Objective: To investigate the effects of the flavonoid quercetin on monosodium urate(MSU) crystal-induced inflammation in rats

as well as the swelling of joint

inflammatory factors and antioxidant activity. Method: Forty-eight male SD rats (200±20) g were divided into six groups with 8 rats each group. Group I (control group) was treated with distilled water

Group II served as model group induced by monosodium urate (MSU) crystal and was treated with distilled water (ig)

Groups III-V were treated with quercetin (100

200

400 mg·kg-1 body weight

i g)

Group VI MSU crystal-induced rats were treated with indomethacin (3.0 mg·kg-1 body weight

ig). quercetin

indomethacin or distilled water was given orally

once daily for seven consecutive days throughout the experiment. On the fifth day

inflammatory reaction was induced by intra-articular injection of 3% MSU crystal suspension 100 μL inside the ankle joint of the right hind limb. The inflammatory reaction was measured by the circumference of the joint with a tie line method at 2

4

8

12

24

48 h

the tissue homogenate of liver

synovial tissue of joint and serum were used for assaying the inflammatory mediators such as interleukin-1β(IL-1β)

tumor necrosis factor(TNF-α)

prostaglandin E2(PGE2) and antioxidant status including malondialdehyde(MDA)

superoxide dismutase(SOD)

catalase(CAT)

glutathione peroxidase(GSH-Px) with enzyme-linked immunosorbent assay and colorimetry. Result: The quercetin had an inhibitory effect on edema in experimental gouty arthritis in a dose-dependant manner

suppressed MSU crystal-induced chemokine production IL-1β

TNF-α

PGE2

decreased levels of the lipid peroxidation end-product MDA

as well as enhanced the activity of antioxidant enzymes SOD

GSH-Px

CAT. Conclusion: The present results clearly indicated that quercetin exerted a strong effect of treatment on acute gouty arthritis by anti-inflammatory and antioxidant effects.