Objective:To observe the effect and pharmacological mechanism of Xitongwan on monosodium urate (MSU)-induced gouty arthritis. Method:Rats were intragastrically treated with Xitongwan (200

400

800 mg·kg-1) for consecutively 7 days. MSU-induced gouty arthritis in rats was prepared through intra-articular injection with MSU crystals in the left ankle joint on the 5th day. Paw volume was measured at 0

6

12

24

48 h

as well as gait score was calculated at 24 h after MSU induction. Histological score in ankle joint was calculated by hematoxylin and eosin staining. Osteoclast formation in ankle joint was detected by tartrate-resistant acid phosphatase (TRAP) staining. Expressions of tumor necrosis factor (TNF)-α

interleukin (IL)-1β

IL-6 and nucleotide-binding domain and leucine-rich repeat region containing family of receptor protein 3 (NLRP3) in articular tissues were analyzed by immunohistochemistry staining or Western blot assay. Result:Intra-articular injection with MSU crystals led to apparently elevated paw volume and gait score compared with control rats. Meanwhile

histological score

osteoclast formation and expressions of TNF-α

IL-1β

IL-6 and NLRP3 of gouty arthritis rats were significantly increased compared with control rats. However

treatment with Xitongwan significantly alleviated paw volume and decreased gait score in gouty arthritis rats compared with control rats. Meanwhile

treatment with Xitongwan significantly reduced histological score

osteoclast formation and expressions of TNF-α

IL-1β

IL-6 and NLRP3 in gouty arthritis rats compared with control rats. Conclusion:Xitongwan could attenuate the inflammatory development and structural damage by inhibiting the production of inflammatory mediators in gouty arthritis rats.