Screening and characterisation of potential antioxidant, hypoglycemic and hypolipidemic components revealed in Portulaca oleracea via multi-target affinity ultrafiltration LC-MS and molecular docking.

Abstract

Portulaca oleracea is a commonly used nutritional vegetable and traditional herbal medicine with plenty of nutrients and manifold pharmacological activities. However, the potential active ingredients for its remarkable antioxidant, hypoglycemic and hypolipidemic activities remain unexplored. The present study aims to systematically evaluate the antioxidant activities of different extracts of P. oleracea and screen bioactive ligands that can interact with α-glucosidase, pancreatic lipase, and superoxide dismutase (SOD). In this research, the antioxidant activities of different parts of P. oleracea and their corresponding total phenolic content (TPC) and total flavonoid content (TFC) were systematically determined. Subsequently, a multi-target affinity ultrafiltration method was developed using affinity ultrafiltration with SOD, α-glucosidase, and pancreatic lipase coupled to liquid chromatography-mass spectrometry (UF-LC-MS). Later, molecular docking was used to further investigate the possible interaction mechanism between these ligands and target enzymes. Among them, the ethyl acetate (EA) fraction showed the highest antioxidant activity along with the highest TPC and TFC, and four compounds in the EA fraction were quickly retrieved as potential SOD, α-glucosidase, and pancreatic lipase ligands, respectively. Molecular docking revealed that these potential ligands exhibited strong binding ability and inhibitory activities on SOD, α-glucosidase, and pancreatic lipase. The present study revealed that P. oleracea can be used as a functional food with excellent antioxidant, hypoglycemic and hypolipidemic effects. Meanwhile, the integrated strategy based on multi-target UF-LC-MS and molecular docking also provided a powerful tool and a multidimensional perspective for further exploration of active ingredients in P. oleracea responsible for the antioxidant, hypoglycemic and hypolipidemic activities.