Precursor ions-guided comprehensive profiling of triterpenoid saponins from the Eleutherococcus senticosus stems and their neuroprotective effect evaluation

Triterpenoid saponins (TS) are the main constituents of Eleutherococcus senticosus, also termed as Siberian ginseng or Ciwujia, a widely used herb in China, Japan, Korea, and Russia for its beneficial effects on memory enhancement, tonifying, heart-nourishing, and tranquilizing. Although the stems, rhizomes, and roots are used identically, a preliminary experiment found TS were specifically distributed in stems rather than the underground parts. However, a comprehensive profiling of the TS compounds in E. senticosus stems (ESS) is still absent. In this study, an MS/MS molecular networking (MN)-based precursor ions (PIs) discovery strategy was applied to fast track the TS compounds from ESS extract. A total of 80 TS were tracked and characterized, among which 78 ones were reported for the first time in ESS. Furthermore, the TS-rich fraction (ESS-TS) was prepared by a series of chromatography separation, and was found with significant neuralprotective effects on attenuating Aβ25-35-induced neurite atrophy, and promoting the outgrowth of damaged neurite in the Aβ25-35-induced primary cortical neuronal damage model. In conclusion, this study highlighted the existence of TS compounds in ESS, a major medicinal parts nowadays adopted as Ciwujia by the Chinese Pharmacopiea and market. In addition, the TS was found with determined roles in the outgrowth of neuritis, and was proposed as crucial constituent when the E. senticosus was used as the therapeutic agents for neural diseases. These results supplies scientific data for the quality control of E. senticosus and the further development of ESS-TS as memory enhancement agents.

The roles of natural triterpenoid saponins against Alzheimer's disease

The aging of the world population and increasing stress levels in life are the major cause of the increased incidence of neurological disorders. Alzheimer's disease (AD) creates a huge burden on the lives and health of individuals and has become a big concern for society. Triterpenoid saponins (TS), representative natural product components, have a wide range of pharmacological bioactivities such as anti-inflammation, antioxidation, antiapoptosis, hormone-like, and gut microbiota regulation. Notably, some natural TS exhibited promising neuroprotective activity that can intervene in AD progress, especially in the early stage. Recently, studies have indicated that TS play a pronounced positive role in the prevention and treatment of AD. This review discusses the recent research on the neuroprotection of TS and proceeds to detail the action mechanisms of TS against AD, hoping to provide a reference for drug development for anti-AD.

Combined Metabolite Analysis and Network Pharmacology to Elucidate the Mechanisms of Therapeutic Effect of Melastoma dodecandrum Ellagitannins on Abnormal Uterine Bleeding

The abnormal uterine bleeding (AUB) is complex and usually leads to severe anemia. Melastomadodecandrum (MD) is clinically used for the treatment of metrorrhagia bleeding. The MD ellagitannins (MD-ETs) had been evidenced being effective at hemorrhage, and exerts biological activities upon their metabolites including ellagic acid and urolithins. In this study, the blood-permeated metabolites from theMD-ETs were analyzed using LC-MS approach, and 19 metabolites including ellagic acid and urolithin A derivatives were identified. Furthermore, a network pharmacology analysis including the target prediction analysis, AUB target analysis, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted to reveal the relationships between "metabolites-targets-pathways", which was further verified by molecular docking analysis. The results showed that methyl ellagic acid, urolithin A and isourolithin A produced from MD-ETs can be absorbed into the blood, and might act on the core targets of VEGFA, SRC, MTOR, EGFR and CCND1. And the hemostatic effects were exerted through PI3K-Akt, endocrine resistance and Rap 1 signaling pathways. These results implied the potential effective constituents and action mechanism of MD-ETs in the therapy of AUB, which will promote the application of MD-ETs as natural agent for the treatment of gynecological bleeding diseases.

Molecular networking-assisted systematical profiling and the in vivo neuroprotective effect of ellagitannins from the Melastoma dodecandrum Lour

BACKGROUND

Ellagitannins (ETs) are a major classification of natural tannins, with relatively large and complex structures. ETs from medicinal plants are focused increasingly due to urolithins, a kind of intestinal metabolite of ETs, which showed promising anti-Alzheimer's disease (AD) effects. Melastoma dodecandrum (MD), a widely used traditional Chinese medicine is rich in ETs, but their chemistry and potential neuroprotective effects have not been investigated.

PURPOSE

This study aimed to identify the chemical composition of ETs in the crude extract of MD and to investigate their neuroprotective effects in vivo.

METHODS

UPLC-QTOF-MS-based molecular networking (MN) and structural characterization were applied to targeted profiling of the MD-ETs. Animal behavior experiments, including the novel object recognition test (NOR), open field test (OFT), and Morris water maze test (MWM), were conducted to assess the memory improvement effects of MD-ETs in AD model mice.

RESULTS

A total of 70 ETs, ranging from monomers to tetramers, were tracked and characterized in the MD extract using MN-guided targeted profiling, with 59 of them reported for the first time in this species. MD-ETs significantly improved memory impairment in AD mice, as indicated by decreased escape latency, increased number of crossings and target quadrant distance in MWM, increased rearing number in OFT, and increased preference index in NOR.

CONCLUSION

This study systematically characterized the composition and structural features of ETs in MD using targeted LC-MS profiling, expanding the chemical information of ETs in MD. Furthermore, the results demonstrate that MD-ETs have significant effects on improving impaired memory in AD mice, suggesting their potential as alternative natural medicines for the treatment of neurodegenerative diseases.

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 β-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 β-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.

Identification of ellagic acid and urolithins as natural inhibitors of Aβ25-35-induced neurotoxicity and the mechanism predication using network pharmacology analysis and molecular docking

Ellagic acid (EA) is a dietary polyphenol that widely exists in grapes, strawberries, and walnuts. It usually exerts multiple biological activities together with its in vivo metabolites called urolithins. EA and urolithins had been proposed as natural agents for applying on the early intervention of Alzheimer’s disease (AD). However, the neuroprotective effects of those small molecules have not been confirmed, and the action mechanism is not clear. Deposition of beta-amyloid (Aβ) protein is well documented as being involved in the initiation and pathological process of AD. In the present study, we investigated the attenuating effects of EA and several urolithins on Aβ_25–35-induced neuronal injury and its underlying molecular mechanism by constructing the in vitro AD cell model of PC12 cells and primary neurons. The results revealed that EA and urolithins especially the UM5 and UM6 exerted promising neuroprotective effects in improving the Aβ_25–35-induced cell damage and lactate dehydrogenase (LDH) leakage, reducing reactive oxygen species (ROS) production, inhibiting neuronal apoptosis, and promoting neurite outgrowth. These results provide new insights into the development of UM5 and UM6 as anti-AD candidates. A network pharmacology analysis combining molecular docking strategy was further adopted to predict the signaling pathway involved in the anti-AD action of EA and urolithins, and the activation of PI3K-Akt, as well as the inhibition of MAPK was found to be involved.

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...

Drug affinity responsive target stability (DARTS) accelerated small molecules target discovery: Principles and application

Drug affinity responsive target stability (DARTS) is a novel target discovery approach and is particularly adept at screening small molecule (SM) targets without requiring any structural modifications. The DARTS method is capable of revealing drug-target interactions from cells or tissues by tracking changes in the stability of proteins acting as receptors of bioactive SMs. Due to its simple operation and high efficiency, the DARTS method has been applied to uncover the drug-action mechanism. This review summarized analytical principles, protocols, validation approaches, applications, and challenges involved in the DARTS method. Due to the innate advantages of the DARTS method, it is expected to be a powerful tool to accelerate SM target discovery, especially for bioactive natural products with unknown mechanisms.

LC-MS-based identification and antioxidant evaluation of small molecules from the cinnamon oil extraction waste

Cinnamon oil is obtained by steam distillation from cinnamon leaves and is usually considered highly cost-effective compared to bark oil, however, which results in tons of waste cinnamon leaves (WCL) discarded annually. By using MS/MS molecular networking (MN) assisted profiling, six main chemical diversities including flavonols and flavones, phenolic acids, lactones, terpenoids, phenylpropanoids and flavanols were rapid revealed from WCL aqueous extract. 101 compounds were tentatively identified by assigning their MS/MS fragments within typical pathways under ESI-MS/MS dissociation. The featured phenolic acids, terpenoids and their glycosides in cinnamon species were recognized as the main constituents of WCL. The hydrophilic lactones, lignans and flavanols were reported for the first time in cinnamon leaves. Furthermore, ABTS and FRAP assays integrated with MN analysis were conducted to uncover an antioxidant fraction, from which 40 potential antioxidant compounds were rapidly annotated. This fundamental information will help expand the utilization of WCL from cinnamon oil industry.

A review of the traditional uses, phytochemistry and biological activities of the Melastoma genus

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Melastoma consists of approximately 100 species distributed widely in tropical and subtropical countries, and Melastoma species are often used for medicinal purposes, such as treatment for bleeding, diarrhea, diabetes, and gynecological tumors by local people, mostly in Southeast Asian countries.

AIM OF THE REVIEW

The present review summarizes the traditional uses, phytochemistry and pharmacology of species belonging to Melastoma to suggest further research strategies and to facilitate the exploitation of the therapeutic potential of Melastoma species for the treatment of human disorders.

MATERIALS AND METHODS

Information related to the traditional uses, phytochemistry and pharmacological activities was systematically collected by searching for the word "Melastoma" in electronic databases, including SciFinder, Web of Science, PubMed, and Google Scholar, from Apr. 1968 until Dec. 2019.

RESULTS

A systematic literature survey revealed that Melastoma spp. are widely distributed in southern Asia to northern Oceania and the Pacific Islands and are traditionally used to treat bleeding, diarrhea, swelling, and gynecological tumors. Approximately 142 compounds, including flavonoids, tannins, phenylpropanoids, organic acids, terpenoids, and steroids, have been reported from Melastoma spp. Different extracts have been evaluated for their pharmacological activities, including anti-inflammatory, hemostatic, anticoagulant, cytotoxic, antibacterial, antioxidant, hepatoprotective, gastroprotective and hypoglycemic activities.

CONCLUSIONS

Melastoma spp. are popularly used in Southeast Asian countries as effective herbs and are rich in flavonoids, tannins and organic acids with valuable medicinal properties. However, additional studies of the chemical constituents and the mechanism-based pharmacological activities of many members of Melastoma are still needed for developing new plant-derived drugs. In addition, studies on the clinical safety and efficacy of Melastoma are also needed.

Minimal residual disease in bone marrow transplant recipients with chronic myeloid leukemia

Bone marrow samples of 70 transplant recipients with CML were studied by Southern blot analysis and RT-PCR using a two-step procedure with nested primers. Twenty-two patients were studied once and 48 were assessed on multiple occasions. All patients remained in a hematological remission during the study. The time of follow-up after the transplant ranged from 2 to 144 months with a median of 42 months. Thirty-nine patients (56%) were negative by RT-PCR and Southern blot studies at the time of their last evaluation. The proportion of RT-PCR negative patients increased with the duration of follow-up after the transplant; 36% of patients were RT-PCR negative after 1 year compared with 60% after 2 years and 78% after > or = 5 years. Patients maintained on immunosuppression had a higher probability of remaining RT-PCR positive. Age, sex, time from diagnosis to BMT, as well as acute and chronic GVHD did not influence the RT-PCR status. The majority of patients studied on multiple occasions demonstrated a stable RT-PCR and Southern blot pattern. Some showed uni- or multi-directional transitions. However, none of the patients studied progressed to a hematological relapse. RT-PCR studies on colonies grown from RT-PCR positive. Southern blot negative patients confirmed that some of the clonogenic progenitors are able to produce BCR/ABL transcripts.

The preliminary observation on immunosuppressive effect of norcantharidin in mice

Norcantharidin (NCTD) is a synthetic analog of cantharidin. It has potent antitumor properties without obvious side effect that Cantharidin has on urinary organs. It has been reported that NCTD is an immunological stimulator to NK, LAK, neutrophil and lymphocyte. In our experiment, however, we observed that NCTD can markedly inhibit lymphocyte proliferation stimulated by mitogen ConA or LPS in vitro, and the mixed lymphocyte reaction (MLR) of mice, in a dose-related manner. This occurred even when the drug was added 40 hours (for lymphocyte proliferation) or 72 hours (for MLR) after the cultures were initiated. On the other hand, NCTD has no effect on inactive lymphocytes that were cultured as control in medium without mitogens, suggesting that NCTD selectively acts on activated lymphocyte.

Monoclonal antibody 55 (CD10) and complement used for purging autologous bone marrow in common acute lymphoblastic leukemia

A CD10 monoclonal antibody 55 (McAb55) was intended for purging residual common acute lymphoblastic leukemia antigen (CALLA) positive leukemic cells from autotransplants of common acute lymphoblastic leukemia (C-ALL) patients. It was found that after two rounds of McAb55 and complement treatment, 4-5 logs of CALLA+ cells were removed from bone marrow detected by clonogenic assay. The standardization of separation, purgation and preservation of bone marrow for C-ALL patients' autotransplants was then set as follows: Following the carboxymethyl starch sedimentation and Ficoll-Hypaque gradient separation, the isolated mononuclear cells (MNCs) were treated with McAb55 and complement twice and kept in room temperature for 48-72 hours prior to infusion. This procedure resulted in the removal of more than 99% of CALLA+ cells, recovery of 10-30% MNCs, and leaving the hematopoiesis stem cells intact. After the intensive cytoreductive therapy, 4 patients with C-ALL received the purged autotransplants giving timely recovery of the hematopoietic function. The patients were all remaining in remission status for more than 40-250 days so far.