UPLC‐Q‐TOF‐MS‐Based Serum Metabolomics Explores the Mechanism of Pingwei Powder in Treating the Damp Retention in the Middle‐Jiao Syndrome

Pingwei powder (PWP) was a classic prescription to treat damp retention in the middle-jiao syndrome (DRMS) in clinic. This study aimed to investigate the therapeutic effects and functional mechanisms of PWP in treating DRMS by analyzing the general characteristics, fecal morphology, clinical chemistry, histopathology, and ultra-performance liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS)-based serum metabolomics. The results indicated that PWP significantly improved the general morphological characteristics, fecal humidity, body weight, and gastrointestinal peristalsis function, as well as inflammation damage and edema in the small intestine, stomach, and kidney tissues of model rats. Additionally, the levels of aquaporin 2 (AQP2) in kidney tissue, aquaporin 3 (AQP3) in small intestine tissue, and AQP2 in urine were reduced, whereas the levels of motilin (MTL) in serum were increased. A total of 33 serum biomarkers was identified, of which 21 biomarkers were recalled after PWP administration, including LysoPC(O-18:0), retinal, 9(10)-EpOME, and so forth. Pathway analysis proved that the therapeutic effect of PWP on DRMS was mainly associated with primary bile acid biosynthesis, arachidonic acid metabolism, glycerophospholipid metabolism, retinol metabolism, alpha-linolenic acid metabolism, histidine metabolism, and so forth. This study utilized metabolomics, general biochemical indicators, and histopathological analysis to elucidate the potential mechanism of PWP treatment for DRMS.