Explore Mechanism of Modified Si Junzitang in Improving Acidic Microenvironment and Reversing Gastric Precancerous Lesions Based on MCT4/CD147 / 中国实验方剂学杂志

Objective:To observe the effect of modified Si Junzitang on the level of lactic acid in gastric mucosa and the expression of Carboxylic acid transporter 1（MCT1）， monocarboxylic acid transporter 4（MCT4）， and extracellular matrix metalloproteinase inducer （CD147）in rats with gastric precancerous lesions（GPL）. Method:Seventy-four SD male rats were randomly divided into normal group （12 rats） and model group （62 rats）. <italic>N</italic>-methyl-<italic>N'</italic>-nitro-<italic>N</italic>-nitrosoguanidine（MNNG）-ammonia compound method was used to establish GPL rat models， and at the 9^th week， the model rats were randomly divided into model group， folic acid group（2.7 mg·kg^-1）， modified Si Junzitang high， medium and low dose groups（12.6， 6.3， 3.15 g·kg^-1）， with 12 rats in each group. After intragastric administration for 12 weeks， the general conditions of the rats were observed. Hematoxylin-eosin（HE）staining was used to observe the histopathological changes of gastric mucosa in rats， chemical colorimetry was used to detect the content of lactic acid in gastric mucosa； immunohistochemistry and real-time polymerase chain reaction（Real-time PCR）were used to detect MCT1， MCT4， CD147 protein and mRNA expression in gastric mucosal tissues. Result:Modified Si Junzitang significantly improved the pathological manifestations in GPL rats such as gastric mucosal epithelial gland structure， disorder of arrangement and cell atypia. Compared with the normal group， the lactic acid content of the gastric mucosa tissue in the model group increased significantly（<italic>P</italic><0.01）， and the protein and mRNA expressions of MCT1， MCT4， CD147 significantly increased（<italic>P</italic><0.05， <italic>P</italic><0.01）. Compared with the model group， the lactic acid content in each dose group of modified Si Junzitang was significantly reduced（<italic>P</italic><0.05， <italic>P</italic><0.01）， and the protein expression levels of MCT4 and CD147 were also significantly reduced in each dose group of modified Si Junzitang（<italic>P</italic><0.05， <italic>P</italic><0.01）. The mRNA expression of MCT4 was significantly reduced in the middle and high dose groups（<italic>P</italic><0.05， <italic>P</italic><0.01）， and the mRNA expression of CD147 was significantly reduced in the high dose group（<italic>P</italic><0.05）. Modified Si Junzitang showed no significant regulatory effect on MCT1. Conclusion:Modified Si Junzitang can significantly improve the abnormal histopathology of gastric mucosal epithelium in GPL model rats. Its mechanism may be related to down-regulating the overexpression of MCT4 and CD147， inhibiting lactic acid outflow， and improving the acidic microenvironment of gastric mucosal epithelium.