Comparative in Vitro Evaluation of N-Heterocyclic Carbene Gold(I) Complexes of the Benzimidazolylidene Type

Gold­(I) complexes with a 1,3-diethylbenzimidazol-2-ylidene
N-heterocyclic
carbene (NHC) ligand of the type NHC-Au-L (L = -Cl, -NHC, or -PPh3) were comparatively evaluated as thioredoxin reductase (TrxR)
inhibitors and antimitochondrial anticancer agents. Different effects
were noted in various biochemical assays (e.g., inhibition of TrxR,
cellular and mitochondrial uptake, or effects on mitochondrial membrane
potential), and this was related to properties of the complexes such
as bond dissociation energies and overall charge. Remarkable antiproliferative
effects, a strong induction of apoptosis, and enhancement of reactive
oxygen species (ROS) formation as well as other effects on tumor cell
metabolism confirmed the promising potential of the complexes as novel
anticancer chemotherapeutics.