Changes in Ileal Flora Induced by Qishengwan in Treatment of Alzheimer's Disease： An Exploration Based on "Interior-Exterior Relationship Between Heart and Small Intestine" / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo explore the effect of Qishengwan on ileal flora during its treatment of Alzheimer's disease （AD） under the guidance of the theory of "interior-exterior relationship between heart and small intestine". MethodThe AD model was established by bilateral intraventricular injection of β-amyloid 1-42 （Aβ1-42）. The rats were then randomly divided into the blank group， sham-operated group， model group， low-， medium-， and high-dose （5.6， 11.2，22.4 g·kg-1·d-1） Qishengwan groups， and donepezil （0.46 mg·kg-1·d-1） group. After medication for 28 successive days， the spatial memory ability of rats was observed in water maze test， and the levels of Aβ1-42， nuclear transcription factor-κB （NF-κB）， tumor necrosis factor-α （TNF-α）， and interleukin-6 （IL-6） in the hippocampus were analyzed by enzyme-linked immunosorbent assay （ELISA）. Additionally， the contents of the ileum were collected and subjected to 16SrRNA-sequencing analysis for figuring out the changes in ileal flora. ResultCompared with the blank group and sham-operated group， the model group exhibited significantly reduced stay time in the target quadrant and number of target quadrant and platform crossings （P<0.05， P<0.01） and elevated Aβ1-42 content in the hippocampus （P<0.01） and central inflammatory factors NF-κB， TNF-α， and IL-6 （P<0.05， P<0.01）. Compared with the model group， Qishengwan at each dose significantly alleviated the impaired spatial memory function （P<0.05， P<0.01）， improved the deposition of Aβ1-42 in the hippocampus of rats （P<0.05， P<0.01）， and reduced the expression of central nervous system inflammatory factors （P<0.05， P<0.01）， thus exerting a good therapeutic effect on AD rats. The 16SrRNA-sequencing analysis results showed that the structure of the ileal flora in the model group was significantly separated from those in the blank group and sham-operated group. The abundance of Lachnospiraceae NK4A136 group was significantly increased （P<0.01）， while that of Escherichia-Shigella was reduced （P<0.05， P<0.01）. Qishengwan at each dose significantly changed the ileal flora structure and regulated the relative abundance of Lachnospiraceae NK4A136 group， Escherichia-Shigella， and Ruminococcaceae. ConclusionQishengwan has a positive therapeutic effect on AD. It can significantly enhance the memory and cognitive abilities in AD rats， which may be related to its regulation of the structure of rat ileal flora and the relative abundance of Lachnospiraceae NK4A136 group， Escherichia-Shigella， and Ruminococcaceae， the attenuation of the central neuroinflammatory response， and the reduction of central Aβ1-42 deposition.