytotoxicity was studied. The diamagnetic cobalt(III) complexes show an irreversible Co(III)-Co(II) redox response and a quasireversible curcuminoid-based reduction near -1.45 and -1.74 V SCE, respectively, in DMF/0.1 M [(n)Bu4N](ClO4). The complexes exhibit a curcumin/mitocurcumin-based absorption band near 420 nm. Complex 1 was structurally characterized by X-ray crystallography. The structure contains the metal in a CoN2O4 distorted octahedral coordination arrangement with curcumin binding to the metal in its enolic form. Binding to cobalt(III) increases the hydrolytic stability of curcumin. Complex 2, having a dicationic curcuminoid, shows significant cellular uptake and photoinduced cytotoxicity compared to its curcumin analogue 1. The dicationic cobalt(III) complex 2 has significantly better cellular uptake and bioactivity than the neutral species 1. Complex 2 with mitochondrial localization releases the mitocurcumin dye upon exposure to visible light (400-700 nm) in human breast cancer MCF-7 cells through photoreduction of cobalt(III) to cobalt(II). Complex 2 displays a remarkable photodynamic therapy (PDT) effect, giving an IC50 value of ∼3.9 μM in visible light (400-700 nm) in MCF-7 cells while being much less toxic in the dark (50 μM). The released mitocurcumin acts as a phototoxin, generating intracellular reactive oxygen species (ROSs). The overall process leads to light-controlled delivery of a curcuminoid (mitocur) into the tumor cells while the dye alone suffers from hydrolytic instability and poor bioavailability. |
| Databáze: | OpenAIRE |
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