Purification and characterization of a novel tetradecapeptide from ginseng polypeptides with enhancing memory activity for mice

Expression of Multicopy Tandem Recombinant Ginseng Hexapeptide in Bacillus subtilis and the Evaluation of Antiaging Activity

Ginseng oligopeptides are naturally occurring small-molecule peptides extracted from ginseng that exhibit positive effects on health and longevity. However, the current industrial production of ginseng oligopeptides primarily relies on plant extraction and chemical synthesis. In this study, we proposed a novel genetic engineering approach to produce active ginseng peptides through multicopy tandem insertion (5 and 15 times). The recombinant ginseng peptides were successfully produced from engineered Bacillus subtilis with an increasing yield from 356.55 to 2900 mg/L as the repeats multiple. Additionally, an oxidative stress-induced aging model caused by H2O2 was established to evaluate whether the recombinant ginseng peptides, without enzymatic hydrolysis into individual peptides, also have positive effects on antiaging. The results demonstrated that all two kinds of recombinant ginseng peptides could also delay cellular aging through various mechanisms, such as inhibiting cell cycle arrest, suppressing the expression of pro-inflammatory factors, and enhancing cellular antioxidant capacity.

Exploring the potential of ginseng glycoprotein to improve learning and memory in mice via Notch signaling pathway and structural analysis using multi-information fusion based on liquid chromatography-mass spectrometry

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng C.A. Meyer reportedly exhibits various beneficial pharmacological activities. Panax ginseng glycoproteins (PGG) are a class of glycosylated protein components extracted from ginseng and can exert significant activity for improving learning and memory abilities.

AIM OF THE STUDY

The objective of the present study was to investigate the PGG-mediated protective mechanism against neurodegenerative diseases via the Notch signaling pathway using proteomic methods.

MATERIALS AND METHODS

We examined learning and memory in mice using the Morris water maze and nest-building paradigms. The PGG structure was determined using multi-information fusion based on liquid chromatography-mass spectrometry (LC/MS). Accurate glycosylation sites of glycoproteins were identified using the advanced glycosylation analysis software Byonic. Furthermore, connection modes of the oligosaccharide chain were clarified by methylation analysis of sugar residues. The differentially expressed proteins (DEPs) between wild-type (WT) and APP/APS1 mice were measured and compared using label-free quantitative proteomics, and related signaling pathways were identified. For validation, we performed a series of in vitro tests, including an assessment of cell viability, apoptosis assay, quantitative real-time polymerase chain reaction, and western blotting.

RESULTS

In the Morris water maze and nesting experiments, PGG-treated WT mice exhibited significantly improved learning and memory. The structures of 171 glycoprotein fragments in PGG matched the credible score, and typical structures were identified using LC/MS data analysis. According to the proteomic analysis results, 188 DEPs were detected between the model and administration groups, and two downregulated DEPs were related to the Notch signaling pathway. Based on the in vitro verification tests, PGG significantly inhibited the expression of key proteins in the Notch signaling pathway in microglia.

CONCLUSIONS

PGG could prevent the development of neuroinflammation by inhibiting excessive activation of the Notch signaling pathway, thereby inhibiting neuroapoptosis.

LC-MS/MS analysis of partial structure of Panax ginseng protein and its distribution in vivo

Protein from Panax ginseng can improve learning, memory, and analgesia. Here, we investigated a fluorescence labeling method that can be used to determine the in vivo distribution of P. ginseng protein (PGP). High-performance liquid chromatography (HPLC) was used to define the amino acid composition and molecular weight of PGP; LC-MS/MS was used to identify the PGP structure, which was fluorescently-labeled using a fluorescein isothiocyanate (FITC) probe. The connection form of the PGP fluorescent marker (PGP-FITC) was identified by ultraviolet and infrared spectrophotometry. The in vivo distribution of PGP was observed by fluorescence imaging, and tissue content was determined. Results showed that PGP was enriched in the brain and that vascular epithelial cells showed specific uptake. We provide an experimental method to label and identify the in vivo distribution of PGP, which forms the basis for future studies to determine whether PGP can penetrate the blood-brain barrier (BBB) and elucidate the transport mechanism.