Antiepileptic C21 steroids from the roots of Cynanchum otophyllum

Chemical constituents with potential cytotoxic activities from Cynanchum otophyllum

Phytochemical investigation of the chloroform extract of the roots of Cynanchum otophyllum (Asclepiadaceae) led to the isolation of a new cardiac aglycone, characterised as Cynanchin A (1), as well as one known cardenolide (2) and nine known C21 steroidal glycosides (3-10), Their structures were established by 1D and 2D NMR spectra referring to the literature, together with high-resolution mass spectrometric analysis. In the present research, the cytotoxic activities of the 11 compounds on five different human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7 and SW480) were evaluated in vitro. Most of the tested compounds showed potent inhibitory activities towards the five cell lines.

Chemically-induced epileptic seizures in zebrafish: A systematic review

The use of zebrafish as a model organism is gaining evidence in the field of epilepsy as it may help to understand the mechanisms underlying epileptic seizures. As zebrafish assays became popular, the heterogeneity between protocols increased, making it hard to choose a standard protocol to conduct research while also impairing the comparison of results between studies. We conducted a systematic review to comprehensively profile the chemically-induced seizure models in zebrafish. Literature searches were performed in PubMed, Scopus, and Web of Science, followed by a two-step screening process based on inclusion/exclusion criteria. Qualitative data were extracted, and a sample of 100 studies was randomly selected for risk of bias assessment. Out of the 1058 studies identified after removing duplicates, 201 met the inclusion criteria. We found that the most common chemoconvulsants used in the reviewed studies were pentylenetetrazole (n = 180), kainic acid (n = 11), and pilocarpine (n = 10), which increase seizure severity in a dose-dependent manner. The main outcomes assessed were seizure scores and locomotion. Significant variability between the protocols was observed for administration route, duration of exposure, and dose/concentration. Of the studies subjected to risk of bias assessment, most were rated as low risk of bias for selective reporting (94%), baseline characteristics of the animals (67%), and blinded outcome assessment (54%). Randomization procedures and incomplete data were rated unclear in 81% and 68% of the studies, respectively. None of the studies reported the sample size calculation. Overall, these findings underscore the need for improved methodological and reporting practices to enhance the reproducibility and reliability of zebrafish models for studying epilepsy. Our study offers a comprehensive overview of the current state of chemically-induced seizure models in zebrafish, highlighting the common chemoconvulsants used and the variability in protocol parameters. This may be particularly valuable to researchers interested in understanding the underlying mechanisms of epileptic seizures and screening potential drug candidates in zebrafish models.

Cynanotophyllosides E-F, two minor pregnane glycosides from the roots of cultivated Cynanchum otophyllum

Cynanotophyllosides E-F, two new minor pregnane glycosides were isolated from the antidepressant active fraction of cultivated Cynanchum otophyllum, and their structures were determined as 12-O-vanilloyl-deacetylmetaplexigenin 3-O-β -D-glucopyranosyl-(1→4)-β -D-glucopyranosyl-(1→4)-β -D-cymaropyranosyl-(1→4)-β -D-oleandropyranosyl-(1→4)-β -D-digitoxopyranoside, and 12-O-nicotinoyl-deacetylmetaplexigenin 3-O-β -D-glucopyranosyl-(1→4)-β -D-glucopyranosyl-(1→4)-β -D-cymaropyranosyl-(1→4)-β -D-oleandropyranosyl-(1→4)-β -D-cymaropyranoside respectively, with the combination of spectroscopic and chemical analysis.

Treating Epilepsy with Natural Products: Nonsense or Possibility?

Epilepsy is a neurological disease characterized by recurrent seizures that can lead to uncontrollable muscle twitching, changes in sensitivity to sensory perceptions, and disorders of consciousness. Although modern medicine has effective antiepileptic drugs, the need for accessible and cost-effective medication is urgent, and products derived from plants could offer a solution. For this review, we have focused on natural compounds that have shown anticonvulsant activity in in vivo models of epilepsy at relevant doses. In some cases, the effects have been confirmed by clinical data. The results of our search are summarized in tables according to their molecular targets. We have critically evaluated the data we present, identified the most promising therapeutic candidates, and discussed these in the text. Their perspectives are supported by both pharmacokinetic properties and potential interactions. This review is intended to serve as a basis for future research into epilepsy and related disorders.

12,20-Epoxypregnane Glycosides from the Roots of Oxypetalum caeruleum

The MeOH extract from dried roots of Oxypetalum caeruleum (Apocynaceae, formerly known as Asclepiadaceae) plants yielded twenty new pregnane glycosides, some of which had a new 12,20-epoxy type aglycone. The structures of these compounds were established using NMR, MS spectroscopic analysis and chemical evidence.

Six C21 steroidal glycosides from Cynanchum wallichii Wight roots and their multidrug resistance reversal activities

Six unidentified C21 steroidal glycosides, cynwallosides A-F, as well as twenty-two known compounds, were isolated from the roots of Cynanchum wallichii Wight. The structures of cynwallosides A-F were determined by spectroscopic analysis and acidic hydrolysis. Most of these twenty-eight compounds were found to significantly reverse drug resistance in both the MCF-7/ADR and HepG2/ADM cell lines by suppressing P-gp protein expression. Further investigation revealed that three compounds suppressed P-gp expression by significantly inactivating the JNK and NF-κB pathways.

Pregnane glycosides from Adonis amurensis and their bioactivity

Seven undescribed pregnane glycosides named amurensides A-G and two known aglycones were isolated from the whole herb of Adonis amurensis Regel & Radde. Their structures were established based on 1D and 2D NMR spectroscopic analyses, high-resolution mass spectrometry, and acid hydrolysis. The cytotoxicity of all compounds against three tumor cell lines (HepG2, Caco-2, and A549) were evaluated. Among them, amurensides A-C and E showed moderate inhibitory effects on the growth of HepG2 cells, with IC₅₀ values ranging from 15.6 to 48.7 μM (sorafenib, 7.5 ± 1.9 μM). Amurensides A、D and F displayed inhibitory effects on the growth of A549 cells with IC₅₀ values of 18.8 ± 1.2, 12.4 ± 0.6, and 30.4 ± 0.1 μM (cis-platinum, 6.1 ± 0.1 μM), respectively.

C21 Steroidal Glycosides from the Roots of Oxypetalum caeruleum

The MeOH extract from dried roots of Oxypetalum caeruleum (Apocynaceae) plants yielded seventeen new pregnane glycosides, some of which had the acylated-ramanone or -isoramanone type aglycone. The structures of these compounds were established using NMR, MS spectroscopic analysis and chemical evidence.

Qingyangshen mitigates amyloid-β and Tau aggregate defects involving PPARα-TFEB activation in transgenic mice of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is the most common neurodegenerative disease. Deposition of amyloid β plaques (Aβ) and neurofibrillary tangles (NFTs) is the key pathological hallmark of AD. Accumulating evidence suggest that impairment of autophagy-lysosomal pathway (ALP) plays key roles in AD pathology.

PURPOSE

The present study aims to assess the neuroprotective effects of Qingyangshen (QYS), a Chinese herbal medicine, in AD cellular and animal models and to determine its underlying mechanisms involving ALP regulation.

METHODS

QYS extract was prepared and its chemical components were characterized by LC/MS. Then the pharmacokinetics and acute toxicity of QYS extract were evaluated. The neuroprotective effects of QYS extract were determined in 3XTg AD mice, by using a series of behavioral tests and biochemical assays, and the mechanisms were examined in vitro.

RESULTS

Oral administration of QYS extract improved learning and spatial memory, reduced carboxy-terminal fragments (CTFs), amyloid precursor protein (APP), Aβ and Tau aggregates, and inhibited microgliosis and astrocytosis in the brains of 3XTg mice. Mechanistically, QYS extract increased the expression of PPARα and TFEB, and promoted ALP both in vivo and in vitro.

CONCLUSION

QYS attenuates AD pathology, and improves cognitive function in 3XTg mice, which may be mediated by activation of PPARα-TFEB pathway and the subsequent ALP enhancement. Therefore, QYS may be a promising herbal material for further anti-AD drug discovery.

Anticancer properties of caudatin and related C-21 steroidal glycosides from Cynanchum plants

Numerous C-21 steroidal glycosides have been isolated from Cynanchum plants. Many of them derive from the aglycone caudatin (CDT) which includes a tetracyclic deacylmetaplexigenin unit and an ikemaoyl ester side chain. CDT can be found in diverse traditional medicines, such as Baishouwu radix used to treat gastro-intestinal disorders. The compound has revealed marked anticancer properties, reviewed here. CDT and its mono-glycoside analogue CDMC display antiproliferative activities against different cancer cell lines in vitro and have revealed significant anticancer effects in tumor xenograft models in vivo. Their mechanism of action is multifactorial, implicating several signaling pathways (Wnt/GSK3/β-catenin, TRAIL/DR5/ER and TNFAIP1/NFκB) which contribute to the antiproliferative, antiangiogenic, antimetastatic and proapoptotic effects of the natural products. CDT also modulates DNA replication, is antioxidant and targets some cancer stem cells. CDT and CDMC are interesting anticancer products, while other CDT glycoside derivatives display antiviral and antifungal activities. Altogether, the present review provides a survey of the pharmacological profiles of CDT and derivatives. The lack of knowledge about the molecular targets of CDT currently limits drug development but the natural product, orally active, warrants further pharmacology and toxicology studies.

In Vivo Screening of Xanthones from Garcinia oligantha Identified Oliganthin H as a Novel Natural Inhibitor of Convulsions

Epilepsy is a chronic neurological disorder, characterized by recurrent, spontaneous, and transient seizures, and affects more than 70 million people worldwide. Although two dozen antiepileptic drugs (AEDs) are approved and available in the market, seizures remain poorly controlled in one-third of epileptic patients who are suffering from drug resistance or various adverse effects. Recently, the xanthone skeleton has been regarded as an attractive scaffold for the discovery and development of emerging anticonvulsants. We had isolated several dihydroxanthone derivatives previously, including oliganthin H, oliganthin I, and oliganthin N, whose structures were similar and delicately elucidated by spectrum analysis or X-ray crystallographic data, from extracts of leaves of Garcinia oligantha. These xanthone analogues were evaluated for anticonvulsant activity, and a novel xanthone, oliganthin H, has been identified as a sound and effective natural inhibitor of convulsions in zebrafish in vivo. A preliminary structure-activity relationship analysis on the relationship between structures of the xanthone analogues and their activities was also conducted. Oliganthin H significantly suppressed convulsant behavior and reduced to about 25% and 50% of PTZ-induced activity, in 12.5 and 25 μM treatment groups (P < 0.01 and 0.001), respectively. Meanwhile, it reduced seizure activity, velocity, seizure duration, and number of bursts in zebrafish larvae (P < 0.05). Pretreatment of oliganthin H significantly restored aberrant induction of gene expressions including npas4a, c-fos, pyya, and bdnf, as well as gabra1, gad1, glsa, and glula, upon PTZ treatment. In addition, in silico analysis revealed the stability of the oliganthin H-GABAA receptor complex and their detailed binding pattern. Therefore, direct interactions with the GABAA receptor and involvement of downstream GABA-glutamate pathways were possible mechanisms of the anticonvulsant action of oliganthin H. Our findings present the anticonvulsant activity of oliganthin H, provide a novel scaffold for further modifications, and highlight the xanthone skeleton as an attractive and reliable resource for the development of emerging AEDs.

Deciphering the multicomponent synergy mechanisms of SiNiSan prescription on irritable bowel syndrome using a bioinformatics/network topology based strategy

BACKGROUND

SiNiSan (SNS) is a traditional Chinese medicine (TCM) prescription that has been widely used in the clinical treatment of irritable bowel syndrome (IBS). However, the underlying active substances and molecular mechanisms remain obscure.

PURPOSE

A bioinformatics/topology based strategy was proposed for identification of the drug targets, therapeutic agents and molecular mechanisms of SiNiSan against irritable bowel syndrome.

MATERIALS AND METHODS

In this work, a bioinformatics/network topology based strategy was employed by integrating ADME filtering, text mining, bioinformatics, network topology, Venn analysis and molecular docking to uncover systematically the multicomponent synergy mechanisms. In vivo experimental validation was executed in a Visceral Hypersensitivity (VHS) rat model.

RESULTS

76 protein targets and 109 active components of SNS were identified. Bioinformatics analysis revealed that 116 disease pathways associated with IBS therapy could be classified into the 19 statistically enriched functional sub-groups. The multi-functional co-synergism of SNS against IBS were predicted, including inflammatory reaction regulation, oxidative-stress depression regulation and hormone and immune regulation. The multi-component synergetic effects were also revealed on the herbal combination of SNS. The hub-bottleneck genes of the protein networks including PTGS2, CALM2, NOS2, SLC6A3 and MAOB, MAOA, CREB1 could become potential drug targets and Paeoniflorin, Naringin, Glycyrrhizic acid may be candidate agents. Experimental results showed that the potential mechanisms of SiNiSan treatment involved in the suppression of activation of Dopaminergic synapse and Amphetamine addiction signaling pathways, which are congruent with the prediction by the systematic approach.

CONCLUSION

The integrative investigation based on bioinformatics/network topology strategy may elaborate the multicomponent synergy mechanisms of SNS against IBS and provide the way out to develop new combination medicines for IBS.

HPLC-Based Activity Profiling for GABAA Receptor Modulators in Extracts: Validation of an Approach Utilizing a Larval Zebrafish Locomotor Assay

Gamma-aminobutyric acid type A (GABA_A) receptors are major inhibitory neurotransmitter receptors in the central nervous system and a target for numerous clinically important drugs used to treat anxiety, insomnia, and epilepsy. A series of allosteric GABA_A receptor agonists was identified previously with the aid of HPLC-based activity profiling, whereby activity was tracked with an electrophysiological assay in Xenopus laevis oocytes. To accelerate the discovery process, an approach has been established for HPLC-based profiling using a larval zebrafish (Danio rerio) seizure model induced by pentylenetetrazol (PTZ), a pro-convulsant GABA_A receptor antagonist. The assay was validated with the aid of representative GABAergic plant compounds and extracts. Various parameters that are relevant for the quality of results obtained, including PTZ concentration, the number of larvae, the incubation time, and the data analysis protocol, were optimized. The assay was then translated into an HPLC profiling protocol, and active compounds were tracked in extracts of Valeriana officinalis and Magnolia officinalis. For selected compounds the effects in the zebrafish larvae model were compared with data from in silico blood-brain barrier (BBB) permeability predictions, to validate the use for discovery of BBB-permeable natural products.