Effect of Hedyotis Diffusa Willd Extract on Gouty Arthritis in Rats

Purpose: To investigate the effect of Hedyotis diffusa Willd extract (HDWE) on gouty arthritis in rats.Method: Monosodium urate (MSU) crystal was injected into the ankle joint of rats to establish a rat model of gouty arthritis. HDWE (4.8, 9.6 and 19.2 g/kg) was administered to the rats treated with MSU crystals. The walking behavior of the rats was observed daily, and the gait score was calculated to evaluate the Oswestry disability index of rats. Levels of IL-1β and TNF-α in lavage fluid of articularcavities were measured using enzyme linked immunosorbent assay (ELISA) kits. The synovial tissues of joint of control, model and 19.2 g/kg HDWE group rats were obtained and NLRP3 inflammasome was analysed by Western blot.Results: The results showed that HDWE ameliorated the symptoms of gouty arthritis and gait score in rats significantly (p < 0.05). Further pharmacological experiments showed that all doses of HDWE decreased the levels of inflammatory cytokines IL-1β and TNF-α (p < 0.05), and inhibited NLRP3, caspase-1, ASC, IL-1β and IL-18 protein expressions of the lavage fluid of articular cavities in MSU crystal-treated rats (p < 0.01).Conclusion: The results indicate that HDWE exhibits a significant effect in ameliorating gouty arthritis via inhibition NLRP3 inflammasome, and thus is a potential new drug choice for the treatment of gouty arthritis. Keywords: Hedyotis diffusa, Caspase, Gouty arthritis, Inflammatory cytokines, NLRP3 inflammasom