Auranofin

Inflammatory arthritis can cause joint swelling, warmth, pain, and tenderness; one cause of this condition is rheumatoid arthritis. In patients with rheumatoid arthritis, gold salts such as auranofin can be administered to decrease joint inflammation and prevent the destruction of bones and cartilage. Though the mechanism of action of auranofin is not fully established in rheumatoid arthritis, this drug has been shown to inhibit phagocytosis and the release of antibodies and enzymes that play a role in cytotoxic reactions, suppressing the inflammatory response.

Aside from its probable immune effects in inflammatory arthritis, studies have shown that auranofin inhibits thioredoxin reductase. This enzyme has various roles in cell homeostasis, including the regulation of free radicals. Thioredoxin reductase can be over expressed in various types of tumours, rendering it an attractive target for anticancer drug development. Studies have shown that inhibiting thioredoxin reductase can cause oxidative stress and apoptosis of tumour cells by increasing the formation of free radicals. Aurofin's thiol ligand binds with high affinity to thiol and selenol groups, forming irreversible reaction products. One study showed that treatment with auranofin increased the production or reactive oxygen species and caused elevation of intracellular calcium concentration in platelets, leading to cell death. Another study showed that auranofin enhanced the production of free radicals, governing T-cell activation.