MS/MS molecular networking-guided in-depth profiling of triterpenoid saponins from the fruit of Eleutherococcus senticosus and their neuroprotectivity evaluation.

INTRODUCTION: Eleutherococcus senticosus fruit (ESF) is a natural health supplement resource that has been extensively applied as a tonic for the nervous system. The structures and neural bioactivities of triterpenoid saponins (TS), which are the major constituents of ESF, have not been comprehensively analyzed thus far. OBJECTIVE: We conducted a complete in-depth MS/MS molecular networking (MN)-based targeted analysis of TS from the crude extract of ESF and investigated its neuroprotective value. METHODS: An MS/MS MN-guided strategy was used to rapidly present a series of precursor ions (PIs) of TS in a compound cluster as TS-targeted information used in the discovery and characterization of TS. In addition, a prepared TS-rich fraction of ESF was assayed for its restraining effects on ß-amyloid-induced inhibition of neurite outgrowth. RESULTS: A total of 87 TS were discovered using a PI tracking strategy, 28 of which were characterized as potentially undescribed structures according to their high-resolution MS values. Furthermore, the TS-rich fraction can significantly reduce ß-amyloid-induced damage to neural networks by promoting the outgrowth of neurites and axons. CONCLUSION: Our findings reveal the richness of TS in ESF and will accelerate their application in the treatment of neurodegenerative diseases.

Identification and localization of morphological feature-specific metabolites in Reynoutria multiflora roots.

Reynoutria multiflora roots are a classical herbal medicine with unique nourishing therapeutic effects. Anomalous vascular bundle (AVB) forming "cloudy brocade patterns" is a typical morphological feature of R. multiflora roots and has been empirically linked to its quality classification. However, scientific evidence, especially for AVB-specific specialised metabolites, has not been comprehensively revealed thus far. Herein, desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) analysis was applied to carry out an in situ analysis of specialised metabolites distributed specifically at the AVB and cork of R. multiflora roots. To enlarge the scope of compounds by DESI detection, various solvent systems including acetone, acetonitrile, methanol, and water were used to assist in the discoveries of 40 specialised metabolites with determined localization. A series of bioactive constituents including stilbenes, flavonoids, anthraquinones, alkaloids, and naphthalenes were found specifically around the brocade patterns. Notably, phospholipids were detected from R. multiflora roots by in situ analysis for the first time and were found mainly in the phloem of AVB (PAB). This is the first study to use gradient solvent systems in DESI-MSI analysis to locate the specialised metabolites distribution. The discovery of feature-specific compounds will bridge the empirical identification to precision quality control of R. multiflora roots.

Memory enhancement effect of saponins from Eleutherococcus senticosus leaves and blood-brain barrier-permeated saponins profiling using a pseudotargeted monitoring strategy.

Dried Eleutherococcus senticosus leaves (ESL), also known as Siberian ginseng tea, are beneficial for human neural disorders. Our previous studies showed that the aqueous extract of ESL enhanced memory in mice, and its saponin fraction (ESL-SAP) exhibited promising neuroprotective activities in vitro; however, the in vivo neurally related effect, bioactive material basis, and possible mechanism of action of ESL-SAP have not been investigated. Here, a series of memory and learning tests were carried out, and the results evidenced a significant enhancement effect of ESL-SAP. Furthermore, an in vivo saponin library-guided pseudotargeted strategy was established to support the rapid monitoring of 26 blood-brain barrier (BBB)-permeated saponins from ESL-SAP-administered rats. A further network pharmacology analysis was conducted on BBB-permeated compounds, which indicated that the in vivo mechanism of ESL-SAP might be effective through multiple targets and pathways, such as the AGE-RAGE signaling pathway and PI3K-Akt signaling pathway, to exert neuroprotective effects. Moreover, the molecular docking experiments demonstrated that key BBB-transferred saponins primarily interacted with targets HRAS, MAPK1, and MAPK8 to produce the neuroprotective effect.