Medicinal applications of bismuth(III): from antimicrobial to anticancer

Bismuth(III) compounds have long been recognized for their therapeutic potential, owing to their versatile biological activities and relatively low toxicity. The medicinal applications of bismuth(III) complexes are comprehensively summarized, spanning established antimicrobial uses-such as in the treatment of Helicobacter pylori-associated peptic ulcers and diarrheal diseases through to compounds like bismuth subsalicylate and colloidal bismuth subcitrate, to emerging roles as antiviral agents. Mechanisms involve interactions with key proteins and enzymes with cysteine-containing motifs, and interference with zinc and iron biocoordination chemistry. Non-radioactive bismuth(III) complexes, including organobismuth derivatives and coordination compounds with ligands such as thiosemicarbazones, dithiocarbamates, and thiolates, exhibit potent in vitro and in vivo antiproliferative effects against various cancer cell lines. Recently, radioactive bismuth isotopes, particularly ²¹³Bi, were explored for targeted alpha therapy (TAT) in radiopharmaceuticals, offering precise delivery of high-energy α-particles for treating micrometastatic and refractory cancers. Advances in synthesis, mechanisms of action, clinical progress, and challenges are also highlighted, underscoring the promise of bismuth(III) as a multifaceted therapeutic platform in modern medicine.