Study on the anti-inflammatory mechanism of moxibustion in rheumatoid arthritis in rats based on phospholipaseA2 signaling inhibition by Annexin 1.

OBJECTIVE: To determine whether moxibustion had an anti-inflammatory effect on rheumatoid arthritis (RA) by regulating Annexin 1 expression and interfering with the phospholipaseA2 signaling pathway. METHODS: Thirty male Sprague-Dawley rats were randomly categorized into five groups (six rats per group): blank control (CON) group, RA model (RA) group, moxibustion (MOX) group, Annexin 1 lentiviral intervention (RNAi-Anxa1) group, and Annexin 1 lentiviral intervention + moxibustion (RNAi-Anxa1 + MOX) group. The rats in the RNAi-Anxa1 and the RNAi-Anxa1 + MOX groups were injected with the lentiviral vector-mediated RNAi-Anxa1 into the rat foot pad. An experimental RA rat model was established by injecting Freund's complete adjuvant (FCA) into the RA, MOX, RNAi-Anxa1, and RNAi-Anxa1 + MOX groups. Rats in the MOX and RNAi-Anxa1 + MOX groups received moxibustion treatment. After modeling, using moxibustion "Shenshu (BL23)" and "Zusanli (ST36)", each point is 5 times, bilateral alternating, once a day, 6 times for a course of treatment, between the courses of rest for a one day. A total of three treatment courses were conducted. Both bilateral pad thicknesses were measured using Vernier calipers on experimental days 1, 7, 14, 21, and 28. The expression of cPLA2α signaling in the synovium of diseased joints was observed using Western blot. The pathology of the rat ankle synovium was observed using hematoxylin-eosin (HE) staining. Interleukin (IL)-1ß, IL-10, prostaglandin E2 (PGE2), and leukotriene B4 (LTB4) were detected using enzyme-linked immunosorbent assay. RESULTS: Moxibustion increased the levels of Annexin 1 and decreased the inflammatory response in rats with RA. After increasing the expression of Annexin 1, the phosphorylated expression of cPLA2α was inhibited, the serum levels of IL-1ß, PGE2, and LTB4 decreased, and the level of IL-10 increased. In moxibustion treated RA rats after the Annexin 1 lentiviral intervention, the serum levels of IL-1ß, PGE2, LTB4, and IL-10 were almost unchanged. CONCLUSION: Moxibustion enhanced the negative regulation of the cPLA2α signaling pathway, increased the synovial Annexin 1 expression, inhibited the cPLA2α signaling pathway, indirectly inhibited the expression of downstream inflammatory factors, and played a role in reducing inflammation.

Moxibustion of Zusanli (ST36) and Shenshu (BL23) alleviates the inflammation of rheumatoid arthritis in rats through regulating macrophage migration inhibitory factor/glucocorticoids signaling.

OBJECTIVE: To test the hypothesis that moxibustion may inhibit rheumatoid arthritis (RA) synovial inflammation by regulating the expression of macrophage migration inhibitory factor (MIF)/glucocorticoids (GCs). METHODS: Fifty male Sprague-Dawley rats were randomly divided into five groups (n = 10 each): blank Control (CON) group, RA Model (RA) group, Moxibustion (MOX) group, MIF inhibitor (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1) group, and Moxibustion + MIF inhibitor ISO-1 (MOX + ISO-1) group. Rats in the ISO-1 group and ISO-1 + MOX group were intraperitoneally injected with the inhibitor ISO-1. The rats in the RA group, ISO-1 group, MOX group, and ISO-1 + MOX group were injected with Freund's complete adjuvant (FCA) in the right hind footpad to establish an experimental RA rat model. In the MOX group and MOX + ISO-1 group, rats were treated with Moxa. The thickness of the footpads of the rats in each group was measured at three-time points before, after modeling and after moxibustion treatment. The contents of serum MIF, corticosterone (CORT), tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) were detected by enzyme-linked immunosorbent assay; and the contents of synovial MIF were detected by Western blot. Hematoxylin-eosin (HE) staining method was used to observe the pathological changes of synovial tissue under a section light microscope, and pathological scoring was performed according to the grading standard of the degree of synovial tissue disease. RESULTS: Moxibustion was found to reduce the level of MIF and alleviate inflammation in RA rats in this study. In addition, after inhibiting the expression of MIF, the level of CORT increased, and the level of TNF-α decreased. Treating RA rats with inhibited MIF by moxibustion, the level of CORT was almost unchanged, but the level of TNF-α further decreased. The correlation analysis data suggested that MIF was positively related to the expression of TNF-α and negatively correlated with the expression of CORT. CONCLUSION: Reducing MIF to increase CORT and decrease TNF-α by moxibustion treatment in RA. MIF may be a factor for moxibustion to regulate the expression of CORT, but the expression of TNF-α is due to the incomplete regulation of the MIF. This study added to the body of evidence pointing to moxibustion's anti-inflammatory mechanism in the treatment of RA.