Syntheses, quantum mechanical modeling, biomolecular interaction and in vitro anticancer - Tubulin activity of thiosemicarbazones

Copper(II) Complexes with Isomeric Morpholine-Substituted 2-Formylpyridine Thiosemicarbazone Hybrids as Potential Anticancer Drugs Inhibiting Both Ribonucleotide Reductase and Tubulin Polymerization: The Morpholine Position Matters

The development of copper(II) thiosemicarbazone complexes as potential anticancer agents, possessing dual functionality as inhibitors of R2 ribonucleotide reductase (RNR) and tubulin polymerization by binding at the colchicine site, presents a promising avenue for enhancing therapeutic effectiveness. Herein, we describe the syntheses and physicochemical characterization of four isomeric proligands H2L3-H2L6, with the methylmorpholine substituent at pertinent positions of the pyridine ring, along with their corresponding Cu(II) complexes 3-6. Evidently, the position of the morpholine moiety and the copper(II) complex formation have marked effects on the in vitro antiproliferative activity in human uterine sarcoma MES-SA cells and the multidrug-resistant derivative MES-SA/Dx5 cells. Activity correlated strongly with quenching of the tyrosyl radical (Y•) of mouse R2 RNR protein, inhibition of RNR activity in the cancer cells, and inhibition of tubulin polymerization. Insights into the mechanism of antiproliferative activity, supported by experimental results and molecular modeling calculations, are presented.

Antiproliferative Activity and DNA Interaction Studies of a Series of N4,N4-Dimethylated Thiosemicarbazone Derivatives

The exploitation of bioactive natural sources to obtain new anticancer agents with novel modes of action may represent an innovative and successful strategy in the field of medicinal chemistry. Many natural products and their chemical analogues have been proposed as starting molecules to synthesise compounds with increased biological potential. In this work, the design, synthesis, and characterisation of a new series of N4,N4-dimethylated thiosemicarbazone Cu(II), Ni(II), and Pt(II) complexes are reported and investigated for their in vitro toxicological profile against a leukaemia cell line (U937). The antiproliferative activity was studied by MTS assay to determine the GI50 value for each compound after 24 h of treatment, while the genotoxic potential was investigated to determine if the complexes could cause DNA damage. In addition, the interaction between the synthesised molecules and DNA was explored by means of spectroscopic techniques, showing that for Pt and Ni derivatives a single mode of action can be postulated, while the Cu analogue behaves differently.

Low-density lipoprotein encapsulated thiosemicarbazone metal complexes is active targeting vehicle for breast, lung, and prostate cancers

Cancer is a leading cause of death worldwide and affects society in terms of the number of lives lost. Current cancer treatments are based on conventional chemotherapy which is nonspecific in targeting cancer. Therefore, intensive efforts are underway to better target cancer-specific cells while minimizing the side effects on healthy tissues by using LDL particles as active drug delivery vehicles. The goal is to encapsulate anticancer agents thiosemicarbazone metal-ligand complexes into LDL particles to increase the cytotoxic effect of the agent by internalization through LDL receptors into MCF7, A549, and C42 cancer cell lines as segregate models for biological evaluations targeting tubulin. Zeta potential data of LDL-particles encapsulated anticancer agents showed an acceptable diameter range between 66-91 nm and uniform particle morphology. The results showed cell proliferation reduction in all tested cell lines. The IC50 values of LDL encapsulated thiosemicarbazone metal-ligand complexes treated with MCF7, A549, and C42 ranged between 1.18-6.61 µM, 1.17-9.66 µM, and 1.01-6.62 µM, respectively. Western blot analysis showed a potent decrease in tubulin expression when the cell lines were treated with LDL particles encapsulated with thiosemicarbazone metal-ligand complexes as anticancer agents. In conclusion, the data provide strong evidence that LDL particles are used as an active drug delivery strategy for cancer therapy.

Synthesis, density functional theory calculation, molecular docking studies, and evaluation of novel 5-nitrothiophene derivatives for anticancer activity

Within the scope of this study, new 2-{2-[(5-nitrothiophen-2-yl)methylene]hydrazinyl}thiazole derivatives (2a-j) were synthesized and investigated for their potential anticancer and enzyme inhibition activities. Spectroscopic techniques were used to determine the structures of substances. The anticancer activities of compounds were detected in A549 human lung carcinoma and L929 murine fibroblast cell lines, determining cytotoxicity, apoptosis, mitochondrial membrane integrity, and caspase-3 activation. Compounds 2b bearing 4-nitrophenyl, 2c bearing phenyl, and 2d bearing 4-cyanophenyl moieties were specified with high anticancer activity, acting through an apoptotic pathway with an apoptosis ratio of 9.61%-15.59%. Mitochondrial membrane depolarization was determined to be 25.53% and 22.33% for compounds 2b and 2c, respectively. Furthermore, compound 2c exhibited excellent caspase-3 activation. A molecular docking study was realized with compound 2c on the caspase-3 enzyme. Furthermore, the electronic characteristics of the active compounds were investigated using density functional theory (DFT) at the B3LYP/6-31G (d, p) level. The frontier molecular orbital energy and atomic net charges were examined.

Design, Synthesis, Cytotoxic Screening and Molecular Docking Studies of Novel Hybrid Thiosemicarbazone Derivatives as Anticancer Agents

Thiosemicarbazones have been the focus of scientists owing to their broad clinical anticancer range. Herein, A Series of new thiosemicarbazone derivatives 5-9 were synthesized and confirmed through the use of different spectroscopic techniques along with elemental analysis. The in vitro cytotoxic activity of compounds 5-9 against MCF-7 and A549 cell lines and normal breast cells were assessed. Several compounds were found to be active. The most active compound 7 caused MCF-7 cell cycle arrest at G1/ S phases; and induced apoptosis at the pre-G1 phase. The apoptosis-inducing activity of compound 7 was proofed by the elevation of caspase 3/7 activity and also by up-regulation of the expression of Bax and p53 proteins together with the down-regulation of the expression of the Bcl-2 protein. It also had a strong inhibitory effect topoisomerase IIβ enzyme. Molecular Docking study revealed that the synthesized compounds had good docking scores compared to the standard drug Etoposide towards the topoisomerase IIβ protein (3QX3). Overall, these findings confirmed that the new thiosemicarbazone derivatives could aid in the development of promising cancer drug candidates.