Antihyperuricemia and antigouty arthritis effects of Persicaria capitata herba in mice

•Persicaria capitata showed remarkable anti-hyperuricemia and anti-gouty arthritis activity.•Persicaria capitata acted as a strong XOD inhibitor to inhibit the uric acid production and as a potent uricosuric agent with GLUT9 and URAT1 down-regulation capacity to promote uric acid excretion.•Persicaria capitata was a potent anti-inflammatory agent against gouty arthritis. : Hyperuricemia (HUA) is an important risk factor for gout, renal dysfunction and cardiovascular diseases. The whole plant of Persicaria capitata (Buch.-Ham. ex D. Don) H. Gross, namely Persicaria capitata herba, is a well-known ethnic herb with potent therapeutic effects on urinary tract infections and urinary calculus, yet previous reports have only focused on its effect on urinary tract infections. : To evaluate the therapeutic potential of P. capitata herba against gout by investigating its antihyperuricemia and antigouty arthritis effects and possible mechanisms. : The ethanol extract (EP) and water extract (WP) of P. capitata herba were prepared by extracting dried and ground whole plants of P. capitata with 75% ethanol and water, respectively, followed by removal of solvents and characterization by UHPLC-Q-TOF/MS. The antihyperuricemia and antigouty arthritis effects of the two extracts were evaluated in a potassium oxonate- and hypoxanthine-induced hyperuricemia mouse model and a monosodium urate crystal (MSUC)-induced acute gouty arthritis mouse model, respectively. The mechanisms were investigated by testing their effects on the expression of correlated proteins (by Western blot) and mRNAs (by RT–PCR). : UHPLC-HRMS fingerprinting and two chemical markers (i.e., quercetin and quercitrin) determination were used for the characterization of the WP and EP extracts. Both WP and EP extracts showed pronounced antihyperuricemia activities, with a remarkable decline in serum uric acid and a marked increase in urine uric acid in hyperuricemic mice. Unlike the clinical xanthine oxidase (XOD) inhibitor allopurinol, WP and EP did not show any distinct renal toxicities. The underlying antihyperuricemia mechanism involves the inhibition of the activity and expression of XOD and the downregulation of the mRNA and protein expression of glucose transporter 9 (GLUT9) and urate transporter 1 (URAT1). The extracts of P. capitata herba also demonstrated remarkable anti-inflammatory activity in MSUC-induced acute gouty arthritis mice. The mechanism might involve inhibitory effects on the expression of