Gold(III) bis(dithiolene) complexes: from molecular conductors to prospective anticancer, antimicrobial and antiplasmodial agents

The anticancer, antimicrobial and antiplasmodial activities of six gold(iii) bis(dithiolene) complexes were studied. Complexes1-6showed relevant anticancer properties against A2780/A2780cisR ovarian cancer cells (IC(50)values of 0.08-2 mu M), also being able to overcome cisplatin resistance in A2780cisR cells. Complex1also exhibited significant antimicrobial activity againstStaphylococcus aureus(minimum inhibitory concentration (MIC) values of 12.1 +/- 3.9 mu g mL(-1)) and bothCandida glabrataandCandida albicans(MICs of 9.7 +/- 2.7 and 19.9 +/- 2.4 mu g mL(-1), respectively). In addition, all complexes displayed antiplasmodial activity against thePlasmodium bergheiparasite liver stages, even exhibiting better results than the ones obtained using primaquine, an anti-malarial drug. Mechanistic studies support the idea that thioredoxin reductase, but not DNA, is a possible target of these complexes. Complex1is stable under biological conditions, which would be important if this compound is ever to be considered as a drug. Overall, the results obtained evidenced the promising biological activity of complex1, which might have potential as a novel anticancer, antimicrobial and antiplasmodial agent to be used as an alternative to current therapeutics.