A Study and In Vitro Evaluation of the Bioactive Compounds of Broad Bean Sprouts for the Treatment of Parkinson's Syndrome

Levodopa (LD) is the first discovered and the most promising and effective medication for Parkinson's disease (PD). As the first identified natural source of LD, Vicia faba L. (broad beans), especially its sprouts, has been confirmed to contain many other potential bioactive compounds that could also be therapeutic for PD. In this study, the bioactive components obtained from broad bean sprout extraction (BSE) that could be beneficial for PD treatment were screened, and the related mechanisms were explored. Solvent extraction combined with column chromatography was used to isolate bioactive fractions and monomer compounds, while UPLC-ESI-MS/MS, HRESI-MS and (1H, 13C) NMR were employed for compound identification. Network pharmacology techniques were applied to screen for potential mechanisms. A total of 52 compounds were identified in a 50% MeOH extract of broad bean sprouts. Moreover, twelve compounds were isolated and identified from ethyl acetate and n-butanol portions, including caffeic acid (1), trans-3-indoleacrylic acid (2), p-coumaric acid (3), protocatechualdehyde (4), isovitexin (5), isoquercetin (6), grosvenorine (7), kaempferol-3-O-rutinoside (8), isoschaftoside (9), narcissin (10), kaempferitrin (11) and trigonelline HCl (12). Compounds 2, 4, 7, 8 and 12 were isolated from Vicia faba L. for the first time. The potential mechanisms were determined by analyzing 557 drug targets, 2334 disease targets and 199 intersections between them using a protein-protein interaction (PPI) network, gene ontology (GO) analysis and Kyoto encyclopedia of genes and genomes (KEGG) enrichment. Further in vitro experiments confirmed that caffeic acid (compound 1) and p-coumaric acid (compound 3) have neuroprotective effects in 6-hydroxydopamine-treated SH-SY5Y cells and lipopolysaccharide-treated PC-12 cells through anti-inflammatory and antioxidant mechanisms. In conclusion, this study explored effective components in broad bean sprouts and performed in vitro evaluations.