OBJECTIVETo observe the impacts of thermosensitive moxibustion (TSM) on the expressions of nitric oxide (NO), typeⅠdisintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4), typeⅡcollagen and proteoglycan (PG) in the rabbit models of knee osteoarthritis (KOA) and explore the mechanism of TSM on KOA.

METHODSA total of 42 Japanese long-eared male rabbits were divided into a blank group (6 rabbits), a model group (6 rabbits), a moxibustion group (24 rabbits) and a sham-operation group (6 rabbits) according to the random number table. In the blank group, the rabbits were fed normally. In the model and moxibustion groups, the papain injection was given to establish KOA models. The rabbits in the sham-operation group were treated with the intracavity injection of 0.9% NaCl solution. The rabbits were forced to move for 30 min every day, continuously for 15 days during modeling. At the end of modeling, in the moxibustion group, moxibusiton was applied at "Dubi" (ST 35), once a day, 40 min each time, for 14 days totally. According to the temperature changes during moxibustion, the rabbits were divided into a TSM group and a non-TSM group. 6 rabbits were collected randomly from the two groups. The usual feeding was given in the blank group, the model group and the sham-operation group, without any intervention. The body mass and behavioristics changes were observed in each group. At the end of treatment, the nitrate reduction method was adopted to determine NO expression in the serum. The real-time PCR was adopted to determine the expressions of ADAMTS-4, typeⅡcollagen and PG in the cartilage.

RESULTS① After modeling, compared with the blank group, the body mass was all reduced and the Lequesne MG score was increased in the model group, TSM group, non-TSM group and sham-operation group (<0.05, <0.01). After intervention, compared with the blank group, the body mass was decreased and the Lequesne MG score was increased in the model and sham-operation groups (<0.05, <0.01). Compared with the model group, the body mass was increased and the lequesne MG score was decreased in the TSM, non-TSM, and sham-operation groups (<0.05, <0.01). Compared with the non-TSM group, the body mass in the TSM group was increased remarkably (<0.05), but the difference in Lequesne MG score was not statistically significant (>0.05). ② After intervention, compared with the blank group, the expressions of NO and ADAMTS-4 were all increased and the expressions of typeⅡcollagen and PG were decreased in the model group, TSM group, non-TSM group and sham-operation group (<0.05, <0.01). Compared with the model group, the expressions of NO and ADAMTS-4 were all remarkably lower and the expressions of typeⅡcollagen and PG were increased in the TSM group, non-TSM group and sham-operation group (<0.05, <0.01). Compared with the non-TSM group, the expressions of NO and ADAMTS-4 were all remarkably lower and the expressions of typeⅡcollagen and PG were increased in the TSM group after intervention (all <0.05).

CONCLUSIONThe thermosensitive moxibustion alleviates the inflammatory reactions and protects the joint cartilage through inhibiting the expressions of NO and ADAMTS-4 to achieve the effects in the treatment of KOA.