Qingshu Yiqi decoction ameliorates exertional heat stroke-induced intestinal barrier injury via NF-κB/MLC pathway and gut microbiota

BACKGROUND: Exertional heat stroke (EHS) is a life-threatening condition induced by high-temperature environments, which poses significant health risks. The Qingshu Yiqi Decoction (QSYQD) is a traditional Chinese medicine (TCM) formula that is known to clear summer heat, replenish Qi, and protect intestinal function. However, experimental evidence and mechanistic insights into its role in EHS prevention are limited. PURPOSE: The aim of this study is to evaluate the protective effects of QSYQD against EHS-induced hyperthermia and multi-organ injury and investigate the underlying molecular mechanisms. METHODS: An EHS rat model was established using treadmill exercise in a high-temperature environment. The rats were pretreated with low, medium, or high doses of the QSYQD. The intestinal barrier function was assessed using biomarkers, an ultrastructural analysis, and key protein expressions. Network pharmacology was used to identify potential targets, and molecular mechanisms were validated using western blot. The gut microbiota composition was analyzed using 16S rRNA sequencing. RESULTS: The QSYQD significantly alleviated hyperthermia and multi-organ injury in the EHS rats, and the medium dose had the most pronounced effects. It preserved intestinal barrier integrity by maintaining the tight junction protein levels and reducing biomarkers of epithelial damage. Network pharmacology and experimental validation revealed that the QSYQD inhibited the NF-κB and MLC signaling pathways, key regulators of intestinal barrier function. Additionally, the QSYQD altered the gut microbiota composition and notably increased the abundance of Lactobacillus, that has known heat stress protective effects. CONCLUSIONS: QSYQD protects against EHS-induced damage by preserving intestinal barrier integrity, modulating gut microbiota, and inhibiting the NF-κB and MLC signaling pathways. Future studies will focus on identifying active compounds within QSYQD that enhance heat tolerance and provide EHS protection.