Effects of oral hyaluronic acid on monosodium iodoacetate-induced osteoarthritis in rats: mechanistic insights and therapeutic implications

This study aimed to meticulously assess the effectiveness of hyaluronic acid (HA) in mitigating symptoms associated with monosodium iodoacetate (MIA)-induced osteoarthritis (OA) symptoms in rodent models and to investigate the underlying mechanistic pathways. Eight-week-old rats were randomly allocated to a normal control group and three experimental groups (n = 10 per group). The normal group did not undergo any treatment. The experimental groups were administered MIA for 1 week to induce osteoarthritis, and orally administered distilled water (control group), 2 mg/kg indomethacin (INDO group), or 20 mg/kg HA (HA20 group) daily for 4 weeks. The HA20 group showed a significant improvement in hind-paw weight-bearing distribution after 4 weeks compared to the control group. HA suppressed inflammatory responses by reducing the overproduction of prostaglandin E2 and leukotriene B4 and protected the vital components of the articular ECM, including glycosaminoglycans and aggrecan. HA treatment effectively reduced inflammation, protected cartilage by inhibiting MMP expression, and suppressed inflammatory mediator production. This study demonstrates that HA has potential to alleviate OA symptoms in a rodent model stimulated with MIA, rendering it a promising therapeutic agent for OA.