ObjectiveTo investigate the mechanism of Si Junzitang in treating liver injury in rats with spleen Qi deficiency syndrome based on transcriptomics and to experimentally verify its effects.MethodsSixty male SD rats were randomly divided into blank group， model group， low-dose Si Junzitang （6 g·kg^-1·d^-1）， medium-dose Si Junzitang group （12 g·kg^-1·d^-1）， high-dose Si Junzitang group （24 g·kg^-1·d^-1）， and natural recovery group， with 10 rats in each group. A composite multifactorial modeling method （forced swimming + intragastric administration of Xiao Chengqi Tang + irregular diet） was used to establish a spleen Qi deficiency model. After 30 days of continuous intervention， body weight and 3-hour food intake were measured， and macroscopic symptom scores for spleen Qi deficiency syndrome were evaluated. Serum levels of aspartate aminotransferase （AST） and alanine aminotransferase （ALT） in each group were detected， and hematoxylin and eosin （HE） staining was used to observe histopathological changes in liver tissue. Transcriptome sequencing （RNA-Seq） was used to identify differentially expressed genes （DEGs） among the blank， model， and high-dose Si Junzitang groups. GO and KEGG enrichment analyses were performed on the DEGs. Immunofluorescence （IF） and Western blot were used to detect NOD-like receptor protein 3 （NLRP3）， apoptosis-associated speck-like protein （ASC）， Caspase-1 （Caspase-1）， and the N-terminal domain of Gasdermin D （GSDMD-N）. Immunohistochemistry （IHC） was used to detect the expression of downstream inflammatory cytokines interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and interleukin-18 （IL-18）.ResultsCompared with the blank group， the model group showed significantly reduced body weight and 3-hour food intake， significantly increased macroscopic symptom scores， and elevated serum AST and ALT levels （P<0.01）， with mild inflammatory liver injury observed histologically. Compared with the model group， Si Junzitang at all doses significantly improved these parameters and alleviated liver injury in a dose-dependent manner （P<0.05，P<0.01）. RNA-Seq analysis revealed 1 254 DEGs between the blank and model groups， and 842 DEGs between the model and high-dose Si Junzitang groups. GO and KEGG enrichment analyses indicated that the NOD-like receptor signaling pathway was activated in liver injury associated with spleen Qi deficiency， suggesting that the NLRP3 inflammasome may be a key target. Results from IF， IHC， and WB showed that compared with the blank group， the expression of NLRP3， ASC， Caspase-1， GSDMD-N， and the downstream inflammatory cytokines IL-1β， IL-6， and IL-18 were significantly increased in the model group （P<0.01）， while these levels were markedly decreased in the high-dose Si Junzitang group （P<0.01）.ConclusionSi Junzitang effectively improves mild inflammatory liver injury in rats with spleen Qi deficiency syndrome in a dose-dependent manner. Its mechanism may be associated with inhibition of the NLRP3/ASC/Caspase-1 signaling pathway， downregulation of the pyroptosis executioner protein GSDMD-N， and reduction of pyroptosis-related inflammatory cytokine release.

Si Junzitang;spleen Qi deficiency syndrome;transcriptomics;NOD signaling pathway;NLRP3 inflammasome;liver inflammatory injury