New uses for old drugs. Auranofin, a clinically established antiarthritic metallodrug, exhibits potent antimalarial effects in vitro: Mechanistic and pharmacological implications.

The clinically established gold-based antiarthritic drug auranofin (AF) manifests a pronounced reactivity toward thiol and selenol groups of proteins. In particular, AF behaves as a potent inhibitor of mammalian thioredoxin reductases causing severe intracellular oxidative stress. Given the high sensitivity of Plasmodium falciparum to oxidative stress, we thought that auranofin might act as an effective antimalarial agent. Thus, we report here new experimental results showing that auranofin and a few related gold complexes strongly inhibit P. falciparum growth in vitro. The observed antiplasmodial effects probably arise from direct inhibition of P. falciparum thioredoxin reductase. The above findings and the safe toxicity profile of auranofin warrant rapid evaluation of AF for malaria treatment in animal models.

A diffusion-ordered NMR spectroscopy study of the solubilization of artemisinin by octanoyl-6-O-ascorbic acid micelles.

Artemisinin (QHS) is a natural drug with a very low solubility in water. To improve its availability in hydrophilic media, it was solubilized in micellar dispersions of octanoyl-6-O-ascorbic acid (ASC8), a relatively novel surfactant that combines surface activity with powerful performance as radical scavenger. In this article we report a study based on diffusion-ordered NMR spectroscopy (DOSY) measurements carried out on QHS/ASC8 micellar dispersions. QHS is efficiently solubilized by ASC8 micelles, with no significant perturbation of the micellisation.