Abstract
In this study, the flavonoids in Poncirus trifoliata fruit ethanol extract (PFE) were identified using UPLC-Q-TOF-MS and their anti-inflammatory effects on Raw 264.7 cells were evaluated. The 40% ethanol extract showed highest concentrations of total phenolic content (TPC), total flavonoid content (TFC), and flavonoids. In naringinase-treated PFE powder (NPFEP), poncirin decreased from 76.47 to 68.62 mg/g (13.20 mM), and isosakuranetin increased to 3.53 mg/g (12.33 mM). NPFEP demonstrated superior anti-inflammatory properties in Raw 264.7 cells compared to naringinase-untreated PFEP (UNPFEP), with decreased ROS production, lower inflammatory mediators (NO and PGE2), extracellular cytokines (TNF-α and IL-1β), and downregulation of COX-2 and intracellular cytokines (IL-1β and IL-6) gene expression. UPLC analysis of NPFEP identified four flavanones (poncirin, naringin, isosakuranetin, and naringenin), one chalcone (2',6'-dihydroxy-4-methoxychalcone-4'-O-neohesperid), and two triterpenes (cucurbitacin D and esculentic acid), which likely contribute to the observed anti-inflammatory effect.