Bio-affinity ultrafiltration combined with UPLC Q-Exactive Plus Orbitrap HRMS to screen potential COX-2 and 5-LOX inhibitors in mulberry (Morus alba L.) leaf

Ethnopharmacological relevance Mulberry ( Morus alba L.) leaf is a well-known herbal medicine in China for thousands of years. Mulberry leaf can regulate arachidonic acid (ARA) metabolism disorder in obesity and type 2 diabetes mellitus. However, the active ingredients involved in this process are still unclear. Aim of study To explore the potential active ingredients in mulberry leaf against ARA metabolism disorder. Materials and methods In this research, an efficient method combining affinity ultrafiltration, molecular docking, and network pharmacology was developed and applied to explore cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibitors from mulberry leaf. Results A total 17 potential inhibitors were screened by affinity ultrafiltration assay and identified by high resolution mass spectrometry. In addition, 8 bioactive ingredients were obtained after re-evaluated by molecular docking and network pharmacology, and their inhibitory activities on COX-2 and 5-LOX were confirmed by in vitro inhibitory assays. The results of cell experiments showed that the expressions of COX-2 and 5-LOX were significantly suppressed by neochlorogenic acid, rutin, isoquercetin, and (−)-syringaresinol-4-O-glucoside. Conclusion Neochlorogenic acid, rutin, isoquercetin, and (−)-syringaresinol-4-O-glucoside may be the potential material basis of mulberry leaf in the regulation of ARA metabolism of obesity and type 2 diabetes mellitus.