Effects of Xinglou Chengqi decoction on central and peripheral immune inflammation in mice with AIS are correlated with intestinal flora

Objective: To explore the effect of Xinglou Chengqi decoction (XCD) on the brain-gut axis in mice with acute ischemic stroke. Methods: A cerebral ischemia-reperfusion model identified as phlegm-heat and fu-organ excess pattern was established by reforming the Longa method and based on the diagnostic criteria of traditional Chinese medicine. Sixty specific-pathogen free male C57BL/6 mice were randomly divided into five groups, and 36 antibiotic-treated (ABX) mice were randomly divided into three groups. Cecum norepinephrine (NE) and motilin (MTL) were detected by enzyme-linked immunosorbent assay, cecum tyrosine hydroxylase (TH) protein expression level was detected by immunohistochemistry, Iba-1 and glial fibrillary acidic protein (GFAP) expression levels were detected by immunofluorescence, and serum inflammatory factor contents were detected using the flow multifactor technique. Results: Compared to the sham group, a significant increase in TH expression level was observed in the cecum in the middle cerebral artery occlusion (MCAO) group (P = .015). MTL levels were significantly increased in the MCAO group compared with the sham group (P < .001) and significantly decreased in the XCD and nimodipine (Nim) groups compared with the MCAO group (P = .003 and P = .007, respectively). Astrocytes and microglia were markedly activated in the MCAO group, whereas activation was decreased in the XCD group compared to the MCAO group. Antibiotic-treated (ABX) mice astrocytes and microglia were obviously activated in the ABX-MCAO group, and activation tended to be lower in the ABX-XCD group. Interleukin-22 level significantly increased in the ABX-XCD group compared with the ABX-MCAO (P = .021). Conclusion: XCD has a significant regulatory effect on the immune pathway of the brain-gut axis in mice with acute ischemic stroke, while the removal of the gut microbiota attenuates the effect considerably