In Vitro DNA-Binding, Anti-Oxidant and Anticancer Activity of Indole-2-Carboxylic Acid Dinuclear Copper(II) Complexes

Abstract

Indole-2-carboxylic acid copper complex (ICA-Cu) was successfully prepared and characterized through elemental analysis, IR, UV-Vis, 1H-NMR, TG analysis, and molar conductance, and its molecular formula was [Cu2(C9H6O2N)4(H2O)2]·2H2O. The binding ability of ICA-Cu to calf thymus DNA (CT-DNA) was examined by fluorescence spectrometry and the viscosity method. The results indicated that, upon the addition of increasing amounts of CT-DNA, the excitation and emission intensity of ICA-Cu decreased obviously and the excitation spectra shifted towards a long wavelength. ICA-Cu could displace ethidium bromide (EB) from the EB-DNA system, making the fluorescence intensity of the EB-DNA system decrease sharply; the quenching constant KSV value was 3.99 × 104 M−1. The emission intensity of the ICA-Cu-DNA system was nearly constant, along with the addition of Na+ in a series of concentrations. The fluorescence of the complex could be protected after the complex interacted with DNA. A viscosity measurement further supported the result that the ICA-Cu complex may interact with DNA in an intercalative binding mode. The antioxidant activities of ICA-Cu were evaluated by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, a hydroxyl radical (OH) scavenging assay, and a 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay. The ICA-Cu exhibited the highest inhibitory effects on the ABTS radical (94% inhibition at 60 µM), followed by OH and DPPH radicals (the degrees of inhibition being 71% and 56%, respectively). The in vitro cytotoxicity activity of ICA-Cu against two human breast cancer cell lines, MDA-MB-231 and MCF-7, was investigated by 3-[4,5-dimethyltiazol2-yl]-2.5-diphenyl-tetrazolium bromide (MTT) assay and cellular morphological analysis. The results showed that, upon increasing the concentration of ICA-Cu, an increase was observed in growth-inhibitory activity and the inhibition percentage were greater than 90% at 20 µM in both cell lines. Also, cellular morphological changes in the two cell lines agreed with the cytotoxicity results.

A novel bidentate ligand containing oxime, hydrazone and indole moieties and its BF2+ bridged transition metal complexes and their efficiency against prostate and breast cancer cells

“…In the test results with MCF‐7 cell line, the inhibition concentration for 50% of cells (IC 50 ) was calculated to be about 5 μ m for [Cu(LH) 2 ]. In this study, the Cu(II) complex of the new ligand was determined to have the strongest antiproliferative activity, with an IC 50 value of 5 μ m for MCF‐7 cells, and these values comply with those reported in previous studies, which are based on indole and hydrazone derivatives [38a,c] …”

Antiwrinkle and Antimelanogenesis Effects of Tyndallized Lactobacillus acidophilus KCCM12625P

“…In addition, treatment with AL prevented cell death by UVB, indicating that AL protects the skin and body from UVB irradiation (Figure 1b). The antioxidant effects of AL were found through ABTS radical-scavenging assays [46][47][48], which again demonstrates that AL exerts antioxidant effects (Figure 1d).…”

Self-recognition of the racemic ligand in the formation of homochiral dinuclear V(V) complex: In vitro anticancer activity, DNA and HSA interaction

“…The EthBr fluorescence displacement experiment was also employed to further investigate DNA-binding of V(V) complex, as previously reported [28]. Here, with the addition of the complex the fluorescence intensity of EthBr-DNA decreases continuously without any change in the emission λ max (Fig.…”