Ultrasound-assisted betaine-based natural deep eutectic solvents for green extraction of total phenols and flavonoids from Lithocarpus litseifolius: Mechanistic insights and anti-hyperuricemic applications.

To develop an ecologically suitable and efficient method for the simultaneous extraction of total polyphenols (TP) and total flavonoids (TF) from Lithocarpus litseifolius (L. litseifolius), this study employed natural deep eutectic solvents (NADES) combined with ultrasound-assisted extraction. Betaine-acetic acid (1:2) was identified as the most effective NADES for extracting the target components. The extraction conditions were optimized using a Box-Behnken design. Under the optimized conditions, the extraction yields were 6.682 % for TP and 9.230 % for TF, closely matching the predicted yields of TP (6.697 %) and TF (9.241 %). These yields were 1.78-4.77 times and 1.73-7.82 times higher than those achieved using traditional solvents, demonstrating their favorable efficiency. HPLC results indicated that phloridzin (38.68 mg/g) and trilobatin (26.36 mg/g) were the primary components of the L.litseifolius extract. The kinetic and thermodynamic models were fitted to the extraction process, and the synergistic effect was verified via SEM, FT-IR, 1H NMR, and IGMH. Experimental results from both in vivo and in vitro studies demonstrated that the extract exhibited a significant uric acid-lowering effect. It significantly reduced serum uric acid, creatinine, and blood urea nitrogen levels, inhibited liver and serum xanthine oxidase activity, and alleviated hepatorenal pathological damage in hyperuricemic mice. Furthermore, microbiome analysis indicated that the extract restored intestinal homeostasis by modulating beneficial bacterial abundance and improving gut microbiota composition. Spearman correlation analysis revealed strong associations between altered gut microbiota and hyperuricemia-related physiological indicators. This study provides a green and efficient extraction method for TP and TF from L.litseifolius and reveals the anti-hyperuricemic potential of its extract.