Effects of Tanshinone ⅡA on Intestinal Microflora Diversity and Immune Function in Rats With Irritable Bowel Syndrome

Objective: To investigate the effects of tanshinone II A on intestinal flora diversity and immune function in a rat model of irritable bowel syndrome (IBS). Methods: Thirty SD rats were randomly divided into three groups: control (A, n=10), model (B, n=10), and experimental (C, n=10). IBS was induced in groups B and C using a water avoidance stress test. After successful modeling, group C received 10 mg/kg of tanshinone II A, while group B received saline. Immunohistochemistry was used to detect CRF expression in the terminal ileum. High-throughput sequencing analyzed microbial abundance and diversity. The expression of IL-6, IL-10, IL-17, IL-23 (via PCR), and STAT3/p-STAT3 (via Western blot) in the ileum were also assessed. Results: CRF expression in the submucosa and muscle layer was higher in group B compared to A, but reduced in group C compared to B. Lactobacillus and Enterobacteriaceae levels were increased in group B compared to A, but decreased in group C compared to B. STAT3 and p-STAT3 levels, along with IL-6, IL-17, and IL-23 mRNA, were elevated in group B, while IL-10 mRNA was reduced. In group C, IL-6, IL-17, and IL-23 levels decreased, and IL-10 increased. Conclusion: Tanshinone II A has a therapeutic effect on IBS in rats by regulating intestinal flora, reducing CRF expression, improving immune function, and inhibiting the STAT3 signaling pathway.