Objective To observe the effect of fire-needle intervention on serum IL-1 and TNF-α contents in rheumatoid arthritis(RA) rats so as to study its underlying mechanism in improving RA.Methods A total of 40 Wistar rats were randomized into normal control

model

methotrexate(MTX

medication) group and fire-needle groups

with 10 cases in each group.RA model was established by injecting Freund's complete adjuvant(0.1 mL) into the rats' right hind paw.Fire-needle was applied to"Jiaji"(EX-B 2)

"Zusanli"(ST 36) and "Ashi point"(the most severe site of the swelling joint)

once every three days and 8 times altogether.The rat's right hindpaw swelling volume was detected by volumetric method

and serum IL-1 and TNF-α contents were determined by double antibody sandwich ELISA.The pathological changes of synovium tissue of the right knee-joint were observed by optical microscope.Results In comparison with the control group

the swollen paw volumes at time-points of 12 d

19 d

26 d and 33 d after modeling and serum IL-1 and TNF-α contents were increased significantly(P<0.01).Compared to the model group

the swollen paw volumes on day 33 in both medication and fire-needle groups were decreased considerably(P<0.01)

while serum IL-1 and TNF-α contents in the medication and fire-needle groups were reduced significantly(P<0.05

P<0.01).No significant differences were found between the medication and fire-needle groups in the swollen paw volumes on day 12(P>0.05).The pathological states(synovial cells' arrangement

inflammatory infiltration

synovial membrane thicke-ning

etc.) of synovium tissue of the right knee-joint in both medication and fire-needle groups were relatively lighter than those of the model group.Conclusion Fire-needle therapy can down-regulate serum IL-1 and TNF-α contents in rheumatoid arthritis rats

and reduce the degree of arthroncus of the affected joint

which may contribute to its effect in improving synovial lesions.