Tenuifolin, a saponin derived from Radix Polygalae, exhibits sleep-enhancing effects in mice

The therapeutic potential of Ziziphi Spinosae Semen and Polygalae Radix in insomnia management: Insights from gut microbiota and serum metabolomics techniques

ETHNOPHARMACOLOGICAL RELEVANCE

Ziziphi Spinosae Semen and Polygalae Radix (ZSS-PR) constitute a traditional Chinese herbal combination with notable applications in clinical and experimental settings due to their evident sedative and calming effects. Aligned with traditional Chinese medicine principles, Ziziphi Spinosae Semen supports cardiovascular health, nourishes the liver, and induces mental tranquillity. Simultaneously, Polygalae Radix elicits calming effects, fosters clear thinking, and reinstates proper coordination between the heart and kidneys. ZSS-PR is commonly employed as a therapeutic intervention for various insomnia types, demonstrating distinct clinical efficacy. Our previous study findings provide evidence that ZSS-PR administration significantly reduces sleep onset latency, increases overall sleep duration, and improves abnormal neurotransmitter levels in a murine insomnia model.

AIM OF STUDY

This investigation aimed to scrutinize the intrinsic regulatory mechanism of ZSS-PR in managing insomnia using gut microbiota and serum metabolomics techniques.

MATERIALS AND METHODS

Mice were given DL-4-Chlorophenylalanine to induce insomnia and then treated with ZSS-PR. The open-field test assessed the animals' spontaneous activity. Concentrations of neurotransmitters, endocrine hormones, and cytokines in the duodenum were measured using enzyme linked immunosorbent assay, and brain histopathology was evaluated with H&E staining. The impact of ZSS-PR on the metabolic profile was examined by liquid chromatography couped to high resolution mass spectrometry, and 16S rDNA sequencing was used to study the influence of ZSS-PR on the gut microbiota. Additionally, the content of short-chain fatty acids (SCFAs) was analyzed by GC-MS. Finally, correlation analysis investigated relationships between biochemical markers, metabolites, SCFAs, and gut microbiota.

RESULTS

ZSS-PR treatment significantly increased movement time and distance in mice with insomnia and improved pathological impairments in the cerebral cortex and hippocampus. It also restored abnormal levels of biochemical markers in the gut of insomnia-afflicted mice, including 5-hydroxytryptamine, dopamine, gastrin, melatonin, tumour necrosis factor-α, and interleukin-1β. Metabolomics findings showed that ZSS-PR had a significant restorative effect on 15 endogenous metabolites in mice with insomnia. Furthermore, ZSS-PR primarily influenced five metabolic pathways, such as phenylalanine, tyrosine, and tryptophan biosynthesis, glutamine, and glutamate metabolism. Additionally, gut microbiota analysis revealed notable alterations in both diversity and microbial composition after ZSS-PR treatment. These changes were primarily attributed to the relative abundances of microbiota, including Firmicutes, Bacteroidota, Fusobacteriota, Muribaculaceae_unclassified, and Ligilactobacillus. The results of SCFAs analysis demonstrated that ZSS-PR effectively restored abnormal levels of acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, and valeric acid in insomniac mice. Subsequent correlation analysis revealed that microbiota show obvious correlations with both biochemical markers and metabolites.

CONCLUSIONS

The results provide compelling evidence that ZSS-PR effectively mitigates abnormal activity, reduces cerebral pathological changes, and restores abnormal levels of neurotransmitters, endocrine hormones, and cytokines in mice with insomnia. The underlying mechanism is intricately linked to the modulation of gut microbiota and endogenous metabolic pathways.

Acute Toxicity of Aqueous Extract from Bredemeyera floribunda Root Bark in an Animal Model

The medicinal plant Bredemeyera floribunda Willd. is used to treat cardiovascular disease, chronic fatigue, low libido, as well as increased diuresis. However, studies considering the toxicity of this plant are scarce. Develop an aqueous extract of B. floribunda considering traditional use and determine the average lethality (LD50), signs, and symptoms of toxicity. The B. floribunda extract was obtained by immersing the root bark in ultrapure water for 18 hours at 4°C, under constant stirring. The test extract was administered in a single dose of 2.000 mg/kg by gavage to rats. Signs and symptoms of toxicity were determined according to the Hippocratic screening test and compared with the control group. In addition, a necropsy was performed for macroscopic evaluation of the organs in the abdominal cavity. A powder was obtained from aqueous extracts that showed the same organoleptic characteristics and emulsification capacity as those presented by the fresh root when prepared according to popular tradition. The LD50 was greater than the test dose with three animals surviving. On the other hand, necropsy of dead rats showed necrosis and reduction in lung mass, in addition to the presence of foam and excessive distension of the stomach and intestines. The main symptoms of toxicity were anesthesia, ataxia, sedation, loss of muscle strength, and excessive drowsiness in the first 24 hours. There was no difference between the control and extract groups with regard to body mass, food, and water intake, as well as in macroscopy of the heart, liver, lungs, intestines, spleen, pancreas, and kidneys. The aqueous extract of the B. floribunda was considered nontoxic or of very low toxicity. However, it is capable of altering the activity of the central nervous system and causing disorders in the respiratory and digestive systems.

Polygalae Radix: review of metabolites, pharmacological activities and toxicology

Polygalae Radix: is the dried root of Polygala tenuifolia Willd. or Polygala sibirica L., which has the effect of improving memory and cognitive function in traditional Chinese medicine. Modern pharmacological studies indicated that Polygalae Radix has rich pharmacological activities in vitro and in vivo, including protective effects on the nervous system, immune system, cardiovascular system and respiratory system, as well as antioxidant and antiepileptic pharmacological activities. Up to now, more than 160 metabolites from Polygalae Radix were identified, including triterpenoid saponins, xanthones, oligosaccharide esters and et al. The clinical practice of traditional Chinese medicine has proved that Polygalae Radix has a certain irritation to the throat, and a large or long-term use will stimulate the digestive tract, and the main toxic metabolite is saponins. Therefore, Polygalae Radix should be pr ocessed or used in combination with other Chinese herbal medicines to reduce the irritation to the throat and reduce gastrointestinal irritation. This article provides a review of the metabolites, pharmacological activity, and toxicology of Polygalae Radix. It also discusses the future research prospects and existing problems of Polygalae Radix, providing reference for further research on Polygalae Radix.

Comprehensive evaluation of chemical constituents and antioxidant activity between crude and processed Polygalae radix based on UPLC-Q-TOF-MS/MS combined with multivariate statistical analysis

Polygalae radix (PR) is a famous herbal medicine obtained by drying the root of Polygala tenuifolia Willd., one of the traditional Chinese medicines (TCM) that can be used for healthy food. There are three main processed methods of PR, including removing the xylem of roots (Polygalae Cortex, PC), frying PC with licorice (LP), and frying PC with honey (HP). While processing is believed to enhance efficacy and reduce toxicity, it is crucial to understand the differences in chemical composition and biological activities between crude and processed PR. This study used ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) combined with multivariate statistical analysis to analyze the chemical profiles and differences between the crude and processed products. Total polyphenol contents (TPC), total flavonoid contents (TFC), total saponin contents (TSC) and antioxidant activity of the processed and crude PR were also investigated. A total of 131 chemical compounds, including 42 saponins, 44 oligosaccharide esters, 25 xanthones, 2 organic acids, 3 Carbohydrates, and 15 components detected in auxiliary materials, were detected in all samples. Notably, PC exhibited significant changes among the three processed products, with the content of 62 compounds being higher. Processing of licorice (LP) and honey (HP) decreased the content of several compounds due to temperature and moisture influences. Comprehensive comparison of the antioxidant capacity of crude and processed PR showed that the antioxidant capacity of PC was higher than that of PR, HP, and LP. Our results can provide a scientific basis for further developing and applying P. tenuifolia resources.

The efficacy and safety of Chinese herbal medicine for mild cognitive impairment: a systematic review and meta-analysis of randomized placebo-controlled trials

Objective: Effective and safe treatments for mild cognitive impairment (MCI) are limited. Chinese herbal medicine (CHM) is commonly used in China to manage MCI. However, its efficacy and safety remain uncertain. This review aims to evaluate the efficacy and safety of CHM for MCI. Methods: Nine databases were searched from their inceptions to January 2023. Randomized, placebo-controlled trials of oral CHM for MCI were included. Study quality was assessed using the Cochrane risk-of-bias tool 2.0, and the certainty of evidence was evaluated via the GRADE approach. Results: Thirteen studies, involving 1,043 participants, were analyzed. Most of the studies (10 out of 13) were associated with "some concerns" regarding the overall risk of bias. Meta-analyses results indicated that CHM significantly improved cognitive function compared to placebo in terms of Mini-Mental State Examination (MMSE) (MD: 1.90 [1.22, 2.58], I2 = 87%, 11 studies, 823 participants) and Montreal Cognitive Assessment (MoCA) (MD: 2.88 [1.69, 4.06], I2 = 81%, 3 studies, 241 participants). The certainty of evidence for MMSE was assessed as "moderate", while it was "low" for MoCA. One study did not report adverse events (AEs), one study reported no statistical difference between the groups in terms of AEs, and 11 studies provided detailed numbers of AE cases where gastrointestinal symptoms were the most commonly reported AEs. Two studies reported no SAEs among participants and one study found no significant difference in SAEs proportions between groups. The meta-analysis revealed no significant difference in AEs between the two groups (RR: 1.31 [0.92, 1.87), I2 = 0%, 11 studies, 839 participants). The cognitive-enhancing function of commonly used herbs (Panax ginseng C.A.Mey., Acorus calamus var. angustatus Besser, and Polygala tenuifolia Willd.) may be attributed to mechanisms including antioxidant, anti-apoptotic, anti-neurotoxic, anti-cytotoxic, and anti-inflammatory actions. Conclusion: Chinese herbal medicine holds potential as an effective intervention to improve cognitive function in MCI patients, supported by meta-analyses evidence of low to moderate certainty. Although current data suggests CHM is generally safe, caution is advised due to the lack of AE reporting or detailed information in some instances. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=400292, identifier [CRD42023400292].

Anti-insomnia Effect of a Polyherbal Formulation on P-chlorophenyalanine Induced Experimental Animal Model

Sleep is a dynamic and controlled set of physiological and behavioural practices during which the stabilisation and restoration processes of the body take place properly. Therefore, sleep disorders, especially chronic insomnia, can harm an individual's physical and mental health. However, the therapeutic alternatives are limited and possess severe side effects. Thus, in this study, we aimed to investigate the anti-insomnia effect of a polyherbal formulation (Sleep) (SLP) on p-chlorophenyalanine (PCPA) induced insomnia in rats. Intraperitoneal injection of PCPA induced the experimental condition, and the therapeutic effect of SLP was evaluated by studying the sleep pattern and expression of various neurotransmitters and receptors, along with neurotrophins. Moreover, insomnia-associated oxidative stress and inflammation were also studied. From the findings, we found that the SLP-supplemented animals improved their sleeping behaviour and that the major neurotransmitters, hormones, and receptors were maintained at an equilibrium level. Furthermore, the neurotrophin level was increased and pro-inflammatory cytokines were reduced. The evaluation of oxidative stress markers shows that the antioxidants were significantly boosted, and as a result, lipid peroxidation was prevented. The overall findings suggest that SLP can be used as an effective medication for the treatment of sleep disorders like insomnia as it triggers the major neurotransmitter system.

Mass spectrum oriented metabolomics for evaluating the efficacy and discovering the metabolic mechanism of Naoling Pian for insomnia

Insomnia is an accompanying symptom of many diseases and is closely associated with neurodegenerative diseases. Naoling Pian (NLP) is a patented Chinese medicine mainly used to treat insomnia. To evaluate the sedative and hypnotic effects of NLP and its modulatory effects on biological metabolites and metabolic pathways, rats with p-chlorophenylalanine (PCPA)-induced insomnia were given different doses of NLP by oral gavage for seven days. Diazepam (DZP) served as a positive control. Behavior was measured using the open field test, and neurotransmitter levels in the brain tissue related to sleep were measured using ELISA. The metabolic profiles and biomarkers of PCPA-induced insomnia in rats before and after NLP administration were analyzed using UPLC-Q/TOF-MS combined with multivariate data analysis. The results showed that the levels of 5-hydroxytryptamine, gamma-aminobutyric acid, norepinephrine, and dopamine in the brain tissue were significantly recovered in the NLP treatment groups, demonstrating similar or even superior therapeutic effects compared to the DZP group. The behavior of the PCPA-model rats partially recovered to normal levels after seven days of treatment. Metabolomics identified 30 metabolites in the urine as potential biomarkers of insomnia, and NLP significantly altered 25 of these, involving 21 metabolic pathways. NLP has a remarkable effect on insomnia, the therapeutic effects of which may be largely due to the rectification of metabolic disturbances. This is the first study of the sedative and hypnotic effects of NLP from a metabolomic perspective.

Tenuigenin promotes non-rapid eye movement sleep via the GABAA receptor and exerts somnogenic effect in a MPTP mouse model of Parkinson's disease

Sleep disturbances are commonly non-motor symptoms in Parkinson's diseases (PD). However, standard dopamine replacement therapies for the treatment of motor symptoms often prove inadequate in combating sleep disturbances. Previous studies conducted by our research group have reported the neuroprotective effects of tenuigenin, a natural extract from Polygala tenuifolia root, which has been traditionally employed in treating insomnia. The objective of this study was to investigate the potential of tenuigenin in modulating sleep-wake behaviors and elucidate the underlying mechanisms. We employed EEG/EMG recordings to evaluate the impact of tenuigenin on sleep-wake profiles. Furthermore, we utilized c-Fos immunostaining, whole-cell patch clamping and local field potentials (LFP) recording to explore the mechanisms involved in sleep-promoting effects of tenuigenin. Additionally, we examined the effects of tenuigenin on sleep-promoting in MPTP PD mice. Here, we found tenuigenin demonstrated a significant increase in NREM sleep and a reduction in sleep latency in mice, without altering the EEG power density. Moreover, tenuigenin increased c-Fos expression in the ventrolateral preoptic area (VLPO) and stimulated sleep-promoting neurons in VLPO. The sleep-promoting effects of tenuigenin were abolished when mice were pretreated with flumazenil, an antagonist at the benzodiazepine site of the GABAA receptor. Furthermore, tenuigenin was found to ameliorate sleep disturbances in MPTP-induced mice. The results suggesting that tenuigenin facilitated a type of NREM sleep comparable to physiological NREM sleep through interaction with the GABAA receptor. Additionally, tenuigenin demonstrated improvements in sleep disturbances in MPTP-induced PD mice, suggesting its potential as a sleep-promoting substance, particularly for PD patients experiencing sleep disturbances.

A novel strategy on the study of whole intestinal metabolic profiles for Polygalae Radix before and after processing

INTRODUCTION

Relieving toxicity and enhancing a calming effect after processing Polygalae Radix (PR) are widely known. Aromatic carboxylic acids (ACAs) may be crucial processed products. However, due to the limited detection methods for ACAs, the whole metabolic profiles via intestinal bacteria are still not very clear.

OBJECTIVE

Designing a novel strategy for the detection of ACAs and tracking the whole metabolic profiles before and after processing PR.

MATERIALS AND METHODS

The stable-isotope labelling derivatisation (SILD) method based on multidimensional ultra-high performance liquid chromatography coupled with a mass spectrometer (UHPLC-MS) technology and UNIFI-pathway mode was firstly designed to systematically study the metabolisms of all the drug-derived ingredients ranging from m/z 100 to 2000 in processing PR via intestinal bacteria. Firstly, the SILD with UHPLC coupled with a triple-quadrupole MS technology was designed to trace eight ACA metabolites of the processed PR with intestinal bacteria. Additionally, the UHPLC coupled with a quadrupole time-of-flight MS with UNIFI-pathway mode was adopted to monitor relatively big metabolites.

RESULTS

The metabolism mechanism of ACAs (eight kinds) and the relatively big molecular metabolites (98 kinds) were deeply traced in PR, PR with refined honey (HP), and PR with licorice (LP) via the intestinal bacteria. Totally 106 intact metabolic profiles of drug-derived ingredients were presented. Importantly, the influence of LP on the metabolism of compounds after incubation of intestinal bacteria was greater than that of HP.

CONCLUSION

This research provides a comprehensive and systematic guidance for further study on in vivo metabolisms of the processed PR.

Tenuifolin ameliorates the sleep deprivation-induced cognitive deficits

Tenuifolin (TEN), a natural neuroprotective compound obtained from the Polygala tenuifolia Willd plant, has improved cognitive symptoms. However, the impact of TEN on memory impairments caused by sleep deprivation (SD) is unclear. Accordingly, the objective of this study was to investigate the mechanisms behind the preventative benefits of TEN on cognitive impairment caused by SD. TEN (10 and 20 mg/kg) and Huperzine A (0.1 mg/kg) were given to mice through oral gavage for 28 days during the SD process. The results indicate that TEN administrations improve short- and long-term memory impairments caused by SD in the Y-maze, object identification, and step-through tests. Moreover, TEN stimulated the generation of anti-inflammatory cytokines (interleukin-10), lowered the production of pro-inflammatory cytokines (interleukin-1β, interleukin-6, and interleukin-18), and activated microglia, improving antioxidant status in the hippocampus. TEN treatments significantly boosted the expression of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 while considerably decreasing the expression of NOD-like receptor thermal protein domain associated protein 3 and caspase-1 p20. Additionally, TEN restored the downregulation of the brain-derived neurotrophic factor signaling cascade and the impaired hippocampal neurogenesis induced by SD. When considered collectively, our data suggest that TEN is a potentially effective neuroprotective agent for cognition dysfunction.

Sedative-hypnotic effects of Boropinol-B on mice via activation of GABAA receptors

OBJECTIVES

Boropinol-B is a phenylpropanoid compound originally isolated from Boronia pinnata Sm. (Rutaceae). This study aimed to evaluate the sedative-hypnotic effects of Boropinol-B and explore the underlying mechanisms.

METHODS

Pentobarbital sodium-induced sleep mouse model and caffeine-induced insomnia mouse model were used to investigate the sedative effects of Boropinol-B. Pharmacokinetics profiles of Boropinol-B in rats were evaluated by high-performance liquid chromatography. The effects of Boropinol-B on the γ-aminobutyric acid (GABA)ergic system were investigated using ELISA assay and patch-clamp technique. Immunohistochemistry and immunofluorescence were carried out to assess the effects of Boropinol-B on sleep-related brain nucleus.

KEY FINDINGS

Boropinol-B showed significant sedative effects, including reduced sleep latency, increased sleep duration in pentobarbital sodium-treated mice and decreased locomotor activity in insomnia mice. Pharmacokinetics studies demonstrated that Boropinol-B had a rapid onset of action, a short half-life and no accumulation. It increased the GABA level in mice's brain, and promoted chloride ions influx mediated by the γ-aminobutyric acid type A (GABAA) receptors in neurons. Also, it increased the c-Fos positive ratio of GABAergic neurons in ventrolateral preoptic nucleus and decreased c-Fos expression in tuberomammillary nucleus.

CONCLUSION

Boropinol-B showed significant sedative-hypnotic effects in mice by activating the GABAA receptors and stimulating the sleep-related brain nucleus.

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.

The potential for traditional Chinese therapy in treating sleep disorders caused by COVID-19 through the cholinergic anti-inflammatory pathway

Since the outbreak of Coronavirus disease (COVID-19) in 2019, it has spread rapidly across the globe. Sleep disorders caused by COVID-19 have become a major concern for COVID-19 patients and recovered patients. So far, there’s no effective therapy on this. Traditional Chinese therapy (TCT) has a great effect on sleep disorders, with rare side effects and no obvious withdrawal symptoms. The cholinergic anti-inflammatory pathway, a neuroregulatory pathway in the central nervous system that uses cholinergic neurons and neurotransmitters to suppress inflammatory responses, has been reported to be associated with sleep disorders and psychiatric symptoms. Many studies have shown that TCT activates the cholinergic anti-inflammatory pathway (CAP), inhibits inflammation, and relieves associated symptoms. Therefore, we believe that TCT may be a potential therapeutic strategy to alleviate sleep disorders induced by COVID-19 through CAP. In this review, we analyzed the relationship between cytokine storm induced by Coronavirus and sleep disorders, explained the influence of CAP on sleep disorders, discussed the TCT’s effect on CAP, and summarized the treatment effect of TCT on sleep disorders. Based on these practical researches and theoretical basis, we propose potential strategies to effectively improve the sleep disorders caused by COVID-19.

Tenuifolin ameliorates chronic restraint stress-induced cognitive impairment in C57BL/6J mice

The general consensus is that stress affects the central nervous system and can lead to cognitive problems. The root of Polygala tenuifolia (P. tenuifolia) is a well-known traditional Chinese medicine used for improving brain function. Tenuifolin (TEN) is the major constituent of P. tenuifolia and has a promising neuroprotective property. The purpose of this study was to investigate the alleviating effect of TEN on cognitive impairment induced by chronic restraint stress (CRS) and its mechanism. Our results showed that CRS exposure resulted in impaired cognitive performance in C57BL/6J mice, as indicated by decreased responses in Y-maze, novel objects recognition, and step-through passive avoidance tests. TEN treated daily orally (10 and 20 mg/kg) for 30 days reversed these behavior changes. Meanwhile, TEN could significantly regulate interleukin (IL)-6 and IL-10 levels in the hippocampus. TEN inhibited the toll-like receptor 4/nuclear factor-kappa B-mediated inflammation, as well as adrenocorticotropic hormone and corticosterone levels in serum. Most importantly, we found that TEN also upregulated the expressions of brain-derived neurotrophic factor, tropomyosin kinase B, glucocorticoid receptor, glutamate receptor 1, and synapse-associated proteins. Collectively, these data suggest that TEN has a potential improvement effect on memory loss caused by CRS.

Preparation of Tenuifolin from Polygala senega L. Root Using a Hydrolytic Continuous Flow System under High-Temperature, High-Pressure Conditions

An improved process for preparing tenuifolin (presenegenin 3-β-d-glucopyranoside) from the root of Polygala senega L. was developed. A crude saponin mixture extracted from P. senega was subjected to hydrolysis, and the reactivity of compounds in the extract was controlled by utilizing the combination of a flow reactor and experimental design. In addition, column chromatography with HP 20, a synthetic polystyrenic adsorbent, allowed the gram-scale preparation of tenuifolin in a continuous manner with fewer steps. This approach shortens the total time required for gram-scale preparation from 16 to 5 h in a continuous manner while improving the yield from 0.59% to 2.08% (w/w).

Modulation of circadian clock by crude drug extracts used in Japanese Kampo medicine

Circadian rhythm is an approximately 24 h endogenous biological rhythm. Chronic disruption of the circadian clock leads to an increased risk of diabetes, cardiovascular disease, and cancer. Hence, it is important to develop circadian clock modulators. Natural organisms are a good source of several medicines currently in use. Crude drugs used in Japanese traditional Kampo medicine or folk medicines are an excellent source for drug discovery. Furthermore, identifying new functions for existing drugs, known as the drug repositioning approach, is a popular and powerful tool. In this study, we screened 137 crude drug extracts to act as circadian clock modulators in human U2OS cells stably expressing the clock reporter Bmal1-dLuc, and approximately 12% of these modulated the circadian rhythm. We further examined the effects of several crude drugs in Rat-1 fibroblasts stably expressing Per2-luc, explant culture of lung from Per2::Luciferase knockin mice, and zebrafish larvae in vivo. Notably, more than half of the major ingredients of these crude drugs were reported to target AKT and its relevant signaling pathways. As expected, analysis of the major ingredients targeting AKT signaling confirmed the circadian clock-modulating effects. Furthermore, activator and inhibitor of AKT, and triple knockdown of AKT isoforms by siRNA also modulated the circadian rhythm. This study, by employing the drug repositioning approach, shows that Kampo medicines are a useful source for the identification of underlying mechanisms of circadian clock modulators and could potentially be used in the treatment of circadian clock disruption.

Saponins isolated from Radix polygalae extent lifespan by modulating complement C3 and gut microbiota

With the increase in human lifespan, population aging is one of the major problems worldwide. Aging is an irreversible progressive process that affects humans via multiple factors including genetic, immunity, cellular oxidation and inflammation. Progressive neuroinflammation contributes to aging, cognitive malfunction, and neurodegenerative diseases. However, precise mechanisms or drugs targeting age-related neuroinflammation and cognitive impairment remain un-elucidated. Traditional herbal plants have been prescribed in many Asian countries for anti-aging and the modulation of aging-related symptoms. In general, herbal plants' efficacy is attributed to their safety and polypharmacological potency via the systemic manipulation of the body system. Radix polygalae (RP) is a herbal plant prescribed for anti-aging and the relief of age-related symptoms; however, its active components and biological functions remained un-elucidated. In this study, an active methanol fraction of RP containing 17 RP saponins (RPS), was identified. RPS attenuates the elevated C3 complement protein in aged mice to a level comparable to the young control mice. The active RPS also restates the aging gut microbiota by enhancing beneficial bacteria and suppressing harmful bacteria. In addition, RPS treatment improve spatial reference memory in aged mice, with the attenuation of multiple molecular markers related to neuroinflammation and aging. Finally, the RPS improves the behavior and extends the lifespan of C. elegans, confirming the herbal plant's anti-aging ability. In conclusion, through the mouse and C. elegas models, we have identified the beneficial RPS that can modulate the aging process, gut microbiota diversity and rectify several aging-related phenotypes.

Role of amber extract in protecting SHSY5Y cells against amyloid β1-42-induced neurotoxicity

Alzheimer disease (AD) is an irreversible, progressive brain disease. Amyloid β plays a critical role in AD development. Some Chinese traditional medicines, such as the fossilized plant resin, amber, have been applied as mental stabilizers. However, the effects of amber on AD pathogenesis remain unknown. Therefore, we aimed to determine the potential of amber extract for treating AD by evaluating its effects on amyloid-β (1-42) (Aβ (1-42))-induced neuronal cell death. We measured levels of ROS, Bcl-2, and Bax mRNA, and found that amber extract decreased Aβ (1-42)-induced cell apoptosis via the reactive oxygen species (ROS)-mediated mitochondrial pathway. Amber extract also decreased β-site amyloid precursor protein cleaving enzyme 1 (BACE1) and increased microtubule-associated proteins 1A/1B light chain 3B (LC3II) and Beclin 1. These findings suggested that amber extract protects neuronal cells against Aβ (1-42)-induced cell apoptosis by upregulating autophagy and downregulating BACE1.

Protein unbound pharmacokinetics of ambroxol in the blood and brains of rats and the interaction of ambroxol with Polygala tenuifolia by multiple microdialysis

ETHNOPHARMACOLOGICAL RELEVANCE

Ambroxol elevates glucocerebrosidase (GCase) activity and reduces nigrostriatal alpha-synuclein burden to better ameliorate motor function in Parkinson's disease (PD). Polygala tenuifolia is a potential alternative botanical medicine for the treatment of many nonmotor symptoms of PD commonly used in Taiwanese patients. Co-administration of these two medicines pose potential herb-drug interaction.

AIM OF THE STUDY

Our hypothesis is that ambroxol and P. tenuifolia may potentially possess herbal drug synergetic effects in the blood and brain.

MATERIALS AND METHODS

To investigate this hypothesis, a multiple microdialysis system coupled with validated ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for rat blood and brain samples. Experimental rats were divided into three groups: low-dose and high-dose ambroxol alone (10 mg/kg, i.v. and 30 mg/kg, i.v., respectively) and ambroxol (10 mg/kg, i.v.) pretreated with P. tenuifolia extract (1 g/kg, p.o. for 5 consecutive days).

RESULTS

Ambroxol easily penetrated into the brain and reached a maximum concentration in the striatum at approximately 60 min after low- and high-dose treatment. The area under the concentration curve (AUC) ratio increased proportionally at the doses of 10 and 30 mg/kg, which suggested a linear pharmacokinetic manner of ambroxol. The brain penetration of ambroxol was approximately 30-34%, which was defined as the ambroxol AUC blood-to-brain distribution ratio (AUCbrain/AUCblood). The P. tenuifolia extract did not significantly alter the pharmacokinetics of ambroxol in the blood and brain of rats.

CONCLUSION

The present study suggests that it is safety without pharmacokinetic interactions for this dosing regimen to use P. tenuifolia extract and ambroxol together.

Discovery of a Novel Lineage Burkholderia cepacia ST 1870 Endophytically Isolated from Medicinal Polygala paniculata Which Shows Potent In Vitro Antileishmanial and Antimicrobial Effects

In this study, we report the isolation and identification of an endophytic strain of Burkholderia cepacia (COPS strain) associated with Polygala paniculata roots. Polygala plants are rich sources of promising microbiomes, of which the literature reports several pharmacological effects, such as trypanocidal, antinociceptive, anesthetic, anxiolytics, and anticonvulsant activities. B. cepacia COPS belongs to a new sequence type (ST 1870) and harbors a genome estimated in 8.3 Mbp which exhibits the aminoglycosides and beta-lactams resistance genes aph(3′)-IIa and bla_TEM-116, respectively. Analysis performed using MLST, average nucleotide identity, and digital DNA-DNA hybridization support its species-level identification and reveals its novel housekeeping genes alleles gyrB, lepA, and phaC. The root endophyte B. cepacia COPS drew our attention from a group of 14 bacterial isolates during the primary screening for being potentially active against Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, Micrococcus luteus ATCC 9341, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231 and exhibited the broad-spectrum activity against phytopathogenic fungi. In addition, COPS strain showed production of protease, lipase, and esterase in solid media, and its natural product extract showed potent inhibition against fungal plant pathogens, such as Moniliophthora perniciosa, whose antagonism index (89.32%) exceeded the positive control (74.17%), whereas Sclerotinia sclerotiorum and Ceratocystis paradoxa showed high percentages of inhibition (85.53% and 82.69%, respectively). COPS crude extract also significantly inhibited S. epidermidis ATCC 35984, E. faecium ATCC 700221 (MIC values of 32 μg/mL for both), E. faecalis ATCC 29212 (64 μg/mL), and S. aureus ATCC 25923 (128 μg/mL). We observed moderate antagonistic activity against A. baumannii ATCC 19606 and E. coli ATCC 25922 (both at 512 μg/mL), as well as potent cytotoxic effects on Leishmania infantum and Leishmania major promastigote forms with 78.25% and 57.30% inhibition. In conclusion, this study presents for the first time the isolation of an endophytic B. cepacia strain associated with P. paniculata and enough evidence that these plants may be considered a rich source of microbes for the fight against neglected diseases.

Protective Effect of Natural Products against Huntington's Disease: An Overview of Scientific Evidence and Understanding Their Mechanism of Action

Huntington's disease (HD), a neurodegenerative disease, normally starts in the prime of adult life, followed by a gradual occurrence of characteristic psychiatric disturbances and cognitive and motor dysfunction. To the best of our knowledge, there is no treatment available to completely mitigate the progression of HD. Among various therapeutic approaches, exhaustive literature reports have confirmed the medicinal benefits of natural products in HD experimental models. Building on this information, this review presents a brief overview of the neuroprotective mechanism(s) of natural products against in vitro/in vivo models of HD. Relevant studies were identified from several scientific databases, including PubMed, ScienceDirect, Scopus, and Google Scholar. After screening through literature from 2005 to the present, a total of 14 medicinal plant species and 30 naturally isolated compounds investigated against HD based on either in vitro or in vivo models were included in the present review. Behavioral outcomes in the HD in vivo model showed that natural compounds significantly attenuated 3-nitropropionic acid (3-NP) induced memory loss and motor incoordination. The biochemical alteration has been markedly alleviated with reduced lipid peroxidation, increased endogenous enzymatic antioxidants, reduced acetylcholinesterase activity, and increased mitochondrial energy production. Interestingly, following treatment with certain natural products, 3-NP-induced damage in the striatum was ameliorated, as seen histologically. Overall, natural products afforded varying degrees of neuroprotection in preclinical studies of HD via antioxidant and anti-inflammatory properties, preservation of mitochondrial function, inhibition of apoptosis, and induction of autophagy.

Involvement of 5-HT-BDNF signaling axis in mediating synergistic antidepressant-like effects after combined administration of two oligosaccharide esters

Potential mechanisms of depression involving herbal medicines and their specific compounds include elevated 5-HT level and downstream BDNF pathway. To identify potentially new combined therapeutic strategies, 3,6'-disinapoylsucrose (DISS) and tenuifoliside A (TFSA) have been observed to show antidepressant-like effects and its related 5-HT-BDNF pathway. We have tried to investigate whether combined administration of DISS and TFSA exerted more effective in the treatment of depression, as assessed through tail suspension test (TST) and forced swimming test (FST). In addition, we also analyzed the expression of three important proteins, cyclic adenosine monophosphate (cAMP) response element binding (CREB), brain-derived neurotrophic factor (BDNF), and cAMP-regulated transcriptional coactivators (CRTC1), which have been shown to be involved in the regulation of the neurotrophic factors in the hippocampus. The DISS and TFSA separately, both at a dose of 5 mg/kg each, displayed small effect in the immobility time. However, combined treatment of these two in multiple doses exhibited better effect. Moreover, combined treatment of DISS and TFSA also demonstrated enhanced levels of 5-hydroxytryptamine (5-HT), and stronger increase in the phosphorylation levels of CREB, BDNF, and CRTC1 proteins in the hippocampus. Overall, our results indicated that coadministration of these two oligosaccharide esters at low dose may induce more pronounced antidepressant activity, in comparison with individual treatment even at high dosage. Thus, the antidepressant properties of both these compounds can be attributed to their ability to influence 5-HT and BDNF pathway, and thereby suggesting that this combination strategy can definitely act as alternative therapy for depression disorder with very limited side effects.

Comparative Study on the Chemical Components and Gastrointestinal Function on Rats of the Raw Product and Licorice-Simmered Product of Polygala tenuifolia

The root of Polygala tenuifolia Willd. (Polygalaceae) (PT) has been listed as a nootropic, anti-inflammatory, and antipsychotic medicine that can cure insomnia. Raw PT (RPT) is toxic and must be processed before clinical use. Licorice-simmered PT (LPT) is one of the most common processed products. We conducted this study in order to investigate the differences in chemical components and gastrointestinal function between RPT and LPT. We used principal component analysis (PCA) and quantitative analysis to study the differences in the chemical components. Animal experiments were conducted to evaluate the effects of PT on the gastrointestinal function of rats before and after simmering. Pathological sections of gastrointestinal tissues, serum hormone levels, and inflammatory cytokines were observed. The PCA results demonstrated that obvious separation was achieved between the RPT and LPT samples. Tenuifoliside B (TFSB), 3,6'-disinapoyl sucrose (DSS), tenuifoliose A (TFOA), tenuifoliose H (TFOH), onjisaponin B (OJB), onjisaponin Z (OJZ), and total saponins levels were decreased after licorice processing, while glomeratose A (GA) and 3,4,5-trimethoxycinnamic acid (TMCA) levels were markedly increased. Compared to the control group, the RPT groups exhibited dramatically lower levels of gastrin (GAS), motilin (MTL), and substance P (SP) and markedly higher levels of vasoactive intestinal peptide (VIP) and somatostatin (SS), but the LPT groups exhibited no significant differences in the above indexes. The levels of interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) in gastrointestinal tissue were markedly increased in the low RPT (L-RPT), high RPT (H-RPT), and H-LPT groups, showing a certain inflammatory effect, but the inflammatory effect in the L-LPT group was relatively weak. Licorice simmering can effectively reduce the inhibitory effect of RPT on gastrointestinal function in rats and reduce damage to gastrointestinal tissue. This study provides a scientific basis for research on the processing mechanism and clinical application of PT.

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.

Lilium davidii extract alleviates p‑chlorophenylalanine‑induced insomnia in rats through modification of the hypothalamic-related neurotransmitters, melatonin and homeostasis of the hypothalamic-pituitary-adrenal axis

CONTEXT

Lilium davidii var. unicolour Cotton (Lilium genus, Liliaceae) is an edible plant and a herb used in China to alleviate insomnia.

OBJECTIVE

To investigate the alleviating insomnia mechanism of L. davidii (LD).

MATERIALS AND METHODS

Wistar rats were intraperitoneally injected with p-chlorophenylalanine (PCPA) to establish an insomnia model. Rats were divided into six groups (n = 8): Control, PCPA, Estazolam (0.5 mg/kg), LD extract in low, medium and high doses (185.22, 370.44, 740.88 mg/kg). Serum hormone levels of the HPA axis, levels of 5-HT, NE and MT, and the expression of GABA_A and 5-HT1A receptors in hypothalamus were determined. Moreover, behavioural and pathological changes in the hypothalamus were evaluated.

RESULTS

After LD administration, body weight and brain coefficient increased by 2.74% and 8.22%, respectively, and the adrenal coefficient decreased by 25%, compared with PCPA group. Elevation of the serum hypothalamic-pituitary-adrenal (HPA) axis hormone CRH (11.24 ± 3.16 ng/mL), ACTH (565.87 ± 103.44 pg/mL) and CORT (44.28 ± 8.73 ng/mL) in the PCPA group was reversed after LD treatment. Furthermore, abnormal excitatory behaviour [5 min movement distance (2096.34 ± 259.51 cm), central exercise time (5.28 ± 1.08 s)] of insomnia rats in the PCPA group was also relieved. LD extract increased 5-HT and MT levels, reduced NE level in the hypothalamus, and upregulated the expression of GABA_A R and 5-HT1A. Moreover, LD extract may improve the pathology of neurons in the hypothalamus.

CONCLUSIONS

LD can be considered to develop health-care food or novel drugs to cope with the increasing number of insomniacs.

Revealing the sedative-hypnotic effect of the extracts of herb pair Semen Ziziphi spinosae and Radix Polygalae and related mechanisms through experiments and metabolomics approach

BACKGROUND

Semen Ziziphi spinosae and Radix Polygalae, two herbs commonly used together in Traditional Chinese Medicine for the treatment of insomnia and anxiety. The study aims to study the sedative-hypnotic effect of the active components of the herbal pair, the possible mechanisms of such effect, and related metabolic pathways in vivo.

METHODS

The sedative and hypnotic effect of the active components (EI30) of the herbal pair was studied by recording influence on the proportion of sleeping within 30 min, sleep latency and sleep length of pentobarbital sodium-induced sleeping on mice. Possible mechanisms of the sedative-hypnotic effect of the active components were investigated by measuring the content of neurotransmitters in the total protein of mice brain tissue. The main chemical compounds of the herbal pair were identified by Liquid Chromatography-Mass Spectrometry (LC-MS). Serum samples of mice were studied, and related differential metabolites between the normal group and model group, and between model group and treatment group were identified by Gas Chromatography Time-Of-Flight Mass Spectrometry (GC-TOF-MS), Principal Components Analysis (PCA), and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA).

RESULTS

Compared with the control group, high dose EI30 group and the Clonazepam group were with significantly higher proportions of sleep within 30 min (P = 0.027 and 0.005 respectively). Compared with the control group, all of the high, medium and low dose of EI30 groups were with significantly shorter sleep latency (P < 0.01) and prolonged sleeping time (P < 0.01). The herbal pair has good sedative-hypnotic effects, although it is weaker than the effect of Clonazepam. The sedative-hypnotic effect of EI30 is possibly related to the adjustment of neurotransmitters 5-hydroxytryptamine (5-HT), norepinephrine (NE), and dopamine (DA) in the total protein of mice brain tissue. There are five metabolic pathways in vivo most related to the sedative-hypnotic effect of EI30, and they are biosynthesis of valine, leucine, and isoleucine, metabolism of glyceride, metabolism of alanine, aspartic acid and glutamic acid, metabolism of phenylalanine, and metabolism of cysteine and methionine.

CONCLUSIONS

This study reveals the mechanisms of sedative and hypnotic effects of herbal pair Semen Ziziphi spinosae and Radix Polygalae by using metabolomics methods. This study provides a basis for further development and utilization of this herbal pair.

Sedative and Hypnotic Effects and Transcriptome Analysis of Polygala tenuifolia in Aged Insomnia Rats

OBJECTIVE

To study the sedative and hypnotic effects and underlying mechanisms of Polygala tenuifolia (PT) on treating aged insomnia rats.

METHODS

Sixty Sprague-Dawley male rats were divided into 6 groups by a random number table, including control group, model group, diazepam group (0.92 mg/kg), as well as PT low-, medium- and high-dose groups (0.0875, 0.175, 0.35 g/kg, respectively), 10 rats in each group. Aged insomnia rat model was established with subcutaneous injection of D-galactose for 42 days and then intraperitoneal injection of para-chlorophenylalanine for 3 days. PT and diazepam were respectively given to aged insomnia rats by intragastric administration for 7 days after model establishment. Then the rats were investigated by body weight, Morris water maze test, pentobarbital test, enzyme-linked immunosorbent assay, and transcriptome sequencing.

RESULTS

Compared with the model group, PT increased the body weight, improved memory ability, and prolonged pentobarbital-induced sleep time of aged insomnia rats (P<0.01 or P<0.05). The medium dose of PT also increased the neurotransmitter levels of 5-hydroxytryptamine (5-HT) and gamma-aminobutyric acid (GABA), and decreased the level of Glu in the hippocampus of aged insomnia rats (P<0.05 or P<0.01). Twenty-four differentially expressed genes (DEGs) were overlapped among model group, medium-dose PT group, and diazepam group in transcriptome analysis. Fuom and Pcp2 were down-regulated by the treatment of medium-dose PT (P<0.01 or P<0.05). The metabolic pathways of PT were relatively less than diazepam (91 vs. 104).

CONCLUSIONS

The sedative and hypnotic effects of PT in aged insomnia rats might be related to neuro, metabolism pathways, especially through GABAergic signaling pathway. It provided more effective herb choice for the treatment of senile insomnia.

A review on the phytopharmacological studies of the genus Polygala

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Polygala, the most representative genus of the Polygalaceae family, comprises more than 600 species from all over the world of which around 40 are distributed in China, some of them, being used in the Traditional Chinese Medicine system.

AIM OF THE REVIEW

We intend to discuss the current knowledge about the traditional uses, and the newest phytochemical and pharmacological achievements with tentative elucidation of the mechanism of action on the genus Polygala covering the period 2013-2019 to provide a scientific support to the traditional uses, and to critically analyze the reported studies to obtain new insights for further researches.

MATERIALS AND METHODS

The data were systematically collected from the scientific electronic data bases including SciFinder, Scopus, Elsevier, PubMed and Google Scholar.

RESULTS

This literature overview reported several traditional uses of different species of Polygala, mainly against wounds, inflammation, cardiovascular and central nervous system disorders. P. altomontana, P caudata, P. flavescens, P. glomerata, P. japonica, P. molluginifolia, P. sibirica, P. tenuifolia are the main species which have been studied in the last few years. Phytochemical studies showed that they contain triterpene saponins, triterpenes, terpenoids, xanthones, flavonoids, coumarins, oligosaccharide esters, styryl-pyrones, benzophenones, and polysaccharides. Pharmacological in vitro and in vivo studies and proposal of the mechanisms of action indicated that pure constituents and extracts of Polygala ssp exhibited significant anti-inflammatory, neuroprotective, antiischemic, antidepressant, sedative, analgesic, antiatherosclerosis, antitumor and enzyme inhibitory properties.

CONCLUSION

This review on traditional uses and phytopharmacological potential of the genus Polygala revealed updated insights which can be explored for further mechanism-based pharmacological activities and structure/activity relationships studies and a better comprehension of the development of Chinese medicine preparations. However some pharmacological studies showed several gaps such as incomplete methodologies and ambiguous findings. More high scientific quality preclinical studies with pharmacokinetic considerations will be required in the future to assess the traditional uses of some species of this genus. This might lead to efficacy and safety issues in clinical trials and to potential medicinal applications.

Shimian granules improve sleep, mood and performance of shift nurses in association changes in melatonin and cytokine biomarkers: a randomized, double-blind, placebo-controlled pilot study

Shift nurses are prone to sleep problems and impaired nighttime alertness, with risk for reduced health status plus decreased performance, handling errors, and workplace accidents. Attention to and improvements in the situation of shift nurses are urgent. Shimian granules (SMG), an improved formula of Jieyuanshen with liver qingre and yangxin tranquilizing effects, for more than a decade has been used in China as a herbal treatment of sleep disorders in clinical practice. However, clinical data on SMG have rarely been reported. This double-blinded, randomized, placebo-controlled, pilot clinical trial (ChiCTR-IOR-17013031) aimed to explore whether Shimian granules (SMG) improves sleep and affective state in shift nurses and in association with changes in concentrations of salivary cytokines. Fifty-three rotating-shift female nurses with a Pittsburgh Sleep Quality Index (PSQI) score ≥8 were orally treated with 10.0 g SMG or placebo 2 times daily (30 min after breakfast and 30 min before bed) for 1 month. The Insomnia Severity Index (ISI), a psychomotor vigilance task, Hospital Anxiety and Depression Scale (HADS-A/HADS-D), and levels of four salivary cytokines were evaluated by single time-of-day sampling at baseline and after 1 month of treatment. Significantly lower ISI, HADS, HADS-A, and HADS-D scores, but higher 1/mean reaction time (1/mRT) score, were found in shift nurses treated with SMG than in those who received placebo, and these effects were associated with changes in salivary melatonin, TNF, IL-1β, and IL-6 levels. These latter findings suggest melatonin, TNF, and IL-6 levels may be suitable biomarkers of ISI score in shift nurses, whereas TNF level may be a suitable biomarker of 1/mRT score and IL-6 level a suitable biomarker of HADS score in response to SMG treatment. The results of this pilot study suggest SMG can effectively improve sleep, alertness, plus anxiety and depression symptoms in shift nurses in association with changes in salivary cytokine levels. The results of this study provide an experimental basis for the evaluation of traditional Chinese medicines for the treatment of insomnia and underlying mechanisms of their actions that require detailed future exploration.

Effects of tenuifolin on rest/wake behaviour in zebrafish

Insomnia is a common sleep disorder with a high prevalence and substantial adverse consequences. There is growing interest in identifying novel therapeutics from herbal medicine. Tenuifolin is a major constituent of the well-known anti-insomnia herb Radix Polygala. The present study investigated the neural activity in response to tenuifolin during rest/wake behaviour in zebrafish and identified the potential biological signalling pathways involved. An automatic video tracking system was used to monitor the behavioural response of zebrafish larvae for 24 h after treatment with tenuifolin. In total, six rest/wake parameters were measured and visualized with a behavioural fingerprint. Time series analysis was conducted by averaging the total rest and waking activity in 10 min intervals. A correlation analysis was performed between tenuifolin and well-known compounds to analyse the underlying biological signalling pathways. Reverse transcription-quantitative PCR was also performed to detect the effects of tenuifolin on the transcription of interesting genes associated with the signalling pathways that were potentially involved. The present results suggested tenuifolin significantly increased the total rest time during the dark phase, with a slight effect on the waking activity in zebrafish larvae. This behavioural phenotype induced by tenuifolin is similar to that of selective serotonin reuptake inhibitors and gamma-aminobutyric acid (GABA) agonists. Furthermore, the expression levels of GABA transporter 1 were significantly increased after tenuifolin treatment. No significant difference was determined in other associated genes in untreated control and tenuifolin-treated larvae. The present results suggested that tenuifolin caused sleep-promoting activity in zebrafish and that these effects may be mediated by the serotoninergic systems and the GABAergic systems.

Tenuifolin Attenuates Amyloid-β42-Induced Neuroinflammation in Microglia Through the NF-κB Signaling Pathway

BACKGROUND

Inflammation and oxidative stress are believed to play an important role in the pathogenesis of Alzheimer's disease (AD). Tenuifolin (TEN) is a natural neuroprotective compound extracted from Polygala tenuifolia Willd, which may improve cognitive symptoms.

OBJECTIVE

This study was designed to evaluate the protective effect of TEN on inflammatory and oxidative stress induced by amyloid-β (Aβ)42 oligomers in BV2 cells, and to explore the underlying mechanisms.

METHODS

We conducted cell viability assays to estimate drug toxicity and drug effects on cells. Quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assays were performed to detect the release of inflammatory factors. Nitric oxide (NO) assays were used to measure the degree of oxidative stress. Western blot and immunofluorescence analysis were used to explore the influence of TEN on the nuclear factor-κB (NF-κB) pathway.

RESULTS

Pretreatment of BV2 microglial cells with TEN inhibited the release of tumor necrosis factor-α, interleukin-6, and interleukin-1β, alleviated NO-induced oxidative stress by inhibiting the expression of inducible nitric oxide synthase and cyclo-oxygenase-2, and protected SH-SY5Y cells from the toxicity induced by the medium conditioned by BV2 cells previously exposed to Aβ42 oligomers. Moreover, TEN suppressed upstream activators of NF-κB, as well as NF-κB translocation to the nucleus in BV2 microglial cells.

CONCLUSION

This study demonstrates that TEN can protect SH-SY5Y cells from Aβ42 oligomer-induced microglia-mediated inflammation, and oxidative stress by downregulating the NF-κB signaling pathway.

A microemulsion high-performance liquid chromatography (MELC) method for the separation and determination of hydrolyzed tenuifolin in Radix Polygalae

Tenuifolin was used as a reliable chemical marker for the quality control of Radix Polygalae. The determination of tenuifolin is challenging because the analyte molecule lacks a suitable chromophore. The aim of this study was to establish a microemulsion high-performance liquid chromatography (MELC) method which is robust and sensitive, and can separate and determine tenuifolin in Radix Polygalae using an oil-in-water (O/W) microemulsion mobile phase. The separations were performed on a C18 (4.6 × 250 mm, 5 μm) column at 25 °C using a flow rate of 1.0 mL/min, and an ultraviolet detection wavelength of 210 nm. The microemulsion mobile phase comprised 2.8% (w/v) sodium dodecyl sulfate (SDS), 7.0% (v/v) n-butanol, 0.8% (v/v) n-octane and 0.1% (v/v) aqueous orthophosphate buffer (H3PO4). The linearity analysis of tenuifolin showed a correlation coefficient of 0.9923 in the concentration range of 48.00-960.00 µg/mL. The accuracy of the method based on three concentration levels ranged from 96.23% to 99.28%; the limit of detection (LOD) was 2.34 µg/mL, and the limit of quantification (LOQ) was 6.76 µg/mL. The results of our study indicated that the optimized MELC method was sensitive and robust, and can be widely applied for the separation and determination of tenuifolin in Radix Polygalae.

Complementary and Alternative Medicine for the Treatment of Insomnia: An Overview of Scientific Evidence from 2008 to 2018

Insomnia is a widespread sleep disorder in the general population, and it is a risk factor for impaired function, the development of other medical and mental disorders, and causes an increase in health care costs. In view of the health hazards of insomnia and the shortcomings of western medicine, Complementary and Alternative Medicine (CAM) should be considered in the management of insomnia. The present overview reports the potential role of herbal medicine and non-pharmacological therapies in the treatment of insomnia and summarizes the scientific evidence reported from 2008 to 2018. PubMed and Web of Science databases were searched for studies published from 2008 to 2018. 17 randomized controlled trials and 22 non-pharmacological therapies were included in this review, and the results showed that CAM had certain advantages in the treatment of insomnia. The safety of CAM for insomnia was acceptable. Meanwhile, based on pre-clinical trial, the possible mechanisms of CAM for insomnia were modulation of circadian rhythm, GABA receptor activation, antagonisms of 5-HT receptors, inhibition of glutamate-mediated pathways, and attenuation of inflammation. CAM for insomnia has made some progress, but high quality evidence-based medical evidence is still needed to provide guidance for clinical application.

Loganin Exerts Sedative and Hypnotic Effects via Modulation of the Serotonergic System and GABAergic Neurons

Corni fructus, the fruit of Cornus officinalis Sieb. et Zucc., has been used as a tonic for the kidney in China for thousands of years. Loganin is one of the major constituents derived from Corni fructus. In this study, we revealed the sedative and hypnotic activity of loganin and investigated its mechanisms for the first time. Pentobarbital-induced sleep test and insomnia mice models [induced by caffeine and p-chlorophenylalanine (PCPA)] were used for the assessment of sedative and hypnotic effects of loganin. It was found that loganin (20–50 mg/kg) exerted sedative effect in normal mice. Loganin exhibited hypnotic effect by increasing sleep onset and sleep duration in pentobarbital-treated mice, recovering PCPA-induced insomnia and exerting synergistic hypnosis effect with 5-HTP. In addition, electroencephalograph (EEG) and electromyography (EMG) recordings of rats showed that loganin (35 mg/kg) prolonged the ratio of non-rapid eye movement (NREM) sleep and shortened wakefulness significantly, further immunohistochemistry showed that loganin (35 mg/kg) increased c-Fos expression in GABAergic neurons of rats in the ventrolateral preoptic nucleus (VLPO). The levels of norepinephrine (NE), dopamine (DA), serotonin (5-HT) and its metabolite were measured in the hippocampus, prefrontal cortex and striatum of mice, 1 h after loganin (35 mg/kg) treatment. 5-HT, 5-HIAA/5-HT, DA, and DOPAC were decreased significantly in the prefrontal cortex. In conclusion, these results indicated that loganin produced beneficial sedative and hypnotic activity, which might be mainly mediated by modification of the serotonergic system and GABAergic neurons.

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.

Melanin-Concentrating Hormone (MCH) and MCH-R1 in the Locus Coeruleus May Be Involved in the Regulation of Depressive-Like Behavior

BACKGROUND

Previous anatomical and behavioral studies have shown that melanin-concentrating hormone is involved in the modulation of emotional states. However, little is known about brain regions other than the dorsal raphe nucleus that relate the melanin-concentrating hormone-ergic system to depressive states. Numerous studies have shown that the locus coeruleus is involved in the regulation of depression and sleep. Although direct physiological evidence is lacking, previous studies suggest that melanin-concentrating hormone release in the locus coeruleus decreases neuronal discharge. However, remaining unclear is whether the melanin-concentrating hormone-ergic system in the locus coeruleus is related to depressive-like behavior.

METHOD

We treated rats with an intra-locus coeruleus injection of melanin-concentrating hormone, intracerebroventricular injection of melanin-concentrating hormone, or chronic subcutaneous injections of corticosterone to induce different depressive-like phenotypes. We then assessed the effects of the melanin-concentrating hormone receptor 1 antagonist SNAP-94847 on depressive-like behavior in the forced swim test and the sucrose preference test.

RESULTS

The intra-locus coeruleus and intracerebroventricular injections of melanin-concentrating hormone and chronic injections of corticosterone increased immobility time in the forced swim test and decreased sucrose preference in the sucrose preference test. All these depressive-like behaviors were reversed by an intra-locus coeruleus microinjection of SNAP-94847.

CONCLUSIONS

These results suggest that the melanin-concentrating hormone-ergic system in the locus coeruleus might play an important role in the regulation of depressive-like behavior.

Intracerebroventricular streptozotocin-induced Alzheimer's disease-like sleep disorders in rats: Role of the GABAergic system in the parabrachial complex

AIM

Sleep disorders are common in Alzheimer's disease (AD) and assumed to directly influence cognitive function and disease progression. This study evaluated sleep characteristics in a rat model of AD that was induced by intracerebroventricular streptozotocin (STZ) administration and assessed the possible underlying mechanisms.

METHODS

Cognition ability was assessed in the Morris water maze in rats. Sleep parameters were analyzed by electroencephalographic and electromyographic recordings. Neuronal activity in brain areas that regulate sleep-wake states was evaluated by double-staining immunohistochemistry. High-performance liquid chromatography with electrochemical detection was used to detect neurotransmitter levels.

RESULTS

Fourteen days after the STZ injection, the rats exhibited sleep disorders that were similar to those in AD patients, reflected by a significant increase in wakefulness and decreases in nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. The c-Fos expression analysis indicated that neuronal activity and the number of neurons in the dorsal raphe nucleus and locus coeruleus decreased in STZ-injected rats. In the ventrolateral preoptic nucleus (VLPO), the activity of γ-aminobutyric acid (GABA) neurons was suppressed. In the arousal-driving parabrachial nucleus (PBN), GABAergic activity was suppressed, whereas glutamatergic activity was promoted. The neurotransmitter analysis revealed a reduction in GABA in the VLPO and PBN and elevation of glutamate in the PBN. A direct injection of the GABA_A receptor antagonist bicuculline in the PBN in normal rats induced a similar pattern of sleep disorder as in STZ-injected rats. A microinjection of GABA in the PBN improved sleep disorders that were induced by STZ.

CONCLUSION

These results suggest that the reduction in GABAergic inhibition in the PBN and VLPO may be involved in sleep disorders that are induced by STZ. Our novel findings encourage further studies that investigate mechanisms of sleep regulation in sporadic AD.

Illumination on "Reserving Phloem and Discarding Xylem" and Quality Evaluation of Radix polygalae by Determining Oligosaccharide Esters, Saponins, and Xanthones

The root of Polygala tenuifolia Willd. or Polygala sibirica L. exhibits protective effects on the central nervous system and is frequently used to treat insomnia, amnesia, and other cognitive dysfunction. In our study, we studied nine bioactive compounds spanning oligosaccharide esters, saponins, and xanthones by using a sensitive, efficient, and validated method established on ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry. The quantified result of interesting compounds proved that accumulation of those compounds were found in phloem rather than in xylem. By taking the standardized result of nine compound contents into account, the “Spider-web” analytical result of xylem and phloem from Radix polygalae (RP) unveiled the rationality of RP’s classical use in clinic including discarding the xylem and reserving the phloem. Moreover, the remarkable variation was also revealed from the quantitative result of 45 samples with different diameters from the different origins, which did not significantly correlate with the variation of RP’s diameter. Our study could shed the light on the quality assessment of RP for further research and illustrate the scientific connotation of the processing method of “discarding the xylem and reserving the phloem”.

Determination of the phytochemical composition of Jingning fang and the in vivo pharmacokinetics of its metabolites in rat plasma by UPLC-MS/MS

Jingning fang (JNF) is an effective Traditional Chinese Medicine (TCM) which is used for the treatment of Attention Deficit Hyperactivity Disorder (ADHD). To clarify the bioactive constituents of JNF, a Thermo Q Exactive™ Plus Orbitrap™ mass spectrometer was used in this study. More than 127 chemical compounds were isolated and identified tentatively in the JNF extract, while 42 prototype constituents with 4 potential metabolites were identified tentatively in rat plasma. A method for simultaneous determination of polygalaxanthone III (PAIII), sibiricose A5 (A5), sibiricose A6 (A6), 3, 6'-disinapoyl sucrose (3,6'-DISS), tenuifoliside C (TEC), tenuifolin B (TNB), verbascoside (VCE), heterophyllin B (HEB) and schisandrin (SCH) in rat was developed and validated using polydatin (PLN) and psoralen (PSN) as internal standards. All calibration curves proved favorable linearity (R2≥0.9923) in linear ranges. The lower limit of quantification (LLOQ) was 2.5ng/mL for PAIII, A5, 3, 6'-DISS, TNB, VCE, HEB and SCH, 1.0ng/mL for A6 and TEC, respectively. Intra-day and inter-day precisions didn't exceed 14.0% for all the analytes. Extraction recoveries and matrix effects of analytes and IS were acceptable. The validated method has been successfully applied to the pharmacokinetics (PK) studies of the nine compounds in JNF. These findings are useful for predicting the bioactive components of JNF, and will aid in optimizing dose regimens of the drug.

A novel neurological function of rice bran: a standardized rice bran supplement promotes non-rapid eye movement sleep in mice through histamine H1 receptors

SCOPE

Although rice bran has been shown to be associated with a wide spectrum of health benefits, to date, there are no reports on its effects on sleep. We investigated the effect of rice bran on sleep and the mechanism underlying this effect.

METHODS AND RESULTS

Electroencephalography was used to evaluate the effects of standardized rice bran supplement (RBS) and doxepin hydrochloride (DH), a histamine H₁ receptor (H₁ R) antagonist used as a positive control, on sleep in mice. The mechanism of RBS action was investigated using knockout (KO) mice and ex vivo electrophysiological recordings. Oral administration of RBS and DH significantly decreased sleep latency and increased the amount of non-rapid eye movement sleep (NREMS) in mice. Similar to DH, RBS fully inhibited H₁ R agonist-induced increase in action potential frequency in tuberomammillary nucleus neurons. In H₁ R KO mice, neither RBS nor DH administration led to the increase in NREMS and decrease in sleep latency observed in WT mice. These results indicate that the sleep-promoting effect of RBS is completely dependent on H₁ R antagonism.

CONCLUSIONS

RBS decreases sleep latency and promotes NREMS through the inhibition of H₁ R, suggesting that it could be a promising therapeutic agent for insomnia.

Treatment of Insomnia With Traditional Chinese Herbal Medicine

Insomnia is a condition with sleep problems and many people suffered from it. Chronic insomnia can last for long time and it will severely affect people's health and the quality of life. In conventional medicine, the most commonly used the medicine is benzodiazepine. It is effective but also has significant side effects. Patients try to use some kinds of alternative medicines. Chinese medicinal herbs and formulas have been used in the treatment of insomnia for more than 2000 years in China. In recent decades, Chinese herbal medicine has been widely used in the Western countries. Many clinical studies including randomized controlled clinical trials and research on pharmacological action mechanisms of the herbs for treatment of insomnia have been conducted. It is very important and very helpful to review the published research papers to gather the available information for a critical analysis. This chapter evaluated the data from both of clinical studies and pharmacological researches on the therapeutic formulas and on some key herbs used in the treatment of insomnia. Clinical studies showed a very wide spectrum of herbs that were used in clinical treatment of insomnia. This was due to different syndrome patterns happened with insomnia. This brought complexity and difficulties to identify which are the essential key herbs or formulas. It was found Suanzaoren decoction (Ziziphus spinose decoction ) is the most frequently used formula for the treatment of insomnia. Based on the clinical data, several herbs were identified as most frequently used sedative and hypnotic herbs in Chinese herbal medicine including Suanzaoren (Ziziphus spinose ), Fuling (Poria cocos ), and Gancao (Glycyrrhiza uralensis ). The underlying pharmacological action mechanisms discovered in the studies on some key herbs used in the treatment of insomnia were evaluated. The major pharmacological action mechanisms shared by most of the sedative herbs are to act through the neurotransmitter gamma-aminobutyric acid (GABA) or via stimulation of GABAA_A receptor. Some herbs exert sedative activities via inhibition of 5-hydroxytryptamine 1A receptor. Another mechanism shown by some herbs is to upregulate the expression of orexin-A, leptin, orexin receptor-1, and leptin receptor in the brain, reducing insomnia-induced negative consequences, and thus indirectly help improvement of insomnia.