[Effect of moxibustion on serum inflammatory response in rat models of rheumatoid arthritis based on GSDMD]

To observe the effects of moxibustion on paw appearance and serum levels of interleukin-1β (IL-1β), interleukin-18 (IL-18) and matrix metalloproteinase-3 (MMP-3) in model rats of rheumatoid arthritis (RA), and to explore the regulatory mechanism of moxibustion on gasdermin D (GSDMD)-mediated cell pyroptosis.

Fifty SD rats were randomly divided into 5 groups, with 10 rats in each group, including a control group, a model group, a moxibustion group, a GSDMD overexpression group, and a GSDMD overexpression combined with moxibustion treatment group (GSDMD overexpression + moxibustion group). Except for the control group, RA rat models were established in the other groups using Freund's complete adjuvant (FCA). In the GSDMD overexpression group and the GSDMD overexpression + moxibustion group, the rats received a GSDMD lentiviral vector to induce GSDMD overexpression. In the moxibustion group and the GSDMD overexpression + moxibustion group, moxibustion was performed at "Shenshu" (BL23) and "Zusanli" (ST36) alternately on both sides, with 5 moxa cones at each point and in each session, for 6 consecutive days followed by 1 day of rest. The intervention completion covered 18 sessions. The general conditions of rats and the changes in right paw volume were observed before modeling, 7 days after modeling, 7 days after lentiviral injection and after intervention completion. After intervention completion, using ELISA, serum levels of IL-1β, IL-18, and MMP-3 were measured.

Compared with the control group, the model group showed the increase in the right paw volume (P<0.05) and serum levels of IL-1β, IL-18 and MMP-3 (P<0.05). Compared with the model group, the moxibustion group exhibited the decrease in the right paw volume (P<0.05) and serum levels of IL-1β, IL-18 and MMP-3 (P<0.05); and in the GSDMD overexpression group, the volume of right paw was higher (P<0.05) and the serum levels of IL-1β, IL-18 and MMP-3 were elevated (P<0.05). In the moxibustion group, the volume of right paw and the serum levels of IL-1β, IL-18 and MMP-3 were all lower when compared with the GSDMD overexpression + moxibustion group (P<0.05).

Moxibustion can alleviate paw swelling and mitigate the serum inflammatory response in RA rats, which may be obtained by regulating GSDMD-mediated pyroptosis.