[Inhibitory action of tiopronin on free radicals]

Free oxygen radicals are involved in many pathological conditions and particularly in the inflammation which characterizes rheumatic disorders. Tiopronin (Acadione), a new basic treatment for rheumatoid arthritis, and sodium 3-aurothio-2-hydroxypropane-1-sulfonate (Allochrysine), the reference treatment for the disease, have been tested in vitro for their ability to regulate the free radicals produced by inflammatory murine macrophages or granulocytes. The production of free radicals was measured using the technique of luminol-dependent chemoluminescence. Results show that tiopronin causes dose-dependent inhibition of chemoluminescence whereas, under the same experimental conditions, sodium 3-aurothio-2-hydroxypropane-1-sulfonate leads to a stimulation in production of the radicals. Taking into consideration the deleterious effects of free radicals in rheumatic disorders, inhibition of the radicals may be considered as forming part of tiopronin's mode of action.