Moxibustion for Pain Model Induction

Moxibustion was carried out respectively for 15 min on formalin-induced pain model before formalin injection (Figure 1(a)) and for 30 min on the fifth day on CFA-induced pain model after CFA injection (Figure 1(b)). Before moxibustion intervention, the fur on moxibustion site was shaved to expose ST36 (Zusanli acupoint, located 2 mm lateral to the anterior tubercle of the tibia in the anterior tibial muscle and 4mm distal to the knee joint lower point, Figure 1(c)). Ipsi-Moxi was done over the left ST36 while contra-Moxi was applied at the right ST36 (Figure 1(c)). For ipsi-smoke-free Moxi group, moxa smoke was eliminated by C200 smoke purifier (Shenzhen Conyson Company, Guangzhou, China). During moxibustion operation, the distance between the skin of ST36 and the lighted end of animal-used moxa sticks (length: 120 mm, diameter: 5 mm, Nanyang Hanyi Moxibustion Technology Development Co., Ltd., China, Figure 1(e)) was controlled within 1-1.5 cm. All procedures were performed at room temperature (24°C). The control and the model groups without moxibustion operation were under the same condition.