Effect of Gold Nanoparticles in the Treatment of Established Collagen Arthritis in Rats

Background and objective. The role of gold nanoparticles (AuNPs) in the treatment of autoimmune diseases remains vague. Therefore, the aim of this study was to determine the effect of AuNPs in the treatment of rats with established collagen-induced arthritis (CIA).
Material and Methods. A total of 24 Wistar male rats with established CIA were used. AuNPs measuring 13-nm and 50-nm were prepared according to standard procedures, and their size was determined using transmission electron microscopy. These gold particles were injected intra-articularly 5 times a week, 12 injections in total. Body and organ weight, arthritic profiles based on paw swelling, histological changes in the joints and internal organs, blood indices, and serum oxidative products were investigated.
Results. An examination of the course of the experimental disease and a subsequent histological analysis as well as hematological studies revealed a nontoxic effect of AuNPs on the vital organs. The treatment of the rats with established CIA by 13-nm and 50-nm gold nanoparticles decreased joint swelling by 49.7% (P<0.002) and 45.03% (P<0.01), respectively. That corresponded to the decrease in statistically significant histological changes in articular tissues. AuNPs showed their antioxidant effect by increasing the level of antioxidant enzyme catalase.
Conclusions. The continuous intra-articular administration of AuNPs not only reduced the inflammation, joint swelling, and development of polyarthritis, but also reduced histological changes in articular tissues without toxic effects on the internal organs. The results obtained disclose the role of AuNPs as antioxidant agents.