Abstract: Objective: To examine the therapeutic effect of oral administration of hyaluronic acid (HA) on adjuvant arthritis (AA) in mice. Methods: Forty 6-weeks-old healthy mice were randomly divided into 4 groups: normal, model, HA and diclofenac groups. AA mouse models were created by injection of Fluoride’s complete adjuvant (FCA) into the right hind paw. After 4 successive weeks of oral HA administration, mouse body weight and footpad thickness were measured and knee swelling was observed and scored. In addition, serum levels of interleukin-1 (IL-1) and HA were assayed. Results: Oral HA administration resulted in a significant reduction in mouse footpad thickness and arthritis index and serum levels of IL-1 and HA and showed no significant differences in various indicators compared with diclofenac. Conclusions: Oral HA administration is effective at alleviating knee swelling, lowering serum interleukin-1 level and enhancing physical activities in AA mice and thus has a powerful therapeutic effect on adjuvant arthritis.

Key words: oral administration of hyaluronic acid, animal model, adjuvant arthritis