The bidentate N-(1-Alkylpyridin-4(1H)-ylidene)amide (PYA) pro-ligands [H2LBn][Cl]2 (2), and [H2LMe][TfO]2 (3) were prepared by simple alkylation reactions of the known compound, N,N-di(pyridin-4-yl)oxalamide (H2L, 1). The Pd(II) complexes, [Pd(LBn)2][Cl]2 (4), [Pd(LMe)2][Cl][TfO] (5), Pd(LBn)Cl2 (6) and Pd(LMe)Cl2 (7) were synthesized through reactions between these pro-ligands and suitable Pd(II) substrates in the presence of base. The molecular structures of 3 and 6 were obtained by single crystal X-ray structure determinations. Studies of the experimental and computational DNA binding interactions of the compounds 1-7 revealed that overall 4 and 6 have the largest values for the binding parameters Kb and ΔGbo. The results showed a good correlation with the steric and electronic parameters obtained by quantitative structure activity relationship (QSAR) studies. In-vitro cytotoxicity studies against four different cell lines showed that the human breast cancer cell lines MCF-7, T47D and cervical cancer cell line HeLa had either higher or similar sensitivities towards 4, 6 and 2, respectively, compared to cisplatin. In general, the cytotoxicity of the compounds, represented by IC50 values, decreased in the order 4 > 6 > 2 > 5 > 3 > 1 > 7 in cancer cell lines. Apoptosis contributed significantly to the cytotoxic effects of these anticancer agents as evaluated by apoptosis studies.
Five new anionic aqueous dioxidovanadium(V) complexes, [{VO2L1,2}A(H2O)n]α (1-5), with the aroylhydrazone ligands pyridine-4-carboxylic acid (3-ethoxy-2-hydroxybenzylidene)hydrazide (H2L1) and furan-2-carboxylic acid (3-ethoxy-2-hydroxybenzylidene)hydrazide (H2L2) incorporating different alkali metals (A = Na+, K+, Cs+) as countercation were synthesized and characterized by various physicochemical techniques. The solution-phase stabilities of 1-5 were determined by time-dependent NMR and UV-vis, and also the octanol/water partition coefficients were obtained by spectroscopic techniques. X-ray crystallography of 2-4 confirmed the presence of vanadium(V) centers coordinated by two cis-oxido-O atoms and the O, N, and O atoms of a dianionic tridentate ligand. To evaluate the biological behavior, all complexes were screened for their DNA/protein binding propensity through spectroscopic experiments. Finally, a cytotoxicity study of 1-5 was performed against colon (HT-29), breast (MCF-7), and cervical (HeLa) cancer cell lines and a noncancerous NIH-3T3 cell line. The cytotoxicity was cell-selective, being more active against HT-29 than against other cells. In addition, the role of hydrophobicity in the cytotoxicity was explained in that an optimal hydrophobicity is essential for high cytotoxicity. Moreover, the results of wound-healing assays indicated antimigration in case of HT-29 cells. Remarkably, 1 with an IC50 value of 5.42 ± 0.15 μM showed greater activity in comparison to cisplatin against the HT-29 cell line.
Cardamonin is a polyphenolic natural product that has been shown to possess cytotoxic activity against a variety of cancer cell lines. We previously reported the semi-synthesis of a novel Cu (II)-cardamonin complex (19) that demonstrated potent antitumour activity. In this study, we further investigated the bioactivity of 19 against MDA-MB-468 and PANC-1 cancer cells in an attempt to discover an effective treatment for triple-negative breast cancer (TNBC) and pancreatic cancer, respectively. Results revealed that 19 abolished the formation of MDA-MB-468 and PANC-1 colonies, exerted growth-inhibitory activity, and inhibited cancer cell migration. Further mechanistic studies showed that 19 induced DNA damage resulting in gap 2 (G2)/mitosis (M) phase arrest and microtubule network disruption. Moreover, 19 generated reactive oxygen species (ROS) that may contribute to induction of apoptosis, corroborated by activation of caspase-3/7, PARP cleavage, and downregulation of Mcl-1. Complex 19 also decreased the expression levels of p-Akt and p-4EBP1, which indicates that the compound exerts its activity, at least in part, via inhibition of Akt signalling. Furthermore, 19 decreased the expression of c-Myc in PANC-1 cells only, which suggests that it may exert its bioactivity via multiple mechanisms of action. These results demonstrate the potential of 19 as a therapeutic agent for TNBC and pancreatic cancer.
Platinum drugs are heavily used first-line chemotherapeutic agents for many solid tumours and have stimulated substantial interest in the biological activity of DNA-binding metal complexes. These complexes generate DNA lesions which trigger the activation of DNA damage response (DDR) pathways that are essential to maintain genomic integrity. Cancer cells exploit this intrinsic DNA repair network to counteract many types of chemotherapies. Now, advances in the molecular biology of cancer has paved the way for the combination of DDR inhibitors such as poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) and agents that induce high levels of DNA replication stress or single-strand break damage for synergistic cancer cell killing. In this review, we summarise early-stage, preclinical and clinical findings exploring platinum and emerging ruthenium anti-cancer complexes alongside PARPi in combination therapy for cancer and also describe emerging work on the ability of ruthenium and gold complexes to directly inhibit PARP activity.
The syntheses of two platinum(ii) dithiocarbamate complexes (1 and 2) that show quinoplatin- and phenanthriplatin-type axial protection of the Pt-plane are described. The Pt-plane of complex 2 is axially more protected than that of complex 1. Furthermore, both complexes adopt two different stereochemical conformations in the solid state (based on single-crystal X-ray structures) owing to the structurally flexible piperazine backbone; i.e., C-e,e-Anti (1) and C-e,a-Syn (2), where "C" stands for the chair configuration, "e" and "a" stand for the equatorial and axial positions and "Anti" (opposite side) and "Syn" (same side) represent the relative orientations in space of the terminal substituents on the piperazine ring. In complex 2, the C-e,a-Syn conformation may provide additional steric hindrance to the Pt-plane. Despite the lower lipophilicity of 2 as compared to that of 1, the in vitro anticancer action against selected cancer cell lines is better for the former revealing the superior role of the axial protection over lipophilicity in modulating anticancer activity. The activity against the cancer promoting protein NF-κB signifies that the mode of cancer cell death may be the result of hindering the activity of NF-κB in the initiation of apoptosis. The apoptotic mode of cell death has been established earlier in a study using Annexin V-FITC. Finally, DNA binding studies revealed that the complex-DNA adduct formation is spontaneous and the mode of interaction is non-intercalative (electrostatic/covalent).
Photodynamic therapy (PDT) is emerging as a significant complementary or alternative approach for cancer treatment. PDT drugs act as photosensitisers, which upon using appropriate wavelength light and in the presence of molecular oxygen, can lead to cell death. Herein, we reviewed the general characteristics of the different generation of photosensitisers. We also outlined the emergence of rhenium (Re) and more specifically, Re(I) tricarbonyl complexes as a new generation of metal-based photosensitisers for photodynamic therapy that are of great interest in multidisciplinary research. The photophysical properties and structures of Re(I) complexes discussed in this review are summarised to determine basic features and similarities among the structures that are important for their phototoxic activity and future investigations. We further examined the in vitro and in vivo efficacies of the Re(I) complexes that have been synthesised for anticancer purposes. We also discussed Re(I) complexes in conjunction with the advancement of two-photon PDT, drug combination study, nanomedicine, and photothermal therapy to overcome the limitation of such complexes, which generally absorb short wavelengths.
Hydroxamic acids [R(CO)N(OH)R'] are flexible compounds for organic and inorganic analyses due to their frailer structures compared to the carboxylic acid. The syntheses and characterization of benzohydroxamic acid (BHA), its CH3-, OCH3-, Cl- para-substituted derivatives and their Cr(III) complexes are reported herein. The metal complexes were synthesized by reacting the hydroxamic acids with chromium(III) chloride hexahydrate in 2:1 molar ratio. The compounds were characterized via melting point, elemental analysis, FTIR, 1H and 13C NMR, TGA, mass spectrometry, molar conductance and UV-Visible. Data analysis suggests that each complex has the Cr(III) center coordinated to the carbonyl and hydroxy oxygen atoms of the hydroxamic acids in bidentate O,O manner and two water molecules to form octahedral geometry. Non-electrolytic behavior of the complexes was shown through their low molar conductivity. Cytotoxicity study against HCT116 and alpha-glucosidase inhibition test revealed that all complexes have higher activity than their parent ligands. Molecular docking study shows that the docking of active complexes is thermodynamically favorable and the inhibition efficiency may depend on the types and the numbers of molecular interactions established in the corresponding stable conformers.
This paper reports the synthesis, characterization, anticancer screening and quantum chemical calculation of a tetradentate Schiff base 2,2'-((1E,1'E)-((2,2-dimethylpropane-1,3-diyl)bis- (azanylylidene))bis(methanylylidene))bis(4-fluorophenol) (L2F) and its Pd (II) complex (PdL2F). The compounds were characterized via UV-Visible, NMR, IR spectroscopy and single crystal x-ray diffraction. Density Functional Theory (DFT) and time-dependent DFT calculations in gas and solvent phases were carried out using B3LYP, B3P86, CAM-B3LYP and PBE0 hybrid functionals combined with LanL2DZ basis set. Complexation of L2F to form PdL2F was observed to cause a bathochromic shift of the maximum absorption bands of n-π* from 327 to 410 nm; an upfield shift for δ (HC = N) from 8.30 to 7.96 ppm and a decreased wavenumber for ν(C = N) from 1637 to 1616 cm-1. Overall, the UV-Vis, NMR and IR spectral data are relatively well reproduced through DFT and TD-DFT methods. L2F and PdL2F showed IC50 of 90.00 and 4.10 μg/mL, respectively, against human colorectal carcinoma (HCT116) cell lines, signifying increased anticancer activity upon complexation with Pd (II).
Today, drug delivery systems based on nanostructures have become the most efficient to be studied. Recent studies revealed that the fullerenes can be used as drug carriers and transport drugs in a target cell. The aim of the present work is to study the interaction of C60 fullerene containing porphyrin-like transition metal-N4 clusters (TMN4C55, TM = Fe, Co, and Ni) with a non-steroidal anti-inflammatory drug (ibuprofen (Ibp)) by employing the method of the density functional theory. Results showed that the C60 fullerene with TMN4 clusters could significantly enhance the tendency of C60 for adsorption of ibuprofen drug. Also, our ultraviolet-visible results show that the electronic spectra of Ibp/TMN4C55 complexes exhibit a blue shift toward lower wavelengths (higher energies). It was found that the NiN4C55 fullerene had high chemical reactivity, which was important for binding of the drug onto the carrier surface. In order to gain insight into the binding features of Ibp/TMN4C55 complexes, the atoms in molecules analysis was also performed. Our results exhibit the electrostatic features of the Ibp/TMN4C55 bonding. Consequently, this study demonstrated that the TMN4C55 fullerenes could be used as potential carriers for delivery of Ibp drug in the nanomedicine domain. Graphical Abstract The TMN4C55 (TM=Fe, Co, and Ni) fullerenes could be used as potential carriers for delivery of ibuprofen drug in the nanomedicine domain.
The bidentate N-cyclohexyl-2-(3-hydroxy-4-methoxybenzylidene)hydrazine-1-carbothioamide Schiff base ligand (HL) was coordinated to divalent nickel, palladium and platinum ions to form square planar complexes. The nickel and palladium complexes, [NiL2 ], [PdL2 ] form square planar complexes with 2:1 ligand to metal ratio. The platinum complex, [PtL(dmso)Cl] formed a square planar complex with 1:1 ligand to metal ratio. Platinum undergoes in situ reaction with DMSO before complexing with the ligand in solution. The cytotoxicity of HL, [NiL2 ], [PdL2 ], and [PtL(dmso)Cl] were evaluated against human colon cancer cell line (HCT-116), human cervical cancer (Hela) cell line, melanoma (B16F10) cells, and human normal endothelial cell lines (Eahy926) by MTT assay. The [NiL2 ] complex displayed selective cytotoxic effect against the HCT 116 cancer cell line with IC50 of 7.9 ± 0.2 μM. However, HL, [PdL2 ], and [PtL(dmso)Cl] only exhibited moderate cytotoxic activity with IC50 = 75.9 ± 2.4, 100.0 ± 1.8, and 101.0 ± 3.6 μM, respectively. The potent cytotoxicity of [NiL2 ] was characterized using Hoechst and Rhodamine assays. The nickel complex, [NiL2 ], caused remarkable nuclear condensation and reduction in mitochondrial membrane potential. In addition, molecular docking studies confirms that [NiL2 ] possesses significant binding efficiency with Tyrosine kinase. Altogether, the results revealed that [NiL2 ] exhibits cytotoxicity against the cancer cells via Tyrosine kinase-induced proapoptosis pathway. This study demonstrates that the [NiL2 ] complex could be a promising therapeutic agent against colorectal carcinoma.
The present work proposed a novel approach for transferring high-risk heavy metals tometal complexes via green chemistry remediation. The method of remediation of heavy metals developed in the present work is a great challenge for global environmental sciences and engineering because it is a totally environmentally friendly procedure in which black tea extract solution is used. The FTIR study indicates that black tea contains enough functional groups (OH and NH), polyphenols and conjugated double bonds. The synthesis of copper complex was confirmed by the UV-vis, XRD and FTIR spectroscopic studies. The XRD and FTIR analysis reveals the formation of complexation between Cu metal complexes and Poly (Vinyl Alcohol) (PVA) host matrix. The study of optical parameters indicates that PVA-based hybrids exhibit a small optical band gap, which is close to inorganic-based materials. It was noted that the absorption edge shifted to lower photon energy. When Cu metal complexes were added to PVA polymer, the refractive index was significantly tuned. The band gap shifts from 6.2 eV to 1.4 eV for PVA incorporated with 45 mL of Cu metal complexes. The nature of the electronic transition in hybrid materials was examined based on the Taucs model, while a close inspection of the optical dielectric loss was also performed in order to estimate the optical band gap. The obtained band gaps of the present work reveal that polymer hybrids with sufficient film-forming capability could be useful to overcome the drawbacks associated with conjugated polymers. Based on the XRD results and band gap values, the structure-property relationships were discussed in detail.
Chiral enantiomers [Cu(phen)(l-ser)(H2O)]NO31 and [Cu(phen)(d-ser)(H2O)]NO32 (ser = serinato) underwent aldol-type condensation with formaldehyde, with retention of chirality, to yield their respective enantiomeric ternary copper(ii) complexes, viz. l- and d-[Cu(phen)(OCA)(H2O)]NO3·xH2O (3 and 4; phen = 1,10-phenanthroline; OCA = oxazolidine-4-carboxylate; x = 1/2, 0-2) respectively. These chiral complexes were characterized by FTIR, elemental analysis, circular dichroism, UV-visible spectroscopy, fluorescence spectroscopy (FL), molar conductivity measurement, ESI-MS and X-ray crystallography. The crystal structures of 1 and 3 showed both the cationic complexes to have a square pyramidal geometry. These complexes were about nine fold more potent than cisplatin against metastatic MDA-MB-231 breast cancer cells, inducing apoptotic cell death via ROS generation and a massive drop in mitochondrial membrane potential. The results of monitoring EZH1, EZH2 and H3K27me3 revealed that the mode of action of 1-4 also involved the downregulation of EZH2 and it seemed to be independent of the H3K27me3 status.
Three metal(II) complexes [CoLCl2], [CuLCl2] and [ZnL2Cl2] {L = 2‑chloro‑3‑((3‑dimethylamino)propylamino)naphthalene‑1,4‑dione} have been synthesized and characterized using analytical, thermal and spectral techniques (FT-IR, UV-Vis, ESR and ESI-MS). The structure of the L has been confirmed by single crystal XRD study. The complexes show good binding propensity to bovine serum albumin (BSA) having relatively higher binding constant values (104 M-1) than the ligand. Fluorescence spectral studies indicate that [CoLCl2] binds relatively stronger with CT DNA through intercalative mode, exhibiting higher binding constant (2.22 × 105 M-1). Agarose gel electrophoresis run on plasmid DNA (pUC18) prove that all the complexes showed efficient DNA cleavage via hydroxyl radical mechanism. The complexes were identified as potent anticancer agents against two human cancer cell lines (MCF7 and A549) by comparing with cisplatin. Co(II) complex demonstrated greater cytotoxicity against MCF7 and A549 cells with IC50 values at 19 and 22 μM, respectively.
Copper complexes have been widely studied for the anti-tumour application as cancer cells are reported to take up greater amounts of copper than normal cells. Preliminary study revealed that the newly synthesised copper complex [Cu(SBCM)2] displayed marked anti-proliferative towards triple-negative MDA-MB-231 breast cancer cells. Therefore, Cu(SBCM)2 has great potential to be developed as an agent for the management of breast cancer. The present study was carried out to investigate the mode of cell death induced by Cu(SBCM)2 towards MDA-MB-231 breast cancer cells. The inhibitory and morphological changes of MDA-MB-231 cells treated with Cu(SBCM)2 was determined by using MTT assay and inverted light microscope, respectively. The safety profile of Cu(SBCM)2 was also evaluated towards human dermal fibroblast (HDF) normal cells. Confirmation of apoptosis and cell cycle arrest were determined by flow cytometry analysis. The expression of p53, Bax, Bcl-2 and MMP2 protein were detected with western blot analysis. Cu(SBCM)2 significantly inhibited the growth of MDA-MB-231 cells in a dose-dependent manner with GI50 18.7 ± 3.06 µM. Indeed, Cu(SBCM)2 was less toxic towards HDF normal cells with GI50 31.8 ± 4.0 µM. Morphological study revealed that Cu(SBCM)2-treated MDA-MB-231 cells experienced cellular shrinkage, membrane blebbing, chromatin condensation and formation of apoptotic bodies, suggesting that Cu(SBCM)2 induced apoptosis in the cells, which was confirmed by Annexin-V/PI flow cytometry analysis. It was also found that Cu(SBCM)2 induced G2/M phase cell cycle arrest towards MDA-MB-231 cells. The induction of apoptosis and cell cycle arrest in the present study is possibly due to the down-regulation of the mutant p53 and MMP2 protein. In conclusion, Cu(SBCM)2 can be developed as a targeted therapy for the treatment of triple-negative breast cancer.
The platinum(II) salphen complex N,N'-Bis-4-(hydroxysalicylidene)-phenylenediamine-platinum(II); (1) and its two derivatives containing hydroxyl functionalized side chains N,N'-bis-[4-[[1-(2-hydroxyethoxy)] salicylidene] phenylenediamine-platinum(II); (2) and N,N'-bis-[4-[[1-(3-hydroxypropoxy)] salicylidene] phenylenediamine-platinum(II); (3) were synthesized and characterized. The structures of the complexes were confirmed by 1H and 13C NMR spectroscopy, FTIR, ESI-MS and CHN elemental analyses. The effects of the hydroxyl substituent on the spectral properties and the DNA binding behaviors of the Pt(II) complexes were explored. The binding mode and interactions of these complexes with duplex DNA (calf thymus DNA and porcine DNA) and also single-stranded DNA were studied by UV-Vis and emission DNA titration. The complexes interact with DNA by intercalation binding mode with the binding constants in the order of magnitude (Kb = 104 M-1, CT-DNA) and (Kb = 105 M-1, porcine DNA). The intercalation of the complex in the DNA structure was proposed to happen by π-π stacking due to its square-planar geometry and aromatic rings structure. The phosphorescence emission spectral characteristics of Pt(II) complexes when interacted with DNA have been studied. Also, the application of the chosen hydroxypropoxy side chains complex (3) as an optical DNA biosensor, specifically for porcine DNA was investigated. These findings will be valuable for the potential use of the platinum(II) salphen complex as an optical DNA biosensor for the detection of porcine DNA in food products.
The novel antifungal agent ASP2397 (Vical's compound ID VL-2397) is produced by the fungal strain MF-347833 that was isolated from Malaysian leaf litter and is identified here as an Acremonium species based on its morphology, physiological properties and 28S ribosomal DNA sequence. Because of its potential importance for producing novel antifungal agents, we determined the taxonomic and biologic properties of MF-347833. We show here that ASP2397 is a cyclic hexapeptide that chelates aluminum ion and is therefore similar to ferrichrome, a hydroxamate siderophore. However, ASP2397 differs structurally from licensed antifungal agents such as amphotericin B, triazoles and echinocandins. To understand the relationship between chemical structure and biological function, we isolated certain ASP2397 derivatives from the culture broth, and we further chemically converted the metal-free form to other derivatives.
Copper (II) complexes synthesized from the products of condensation of S-methyl- and S-benzyldithiocarbazate with 2,5-hexanedione (SMHDH2 and SBHDH2 respectively) have been characterized using various physicochemical (elemental analysis, molar conductivity, magnetic susceptibility) and spectroscopic (infrared, electronic) methods. The structures of SMHDH2, its copper (II) complex, CuSMHD, and the related CuSBHD complex as well as a pyrrole byproduct, SBPY, have been determined by single crystal X-ray diffraction. In order to provide more insight into the behaviour of the complexes in solution, electron paramagnetic resonance (EPR) and electrochemical experiments were performed. Antibacterial activity and cytotoxicity were evaluated. The compounds, dissolved in 0.5% and 5% DMSO, showed a wide range of antibacterial activity against 10 strains of Gram-positive and Gram-negative bacteria. Investigations of the effects of efflux pumps and membrane penetration on antibacterial activity are reported herein. Antiproliferation activity was observed to be enhanced by complexation with copper. Preliminary screening showed Cu complexes are strongly active against human breast adenocarcinoma cancer cell lines MDA-MB-231 and MCF-7.
Ruthenium(II) polypyridyl complexes can intercalate DNA with high affinity and prevent cell proliferation; however, the direct impact of ruthenium-based intercalation on cellular DNA replication remains unknown. Here we show the multi-intercalator [Ru(dppz)2(PIP)](2+) (dppz = dipyridophenazine, PIP = 2-(phenyl)imidazo[4,5-f][1,10]phenanthroline) immediately stalls replication fork progression in HeLa human cervical cancer cells. In response to this replication blockade, the DNA damage response (DDR) cell signalling network is activated, with checkpoint kinase 1 (Chk1) activation indicating prolonged replication-associated DNA damage, and cell proliferation is inhibited by G1-S cell-cycle arrest. Co-incubation with a Chk1 inhibitor achieves synergistic apoptosis in cancer cells, with a significant increase in phospho(Ser139) histone H2AX (γ-H2AX) levels and foci indicating increased conversion of stalled replication forks to double-strand breaks (DSBs). Normal human epithelial cells remain unaffected by this concurrent treatment. Furthermore, pre-treatment of HeLa cells with [Ru(dppz)2(PIP)](2+) before external beam ionising radiation results in a supra-additive decrease in cell survival accompanied by increased γ-H2AX expression, indicating the compound functions as a radiosensitizer. Together, these results indicate ruthenium-based intercalation can block replication fork progression and demonstrate how these DNA-binding agents may be combined with DDR inhibitors or ionising radiation to achieve more efficient cancer cell killing.
Like chiral organic drugs, the chemical and biological properties of metal complexes can be dependent on chirality. Two pairs of [Cu(phen)(ala)(H2O)]X·xH2O (phen=1.10-phenanthroline: X=NO3(-); ala: l-alanine (l-ala), 1 and d-alanine (d-ala) 2; and (X=Cl(-); ala: l-ala, 3 and d-ala, 4) complex salts (x=number of lattice water molecules) have been synthesized and characterized. The crystal structure of 3 has been determined. The same pair of enantiomeric species, viz. [Cu(phen)(l-ala)(H2O)](+) and [Cu(phen)(d-ala)(H2O)](+), have been identified to be present in the aqueous solutions of both 1 and 3, and in those of both 2 and 4 respectively. Both 3 and 4 bind more strongly to ds(AT)6 than ds(CG)6. There is no or insignificant effect of the chirality of 3 and 4 on the production of hydroxyl radicals, binding to deoxyribonucleic acid from calf thymus (CT-DNA), ds(CG)6, G-quadruplex and 17-base pair duplex, and inhibition of both topoisomerase I and proteasome. Among the three proteasome proteolytic sites, the trypsin-like site is inhibited most strongly by these complexes. However, the chirality of 3 and 4 does affect the number of restriction enzymes inhibited, and their binding constants towards ds(AT)6 and serum albumin.
The current mechanistic study was conducted to explore the effects of increased lipophilicity of binuclear silver(I)-NHC complexes on cytotoxicity. Two new silver(I)-N-Heterocyclic Carbene (NHC) complexes (3 and 4), having lypophilic terminal alkyl chains (Octyl and Decyl), were derived from meta-xylyl linked bis-benzimidazolium salts (1 and 2). Each of the synthesized compounds was characterized by microanalysis and spectroscopic techniques. The complexes were tested for their cytotoxicity against a panel of human cancer c as well normal cell lines using MTT assay. Based on MTT assay results, complex 4 was found to be selectively toxic towards human colorectal carcinoma cell line (HCT 116). Complex 4 was further studied in detail to explore the mechanism of cell death and findings of the study revealed that complex 4 has promising pro-apoptotic and anti-metastatic activities against HCT 116 cells. Furthermore, it showed pronounced cytostatic effects in HCT 116 multicellular spheroid model. Hence, binuclear silver(I)-NHC complexes with longer terminal aliphatic chains have worth to be further studied against human colon cancer for the purpose of drug development.