The discovery of Yuanzhi-1, a triterpenoid saponin derived from the traditional Chinese medicine, has antidepressant-like activity

Pharmacometabolomics and mass spectrometry imaging approach to reveal the neurochemical mechanisms of Polygala tenuifolia

Polygala tenuifolia, commonly known as Yuanzhi (YZ) in Chinese, has been shown to possess anti-insomnia properties. However, the material basis and the mechanism underlying its sedative-hypnotic effects remain unclear. Herein, we investigated the active components and neurochemical mechanism of YZ extracts using liquid chromatography tandem mass spectrometry (LC-MS/MS)-based pharmacometabolomics and mass spectrometry imaging (MSI)-based spatial resolved metabolomics. According to the results, 17 prototypes out of 101 ingredients in the YZ extract were detected in both the plasma and brain, which might be the major components contributing to the sedative-hypnotic effects. Network pharmacology analysis revealed that these prototypes may exert their effects through neuroactive ligand-receptor interaction, serotonergic synapse, dopaminergic synapse, and dopaminergic synapse, among other pathways. LC-MS/MS-based targeted metabolomics and Western blot (WB) revealed that tryptophan-serotonin-melatonin (Trp-5-HT-Mel) and tyrosine-norepinephrine-adrenaline (Tyr-Ne-Ad) are the key regulated pathways. Dopa decarboxylase (DDC) upregulation and phenylethanolamine N-methyltransferase (PNMT) downregulation further confirmed these pathways. Furthermore, MSI-based spatially resolved metabolomics revealed notable alterations in 5-HT in the pineal gland (PG), and Ad in the brainstem, including the middle brain (MB), pons (PN), and hypothalamus (HY). In summary, this study illustrates the efficacy of an integrated multidimensional metabolomics approach in unraveling the sedative-hypnotic effects and neurochemical mechanisms of a Chinese herbal medicine, YZ.

The Antidepressant Effect of Magnolol on Depression-Like Behavior of CORT-Treated Mice

Although the antidepressant-like effect of magnolol has been revealed in previous reports, the mechanism remains unclear. In this study, the antidepressant-like effect of magnolol on corticosterone-induced (CORT-induced) mice was investigated in vivo. After 21 days of CORT induction, the mice showed marked depressive-like behaviors, with a decrease in sucrose preference score and an increase in immobility time in the tail suspension test (TST) and forced swimming test (FST). Pretreatment with either magnolol (50 mg/kg, i.p.) or the kappa opioid receptor (KOR) antagonist nor-BNI (10 mg/kg, i.p.) prevented CORT-induced depression-like behavior and reduced CORT-induced dynorphin (DYN A) elevation in the hippocampal ventral DG. However, no depression-like behavior was observed in mice with KOR downregulation in the ventral DG. We further found that upregulation of DYN A in the DG caused depression-like behavior, which was blocked by intraperitoneal injection of nor-BNI and modulated by magnolol. The present study demonstrated that magnolol could ameliorate CORT-induced depression-like behaviors, by modulating the DYN A/KOR system in the ventral DG of the hippocampus.

Polygalae Radix Oligosaccharide Esters May Relieve Depressive-like Behavior in Rats with Chronic Unpredictable Mild Stress via Modulation of Gut Microbiota

Polygalae radix (PR) is a well-known traditional Chinese medicine that is used to treat depression, and polygalae radix oligosaccharide esters (PROEs) are the main active ingredient. Although gut microbiota are now believed to play key role in depression, the effects of PROEs on depression via modulation of gut microbiota remain unknown. In this article, we investigate the effect of PROEs on the gut microbiota of a depression rat and the possible mechanism responsible. The depression rat model was induced by solitary rearing combined with chronic unpredictable mild stress (CUMS). The depression-like behavior, the influence on the hypothalamic-pituitary-adrenal (HPA) axis, the contents of monoamine neurotransmitter in the hippocampus, and the quantity of short-chain fatty acids (SCFAs) in the feces were each assessed, and the serum levels of lipopolysaccharide (LPS) and interleukin-6 (IL-6) were measured by ELISA. Additionally, ultrastructural changes of the duodenal and colonic epithelium were observed under transmission electron microscope, and the gut microbiota were profiled by using 16S rRNA sequencing. The results show that PROEs alleviated the depression-like behavior of the depression model rats, increased the level of monoamine neurotransmitters in the brain, and reduced the hyperfunction of the HPA axis. Furthermore, PROEs regulated the imbalance of the gut microbiota in the rats, relieving intestinal mucosal damage by increasing the relative abundance of gut microbiota with intestinal barrier protective functions, and adjusting the level of SCFAs in the feces, as well as the serum levels of LPS and IL-6. Thus, we find that PROEs had an antidepressant effect through the restructuring of gut microbiota that restored the function of the intestinal barrier, reduced the release of intestinal endotoxin, and constrained the inflammatory response.

Therapeutic potential of Polygala saponins in neurological diseases

BACKGROUND

There are many types of neurological diseases with complex etiologies. At present, most clinical drugs can only relieve symptoms but cannot cure these diseases. Radix Polygalae, a famous traditional Chinese medicine from the root of plants of the genus Polygala, has the traditional effect of treating insomnia, forgetfulness, and palpitation and improving intelligence and other symptoms of neurological diseases. Saponins are important bioactive components of plants of the genus Polygala and exhibit neuroprotective effects.

PURPOSE

This review aimed to summarize the traditional use of Polygala species and discuss the latest phytochemical, pharmacological, and toxicological findings, mainly with regard to Polygala saponins in the treatment of neurological disorders.

METHODS

Literature was searched and collected using databases, including PubMed, Science Direct, CNKI, and Google Scholar. The search terms used included "Polygala", "saponins", "neurological diseases", "Alzheimer's disease", "toxicity", etc., and combinations of these keywords. A total of 1202 papers were retrieved until August 2022, and we included 135 of these papers on traditional uses, phytochemistry, pharmacology, toxicology and other fields.

RESULTS

This literature review mainly reports on the traditional use of the Polygala genus and prescriptions containing Radix Polygalae in neurological diseases. Phytochemical studies have shown that plants of the genus Polygala mainly include saponins, flavonoids, oligosaccharide esters, alkaloids, coumarins, lignans, flavonoids, etc. Among them, saponins are the majority. Modern pharmacological studies have shown that Polygala saponins have neuroprotective effects on a variety of neurological diseases. Its mechanism of action involves autophagic degradation of misfolded proteins, anti-inflammatory, anti-apoptotic, antioxidative stress and so on. Toxicological studies have shown that Polygala saponins trigger gastrointestinal toxicity, and honey processing and glycosyl disruption of Polygala saponins can effectively ameliorate its gastrointestinal side effect.

CONCLUSION

Polygala saponins are the major bioactive components in plants of the genus Polygala that exhibit therapeutic potential in various neurological diseases. This review provides directions for the future study of Polygala saponins and references for the clinical use of prescriptions containing Radix Polygalae for the treatment of neurological diseases.

Natural products for the treatment of stress-induced depression: Pharmacology, mechanism and traditional use

ETHNOPHARMACOLOGICAL RELEVANCE

Depression, one of the most common psychiatric disorders, is the fourth leading cause of long-term disability worldwide. A series of causes triggered depression, including psychological stress and conflict, as well as biological derangement, among which stress has a pivotal role in the development of depression. Traditional herbal medicine has been used for the treatment of various disorders including depression for a long history with multi-targets, multi-levels and multi-ways, attracting great attention from scholars. Recently, natural products have been commercialized as antidepressants which have become increasingly popular in the world health drug markets. Major research contributions in ethnopharmacology have generated and updated vast amount of data associated with natural products in antidepressant-like activity.

AIMS OF THE REVIEW

This review aims to briefly discuss the pathological mechanism, animal models of stress-induced depression, traditional use of herbal medicines and especially recapitulate the natural products with antidepressant activity and their pharmacological functions and mechanism of action, which may contribute to a better understanding of potential therapeutic effects of natural products and the development of promising drugs with high efficacy and low toxicity for the treatment of stress-induced depression.

MATERIALS AND METHODS

The contents of this review were sourced from electronic databases including PubMed, Sci Finder, Web of Science, Science Direct, Elsevier, Google Scholar, Chinese Knowledge On frastructure (CNKI), Wan Fang, Chinese Scientific and Technological Periodical Database (VIP) and Chinese Biomedical Database (CBM). Additional information was collected from Yao Zhi website (https://db.yaozh.com/). Data were obtained from April 1992 to June 2021. Only English language was applied to the search. The search terms were 'stress-induced depression', 'pathological mechanism' in the title and 'stress', 'depression', 'animal model' and 'natural products' in the whole text.

RESULTS

Stress-induced depression is related to the monoaminergic system, hypothalamic-pituitary-adrenal (HPA) axis, neuronal plasticity and a series of inflammatory factors. Four main types of animal models of stress-induced depression were represented. Fifty-eight bioactive phytochemical compounds, fifty-six herb medicines and five formulas from traditional Chinese medicine were highlighted, which exert antidepressant effects by inhibiting monoamine oxidase (MAO) reaction, alleviating dysfunction of the HPA axis and nerve injury, and possessing anti-inflammatory activities.

CONCLUSIONS

Natural products provide a large number of compounds with antidepressant-like effects, and their therapeutic impacts has been highlighted for a long time. This review summarized the pathological mechanism and animal models of stress-induced depression, and the natural products with antidepressant activity in particular, which will shed light on the action mechanism and clinical potential of these compounds. Natural products also have been a vital and promising source for future antidepressant drug discovery.

Polygala saponins inhibit NLRP3 inflammasome-mediated neuroinflammation via SHP-2-Mediated mitophagy

Activation of the NLRP3 inflammasome and its mediated neuroinflammation are implicated in neurodegenerative diseases, while mitophagy negatively regulates NLRP3 inflammasome activation. SHP-2, a protein-tyrosine phosphatase, is critical for NLRP3 inflammasome regulation and inflammatory responses. In this study, we investigated whether triterpenoid saponins in Radix Polygalae inhibit the NLRP3 inflammasome via mitophagy induction. First, we isolated the active fraction (polygala saponins (PSS)) and identified 17 saponins by ultra-performance liquid chromatography coupled with diode-array detection and tandem quadrupole time-of-flight mass spectrometry (UHPLC-DAD-Q/TOF-MS). In microglial BV-2 cells, PSS induced mitophagy as evidenced by increased co-localization of LC3 and mitochondria, as well as an increased number of autophagic vacuoles surrounding the mitochondria. Furthermore, the mechanistic study found that PSS activated the AMPK/mTOR and PINK1/parkin signaling pathways via the upregulation of SHP-2. In Aβ(1-42)-, A53T-α-synuclein-, or Q74-induced BV-2 cells, PSS significantly inhibited NLRP3 inflammasome activation, which was attenuated by bafilomycin A1 (an autophagy inhibitor) and SHP099 (an SHP-2 inhibitor). In addition, the co-localization of LC3 and ASC revealed that PSS promoted the autophagic degradation of the NLRP3 inflammasome. Moreover, PSS decreased apoptosis in conditioned medium-induced PC-12 cells. In APP/PS1 mice, PSS improved cognitive function, ameliorated Aβ pathology, and inhibited neuronal death. Collectively, the present study, for the first time, shows that PSS inhibit the NLRP3 inflammasome via SHP-2-mediated mitophagy in vitro and in vivo, which strongly suggests the therapeutic potential of PSS in various neurodegenerative diseases.

Protective Effects and Mechanism of Radix Polygalae Against Neurological Diseases as Well as Effective Substance

Radix Polygalae (also known as Yuanzhi in China) is the dried rhizome of Polygala tenuifolia Willd. or Polygala sibirica L., which is a famous Chinese herb and has been widely used for centuries in traditional medicines including expectorants, tonics, tranquilizers, antipsychotic, and so on. This article reviews the neuroprotective effects of Radix Polygalae in preclinical models of central nervous system (CNS) disorders, especially anxiety, depression, declining cognition, Alzheimer's disease (AD), and Parkinson's disease (PD). The chemical composition of Radix Polygalae as well as the underlying mechanisms of action were also reviewed. We found that Radix Polygalae possesses a broad range of beneficial effects on the abovementioned conditions. The multifold mechanisms of action include several properties such as antioxidant and associated apoptotic effects; anti-inflammatory and associated apoptotic effects; neurogenesis, regeneration, differentiation, and neuronal plasticity improvement; hypothalamic-pituitary-adrenal axis (HPA) regulation; neurotransmitter release; and receptor activation (A_2AR, NMDA-R, and GluR). Nevertheless, the detailed mechanisms underlying this array of pharmacological effects observed in vitro and in vivo still need further investigation to attain a coherent neuroprotective profile.

Traditional Chinese Medicine in Depression Treatment: From Molecules to Systems

Depression is a multigenetic or multifactorial syndrome. The central neuron system (CNS)-orientated, single target, and conventional antidepressants are insufficient and far from ideal. Traditional Chinese Medicine (TCM) has historically been used to treat depression up till today, particularly in Asia. Its holistic, multidrug, multitarget nature fits well with the therapeutic idea of systems medicine in depression treatment. Over the past two decades, although efforts have been made to understand TCM herbal antidepressants at the molecular level, many fundamental questions regarding their mechanisms of action remain to be addressed at the systems level in order to better understand the complicated herbal formulations in depression treatment. In this Mini Review, we review and discuss the mechanisms of action of herbal antidepressants and their acting targets in the pathological systems in the brain, such as monoamine neurotransmissions, hypothalamic–pituitary–adrenal (HPA) axis, neurotropic factor brain-derived neurotrophic factor (BDNF) cascade, and glutamate transmission. Some herbal molecules, constituents, and formulas are highlighted as examples to discuss their mechanisms of action and future directions for comprehensive researches at the systems level. Furthermore, we discuss pharmacological approaches to integrate the mechanism of action from the molecular level into the systems level for understanding of systems pharmacology of TCM formulations. Integration of the studies at the molecular level into the systems level not only represents a trend in TCM study but also promotes our understanding of the system-wide mechanism of action of herbal antidepressant formulations.

Efficacy and safety of TCM Yangxin Anshen Therapy for insomnia: A systematic review and meta-analysis

BACKGROUND

Traditional Chinese Medicine (TCM) has gradually drawn the attention of clinicians as an alternative choice for insomniacs and TCM Yangxin Anshen Therapy (TYAT) is a crucial therapy of treating insomniacs. The purpose of this study was to evaluate the efficacy and safety of TYAT for insomnia.

METHODS

Seven electronic databases were searched from inception to July 2019. Two authors independently identified Randomized Controlled Trials (RCTs), extracted data and assessed risk of bias by Cochrane risk bias assessment tool. Comprehensive meta-analysis was conducted with the Review Manager for eligible and appropriate studies.

RESULTS

Fourteen trials (1549 participants) were finally included in this study. The included studies were of moderate-to-high quality. Twelve trials reported the specific methods of random sequence generation, and 4 of them used the allocation concealment. Blinding of participants and personnel were used in 7 studies, and blinding of outcome assessment was performed in 3 studies. The main meta-analysis showed: CONCLUSION:: TYAT is an effective alternative therapy for insomnia, and its clinical application appears safe. The conclusions of this paper have a certain reference value for further research and clinical practice.

TRIAL REGISTRATION NUMBER

PROSPERO CRD 42019135115.

Intestinal Absorption Profile of Three Polygala Oligosaccharide Esters in Polygalae Radix and the Effects of Other Components in Polygalae Radix on Their Absorption

Oligosaccharide esters, which are among the main active components of Polygalae Radix (PR), demonstrate significant pharmacological activities in the human nervous system. In our previous research, some other constituents in PR were able to improve the bioavailability of oligosaccharide esters such as sibiricose A5 (SA5), sibiricose A6 (SA6), and 3,6'-disinapoyl sucrose (DISS), but the related components and their underlying mechanisms remain unknown. The present study aimed to investigate the intestinal absorptive profile of SA5, SA6, and DISS and the absorptive behavior influenced by the coadministration of polygalaxanthone III and total saponins of PR (TS) using an in vitro everted rat gut sac model, along with the possible mechanisms that may influence absorption. The results showed that TS could significantly enhance the absorption of SA5, SA6, and DISS monomers. Verapamil, a P-glycoprotein inhibitor, was able to elevate the absorption of SA5 and SA6, and an absorption experiment using Rho123 led us to conclude that TS influenced the absorption of SA5 and SA6 in a manner similar to that of a P-glycoprotein inhibitor. Sodium caprate, a paracellular absorption enhancer, was found to increase the absorption of SA5, SA6, and DISS. Results showed that the absorption mechanisms of SA5 and SA6 may combine active transport with paracellular passive penetration, while DISS's absorption was dominated by paracellular passive penetration. However, the relationship between polygala saponins and the absorption of SA5, SA6, and DISS by paracellular passive penetration remain to be examined. This is the direction of our future research.

Study on the safety of Polygala tenuifolia Willdenow root extract powder (BT-11) in young person aged from 9 to 19 years old

ETHNOPHARMACOLOGICAL RELEVANCE

Polygala tenuifolia Willdenow root extract (BT-11) has beneficial effects on central nervous system disorders in human. The safety of BT-11 should be elucidated in younger person further.

AIM OF THE STUDY

To evaluate the safety of BT-11 in human aged from 9 to 19 years old.

MATERIAL AND METHODS

The safety was evaluated in randomly assigned subjects who received the test products (61 subjects in BT-11 300 mg daily or 60 subjects in matching placebo) for 12 weeks. Adverse reactions were analyzed by the incidence rate, type, and severity. The clinical examination included hematology and blood chemistry tests, urinalysis, vital signs, body weight, and electrocardiogram (ECG).

RESULTS

Eleven adverse reactions were observed in ten subjects receiving BT-11 while seven adverse reactions in six subjects receiving placebo. There were no statistical differences in the incidence of adverse reactions between the two groups. Serious adverse reactions such as acute appendicitis and acute viral gastroenteritis were observed in the BT-11 group4 and the placebo group, respectively. However, it was confirmed that they were not associated with the test product. All other adverse reactions observed during the test period were resolved completely without special treatment. No statistical difference was also observed in safety laboratory tests, vital signs, and ECG between two groups.

CONCLUSIONS

This study demonstrates the safety of BT-11 in the adolescent by showing no apparent adverse reactions related to it.

Challenge and Prospect of Traditional Chinese Medicine in Depression Treatment

Current medication for depression is inadequate and far from ideal. Development of novel antidepressant drugs is a pressing task. The discovery of ketamine and related agents represents a new era in drug discovery for the rapid treatment of depression. Due to potential neurotoxicity, short-lasting efficacy, the limitation of a single target approach, and a limited role in depression prevention of these agents, additional approaches or drugs that exert synergy and compatibility, with the rapid-acting agents are required for better treatment of depression. Traditional Chinese Medicine (TCM) is a systems medicine and its clinical experience and integrated theory for diagnosis and treatment provides an alternative method of novel drug discovery in depression treatment. In TCM, there are numerous claimed effective antidepressant formulas, but comprehensive research and evidence-based clinical studies are required for their acceptance as a treatment. In this essay, we review current attempts in the discovery of new agents, TCM drug formulation, and TCM treatment of depression, and discuss the challenges and opportunities of TCM in the new era of antidepressant discovery. TCM could provide an important resource in the discovery of novel agents, assistance of the rapid-acting antidepressants, development of new agents for female patients, and the prevention of depression at its early stages. The study of depression in conjunction with TCM therefore not only provides an opportunity to scientifically evaluate the benefits and risks of TCM, but also accelerates the development of novel antidepressant agents by combining the principle of modern molecular medicine with the ideas of empirical systems medicine.

Comprehensive characterization of in vivo metabolic profile of Polygalae radix based on ultra-high-performance liquid chromatography-tandem mass spectrometry

In this study, a novel analysis strategy for progressively targeted screening and characterization of drug ingredients from in vitro to in vivo was proposed based on ultra-high performance liquid chromatography-tandem mass spectrometry for comprehensive characterization of in vivo metabolic profile of Polygalae radix (PR). First, an in vitro chemical profile of PR was described with the assistance of UNIFI™ software. The characteristic neutral small molecule losses were summarized to distinguish different chemical structures in the PR extract. Second, the in vitro intestinal microflora metabolism model was applied to describe an in vitro metabolic profile of the main ingredients of PR. The metabolic rule and metabolites were integrated for subsequent targeted screening of metabolites in vivo. Finally, an integrated strategy was established and applied to screen and characterize the major absorbed components in vivo, including blood, urine, brain, feces, and liver, based on the prototypes and metabolic rules obtained in vitro. As a result, in vitro and in vivo metabolic profiles of PR were effectively depicted. A total of 136 compounds were isolated and identified from the crude extract in vitro, and 12 compounds were reported for the first time based on the proposed fragmentations. A total of 13, 32, and 3 compounds were identified and characterized in the dosed plasma, liver, and brain, respectively. A total of 40 and 73 compounds were identified in urine and feces, respectively. This strategy not only provided a comprehensive insight into the chemical and metabolic profiles of PR but also presented a new perspective for the discovery of new drugs for medicinal application.

Polygala tenuifolia extract inhibits lipid accumulation in 3T3-L1 adipocytes and high-fat diet-induced obese mouse model and affects hepatic transcriptome and gut microbiota profiles

Obesity, the excessive accumulation of lipids in the body, is closely associated with many prevalent human disorders. Continued efforts to identify plant extracts that exhibit anti-obesity effects have drawn much attention. This study investigated whether a Polygala tenuifolia extract (PTE) possesses anti-obesity activity and how PTE may affect liver gene expression and gut microbiota. We used 3T3-L1 adipocytes and a high-fat diet–induced obese mouse model to determine the effects of PTE on lipid accumulation. Next-generation sequencing analysis of liver gene expression and gut microbiota profiles following PTE treatment were conducted to elucidate possible mechanisms. We found that treatment of fully differentiated 3T3-L1 adipocytes with PTE inhibited lipid accumulation in the cells through reducing lipid formation and triglyceride content and by increasing lipase activity. No cytotoxicity was observed from the PTE treatment. After 5 weeks of treatment with PTE, the increased body weight, elevated serum triglyceride content, and liver steatosis in the high-fat diet–induced obese mice were each reduced. Liver transcriptomic analysis revealed that expression of genes involved in lipid and cholesterol metabolism was significantly altered. The low-grade chronic inflammation of obesity caused by a high-fat diet was also decreased after PTE treatment. In addition, treatment with PTE improved the relatively low Bacteroidetes/Firmicutes ratio in the gut of high-fat diet–fed mice through enrichment of the Proteobacteria population and reduction of the Deferribacteres population. In conclusion, treatment with PTE inhibited lipid accumulation by inducing the expression of the master transcription factor PPARα, attenuated the low-grade chronic inflammation of obesity, and also altered gut microbiota profiles. These results indicate that PTE has the potential to be developed into an anti-obesity food supplement and therapy.

Abbreviations: Abcg5: ATP-binding cassette subfamily G member 5; ALT: alanine aminotransferase; AMPK: adenosine monophosphate-activated protein kinase; AST: aspartate aminotransferase; B/F: Bacteroidetes to Firmicutes [ratio]; C/EBPα: CCAAT/enhancer-binding protein alpha; CR: creatinine; Cyp51: cytochrome P450 family 51; DMEM: Dulbecco’s modified Eagle’s medium; Fabp5: fatty acid-binding protein 5; FBS: fetal bovine serum; Fdps: farnesyl diphosphate synthase; Glc: Glucose; HFD: high-fat diet; GO: gene ontology; HPRT: hypoxanthine guanine phosphoribosyl transferase; IBMS: 3-isobutyl-1-methylxanthine; Idi1: isopentenyl-diphosphate delta isomerase 1; IL-1β: interleukin-1-beta; Lpin1: phosphatidic acid phosphohydrolase; LPS: lipopolysaccharide; Mvd: mevalonate diphosphate decarboxylase; ND: normal diet; OTU: operational taxonomic units; Pcsk9: proprotein convertase subtilisin/kexin 9; Pctp: phosphatidylcholine transfer protein; PPARα: peroxisome proliferator-activated receptor alpha; PPARγ: peroxisome proliferator-activated receptor gamma; PTE: Polygala tenuifolia extract; Saa1: serum amyloid A1; SD: standard deviation; SEM: standard error of the mean; Serpina12: serpin family member 12; Sqle: squalene monooxygenase; SREBP1C: sterol regulatory element-binding protein 1C; TCHO: total cholesterol; TG: triglyceride

Active fragments-guided drug discovery and design of selective tropane alkaloids using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry coupled with virtual calculation and biological evaluation

Tropane alkaloids (TAs), rich in the plant of Physochlaina infundibularis Kuang, which is named Huashanshen (HSS) in China, showed good effects on types of spasms. However, no data were collected to explore the relationship between the specificity for muscarinic receptor subtypes and the structures of these TAs. To address this issue, an extracted ion chromatogram (EIC) strategy using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF-MS) based on the fragmentation behavior of the TA standards was established to rapidly capture the varied TAs from HSS. Based on the provided structural information of diagnostic ions or neutral loss, 29 TAs were efficiently profiled, especially some trace ingredients. In additional, via virtual validation combined with molecular dynamic simulation, approximately a dozen alkaloids were found with high selectivity for muscarinic receptors. In additional, N-acetyl convolicine was chosen for selectivity evaluation of M₂ or M₃ receptors through the use of a dual-luciferase reporter assay system at the cellular level and an ACh-induced constricted strip test in vitro. After summarizing the active fragments and the structure-activity relationship (SAR) information, a new modified TA that takes advantage of both the high affinity and high selectivity for M₃ receptors was proposed and evaluated successfully. This study provided an effective approach for the discovery and design of natural products based on highly selective drugs by UPLC-Q/TOF-MS coupled with virtual calculation and biological evaluation. Graphical Abstract Active fragments-guided strategy for selective inhibitors from HSS.

Receptor and transporter binding and activity profiles of albiflorin extracted from Radix paeoniae Alba

Albiflorin, a traditional Chinese herb, is a main component of Radix paeoniae Alba, which has been used for the treatment of depressive disorders since ancient times. However, the mechanism of the antidepressant effect of albiflorin is poorly understood. Thus, we explored the binding profile of albiflorin at neurotransmitter receptors and transporters. We also characterised the in vivo effect of albiflorin on monoaminergic systems by using microanalysis to determine the extracellular levels of serotonin (5-HT) and norepinephrine (NE) in the hypothalamus of freely moving rats administered albiflorin. We found that albiflorin inhibited the uptake of 5-HT and NE and displayed robust binding affinities for the transporters of both neurotransmitters. By contrast, albiflorin (10 μM) showed no significant affinity to a wide array of central nervous system receptors. The results of our in vivo microdialysis studies showed that administration of albiflorin (3.5, 7.0, 14.0 mg/kg) significantly increased extracellular concentrations of 5-HT and NE in the hypothalamus of freely moving rats. Overall, the current study showed that albiflorin is a novel 5-HT and NE reuptake inhibitor with high selectivity.

The antidepressant-like pharmacological profile of Yuanzhi-1, a novel serotonin, norepinephrine and dopamine reuptake inhibitor

Triple reuptake inhibitors that block dopamine transporters (DATs), norepinephrine transporters (NETs), and serotonin transporters (SERTs) are being developed as a new class of antidepressants that might have better efficacy and fewer side effects than traditional antidepressants. In this study, we performed in vitro binding and uptake assays as well as in vivo behavioural tests to assess the pharmacological properties and antidepressant-like efficacy of Yuanzhi-1. In vitro, Yuanzhi-1 had a high affinity for SERTs, NETs, and DATs prepared from rat brain tissue (Ki=3.95, 4.52 and 0.87nM, respectively) and recombinant cells (Ki=2.87, 6.86 and 1.03nM, respectively). Moreover, Yuanzhi-1 potently inhibited the uptake of serotonin (5-hydroxytryptamine; 5-HT), norepinephrine (NE) and dopamine (DA) into rat brain synaptosomes (Ki=2.12, 4.85 and 1.08nM, respectively) and recombinant cells (Ki=1.65, 5.32 and 0.68nM, respectively). In vivo, Yuanzhi-1 decreased immobility in a dose-dependent manner, which was shown among rats via the forced-swim test (FST) and mice via the tail-suspension test (TST). The results observed in the behavioural tests did not appear to result from the stimulation of locomotor activity. Repeated Yuanzhi-1 treatment (2.5, 5 or 10mg/kg) significantly reversed depression-like behaviours in chronically stressed rats, including reduced sucrose preference, decreased locomotor activity, and prolonged time to begin eating. Furthermore, in vivo microdialysis studies showed that 5- and 10-mg/kg administrations of Yuanzhi-1 significantly increased the extracellular concentrations of 5-HT, NE and DA in the frontal cortices of freely moving rats. Therefore, Yuanzhi-1 might represent a novel triple reuptake inhibitor and possess antidepressant-like activity.