Moxibustion Alleviates Airway Inflammatory Response in Rats with Experimental Asthma by Increasing Short Chain Fatty Acids in Bone Marrow and Blood

Objective: This study aimed to examine how moxibustion regulates short chain fatty acids (SCFAs) production to reduce airway inflammation in asthmatic rats. Materials and Methods: An asthmatic rat model was prepared by ovalbumin (OVA) sensitization and atomization. After successful modeling, the animals were assigned to the BL13 (moxibustion at the Feishu [BL13] point), ST25 (moxibustion at the Tianshu [ST25] point), and BL13-ST25 (moxibustion at the BL13 and ST25 points) groups. A 30-min moxibustion intervention was performed once daily for 14 consecutive days. After treatment, the levels of interleukin (IL)-4, IL-5, IL-13, and IL-17 proteins and mRNA in lung tissue were assessed by enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction, respectively. SCFA levels in bone marrow and blood were quantitated using gas chromatography-mass spectrometry. The expression of immunocostimulatory molecules, including CD11b, CD40, CD86, and PD-L1, in bone marrow and blood was assessed by ELISA and immunoblotting. Results: Compared with the model group, the numbers of eosinophils and neutrophils in bronchoalveolar lavage fluid were significantly reduced in the BL13-ST25 group ( P < 0.05). In addition, IL-4, IL-5, IL-13, and IL-17 protein and mRNA amounts were markedly decreased in the BL13-ST25 group versus the model group ( P < 0.05), while bone marrow and blood acetic, propionic, and butyric acid amounts were remarkably elevated ( P < 0.05). Finally, bone marrow and blood CD11b, CD40, CD86, and PD-L1 levels were significantly lower ( P < 0.05). Conclusion: Moxibustion can alleviate airway inflammation in asthmatic rats, which may be related to the regulation of SCFAs in blood and bone marrow, affecting the expression of immune cell co-stimulatory molecules, thereby influencing T-cell differentiation.