Sepsis involves a complex cascade of inflammatory reactions and immune system dysregulation. Neutrophils play a crucial role in modulating the anti-inflammatory response, which is vital for managing sepsis. Impaired chemotaxis of granulocytes can significantly impact the outcome of sepsis. Shenfu Decoction, by tonifying Qi and warming Yang, enhances the propelling function of Qi for promoting the chemotactic function of neutrophils. This study aimed to investigate the effects of Shenfu Decoction on the chemotactic function of neutrophils in septic mice and the underlying mechanisms.
Thirty 10-week-old specific-pathogen-free male C57BL/6J mice were randomly divided into five groups: sham operation, model, and low-, medium-, and high-dose Shenfu Decoction treatment groups (n = 6 in each group). Sepsis was induced using cecum ligation and puncture procedures. The sham-operated group served as the control. The drug was administered 6 h after surgery; the sham-operated and model groups received saline, while the treatment groups were gavaged every 12 h with the respective concentrations of Shenfu Decoction. Four hours after the last gavage, the mice were euthanized, and samples were collected to determine neutrophil counts and related indices. Primary neutrophils were extracted from the peripheral blood of septic mice and divided into blank control, sham-operated, low-dose, and high-dose groups. These cells were cultured with serum containing the respective treatments to measure neutrophil chemotactic distance, intracellular calcium ion concentration, and the expression levels of chemokine receptors and P2X1 receptors.
Compared with the sham-operated group, the total number of colonies and the number of neutrophils in the peritoneal lavage fluid were increased in the model group (P < 0.05). In the treatment groups, the number of neutrophils in the peritoneal lavage fluid was significantly increased (P < 0.05), while the number of neutrophils in the blood was decreased. Compared with the blank control group, the neutrophil chemotaxis distance was significantly prolonged in the sham-operated group. Additionally, the expression levels of P2X1 and FPR1 receptors were decreased, the expression levels of CXCR1 and CXCR2 receptors were increased (P < 0.05), and the calcium ion concentration was decreased (P > 0.05). Compared with the sham-operated group, the treatment groups exhibited a prolonged neutrophil chemotaxis distance, significantly decreased expression levels of P2X1 and FPR1 receptors, significantly increased expression levels of CXCR1 and CXCR2 receptors (P < 0.05), and significantly decreased calcium ion concentrations (P < 0.05). These effects were positively correlated with the Shenfu Decoction dosage.
Shenfu Decoction can improve the chemotactic function of neutrophils, possibly through the downregulation of P2X1 receptor expression. Its effects are positively correlated with the dosage.
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