[Mechanism of acupuncture-moxibustion with "Biao-Ben" acupoint combination in treating irritable bowel syndrome rats by regulating serum metabolites and metabolic pathway based on TM widely targeted metabolomics method].

Objective: To investigate the effect of acupuncture-moxibustion with "Biao-Ben" acupoint combination (BB) on the serum metabolites and metabolic pathway in irritable bowel syndrome (IBS) model rats, so as to explore the mechanisms of BB in the prevention and treatment of IBS.

Methods: Thirty SD rats were randomly divided into three groups: control group, model group, and BB group, with 10 rats in each group. The IBS model was established by the combination of acute stress method and chronic stress method, and the success of the model establishment was evaluated by abdominal wall reflex (AWR). BB group received acupuncture-moxibustion treatment at "Neiguan" (PC6), "Zusanli" (ST36), and "Guanyuan" (CV4) for 15 min, once a day, for a total of 28 days. Bristol's fecal character score was evaluated, and intestinal propulsion rate was calculated. The open-field experiment was used to observe the behaviour of rats. Pathological changes in the colon were observed by H.E. staining. TM widely targeted metabolomics technology was used to detect the metabolic profile of serum samples from 3 groups of rats. Principal component analysis and orthogonal partial least-squares discrimination analysis techniques were combined with database screening to screen differential metabolites, and the KEGG database was utilized to map the enriched metabolic pathway.

Results: Compared with the control group, AWR, and the total distance, speed, duration traveled autonomously, the distance of central grid traveling, the number of central grid crossings of the open-field experiment were significantly decreased (P<0.01，P<0.05), while Bristol's fecal character score, intestinal propulsion rate and rest duration in the open-field experiment were significantly increased(P<0.01) in the model group. Compared with the model group, Bristol's fecal character score, the intestinal propulsion rate, rest duration, and rest episode were significantly decreased(P<0.01, P<0.05), while AWR, the total distance, speed, duration traveled autonomously, the distance of central grid traveling, the number of central grid crossings, and the residence time of the central grid were significantly increased(P<0.01，P<0.05) in the BB group. H.E. staining showed a discontinuous mucosal layer of colon tissue, a slightly disordered arrangement of glands, and more inflammatory cell infiltration in the submucosa and muscle layer in the model group, which was relatively milder in the BB group. After comparing the model and control group, 123 differential metabolites were screened, while 57 were screened after comparing the model and BB group. Six differential metabolic pathways were acquired when comparing the model and the control group, while 8 were acquired when comparing the model and BB group using KEGG enrichment analysis, both of which included the arachidonic acid metabolism pathway.

Conclusion: "Biao-Ben" acupoint combination can improve symptoms of IBS by regulating metabolites of the arachidonic acid metabolism pathway, which may be a potential target for the treatment of IBS.