Revealing the antioxidant potential of Artemisia integrifolia L.: Integrated discovery of bioactive compounds via UHPLC-DPPH and activation of the Nrf2/HO-1 signaling pathway.

Reactive oxygen species (ROS) serve as essential signaling molecules under physiological conditions, but their excessive production leads to oxidative stress, which contributes to the pathogenesis of various diseases. Artemisia integrifolia L., a traditional medicinal and edible plant, has shown potential antioxidant properties; however, its bioactive constituents remain insufficiently characterized. This work systematically investigated the antioxidant components and mechanisms of A. integrifolia. Phytochemical analysis of 70% ethanol extract from the aerial parts led to the isolation and structural identification of 91 compounds, including 7 previously undescribed (1-7) and 84 known (8-91) ones. A total of 103 reference compounds, comprising those identified in this work (1, 3-61, 63-91) together with previously reported analogues (92-105), were used as standards for comprehensive chemical profiling. By integrating LC-MS/MS with a UHPLC-DPPH screening approach, 103 constituents were rapidly characterized, 22 of which (primarily flavonoids, quinic acid derivatives, and sesquiterpenoids) were highlighted as possessing potential antioxidant activity. Cellular assays demonstrated that 18 compounds significantly reduced intracellular ROS levels in H2O2-stimulated RAW 264.7 macrophages. Mechanistic studies revealed that representative compounds exert antioxidant effects by activating the Nrf2/HO-1 signaling pathway. These findings elucidate the material basis for the antioxidant activity of A. integrifolia and underscore its potential as a dietary or therapeutic agent for managing oxidative stress-related diseases. This study provides a foundation for the further development and clinical application of natural antioxidants derived from A. integrifolia.