Bushen Huoxue formula attenuates recurrent spontaneous abortion by modulating arginine metabolism and macrophage polarization at the maternal-fetal interface.

The aim of this study was to clarify the effects of BSHXF on pregnancy outcome and macrophage polarization at the maternal-fetal interface in a mouse model of recurrent spontaneous abortion (RSA). The RSA model was established using the CBA/J × DBA/2 mating method. Network pharmacology predicted the mechanism of BSHXF intervention in RSA and verified by Western blotting. Immunofluorescence and RT-qPCR were used to measure the levels of macrophage-associated cytokines at the maternal-fetal interface. Placental metabolomics was used to analyze the mechanism of macrophage regulation by BSHXF and verified by ELISA. BSHXF improved embryonic resorption and hormone levels in RSA mice and restored abnormal NF-κB signaling, which was achieved in part by modulating macrophage polarisation status. BSHXF intervention decreased M1 macrophage polarization while elevating M2 macrophage levels. Metabolomics indicated that decreased inducible nitric oxide synthase (iNOS) pathway and elevated arginase-1 pathway (Arg-1) pathway in the placenta were the key mechanisms of macrophage polarization. This study provides innovative insights into the mechanism by which BSHXF ameliorates RSA in mice, providing a scientific basis for further pharmacological research.