Effect of Fire-needle Intervention on JNK and p38MAPK in Ankle-joint of Rheumatoid Arthritis Rats

OBJECTIVE To observe the influence of fire-needle therapy on JNK and p38MAPK in ankle-joint of rheumatoid arthritis(RA) rats to explore its underlying mechanism in RA treatment. METHODS 40 male SD rats were randomly divided into normal group， model group， fire-needle group and medication(methotrexate， MTX) group， with 10 cases in each group. Fire-needle was applied to Jiaji(EX-B2) and Ashi point every other day， twice altogether. The right hindpaw swelling volume of rats were detected on the 1st， 2nd， 4th， 6th and 8th day， respectively. The pathological changes in synovial tissue of the right ankle joint were observed by optical microscope. The expression of JNK and p38 was detected by immunohistochemical method and Western blot. RESULTS In comparison with the control group， the swelling paw volumes at the 2nd day significantly increased of the rest 3 groups（P<0.01）. Compared to the model group， the swelling paw volumes on the 8th day in fire-needle group decreased significantly（P<0.05）. Serum TNF-α and IL-1β（P<0.05） contents increased in model group comparing with normal group， while decreased in fire-needle group and medication group comparing with model group. The pathological states of synovial tissue of the right ankle joint in both fire-needle and medication groups were relatively lighter than those of the model group. In comparison with normal group， the expression of JNK and p38 in local synovial tissue of the right ankle joint increased significantly in model group（P<0.05～0.01）. Compared with model group， the expression of JNK and p38 of fire-needle and medication group both decreased significantly（P<0.05）. These changes were also found in photographs made by immunohistochemical method. CONCLUSION Fire-needle therapy can dowmregulate the expression of JNK and p38 in local synovial tissue of the right ankle join in MAPK signal transduction pathways， which is the possible mechanism of fire-needle therapy for RA treatment.