The Effects of Cerium Oxide Nanoparticles on the Rat Model of Rheumatoid Arthritis

Previous studies have shown that cerium oxide nanoparticles (CeO2-NPs) have high pharmacological capacity due to their antioxidant and anti-inflammatory properties. Rheumatoid arthritis is a chronic and systemic autoimmune disease of unknown etiology. The aim of this study was to determine and effect of cerium oxide nanoparticles in rheumatoid arthritis model.

In the present experimental study, 40 Wistar rats weighing 90 to 110 g were collected from the laboratory animal center of the Faculty of Veterinary Medicine, Urmia University. Rats were randomly divided into four equal groups of healthy, RA affected and treated with Serium Oxide Nanoparticles(30 mg/kg oral, daily) and treated with Methotrexate(1 mg/kg oral, weekly). Rheumatoid arthritis was induced by Freund's complete adjuvant injection(0.1ml). Treatment was started when the rats exposed inflammatory symptoms in the tharsus joint (day 8) and continued until day 28 of the rats’ slaughter. Data were analyzed using one-way ANOVA and Tukey tests.

Cerium oxide nanoparticles had a good anti-inflammatory effect to reduce the severity of foot-pad inflammation in a pattern similar to methotrexate (p=0.27). The level of neutral red uptake in the peripheral blood phagocytic cell population and the blood level of myeloperoxidase in the treated and cerium oxide groups were 0.76 0 0.08 and 10.39 ± 1.99 mmol / ml, respectively. Significantly lower levels were observed in the methotrexate group (0.98 0 0.07 and 19.2 2 2.59 mmol / ml) (p<0.05). Conversely, blood levels of nitric oxide in the methotrexate treated and recipient group (137.81±12.18 μM)) exhibited a greater decrease than that of the cerium oxide nanoparticles (165.9 13 13.29 mmol). / 0> p). There was no significant difference in severity of respiratory burst (p = 0.09) and CRP (p=0.13) in both treatment groups. Most importantly, unlike methotrexate, the intensity of lymphocyte proliferation in rats with arthritis treated with cerium oxide did not decrease significantly (p=0.13).

Due to the improved clinical and experimental appearance of affected rats, it seemed that, treatment with CeO2-NPs is a promising strategy to improve the inflammation in a rat model of RA.