Characterisation of Dandelion Polyphenols and Their In Vitro Neuroprotective Effects During Simulated Digestion

Dandelion, a herb with medicinal and nutritional properties, was studied for the stability and neuroprotective effects of polyphenols from its flowers, roots, and leaves during in vitro simulated digestion. Using UPLC-QTOF-ESI-MS/MS, 84 phenolic metabolites were identified, with flavonoids being most abundant in flowers and phenolic acids in leaves and roots. In vitro neuroprotection assays revealed that leaf polyphenols exhibited the highest inhibition rates against acetylcholinesterase and lipoxygenase, while flower polyphenols showed the strongest scavenging activity against reactive nitrogen species. After simulated digestion, total phenol and flavonoid contents increased significantly. Notably, polyphenols from all dandelion parts demonstrated the strongest inhibition of acetylcholinesterase during the oral phase, while the small intestine phase showed the greatest inhibition of lipoxygenase and reactive nitrogen species. Moreover, leaf polyphenols maintained the highest inhibitory effect on acetylcholinesterase throughout all digestive stages, suggesting that dandelion leaves are a promising functional food for preventing neurodegenerative diseases.