The effects of Cerium oxide nanoparticles on the rat model of rheumatoid arthritis

Background & aim: The previous document indicated that Cerium oxide nanoparticles (CeO2-NPs), possess an astonishing pharmacological potential due to their antioxidant and anti-inflammatory properties. This study was designed to evaluate the effects of CeO2-NPs on the rheumatoid arthritis (RA) induced by Complete Freund's adjuvant in Wistar Rats. Methods: Forty male Wistar rats were divided into equal four groups: normal control, positive control group, CeO2-NPs treated group (30 mg/kg-daily; P.O) and treated the group with Methotrexate (1 mg/kg- weekly; P.O). The rheumatoid arthritis was induced by intera-footpad injection of (0.1 ml) complete Freund's adjuvant. Treatment was initiated in rats when all animals showed inflammation in tarsus joint (day 8) and followed throughout study when the animals were sacrificed at day 28. P <0.05 was considered as the significant level. Results: CeO2-NPs have a professional anti-inflammatory beneficiary in the redaction of foot-pad edema in a similar manner with Methotrexate (p=0.27). The level of neutral red uptake in the peripheral blood phagocytic cell population and blood level of myeloperoxidase in RA rats received cerium oxide were 0.76±0.08 and 10.39±1.99 Mu/ml, respectively so that these levels were significantly lower in RA rats treated with methotrexate (0.98±0.07 and 19.2±2.29 Mu/ml, respectively) (p <0.05). Conversely, the blood level of nitric oxide in the RA rats treated with methotrexate (137.81±12.18 μM) showed a greater decrease compared to RA rats treated with cerium oxide nanoparticles (165.9± 3.29 μM) (p <0.05). There was no significant difference in the reduction of respiratory burst intension (p=0.09) and CRP level (p= 0.13) in both treatment groups. More importantly, Despite RA rats treated with Methotrexate, the levels of lymphocyte proliferation were not decreased in RA rats treated with CeO2–NPs compared to RA rats without treatment (p=012). Conclusion: It seems that, treatment with CeO2-NPs is a promising strategy to improve the inflammation in a rat model of RA. Conclusion: It seems that, treatment with CeO2-NPs is a promising strategy to improve the inflammation in a rat model of RA.