[Study on Cellular Immunity Mechanisms of Suspended Moxibustion for Treating Neutrophilic Asthma in Rats].

OBJECTIVE: To observe the influence of suspended moxibustion on neutrophilic asthma related signal factors in asthma rats.

METHODS: Thirty-two SD rats were randomly divided into normal control, model, dexamethasone(DEX) and suspended moxibustion (MOX) groups, with 8 rats in each group. The neutrophil granulocyte asthma model was made by intranasal instillation of lipopolysaccharide (LPS), intraperitoneal injection of ovalbumin(OVA) and inhalation of OVA, once a day for 14 d. After modeling, rats of the DEX group received intraperitoneal injection of DEX (0.5 mg/kg), once daily for 14 d, and those of the MOX group treated by suspended MOX at "Danzhong" (CV 17), and bilateral "Feishu" (BL 13), "Pishu" (BL 20), and "Shen-shu" (BL 23) for 40 min, once a day, for 14 d. The total number of leukocytes and Wright's stain-displayed differential counts in the bronchoalveolar lavage fluid (BALF) were counted, and the content of IL-17 in the BALF was assayed by ELISA. The contents of T-helper 17 (Th 17) cells in the spleen and peripheral blood were detected using flow cytometry, and the expression of retinoic acid-related orphan receptor gamma t (ROR-γt) mRNA and protein in the inferior lobe of the right lung were detected by quantitative real-time PCR, immunohistochemical stain and Western blot, respectively.

RESULTS: Compared with the normal control group, the total number of leukocytes, the percentages of neutrophils, eosinophilis and lymphcytes and IL-17 content in the BALF, and Th 17 contents in the peripheral blood and spleen tissue were significantly increased in the model group ( P <0.01). After the treatment, the total numbers of leukocytes, the percentages of neutrophils, eosinophils and lymphocytes and IL-17 contents in the BALF, and Th 17 contents in the peripheral blood and spleen tissues were down-regulated considerably in both the DEX and MOX groups ( P <0.05, P <0.01). Immunohistochemical stain, real-time PCR and Western blot measurements showed that the expression levels of ROR-γt protein and mRNA in the lung tissues were notably higher in the model group than in the normal control group ( P <0.01), and significantly down-regulated in both DEX and MOX groups relevant to the model group ( P <0.05, P <0.01). No significant differences were found between the DEX and MOX groups in all the aforementioned indexes ( P <0.05), except plasma Th 17 ( P <0.05).

CONCLUSIONS: Suspended moxibustion, being comparable to DEX treatment, can reduce the inflammatory reactions of neutrophilic asthma rats by down-regulating the expression of ROR -γt in the lung, and lowering IL-17 and neutrophils levels in the airway, and Th 17 in the peripheral blood and spleen.