Phenolic constituents from the twigs of Betula schmidtii collected in Goesan, Korea

Diverse terpenoid glycosides with in vitro cytotoxicity from Glechoma longituba

Terpenoids are the largest class of all known natural products, possessing structural diversity and numerous biological activities. Ten previously undescribed terpenoid glycosides, glechlongsides A-J (1-10), were isolated from the ethanol extract of the whole plant of Glechoma longituba, including diterpenoid glycoside and pentacyclic triterpenoid saponin. The structures of these compounds were characterized by extensive analysis of 1D and 2D NMR as well as HRESIMS spectra. In addition, glechlongsides F-I (6-9) exhibited weak cytotoxicity against human cancer cell lines BGC-823, Be1, HCT-8, A2780, and A549 with IC50 values ranging from 3.77 to 30.95 μM, respectively.

LC-MS guided isolation of phenolic glycosides from Viburnum luzonicum Rolfe leaves and their α‑amylase and α-glucosidase inhibitory activities

Viburnum luzonicum Rolfe is widely used in China as folk medicine. The bioactivity evaluation indicated that the n-BuOH fraction of V. luzonicum leaves (VLLB) could significantly inhibit α‑amylase and α-glucosidase. In order to clarify its active constituents, the phytochemical analysis on VLLB was first performed using HPLC-QTOF-MS/MS, and three new phenolic compounds, viburosides A-C (1-3), along with seven known analogues (4-10) were isolated through preparative HPLC. The undescribed compounds were determined by extensive spectroscopic analyses (1H and 13C NMR, HSQC, HMBC, HRESIMS, and ORD) and enzymatic hydrolysis. In the in vitro enzyme assays, compounds 1-8 showed potent α‑amylase and α-glucosidase inhibitory activities. The enzymatic kinetics and molecular docking of the strongest inhibitors 2 and 3 against the corresponding target enzyme were also performed.

Terpenoids from Glechoma hederacea var. longituba and their biological activities

Glechoma hederacea var. longituba (common name: ground ivy) has been used for the treatment of asthma, bronchitis, cholelithiasis, colds, and inflammation. In the present study, three new sesquiterpene glycosides (1–3), two new diterpene glycosides (4 and 5), and four known compounds (6–9) were isolated from its MeOH extract. A structure elucidation was performed for the five new compounds (1–5) using 1D and 2D NMR, HRESIMS, DP4+ and ECD calculations, and chemical methods. All the isolates (1–9) were assessed for their antineuroinflammatory activities on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells, nerve growth factor (NGF) secretion stimulation activities in C6 glioma cells, and cytotoxic activities against four human cancer cell lines (A549, SK-OV-3, SK-MEL-2, and HCT15). Compounds 2 and 5–7 exhibited inhibitory effects on the NO production with IC50 values of 52.21, 47.90, 61.61, and 25.35 μM, respectively. Compound 5 also exhibited a significant stimulating effect on NGF secretion (122.77 ± 8.10%). Compound 9 showed potent cytotoxic activity against SK-OV-3 (IC50 = 3.76 μM) and SK-MEL-2 (IC50 = 1.48 μM) cell lines, while 7 displayed a strong cytotoxic activity against the SK-MEL-2 (IC50 = 9.81 μM) cell line.

Anti-inflammatory and antioxidant activities of chemical constituents from the flower buds of Buddleja officinalis

Five new glycosides including mimenghuasu A and B (1-2), isolinarin (3), cyclocitralosides A and B (4-5), along with forty-seven known compounds were isolated from the flower buds of Buddleja officinalis. These structures were elucidated by extensive spectroscopic analysis (UV, IR, 1 D, 2 D NMR, and MS spectra). The anti-inflammatory activities of the isolated compounds were determined by enzyme-linked immunosorbent assay (ELISA) on the expression of TNF-α (LPS-activated RAW264.7 cells) and MTT experiment on LPS-induced HUVECs proliferation effects. Good suppressive effects on the expression of TNF-α were shown by 4 and 5 with IC₅₀ values of 19.35 and 22.10 μM, respectively, compared to positive control indomethacin (IC₅₀ 16.40 μM). In addition to this, some isolated compounds exhibited excellent antioxidant activities including compounds 16, 18, 29, 39, and 47 (IC₅₀ μM: 82.59, 72.94, 33.65, 46.67, and 20.81, respectively) with almost the same or stronger potency with reference to vitamin C as positive control (IC₅₀ 81.83 μM).

Nitric Oxide as a Target for Phytochemicals in Anti-Neuroinflammatory Prevention Therapy

Nitric oxide (NO) is a neurotransmitter that mediates the activation and inhibition of inflammatory cascades. Even though physiological NO is required for defense against various pathogens, excessive NO can trigger inflammatory signaling and cell death through reactive nitrogen species-induced oxidative stress. Excessive NO production by activated microglial cells is specifically associated with neuroinflammatory and neurodegenerative conditions, such as Alzheimer’s and Parkinson’s disease, amyotrophic lateral sclerosis, ischemia, hypoxia, multiple sclerosis, and other afflictions of the central nervous system (CNS). Therefore, controlling excessive NO production is a desirable therapeutic strategy for managing various neuroinflammatory disorders. Recently, phytochemicals have attracted considerable attention because of their potential to counteract excessive NO production in CNS disorders. Moreover, phytochemicals and nutraceuticals are typically safe and effective. In this review, we discuss the mechanisms of NO production and its involvement in various neurological disorders, and we revisit a number of recently identified phytochemicals which may act as NO inhibitors. This review may help identify novel potent anti-inflammatory agents that can downregulate NO, specifically during neuroinflammation and neurodegeneration.

A Network Pharmacological Approach to Reveal the Pharmacological Targets and Its Associated Biological Mechanisms of Prunetin-5-O-Glucoside against Gastric Cancer

Simple Summary

Identification of pharmacological targets in cancer provides a major walkthrough toward treatment strategies. The present research adopted a network pharmacology approach utilizing a flavonoid glucoside prunetin-5-O-glucoside (PG) compound against gastric cancer. The correlative targets were analyzed using Swiss target prediction and DiGeNET databases. Functional enrichment and significant pathways enriched were predicted for the targets to associate its biological mechanisms with cancer. Protein interaction network and cluster analysis was performed using Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). Our analysis revealed three core targets among the clustered modules that plays a crucial role in relation with cancer. With this information, the core targets were examined for the binding affinity with PG using molecular docking analysis and validations on the protein targets was performed using western blot analysis and Human Protein Atlas. Our analysis through comprehensive network pharmacology resulted in the prediction of three core targets of PG that can be significant biomarkers against gastric cancer.

Abstract

Gastric cancer (GC) is an aggressive malignancy with increased mortality rate and low treatment options. Increasing evidence suggests that network pharmacology will be a novel method for identifying the systemic mechanism of therapeutic compounds in diseases like cancer. The current study aimed to use a network pharmacology approach to establish the predictive targets of prunetin-5-O-glucoside (PG) against gastric cancer and elucidate its biological mechanisms. Primarily, genes associated with the pathogenesis of GC was identified from the DiGeNET database and targets of PG was obtained from the Swiss target prediction database. In total, 65 correlative hits were identified as anti-gastric cancer targets of PG. Functional enrichment and pathway analysis revealed significant biological mechanisms of the targets. Interaction of protein network and cluster analysis using STRING resulted in three crucial interacting hub targets namely, HSP90AA1, CDK2, and MMP1. Additionally, the in vitro cytotoxic potential of PG was assessed on three gastric cancer cells (AGS, MKN-28, and SNU-484). Furthermore, the crucial targets were validated using molecular docking, followed by their expressions being evaluated by western blot and Human Protein Atlas. The findings indicate that the pharmacological action of PG against GC might be associated with the regulation of three core targets: HSP90AA1, CDK2, and MMP1. Thus, the network pharmacology undertaken in the current study established the core active targets of PG, which may be extensively applied with further validations for treatment in GC.

Flavonoids from Sophora alopecuroides L. improve palmitate-induced insulin resistance by inhibiting PTP1B activity in vitro

Seventeen flavonoids (1-17) were isolated from Sophora alopecuroides L.. Compounds 1 and 2 were new compounds, and compounds 5, 8, 11, 12, and 17 were isolated from S. alopecuroides for the first time. The sources of compounds 1 and 2 were determined from the seeds of S. alopecuroides by UPLC-QE-Orbitrap-MS, and compounds 1, 2, 7, 13, 14, 15, 16, and 17 were proven to improve the insulin resistance of C2C12 myotubes and significantly increase glucose consumption levels. Among them, compounds 1, 2, 13, 14, 16, and 17 could bind to protein tyrosine phosphatase 1B (PTP1B), thereby significantly inhibiting the enzyme activity of PTP1B. Compound 2 had the strongest inhibitory effect, with an inhibition rate of 95.22% at 0.1 μg mL^-1.

Morolic Acid 3-O-Caffeate Inhibits Adipogenesis by Regulating Epigenetic Gene Expression

Obesity causes a wide range of metabolic diseases including diabetes, cardiovascular disease, and kidney disease. Thus, plenty of studies have attempted to discover naturally derived compounds displaying anti-obesity effects. In this study, we evaluated the inhibitory effects of morolic acid 3-O-caffeate (MAOC), extracted from Betula schmidtii, on adipogenesis. Treatment of 3T3-L1 cells with MAOC during adipogenesis significantly reduced lipid accumulation and decreased the expression of adiponectin, a marker of mature adipocytes. Moreover, the treatment with MAOC only during the early phase (day 0-2) sufficiently inhibited adipogenesis, comparable with the inhibitory effects observed following MAOC treatment during the whole processes of adipogenesis. In the early phase of adipogenesis, the expression level of Wnt6, which inhibits adipogenesis, increased by MAOC treatment in 3T3-L1 cells. To identify the gene regulatory mechanism, we assessed alterations in histone modifications upon MAOC treatment. Both global and local levels on the Wnt6 promoter region of histone H3 lysine 4 trimethylation, an active transcriptional histone marker, increased markedly by MAOC treatment in 3T3-L1 cells. Our findings identified an epigenetic event associated with inhibition of adipocyte generation by MAOC, suggesting its potential as an efficient therapeutic compound to cure obesity and metabolic diseases.

Neurotrophic and anti-neuroinflammatory constituents from the aerial parts of Coriandrum sativum

In the course of our continuing search for biologically active compounds from medicinal sources, we investigated the MeOH extract of the aerial parts of Coriandrum sativum Linn. An extended phytochemical investigation of the aerial parts of C. sativum led to the isolation and identification of seven compounds (1-7) including two new isocoumarin glycosides (1-2) and a new phenolic glycoside (5). The chemical structures of the new compounds (1, 2, and 5) were elucidated by analysis of 1D and 2D NMR (¹H and ¹³C NMR, COSY, HSQC, and HMBC) and HRESIMS data as well as by using chemical methods. All the isolates were evaluated not only for their potential neurotrophic activity by means of induction of nerve growth factor (NGF) in C6 glioma cells but also for production of nitric oxide (NO) levels in lipopolysaccharide (LPS)-activated murine microglia BV-2 cells to assess their anti-neuroinflammatory activity. Compounds 1-3 and 7 were stimulants of NGF release, with levels of NGF stimulated at 127.23 ± 1.89%, 128.22 ± 5.45%, 121.23 ± 6.66%, and 120.94 ± 3.97%, respectively. Furthermore, the aglycones of 1 and 2 (1a and 2a) showed more potent NGF secretion activity and anti-neuroinflammatory effect than did their glycosides (1a : 130.81 ± 5.45% and 2a : 134.44 ± 5.45%).

Natural therapeutic agents for neurodegenerative diseases from the shells of Xanthoceras sorbifolium

Neuroinflammation is linked to neurodegenerative diseases, manifested by the microglial-released over-production of nitric oxide (NO). However, so far there is no effective strategy regarding curing or preventing neurodegenerative diseases. Triterpene saponins from Xanthoceras sorbifolium were proved to be capable of eliciting a protective effect in neurodegenerative diseases. Thus, a systematic chemical study on the 70% ethanol extract of X. sorbifolium was conducted, leading to the identification of 22 compounds, including four previously undescribed triterpenes saponins and 14 known ones, along with four alkaloids. Their structures were elucidated by physicochemical and spectral methods. The in vivo anti-AD effects of 1-18 were predicted with a field-based 3D-QSAR model and anti-neuroinflammatory activities were assayed in BV-2 cells by assessing LPS-induced NO production and examine levels of iNOS, TNF-α, IL-1β, and IL-6 to support the predicted results. As a result, compounds 14, 16, 19, and 20 could have therapeutic potentials for neurodegenerative diseases due to their potent anti-neuroinflammatory activities.