Objective To observe the effect of herbal cake-partitioned moxibustion(Moxi) on the expressions of inflammatory factors and M1/M2 polarization in colonic mucosal macrophages in Crohn's disease(CD) rats

so as to explore its underlying mechanisms in the treatment of CD. Methods Forty male SD rats were randomly divided into normal

model

Moxi and medication groups(n=10). The CD model was established by enema of 2

4

6-trinitrobenzene sulfonic acid(TNBS) solution(5%TNBS∶50% alcohol=2∶1

3 mL/kg)

once every 7 days

4 times altogether. For rats of the Moxi group

cake-partitioned moxibustion was given to “Tianshu”(ST25) and “Qihai”(CV6)

two moxa-cones for each acupoint every time

once daily for 10 days. For rats of the medication group

intragastric perfusion of mesalazine solution was given twice daily for 10 days. After the treatment

the colonic mucosa tissue was sampled

and the macrophages were isolated

purified and cultured. The pathological changes of colon tissues were observed by H.E. staining. The ultrastructure of colon tissue was observed by transmission electron microscopy. The expression levels of α7nAChR

NF-κB p65 and TNF-α in colon mucosal macrophages were detected by Western blot. The number of M1 and M2 macrophages in colon mucosa was detected by flow cytometry and immunofluorescence assay. Results Compared with the normal group

the colon tissue of rats presented huge ulceration and inflammatory manifestations

the junction of colon epithelial cells was loose

the structure of organelles was damaged; the expression level of α7nAChR in macrophages of colon mucosa was significantly decreased(P<0.01)

while the expression levels of NF-κB p65 and TNF-α

and the number of M1 and M2 macrophages were increased(P<0.01

P<0.05) in the model group. In comparison with the model group

the morphology and structure of colon mucosa tissues of rats in Moxi and medication groups were improved; the expression level of α7nAChR

the number of M2 macrophage in colon mucosa were significantly increased(P<0.01

P<0.05)

while the expression levels of NF-κB p65 and TNF-α

and the number of M1 macrophage were significantly decreased(P<0.01

P<0.05) in both the Moxi and medication groups. Conclusion Herbal cake-partitioned moxibustion may inhibit NF-κB activation by up-regulating the expression level of α7nAChR to promote the polarization of macrophages from M1 to M2 type

and reduce the proportion of M1 macrophages

inhibit the expression of TNF-α in colonic mucosa of CD rats

so as to relieve the intestinal inflammation.