[Effect of different suspension moxibustion methods on syndrome characteristics of rats with rheumatoid arthritis of heat bi syndrome based on "moxibustion can be used for heat syndrome"].

Objective: To observe the effects of different suspension moxibustion methods on the syndrome characteristics and inflammatory factors of rats with rheumatoid arthritis (RA) of heat bi syndrome and to prove the concept of "moxibustion can be used for heat syndrome".

Methods: Among seventy Wistar rats, 12 rats were randomly selected as a normal group, and the remaining rats were induced by collagen combined with wind, dampness, and heat environmental stimulation to establish the RA model of heat bi syndrome. Forty-eight rats with successful model establishment were further randomly divided into a model group and three moxibustion groups (mild moxibustion group, rotating moxibustion group and sparrow-pecking moxibustion group), with 12 rats in each group. The acupoints "Quchi" (LI 11), "Dazhui" (GV 14) and ashi point were used in all moxibustion groups, with mild moxibustion, rotating moxibustion, and sparrow-pecking moxibustion intervention given respectively, each acupoint was treated with moxibustion for 10 min a day, and 6 days were considered one course of treatment, with a total of three courses. After the intervention, the arthritis index (AI), the Evans blue (EB) extravasated volume in the soft tissue of the right hind paw, and the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-10 in the serum were measured by ELISA in each group. The volume of the bilateral hind paw was measured; the infrared thermal imaging was collected to analyze the temperature of the plantar area of the bilateral foot pads, and the reaction time of plantar heat pain was calculated before and after modeling, as well as after the 1st, 2nd and 3rd courses of interrention. The ankle dorsiflexion angle of the right hind foot was also measured before and after modeling, as well as after the intervention.

Results: After modeling, compared with the normal group, the rats in the model group had more high-temperature areas in the bilateral hind limbs, abnormal AI score, abnormal bilateral hind paw volume, abnormal temperature of the plantar area of the bilateral foot pads, abnormal foot pain response time, abnormal right hind ankle dorsiflexion angle, abnormal right hind paw soft tissue EB extravasation, and abnormal serum TNF-α and IL-10 levels (P<0.01, P<0.05). After the intervention, compared with the model group, the rats in each moxibustion group had decreased or disappeared high-temperature areas in the bilateral hind limbs, EB extravasated volume in the soft tissue of the right hind paw was reduced (P<0.05), and the right ankle dorsiflexion angle was increased (P<0.05), serum level of TNF-α was reduced, and level of IL-10 increased (P<0.05); the AI scores in the mild moxibustion group and the sparrow-pecking moxibustion group was decreased (P<0.01, P<0.05). After the 1st, 2nd and 3rd courses of intervention, compared with the model group, the bilateral hind paw volume of rats in each moxibustion group was decreased (P<0.05, P<0.01), and plantar heat pain reaction time was increased (P<0.05). After the 2nd course and the 3rd course of intervention, the temperature of the right hind paw pad area was decreased in each moribustion group (P<0.05); after the 3rd courses of intervention, the temperature of the left hind paw pad area was decreased in the mild moxibustion group (P<0.05).

Conclusion: Suspension moxibustion could adjust the serum levels of TNF-α and IL-10 to improve the syndrome characteristics of RA rats of heat bi syndrome, such as joint redness, swelling, heat, pain and activity restriction. The effect of mild moxibustion is the most prominent. The findings could provide scientific basis for "moxibustion can be used for heat syndrome".