Anticancer Properties of Imidazolium Salt Derivatives: Current Advances and Therapeutic Perspectives

Imidazolium salt derivatives (IMSDs) represent a structurally diverse class of compounds that has attracted increasing interest as a source of novel anticancer agents due to their tunable chemical architecture and broad spectrum of biological activities. This review summarizes current advances in the development of organic imidazolium derivatives and metal–N-heterocyclic carbene (NHC) complexes, with particular emphasis on their structure–activity relationships (SARs), mechanisms of action, and therapeutic potential. Numerous IMSDs exhibit significant antiproliferative activity against a wide range of cancer cell lines through multiple mechanisms, including DNA damage, reactive oxygen species generation, mitochondrial dysfunction, thioredoxin reductase inhibition, cell-cycle arrest, and apoptosis induction. Among the reported compounds, Au(I)-, Pt(II)-, and Ag(I)-NHC complexes consistently demonstrate the highest cytotoxic potency, whereas hybrid derivatives incorporating pharmacologically active moieties, such as lithocholic acid, have been investigated as potential approaches to improving selectivity and multitarget activity. Current SAR analyses indicate that metal coordination, bulky aromatic substituents, molecular hybridization, and balanced lipophilicity are key determinants of enhanced biological activity. Despite these encouraging findings, most available evidence is limited to in vitro studies, while comprehensive in vivo evaluation, pharmacokinetic characterization, and systematic toxicological assessment remain insufficient. Consequently, the clinical relevance of these compounds has yet to be established. Future research should focus on rational structural optimization, standardized preclinical evaluation, combination therapies, and advanced drug delivery strategies, including nanomedicine, to facilitate the translation of IMSDs into clinically useful anticancer agents.