Characterisation of Xianling Cifang Formula and its metabolites in the mice lung tissue and blood by UHPLC-HR-MS...

Xianling Cifang Formula (XLCF) is a specialized Traditional Chinese Medicine prescription for metastatic breast cancer (BC) at Longhua Hospital, though its material basis remains unclear. This study aimed to comprehensively identify XLCF ingredients and its lung-entering components using ultraperformance liquid chromatography-high-resolution mass spectrometry. A total of 493 components were identified from XLCF. In lung tissues of BALB/c mice treated with XLCF, 78 absorbable components were detected, including terpenes, flavonoids, phenylpropanoids, carbohydrates, and alkaloids. Flavonoids and terpenes were particularly abundant and may represent key substances contributing to XLCF's inhibitory effects on pulmonary metastasis. Notably, nine components overlapped with 122 previously identified blood-entering components, including icariin, zederone, and D-salicin. Among these, icariin was the most abundant component detected in the lung and is expected to be a key active constituent for treating BC pulmonary metastasis. This comprehensive characterization provides a foundation for further mechanistic research.