Copper(II) (1(Cu)-21(Cu)) and previously established experimental anticancer platinum(II) metallointercalator complexes (1(Pt)-16(Pt)) have been prepared and investigated for their antimicrobial properties. These complexes are of the general structure [M(I(L))(A(L))](2+) where I(L) represents functionalised 1,10-phenanthrolines (1(IL)-10(IL)), and A(L) represents 1,2-diaminoethane, 1S,2S- or 1R,2R-diaminocyclohexane. The structures of synthesised complexes were confirmed using a combination of elemental analysis, UV spectrometry, circular dichroism, (1)H and [(1)H-(195)Pt]-HMQC NMR, X-ray crystallography, and electrospray ionisation mass spectrometry and where appropriate. Crystallisation attempts yielded single crystals of [Cu(4-methyl-1,10-phenanthroline)(1R,2R-diaminocyclohexane)](ClO(4))(2) (4(Cu)), [Cu(5,6-dimethyl-1,10-phenanthroline)(1R,2R-diaminocyclohexane)(H(2)O)](ClO(4))(2)·1.5H(2)O (10(Cu)) and [Cu(5,6-dimethyl-1,10-phenanthroline)(3)](ClO(4))(2)·5,6-dimethyl-1,10-phenanthroline·2H(2)O (21(Cu)). Growth inhibition of liquid cultures of bacteria (Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa), and yeast (Saccharomyces cerevisiae) discerned the most antimicrobially potent metal complexes ≤20 μM, as well as that of their intercalating ligands alone. To further investigate their mode of antimicrobial activity, membrane permeabilisation caused by selected complexes was visualised by means of a cell viability kit under fluorescence microscopy.

these results suggest that 56MESS is capable of causing cell-cycle arrest, and that mitochondrial and cell cycle proteins may be involved in the mode of action of cytotoxicity of 56MESS.

2',7'-dichlorofluorescein (DCF) and derivatives are commonly used as fluorescent indicators of a broad spectrum of reactive oxygen species (ROS) generation in cell-based assays. However, there are numerous challenges inherent to the utilization of DCF probes for intracellular microscopic analysis, including photostability and probe efflux. Plate spectroscopy is comparatively simple and scalable compared to microscopy or flow cytometry-based acquisition, however is often subject to artefacts, including those introduced by thermal gradients and normalization methods. In this protocol we demonstrate a simple and sensitive plate spectrometry-based protocol utilizing the probes H2DCFDA and sulforhodamine B. The rapid sulforhodamine B assay (SRB) for cellular protein allows for a stable endpoint measurement of total cell population while also preserving morphology, can be combined or run in parallel with any other assay for normalization of readout to cell mass, and complemented by microscopic scoring of cell number and nuclear count. The oxidative stress and normalisation methods may enhance fields of research investigating cell differentiation, stress, or toxicity..

Background Vanishing white matter disease (VWMD) is a rare disease caused by mutations of the guanine exchange factor eIF2B. VWMD typically presents with juvenile onset, and there are few treatments for the disease. Recent progress in the field has established mitochondrial dysfunction and endoplasmic reticulum (ER) stress to be strongly implicated in observed glial cell pathology. Drug repurposing offers a rapid approach toward translation of therapeutics using already-licensed drugs. Objective The aim of this study was to use fibroblasts and induced pluripotent stem cell (iPSC)-derived astrocytes from patients bearing the EIF2B5R113H/A403V or EIF2B2G200V/E213G VWMD mutations to identify potential repurposable FDA-approved drugs based on in vitro assays. Methods Cell viability in the presence or absence of stress was assessed by resazurin reduction activity and assays for mitochondrial membrane potential and oxidative stress by tetramethylrhodamine and dichlorofluorescein-based assays, respectively. Integrated stress response markers, including eIF2α phosphorylation, GADD34 and CHOP were quantified by fluorescent western blot. Results Dysregulated GADD34 and CHOP were identified in patient fibroblasts and iPSC-derived astrocytes under induced stress conditions. A drug screen from a 2400 FDA-approved drug library with EIF2B5R113H/A403V VWMD patient fibroblasts identified 113 anti-inflammatory drugs as a major class of hits with cytoprotective effects. A panel of candidate drugs, including berberine, deflazacort, ursodiol, zileuton, guanabenz and Anavex 2–73, and preclinical ISRIB, increased cell survival of EIF2B5R113H/A403V or EIF2B2G200V/E213G VWMD astrocytes, and were further investigated for their effect on the integrated stress response and mitochondrial stress. Ursodiol demonstrated capacity to ameliorate oxidative stress and loss of mitochondrial membrane potential in VWMD patient iPSC-derived astrocytes in the presence or absence of stress conditions. Conclusion Patient-derived cells can be used to identify cellular phenotypes and for large-scale drug screening. Anti-inflammatory compounds, such as berberine, deflazacort, ursodiol and zileuton are potentially repurposable drug candidates for VWMD that should be further investigated for translation in vivo.

No abstract

No abstract

Deoxyribonucleic acid is generally accepted as the primary biomolecular target of the first platinum-based chemotherapeutic agent, cisplatin, which was documented in 1845, characterised in 1893 and its potential discovered in 1965. Initial attempts to understand the structural significance of the compound by combinatorial means saw early conceptions of structure–activity relationships that were soon challenged. Almost 50 years and thousands of complexes later, DNA still remains the primary target in a variety of interactions ranging from differences in base-pair preference, irreversible covalent binding, and reversible minor/major groove binding and intercalation. Developmental efforts have seen active cytotoxic platinum complexes with structures derived beyond initial assumptions through a diversity of ligand substitution and multinuclear linkages. Nonetheless nephrotoxicity and neurotoxicity pose as dire inherent side-effects in clinical trials and application of platinum therapeutics. Subsequent development has called for means to avoid diminished efficacy due to inactivation by endogenous glutathione and other complex-binding or chelating proteins. Platinum(IV) derivatives may solve issues of unintended toxicity by means of intrinsic extracellular stability, degrading to their active platinum(II) forms once internalised within a cytosol and in acidic tumour environments. Selectivity may also be gained by the axial/apical coordination of ligands that typically bind to receptors that are overexpressed in certain tumours, such as modified-estrogen ligands. The development of platinum complexes has required an in-depth understanding of their DNA-binding interactions in order to facilitate further structural modification without loss of effective function for their eventual application as chemotherapeutics. Although platinum complexes are the focus of this chapter, some other metal complexes that interact with nucleic acids, such as ruthenium, iridium, osmium, iron, copper, titanium, vanadium gold and silver, are discussed.

No abstract