Effect of Sodium Benzoate on Reducing Inflammatory Symptoms in AnimalModels of RheumatoidArthritis

Rheumatoid arthritis (RA) or arthritis is the most common systemic inflammatory disease of the joints and one of the chronic autoimmune diseases. The global prevalence of rheumatoid arthritis has been reported at 1%. Sodium benzoate (NaB) is a cinnamon metabolite used as a food preservative. This study aimed to evaluate the changes of CD52 in the animal model of rheumatoid arthritis treated with NaB. Moreover, it was attempted to investigate the relationship between serum CD52 and RA severity.

The male rats were divided into four groups of healthy, RA, RA treated with NaB, and RA treated with prednisolone. The RA was induced by intradermal injection of heat-killed Mycobacterium tuberculosis suspended in the Freund's incomplete adjuvant. During two weeks, from the 10th to 23rd days after RA induction, the disease progression was assessed through macroscopic examinations, including walking ability, redness of the skin, as well as swelling at the ankle, wrist, and small joints of the fingers. Clinical, radiological, and histological symptoms, as well as the serum protein levels of CD52, were also investigated in this study. Ethics code: IR.sums.med.rec.1398.353

According to the results, the overall activity and walking ability of the RA rats decreased, compared to the healthy control group. Moreover, the severity of RA clinical symptoms was significantly reduced in the group treated with NaB and prednisolone, compared to the control group. There were no significant differences among the groups regarding the serum levels of CD52..

 There were no significant differences among the groups regarding the serum change of CD52 expression level indicating that the mechanism of the effect of NaB was not induced by CD52.