Determination of monoamine and amino acid neurotransmitters and their metabolites in rat brain samples by UFLC-MS/MS for the study of the sedative-hypnotic effects observed during treatment with S. chinensis

Zhumian Granules improves PCPA-induced insomnia by regulating the expression level of neurotransmitters and reducing neuronal apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Sleep problems, according to Traditional Chinese medicine (TCM) philosophy, are attributed to the imbalance between yin and yang. Zhumian Granules, also known as Sleep-aid Granules or ZG, are a traditional Chinese herbal remedy specifically designed to alleviate insomnia. This formula consists of many components, including Wu Wei Zi (Schisandrae Chinensis Fructus), Suan Zao Ren (Ziziphi Spinosae Semen), and other medicinal plants. According to the pharmacology of Traditional Chinese Medicine (TCM), Wu Wei Zi and Suan Zao Ren have the ability to relax the mind and promote sleep. When taken together, they may balance the opposing forces of yin and yang. Therefore, ZG may potentially be used as a therapeutic treatment for insomnia.

AIM OF THE STUDY

This research was specifically developed to establish a strong empirical basis for the subsequent advancement and utilization of ZG in the management of insomnia. This research aimed to gather empirical data to support the effectiveness of ZG, thereby providing useful insights into its potential therapeutic advantages for persons with insomnia.

MATERIALS AND METHODS

This study utilized Zhumian Granules (ZG), a traditional Chinese herbal decoction, to examine its sedative and hypnotic effects on mice with PCPA-induced insomnia. The effects were assessed using the pentobarbital-induced sleep test (PIST), Morris water maze test (MWM), and autonomic activity test. The levels of neurotransmitters in each group of mice were evaluated using UPLC-QQQ-MS. The impact of ZG on the quantity and structure of hippocampal neurons was seen in brain tissue slices using immunofluorescence labeling.

RESULTS

ZG was shown to possess active sedative properties, effectively lowering the distance of movement and lengthening the duration of sleep. ZG mitigated the sleeplessness effects of PCPA by elevating the levels of 5-hydroxytryptamine (5-HT), 4-aminobutyric acid (GABA), and 5-hydroxyindoleacetic acid (5-HIAA), while reducing the levels of dopamine (DA) and norepinephrine (NE), as well as decreasing neuronal death.

CONCLUSIONS

This research confirmed the sedative and hypnotic properties of ZG and elucidated its probable mechanism involving neurotransmitters.

A comprehensive review on Schisandrin and its pharmacological features

Schisandrin stands as one of the primary active compounds within the widely used traditional medicinal plant Schisandra chinensis (Turcz.) Baill. This compound exhibits sedative, hypnotic, anti-aging, antioxidant, and immunomodulatory properties, showcasing its effectiveness across various liver diseases while maintaining a favorable safety profile. However, the bioavailability of schisandrin is largely affected by hepatic and intestinal first-pass metabolism, which limits the clinical efficacy of schisandrin. In this paper, we review the various pharmacological effects and related mechanisms of schisandrin, in order to provide reference for subsequent drug research and promote its medicinal value.

In Silico Analysis, Anticonvulsant Activity, and Toxicity Evaluation of Schisandrin B in Zebrafish Larvae and Mice

The aim of this study is to evaluate the anticonvulsant potential of schisandrin B, a main ingredient of Schisandra chinensis extracts. Schisandrin B showed anticonvulsant activity in the zebrafish larva pentylenetetrazole acute seizure assay but did not alter seizure thresholds in the intravenous pentylenetetrazole test in mice. Schisandrin B crosses the blood-brain barrier, which we confirmed in our in silico and in vivo analyses; however, the low level of its unbound fraction in the mouse brain tissue may explain the observed lack of anticonvulsant activity. Molecular docking revealed that the anticonvulsant activity of the compound in larval zebrafish might have been due to its binding to a benzodiazepine site within the GABAA receptor and/or the inhibition of the glutamate NMDA receptor. Although schisandrin B showed a beneficial anticonvulsant effect, toxicological studies revealed that it caused serious developmental impairment in zebrafish larvae, underscoring its teratogenic properties. Further detailed studies are needed to precisely identify the properties, pharmacological effects, and safety of schisandrin B.

Investigation on property differences of ginseng and American ginseng by spatial metabolomics of neurochemicals with desorption electrospray ionization mass spectrometry imaging

ETHNOPHARMACOLOGICAL RELEVANCE

The properties are the body's response to traditional Chinese medicine (TCM). The essence of traditional Chinese medicine properties are cold, hot, warm, and cool. In the theory of traditional Chinese medicine, ginseng is warm and American ginseng is cool, they present two opposite properties. The material basis of property differences and effect mechanism of property degree need further investigation.

AIM OF THE STUDY

The aim of this work was to screen out the neurochemicals related to warm and cool properties of ginseng and American ginseng, and investigate the distributions of identified neurochemicals in rat brain and the metabolic mechanism.

MATERIALS AND METHODS

Spatial metabolomics was applied to study the effects of ginseng and American ginseng on the distributions of neurochemicals in rat brain by desorption electrospray ionization mass spectrometry imaging (DESI-MSI). Based on discriminant coefficients in partial least square discriminant analysis (PLS-DA) processing, neurochemicals related to warm and cool properties were classified. In addition, the score contributions of the neurochemicals markers could be used to evaluate the warm and cool property degrees.

RESULTS

A total of 25 neurochemicals were imaged and identified in brain section. The distribution regions of main neurochemicals were consistent with in sagittal and coronal sections of brain reported in literature. 17 neurochemicals were classified as warm markers. Meanwhile, 8 neurochemicals were identified as cool markers, correlated with the cool properties of American ginseng. It demonstrated that the score contributions of the 25 neurochemicals markers could be used to evaluate the warm and cool property degrees. Based on the regulatory effects of neurochemicals, the warm markers could promote the body's energy metabolism, improve the function of endocrine system, and enhance the excitability of central nervous system. The cool property markers have reduced excitability of central nervous system, weakened metabolism and stress response ability, thus presented the biological activity of cool and cold.

CONCLUSIONS

Our findings provided a rapid and effective visualization method for the spatial distribution and metabolism of small molecular neurochemicals in rat brain. DESI-MSI was a reference methodology for evaluating the properties of TCM.

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.

Raw and Wine Processed Schisandra chinensis Regulate NREM-Sleep and Alleviate Cardiovascular Dysfunction Associated with Insomnia by Modulating HPA Axis

Clinical studies have shown that insomnia and anxiety are usually accompanied by cardiovascular dysfunction. In traditional Chinese medicine, Schisandra chinensis (SC) and wine processed Schisandra chinensis (WSC) are mainly used for the treatment of dysphoria, palpitation and insomnia. However, little attention was paid to its mechanism. In this study, we monitored the effect of SC and WSC on the nervous system and cardiovascular system of free-moving rats in the real-time. Our results show that SC and WSC can alleviate cardiovascular dysfunction while promoting sleep, and we further explored their potential mechanisms. HPLC-QTOF-MS was used for the quality control of chemical components in SC and WSC. Data sciences international (DSI) physiological telemetry system was applied to collect the electroencephalogram (EEG), electrocardiogram (ECG) and other parameters of free-moving rats to understand the effects of long-term intake of SC and WSC on rats. The content of Cortisol (CORT), neurotransmitters and amino acids in rat pituitary and hypothalamus were analyzed by UPLC-MS to determine the activity of HPA axis. The expression of melatonin receptor MT1 was analyzed by immunofluorescence technique. Our results suggested that SC and WSC may play the role of promoting sleep by increasing the expression level of melatonin receptor MT1 in hypothalamus, and modulate the activity of HPA axis by regulating the levels of the related neurotransmitters and amino acid, so as to improve the abnormal cardiovascular system of rats. This study may provide theoretical support for explicating the advantages of SC and other phytomedicines in the treatment of insomnia.

Develop a stepwise integrated method to screen biomarkers of Baihe-Dihuang Tang on the treatment of depression in Rats Applying with composition screened, untargeted and targeted metabolomics analysis

Baihe-Dihuang Tang is a commonly prescribed remedy for depression. In this study, component screening with untargeted and targeted metabolomics was used to to identify potential biomarkers for depression in chronic unpredictable mildly-stressed rats. Using this novel identification method, the screening of organic acids, lily saponins, iridoids, and other ingredients formed the basis for subsequent metabolomics research. Baihe-Dihuang Tang supplementation in chronic unpredictable mild-stress -induced depression models, increased their body weight, sucrose preference, brain-derived neurotrophic factor deposition, and spatial exploring. Untargeted metabolomics revealed that Baihe-Dihuang Tang exerts its antidepressant effects by regulating the levels of lipids, organic acids and its derivatives, and benzenoids in the brain, plasma, and urine of the depressed rats. Moreover, it also modulates the D-glutamine and D-glutamate metabolism and purine metabolism. Targeted metabolomics demonstrated significant reduction in L-glutamate levels in the brains of depressed rats. This could be a potential biomarker for depression. Baihe-Dihuang Tang alleviated depression by regulating the levels of L-glutamate, xanthine, and adenine in the brains of depressed rats. Together, these findings conclusively established the promising therapeutic effect of Baihe-Dihuang Tang on depression and also unraveled the underlying molecular mechanism of its potential antidepressant function. This article is protected by copyright. All rights reserved.

A comprehensive review of ethnopharmacology, phytochemistry, pharmacology, and pharmacokinetics of Schisandra chinensis (Turcz.) Baill. and Schisandra sphenanthera Rehd. et Wils

ETHNOPHARMACOLOGICAL RELEVANCE

Schisandra chinensis (called bei-wuweizi in Chinese, S. chinensis) and Schisandra sphenanthera (called nan-wuweizi in Chinese, S. sphenanthera) are two highly similar plants in the Magnoliaceae family. Their dried ripe fruits are commonly used as traditional Chinese medicine in the treatment of coughs, palpitation, spermatorrhea, and insomnia. They also are traditionally used as tonics in Russia, Japan, and Korea.

AIM OF THE REVIEW

S. chinensis and S. sphenanthera are similar in appearance, traditional applications, ingredient compositions, and therapeutic effects. This review, therefore, aims to provide a systematic insight into the botanical background, ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics, quality control, and toxicology of S. chinensis and S. sphenanthera, and to explore and present the similarities and differences between S. chinensis and S. sphenanthera.

MATERIALS AND METHODS

A comprehensive literature search regarding S. chinensis and S. sphenanthera was collected by using electronic databases including PubMed, SciFinder, Science Direct, Web of Science, CNKI, and the online ethnobotanical database.

RESULTS

In the 2020 Edition of Chinese Pharmacopoeia (ChP), there were 100 prescriptions containing S. chinensis, while only 11 contained S. sphenanthera. Totally, 306 and 238 compounds have been isolated and identified from S. chinensis and S. sphenanthera, respectively. Among these compounds, lignans, triterpenoids, essential oils, phenolic acid, flavonoids, phytosterols are the major composition. Through investigation of pharmacological activities, S. chinensis and S. sphenanthera have similar therapeutic effects including hepatoprotection, neuroprotection, cardioprotection, anticancer, antioxidation, anti-inflammation, and hypoglycemic effect. Besides, S. chinensis turns out to have more effects including reproductive regulation and immunomodulatory, antimicrobial, antitussive and antiasthmatic, anti-fatigue, antiarthritic, and bone remodeling effects. Both S. chinensis and S. sphenanthera have inhibitory effects on CYP3A and P-gp, which can mediate metabolism or efflux of substrates, and therefore interact with many drugs.

CONCLUSIONS

S. chinensis and S. sphenanthera have great similarities. Dibenzocyclooctadiene lignans are regarded to contribute to most of the bioactivities. Schisandrin A-C, schisandrol A-B, and schisantherin A, existing in both S. chinensis and S. sphenanthera but differing in the amount, are the main active components, which may contribute to the similarities and differences. Study corresponding to the traditional use is needed to reveal the deep connotation of the use of S. chinensis and S. sphenanthera as traditional Chinese medicine. In addition, a joint study of S. chinensis and S. sphenanthera can better show the difference between them, which can provide a reference for clinical application. It is worth mentioning that the inhibition of S. chinensis and S. sphenanthera on CYP3A and P-gp may lead to undesirable drug-drug interactions.

Vcp Overexpression and Leucine Supplementation Increase Protein Synthesis and Improve Fear Memory and Social Interaction of Nf1 Mutant Mice

Neurofibromatosis type 1 (NF1) is a dominant genetic disorder manifesting, in part, as cognitive defects. Previous study indicated that neurofibromin (NF1 protein) interacts with valosin-containing protein (VCP)/P97 to control dendritic spine formation, but the mechanism is unknown. Here, using Nf1^+/- mice and transgenic mice overexpressing wild-type Vcp/p97, we demonstrate that neurofibromin acts with VCP to control endoplasmic reticulum (ER) formation and consequent protein synthesis and regulates dendritic spine formation, thereby modulating contextual fear memory and social interaction. To validate the role of protein synthesis, we perform leucine supplementation in vitro and in vivo. Our results suggest that leucine can effectively enter the brain and increase protein synthesis and dendritic spine density of Nf1^+/- neurons. Contextual memory and social behavior of Nf1^+/- mice are also restored by leucine supplementation. Our study suggests that the "ER-protein synthesis" pathway downstream of neurofibromin and VCP is a critical regulator of dendritic spinogenesis and brain function.

Raw and wine processed Schisandra chinensis attenuate anxiety like behavior via modulating gut microbiota and lipid metabolism pathway

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine, the fruit of Schisandra chinensis (Turcz.) Baill (SC) is used to treat various nervous system diseases, such as dysphoria, anxiety, insomnia and many dreams. It is worthy to be noted that wine processed Schisandra chinensis (WSC) has been applied in clinic for thousands of years.

AIM OF STUDY

This study aimed to investigate the possible mechanism and related metabolism of SC and WSC ameliorating anxiety behavior through modulating gut microbiota.

MATERIALS AND METHODS

The ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used for the quality control of chemical components in SC and WSC. Chronic unpredictable stress procedure (CUSP)-induced anxiety rats were administrated with SC and WSC via gavage for five weeks. An untargeted UPLC/LTQ-Orbitrap MS metabolomic analysis of plasma was conducted to understand the effects of long-term intake of WSC and SC extracts on anxious rats. 16S rRNA microbial sequencing technology was applied to investigate gut microbiota structure. Expression of GPR81, TNF-α, S1PR2 as well as molecules in cAMP pathway was assayed by immunohistochemistry staining, RT-qPCR, or Western blot, respectively.

RESULTS

12 compounds were identified using UPLC-QTOF-MS technology, all of which are lignans. Results demonstrate that the amounts of 6-O-Benzoylgomisin O, Schisandrin, Gomisin D, Schizandrin A, Gomisin T, Schizandrin B, Schisandrin C were higher in wine-processed samples than in raw samples. Furthermore, both SC and WSC significantly ameliorated anxiety- and depression-like behavior and lipid metabolism dysfunction and attenuated hippocampal neuritis in anxiety rats. After WSC treatment, the structure and composition of gut microbiota in anxiety rats changed significantly, and gut microbiota derivatives lactate level was significantly lower in the plasma and feces. WSC treatment help restore gut microbial ecosystem dysbiosis and reverse the changes in Lachnospiraceae, Lactobacillus, Alloprevotella, and Bacteroidales in anxiety rat. In addition, the expression of liver GPR81 was decreased, and the molecules in cAMP pathway were increased in SC and WSC-treated anxiety rat.

CONCLUSION

Raw and wine processed Schisandra chinensis treatment improved anxiety- and depression-like behavior through modulating gut microbiota derivatives in association with GPR81 receptor-mediated lipid metabolism pathway. And WSC has more exhibition than SC.

Simultaneous Determination of Four Monoamine Neurotransmitters and Seven Effective Components of Zaoren Anshen Prescription in Rat Tissue using UPLC-Ms/Ms

Background:

Zaoren Anshen Prescription (ZAP) is widely used as a classic Chinese Traditional Medicine (TCM) prescription for the treatment of palpitations and insomnia in China. Some studies have identified the main active components for its anti-insomnia effect and observed changes of some endogenous components that are closely related to its anti-insomnia effect. However, simultaneous determination of four monoamine neurotransmitters and seven effective components of ZAP and the investigation of their distribution in tissues by using ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) have not been reported.

Methods:

An ultra-performance liquid chromatography with tandem mass spectrometry method was developed and validated for simultaneous quantification of four monoamine neurotransmitters (norepinephrine, dopamine, 5-hydroxy tryptamine and 5-hydroxyindoleacetic acid) and seven prescription components (danshensu, protocatechualdehyde, spinosin, 6´´´-feruylspinosin, salviaolic acid B, schisandrin and deoxyschisandrin) in rats’ tissues. Tissue samples were prepared by protein precipitation with acetonitrile. Chromatographic separation was carried out on a C18 column with a gradient mobile phase consisting of acetonitrile and 0.01% formic acid water. An electrospray ionization triple quadrupole concatenation mass spectrometer was set to switch between positive and negative modes in single run time. All the components were quantitated by multiple-reaction monitoring scanning.

Results:

: The lower limits of quantitation for all analytical components were 0.78 ng/mL-1.99 ng/mL in the heart, liver, spleen, lung, kidney and brain. All the calibration curves displayed good linearity (r > 0.99544). The precision was evaluated by intra-day and inter-day assays, and the relative standard deviation (RSD) values were all within 12.67%. The relative errors of the accuracy were all within ± 19.88%. The recovery ranged from 76.00% to 98.78% and the matrix effects of eleven components were found to be between 85.10% and 96.40%.

Conclusion:

This method was successfully applied to study the distribution of seven components from ZAP and the concentration changes of four monoamine neurotransmitters after oral ZAP in six tissues.

Inhibitory Effectiveness of Gomisin A, a Dibenzocyclooctadiene Lignan Isolated from Schizandra chinensis, on the Amplitude and Gating of Voltage-Gated Na+ Current

Gomisin A (Gom A), a lignan isolated from Schisandra chinensis, has been reported produce numerous biological activities. However, its action on the ionic mechanisms remains largely unanswered. The present experiments were undertaken to investigate the possible perturbations of Gom A or other related compounds on different types of membrane ionic currents in electrically excitable cells (i.e., pituitary GH₃ and pancreatic INS-1 cells). The exposure to Gom A led to the differential inhibition of peak and end-pulse components of voltage-gated Na⁺ current (I_Na) in GH₃ cells with effective IC₅₀ of 6.2 and 0.73 μM, respectively. The steady-state inactivation curve of I_Na in the presence of Gom A was shifted towards a more hyperpolarized potential. However, neither changes in the overall current-voltage relationship nor those for the gating charge of the current were demonstrated. The application of neither morin (10 μM) nor hesperidin (10 μM) perturbed the strength of I_Na, while sesamine could suppress it. However, in the continued presence of Gom A, the addition of sesamine failed to suppress I_Na further. Gom A also effectively suppressed the strength of persistent I_Na activated by long ramp voltage command, and further application of tefluthrin effectively attenuated Gom A-mediated inhibition of the current. The presence of Gom A mildly inhibited erg-mediated K⁺ current, while a lack of change in the amplitude of hyperpolarization-activated cation current was observed in its presence. Under cell-attached current recordings, the exposure to Gom A resulted in the decreased firing of spontaneous action currents with a minimal change in AC amplitude. In pancreatic INS-1 cells, the presence of Gom A was also noticed to inhibit peak and end-pulse components of I_Na differentially with the IC₅₀ of 5.9 and 0.84 μM, respectively. Taken together, the emerging results presented herein provide the evidence that Gom A can differentially inhibit peak and sustained I_Na in endocrine cells (e.g., GH₃ and INS-1 cells).

Chemical-neuroanatomical organization of peripheral sensory-efferent systems in the pond snail (Lymnaea stagnalis)

Perception and processing of chemical cues are crucial for aquatic gastropods, for proper elaboration of adaptive behavior. The pond snail, Lymnaea stagnalis, is a model species of invertebrate neurobiology, in which peripheral sensory neurons with different morphology and transmitter content have partly been described, but we have little knowledge regarding their functional morphological organization, including their possible peripheral intercellular connections and networks. Therefore the aim of our study was to characterize the sensory system of the tentacles and the lip, as primary sensory regions, and the anterior foot of Lymnaea with special attention to the transmitter content of the sensory neurons, and their relationship to extrinsic elements of the central nervous system. Numerous bipolar sensory cells were demonstrated in the epithelial layer of the peripheral organs, displaying immunoreactivity to antibodies raised against tyrosine hydroxylase, histamine, glutamate and two molluscan type oligopeptides, FMRFamide and Mytilus inhibitory peptide. A subepithelial plexus was formed by extrinsic serotonin and FMRFamide immunoreactive fibers, whereas in deeper regions axon processess of different origin with various immunoreactivities formed networks, too. HPLC-MS assay confirmed the presence of the low molecular weight signal molecules in the three examined areas. Following double-labeling immunohistochemistry, close arrangements were observed, formed by sensory neurons and extrinsic serotonergic (and FMRFamidergic) fibers at axo-dendritic, axo-somatic and axo-axonic levels. Our results suggest the involvement of a much wider repertoire of signal molecules in peripheral sensory processes of Lymnaea, which can locally be modified by central input, hence influencing directly the responses to environmental cues.

The antidepressant effects of l-arginine on chronic mild stress-induced depression by augmenting the expression of brain-derived neurotrophic factor in rats

In the present study, the antidepressant effects of l-arginine in a rat model of chronic mild stress-induced depression were investigated. Animals were divided into group I (sham), group II (control, depression), group III (10 mg/kg l-arginine), group IV (20 mg/kg l-arginine), and group V (10 mg/kg venlafaxine, positive control). The doses were orally administered for 30 consecutive days. Sucrose preference analysis as well as forced swim and open field tests were performed. Serum cortisol, nitric oxide (NO), and monoamine levels in brain tissue were then measured. Brain-derived neurotrophic factor (BDNF) expression was also examined. Supplementation with l-arginine significantly increased the sucrose preference ratio, locomotor activity, and monoamines and decreased serum cortisol and NO levels. The mRNA and protein expression of BDNF in the brain tissue was significantly reduced (>50 %) in control rats. However, supplementation with l-arginine significantly increased BDNF mRNA expression (>50 %) in both groups. Similarly, increased BDNF protein expression after l-arginine treatment was confirmed using Western blot and immunohistochemical analyses. In conclusion, l-arginine supplementation may be effective against chronic stress-induced depression.

Simultaneous determination of thirteen substances related to NAFLD in mouse brain tissue using 3-aminobutyric acid as internal standard by HPLC-FLD

Disorders of certain branched-chain amino acids may be associated with the occurrence and development of non-alcoholic fatty liver disease. Measurement of related branched-chain amino acid levels could provide a reference for the clinical and scientific research of the non-alcoholic fatty liver disease. An established HPLC-FLD method was used to quantify aspartic acid, glutamate, glutamine, glycine, taurine, tyrosine, 4-amino butanoic acid, tryptophan, methionine, valine, phenylalanine, isoleucine and leucine in mouse brain tissue. Brain tissue samples mixed with internal standard (3-aminobutyric acid) were processed, then derivatized with 2-O-phthaldialdehyde, and finally separated on an ODS2 column through gradient elution at a flow rate of 1.0 ml·min^-1 . The excitation and emission wavelengths were set at 340 and 455 nm, respectively. The mobile phase A was 100% methanol and the mobile phase B consisted of 30 mmol·L^-1 sodium acetate (pH 6.8). The injection volume was 20 μl and the single run time was 45 min. Several parameters, accuracy, precision, and stability, were verified and the results showed the established method had good sensitivity and resolution for all of the 13 compounds and internal standard in mouse brain.

Mechanism-based pharmacokinetics-pharmacodynamics studies of harmine and harmaline on neurotransmitters regulatory effects in healthy rats: Challenge on monoamine oxidase and acetylcholinesterase inhibition

BACKGROUND

β-Carboline alkaloid harmine (HAR) and harmaline (HAL) are monoamine oxidase (MAO) and acetylcholinesterase (AChE) inhibitors. However, whether HAR and HAL inhibit MAO or AChE selectively and competitively is unclear.

PURPOSE

The purpose of this study was to investigate the potential competition inhibition of HAR and HAL on MAO and AChE in brain endothelial cells (RBE4) and in healthy rats to provide a basis for the application of the inhibitors in the treatment of patients with depression and with Parkinson's disease or Alzheimer's disease.

STUDY DESIGN/METHODS

The transport properties of HAR and HAL by using blood-brain barrier models constructed with RBE4 were systematically investigated. Then, the modulation effects of HAR and HAL on CNS neurotransmitters (NTs) in healthy rat brains were determined by a microdialysis method coupled with LC-MS/MS. The competition inhibition of HAR and HAL on MAO and AChE was evaluated through real time-PCR, Western blot analysis, and molecular docking experiments.

RESULTS

Results showed that HAL and HAR can be detected in the blood and striatum 300 min after intravenous injection (1 mg/kg). Choline (Ch), gamma-aminobutyric acid (GABA), glutamate (Glu), and phenylalanine (Phe) levels in the striatum decreased in a time-dependent manner after the HAL treatment, with average velocities of 1.41, 0.73, 3.86, and 1.10 (ng/ml)/min, respectively. The Ch and GABA levels in the striatum decreased after the HAR treatment, with average velocities of 1.16 and 0.22 ng/ml/min, respectively. The results of the cocktail experiment using the human liver enzyme indicated that the IC₅₀ value of HAL on MAO-A was 0.10 ± 0.08 µm and that of HAR was 0.38 ± 0.21 µm. Their IC₅₀ values on AChE were not obtained. These findings indicated that HAL and HAR selectively acted on MAO in vitro. However, RT-PCR and Western blot analysis results showed that the AChE mRNA and protein expression decreased in a time-dependent manner in RBE4 cells after the HAR and HAL treatments.

CONCLUSION

NT analysis results showed that HAL and HAR selectively affect AChE in vivo. HAL and HAR may be highly and suitably developed for the treatment of Alzheimer's disease.

Ambient PM2.5 caused depressive-like responses through Nrf2/NLRP3 signaling pathway modulating inflammation

PM2.5 pollution has been associated with numerous adverse effects including cardiovascular, respiratory and metabolic diseases as well as emotional disorders. However, the potential mechanism has not known clearly. Twenty-four rats were divided into 3 groups and exposed to various airs: filtered air (FA), unfiltered air (UA) and concentrated PM2.5 air (CA), respectively. Thirty wild type (WT) and 30 Nrf2 knockout (KO) mice were divided into 2 groups and exposed to FA and UA, respectively. The changes of neurobehavioral function, neurotransmitter secretion, toxic elements deposition, oxidative stress and the inflammation in prefrontal cortex were investigated during 9-12 weeks with/without PM2.5 exposure. Results showed that CA rats and KO-UA mice emerged obviously depressive-like responses. Li, Be, Al, Cr, Co, Ni, Se, Cd, Ba, Ti and Pb could deposit in the prefrontal cortex of rats after PM2.5 exposure. The neurotransmitters were significantly disorder in prefrontal cortex of CA rats. The NLRP3 signaling pathway was more activated in Nrf2^-/- than WT mice after PM2.5 exposure for 9 weeks. Nrf2/ NLRP3 signaling pathway modulating the inflammation might play an important role in the depression induced by ambient PM2.5.

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.

Anxiolytic effect of a novel 9,10-dihydrophenanthrene, juncuenin H, is associated with metabolic changes in cortical serotonin/dopamine levels in mice

Two novel phenanthrenoids, juncuenin H (1) and dijuncuenin B (2), together with eight known phenanthrenoids, effusol (3), dehydroeffusol (4), juncusol (5), dehydrojuncusol (6), juncuenin B (7), dehydrojuncuenin B (8), juncuenin A (9), and dehydrojuncuenin A (10), were isolated from the underground parts of Juncus setchuenensis. The structures of the compounds were determined by 1D and 2D NMR and mass spectroscopy. The anxiolytic activities of compounds 1, 6, 9, and 10 were evaluated. In order to explore the mechanisms underlying their anxiolytic activities, the levels of serotonin (5-HT), dopamine (DA), and their metabolites in the cerebral cortex and hippocampus of mice treated with compound 1 were determined by quantitative mass spectrometry. The mice treated with compound 1 had significantly lower levels of 5-HT, 3-methoxytyramine (3-MT), 5-hydroxyindole-3-acetic acid (5-HIAA), homovanillic acid (HVA), and 3, 4-dihydroxyphenylacetic acid (DOPAC) in the cerebral cortex than those of the vehicle control-treated mice. The levels of HVA and 5-HIAA in the hippocampus were also significantly lower in the mice treated with compound 1 than in the control group mice. These results suggest that the metabolic changes, reflected in the levels of DA and/or 5-HT, may contribute to the anxiolytic activity of the phenanthrenoids studied herein.

Targeted Neurotransmitters Profiling Identifies Metabolic Signatures in Rat Brain by LC-MS/MS: Application in Insomnia, Depression and Alzheimer's Disease

Epidemiological, cross-sectional, and prospective studies have suggested that insomnia, Alzheimer’s disease (AD) and depression are mutually interacting conditions and frequently co-occur. The monoamine and amino acid neurotransmitter systems in central nervous system were involved in the examination of neurobiological processes of this symptom complex. However, few studies have reported systematic and contrastive discussion of different neurotransmitters (NTs) changing in these neurological diseases. Thus, it is necessary to establish a reliable analytical method to monitoring NTs and their metabolite levels in rat brain tissues for elucidating the differences in pathophysiology of these neurological diseases. A rapid, sensitive and reliable LC-MS/MS method was established for simultaneous determination of the NTs and their metabolites, including tryptophan (Trp), tyrosine (Tyr), serotonin (5-HT), 5-hydroxyindolacetic acid (5-HIAA), dopamine (DA), acetylcholine (ACh), norepinephrine (NE), glutamic acid (Glu), and γ-aminobutyric acid (GABA) in rat brain tissues. The mobile phase consisting of methanol and 0.01% formic acid in water was performed on an Inertsil EP C18 column, and the developed method was validated well. Results demonstrated that there were significant differences for 5-HT, DA, NE, Trp, Tyr and ACh between model and control group in all three models, and a Bayes linear discriminant function was established to distinguish these three kinds of nervous system diseases by DA, Tyr and ACh for their significant differences among control and three model groups. It could be an excellent strategy to provide perceptions into the similarity and differentia of mechanisms from the point of NTs’ changing in brain directly and a new method to distinguish insomnia, depression and AD from view of essence.

Neuroprotective effect of total glycosides from paeonies against neurotoxicity induced by strychnos alkaloids related to recovering the levels of neurotransmitters and neuroendocrine hormones in rat serum and brain

Semen Strychni, a classical traditional Chinese medicine, has been widely used for its anti-tumor, analgesic and anti-inflammatory angiogenesis effects. However, taking an overdose of Semen Strychni might result in extreme neurotoxicity. Strychnos alkaloids are the main toxic constituents of Semen Strychni. Total glycosides from paeonies are considered to have neuroprotective effects. In this study, twelve potential endogenous biomarkers in rat serum and brain were monitored to investigate the protective effect of total glycosides from the paeony against strychnos alkaloids-induced neurotoxicity. A sensitive liquid chromatography-tandem mass spectrometry method was developed and validated to monitor eight neurotransmitters including glutamate, γ-aminobutyric acid, acetylcholine serotonin, dopamine, norepinephrine, tryptophan and tyrosine. An enzyme-linked immunosorbent assay method was selected for determination of four neuroendocrine hormones including thyrotrophin-releasing hormone, corticotrophin-releasing hormone, antidiuretic hormone and prolactin. Results showed that continuous administration of strychnos alkaloids for 15 days caused significant changed levels of the biomarkers (especially the four neuroendocrine hormones). Meanwhile, total glycosides from paeony pretreated rats (administrated with total glycosides from the paeony for 15 days before exposure to strychnos alkaloids) showed recovered levels of these biomarkers. The results suggested that the neurotransmitters and neuroendocrine hormones in serum and brain might play potential roles as biomarkers. This study provides the possibility of alleviating the Semen Strychni-induced neurotoxicity in clinic by pre-protection with total glycosides from paeonies.

Eight neurotransmitters and four neuroendocrine hormones in rat serum and brain were quantified to investigate the neuroprotective effect of total glycosides from paeony against neurotoxicity induced by strychnos alkaloids.

Schisandra chinensis Fructus and Its Active Ingredients as Promising Resources for the Treatment of Neurological Diseases

Neurological diseases (NDs) are a leading cause of death worldwide and tend to mainly affect people under the age of 50. High rates of premature death and disability caused by NDs undoubtedly constrain societal development. However, effective therapeutic drugs and methods are very limited. Schisandra chinensis Fructus (SCF) is the dry ripe fruit of Schisandra chinensis (Turcz.) Baill, which has been used in traditional Chinese medicine for thousands of years. Recent research has indicated that SCF and its active ingredients show a protective role in NDs, including cerebrovascular diseases, neurodegenerative diseases, or depression. The key neuroprotective mechanisms of SCF and its active ingredients have been demonstrated to include antioxidation, suppression of apoptosis, anti-inflammation, regulation of neurotransmitters, and modulation of brain-derived neurotrophic factor (BDNF) related pathways. This paper summarizes studies of the role of SCF and its active ingredients in protecting against NDs, and highlights them as promising resources for future treatment. Furthermore, novel insights on the future challenges of SCF and its active ingredients are offered.

Development, validation and comparison of surrogate matrix and surrogate analyte approaches with UHPLC-MS/MS to simultaneously quantify dopamine, serotonin and γ-aminobutyric acid in four rat brain regions

As biomarkers, endogenous neurotransmitters play critical roles in the process of neuropsychiatric diseases, and neurotransmitter levels in different brain regions can contribute to neurological disease diagnosis and treatment. Due to the lack of a blank matrix for endogenous neurotransmitters, surrogate-matrix and surrogate-analyte approaches have been used for the determination of neurotransmitters to solve this problem. In this study, we capitalised on the high accuracy, precision, and throughput of UHPLC-MS/MS and developed new methods based on the two approaches. Both approaches satisfied FDA and EMA validation criterias after an appropriate parallelism assessment, and they were used to further quantify the three endogenous neurotransmitters, including dopamine (DA), serotonin (5-HT) and γ-aminobutyric acid (GABA) in rat brain four regions (cortex, striatum, hypothalamus and hippocampus) which represent the catecholamines, indolamines, and amino acids, respectively. Comparison of the results in the same rats (n = 10) showed there was no significant difference in DA, 5-HT, or GABA levels between the two approaches (P > 0.05). The concentrations of DA and GABA were highest in striatum and hypothalamus, respectively, and the levels of 5-HT were paralleled in striatum and hippocampus almost 2-fold higher than other regions. This is the first study to compare these two approaches in the determination of endogenous neurotransmitter content in the rat brain, and the surrogate-matrix approach proved to be simple, rapid, and reliable, considering cost, matrix similarity, and practicality.

Profiling of small molecule metabolites and neurotransmitters in crustacean hemolymph and neuronal tissues using reversed-phase LC-MS/MS

Crustaceans have been long used as model animals for neuromodulation studies because of their well-defined neural circuitry. The identification of small molecule metabolites and signaling molecules in circulating fluids and neuronal tissues presents unique challenges due to their diverse structures, biological functions, and wide range of concentrations. LC combined with high resolution MS/MS is one of the most powerful tools to uncover endogenous small molecules. Here we explored several sample preparation techniques (solid-phase extraction and denaturing) and MS data acquisition strategies (data-dependent acquisition and targeted MS2-based acquisition) that provided complementary coverage and improved overall identification rate in C18 LC-MS/MS experiment. By MS/MS spectral matching with mzCloud database and those generated from standard compounds, a total of 129 small molecule metabolites and neurotransmitters were identified from crustacean hemolymph and neuronal tissues. These confidently identified small molecules covered predominant biosynthetic pathways for major neurotransmitters, validating the effectiveness of the high-throughput RPLC-MS/MS approach in studying the metabolism of neurotransmitters.

The investigation of immunoprotective and sedative hypnotic effect of total polysaccharide from Suanzaoren decoction by serum metabonomics approach

Suanzaoren decoction, as one of the traditional Chinese medicine prescriptions, has been most commonly used in Asian countries and reported to inhibit the process of immunodeficiency insomnia. Polysaccharide is important component which also contributes to the role of immunoprotective and sedative hypnotic effects. This study was aimed to explore the immunoprotective and sedative hypnotic mechanisms of polysaccharide from Suanzaoren decoction by serum metabonomics approach. With this purpose, complex physical and chemical immunodeficiency insomnia models were firstly established according to its multi-target property. Serum samples were analyzed using UHPLC/Q-TOF-MS spectrometry approach to determine endogenous metabolites. Then, principal component analysis was used to distinguish the groups, and partial least squares discriminate analysis was carried out to confirm the important variables. The serum metabolic profiling was identified and pathway analysis was performed after the total polysaccharide administration. The twenty-one potential biomarkers were screened, and the levels were all reversed to different degrees in the total polysaccharide treated groups. These potential biomarkers were mainly related to vitamin, sphingolipid, bile acid, phospholipid and acylcarnitine metabolisms. The result has indicated that total polysaccharide could inhibit insomnia triggered by immunodeficiency stimulation through regulating those metabolic pathways. This study provides a useful approach for exploring the mechanism and evaluating the efficacy of total polysaccharide from Suanzaoren decoction.

A simple and sensitive high-performance liquid chromatography-electrochemical detection assay for the quantitative determination of monoamines and respective metabolites in six discrete brain regions of mice

A rapid, sensitive, and reproducible assay is described for the quantitative determination of the monoamine neurotransmitters dopamine, norepinephrine and serotonin, their metabolites, and the internal standard 3,4-dihydroxybenzlyamine hydro-bromide in mouse brain homogenate using high-performance liquid chromatography with electrochemical detection. The method was validated in the following brain areas: frontal cortex, striatum, nucleus accumbens, hippocampus, substantia nigra pars compacta and ventral tegmental area. Biogenic amines and relevant metabolites were extracted from discrete brain regions using a simple protein precipitation procedure, and the chromatography was achieved using a C₁₈ column. The method was accurate over the linear range of 0.300-30 ng/mL (r = 0.999) for dopamine and 0.300-15 ng/mL (r = 0.999) for norepinephrine, 3,4-dihydroxybenzlyamine hydro-bromide, homovanillic acid and 5-hydroxyindolacetic acid, with detection limits of ~0.125 ng/mL (5 pg on column) for each of these analytes. Accuracy and linearity for serotonin were observed throughout the concentration range of 0.625-30 ng/mL (r = 0.998) with an analytical detection limit of ~0.300 ng/mL (12 pg on column). Relative recoveries for all analytes were approximately ≥90% and the analytical run time was <10 min. The described method utilized minimal sample preparation procedures and was optimized to provide the sensitivity limits required for simultaneous monoamine and metabolite analysis in small, discrete brain tissue samples.

Pituitary adenylate cyclase-activating polypeptide (PACAP) has a neuroprotective function in dopamine-based neurodegeneration in rat and snail parkinsonian models

Pituitary adenylate cyclase-activating polypeptide (PACAP) rescues dopaminergic neurons from neurodegeneration and improves motor changes induced by 6-hydroxy-dopamine (6-OHDA) in rat parkinsonian models. Recently, we investigated the molecular background of the neuroprotective effect of PACAP in dopamine (DA)-based neurodegeneration using rotenone-induced snail and 6-OHDA-induced rat models of Parkinson's disease. Behavioural activity, monoamine (DA and serotonin), metabolic enzyme (S-COMT, MB-COMT and MAO-B) and PARK7 protein concentrations were measured before and after PACAP treatment in both models. Locomotion and feeding activity were decreased in rotenone-treated snails, which corresponded well to findings obtained in 6-OHDA-induced rat experiments. PACAP was able to prevent the behavioural malfunctions caused by the toxins. Monoamine levels decreased in both models and the decreased DA level induced by toxins was attenuated by ∼50% in the PACAP-treated animals. In contrast, PACAP had no effect on the decreased serotonin (5HT) levels. S-COMT metabolic enzyme was also reduced but a protective effect of PACAP was not observed in either of the models. Following toxin treatment, a significant increase in MB-COMT was observed in both models and was restored to normal levels by PACAP. A decrease in PARK7 was also observed in both toxin-induced models; however, PACAP had a beneficial effect only on 6-OHDA-treated animals. The neuroprotective effect of PACAP in different animal models of Parkinson's disease is thus well correlated with neurotransmitter, enzyme and protein levels. The models successfully mimic several, but not all etiological properties of the disease, allowing us to study the mechanisms of neurodegeneration as well as testing new drugs. The rotenone and 6-OHDA rat and snail in vivo parkinsonian models offer an alternative method for investigation of the molecular mechanisms of neuroprotective agents, including PACAP.

Summary: PACAP has a neuroprotective effect in different toxin-induced rat and snail parkinsonian models, acting partially through the same mechanisms.

Kampo Medicine: Evaluation of the Pharmacological Activity of 121 Herbal Drugs on GABAA and 5-HT3A Receptors

Kampo medicine is a form of Japanese phytotherapy originating from traditional Chinese medicine (TCM). During the last several decades, much attention has been paid to the pharmacological effects of these medical plants and their constituents. However, in many cases, a systematic screening of Kampo remedies to determine pharmacologically relevant targets is still lacking. In this study, a broad screening of Kampo remedies was performed to look for pharmacologically relevant 5-HT_3A and GABA_A receptor ligands. Several of the Kampo remedies are currently used for symptoms such as nausea, emesis, gastrointestinal motility disorders, anxiety, restlessness, or insomnia. Therefore, the pharmacological effects of 121 herbal drugs from Kampo medicine were analyzed as ethanol tinctures on heterologously expressed 5-HT_3A and GABA_A receptors, due to the involvement of these receptors in such pathophysiological processes. The tinctures of Lindera aggregata (radix) and Leonurus japonicus (herba) were the most effective inhibitory compounds on the 5-HT_3A receptor. Further investigation of known ingredients in these compounds led to the identification of leonurine from Leonurus as a new natural 5-HT_3A receptor antagonist. Several potentiating herbs (e.g., Magnolia officinalis (cortex), Syzygium aromaticum (flos), and Panax ginseng (radix)) were also identified for the GABA_A receptor, which are all traditionally used for their sedative or anxiolytic effects. A variety of tinctures with antagonistic effects Salvia miltiorrhiza (radix) were also detected. Therefore, this study reveals new insights into the pharmacological action of a broad spectrum of herbal drugs from Kampo, allowing for a better understanding of their physiological effects and clinical applications.

Metabolomics of Neurotransmitters and Related Metabolites in Post-Mortem Tissue from the Dorsal and Ventral Striatum of Alcoholic Human Brain

We report on changes in neurotransmitter metabolome and protein expression in the striatum of humans exposed to heavy long-term consumption of alcohol. Extracts from post mortem striatal tissue (dorsal striatum; DS comprising caudate nucleus; CN and putamen; P and ventral striatum; VS constituted by nucleus accumbens; NAc) were analysed by high performance liquid chromatography coupled with tandem mass spectrometry. Proteomics was studied in CN by two-dimensional gel electrophoresis followed by mass-spectrometry. Proteomics identified 25 unique molecules expressed differently by the alcohol-affected tissue. Two were dopamine-related proteins and one a GABA-synthesizing enzyme GAD65. Two proteins that are related to apoptosis and/or neuronal loss (BiD and amyloid-β A4 precursor protein-binding family B member 3) were increased. There were no differences in the levels of dopamine (DA), 3,4-dihydrophenylacetic acid (DOPAC), serotonin (5HT), homovanillic acid (HVA), 5-hydroxyindoleacetic acid (HIAA), histamine, L-glutamate (Glu), γ-aminobutyric acid (GABA), tyrosine (Tyr) and tryptophan (Tryp) between the DS (CN and P) and VS (NAc) in control brains. Choline (Ch) and acetylcholine (Ach) were higher and norepinephrine (NE) lower, in the VS. Alcoholic striata had lower levels of neurotransmitters except for Glu (30 % higher in the alcoholic ventral striatum). Ratios of DOPAC/DA and HIAA/5HT were higher in alcoholic striatum indicating an increase in the DA and 5HT turnover. Glutathione was significantly reduced in all three regions of alcohol-affected striatum. We conclude that neurotransmitter systems in both the DS (CN and P) and the VS (NAc) were significantly influenced by long-term heavy alcohol intake associated with alcoholism.

Simultaneous determination of amino acid and monoamine neurotransmitters in PC12 cells and rats models of Parkinson's disease using a sensitizing derivatization reagent by UHPLC-MS/MS

Multi-analytes simultaneous monitoring of amino acid and monoamine neurotransmitters (NTs) has important scientific significance for their related pathology, physiology and drug screening. In this work, in virtue of a mass spectrometry sensitizing reagent 10-ethyl-acridone-3-sulfonyl chloride (EASC) as derivatization reagent, an Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS) method was developed and validated for simultaneous determination of six amino acid NTs, two monoamine ones and its one metabolite. The simple and rapid derivatization reaction was innovatively combined with plasma preparation by using EASC acetonitrile solution as protein precipitant. This interesting combination brought the advantages of speediness, simpleness and high-throughput in a cost-effective way. Under the optimized conditions, LODs (0.004-3.80nM) and LOQs (0.014-13.3nM) of EASC derivatized-NTs were calculated and found to be significantly lower than those of direct UHPLC-MS/MS detection about 11.5-275.0 and 14.4-371.4 times, respectively. Moreover, EASC derivatization significantly improved chromatographic resolution and matrix effect when compared with direct UPLC-MS/MS detection method without derivatization. Meanwhile, it also brought acceptable precision (3.0-13.0%, peak area CVs%), accuracy (86.4-112.9%), recovery (88.3-107.8%) and stability (3.8-8.5%, peak area CVs%) results. This method was successfully applied for the antiparkinsonian effect evaluation of levodopa and Ginsenoside Rg1 using PC12 cells and rats models by measuring multiple NTs. This provided a new method for the NTs related studies in the future.

Liquid chromatography-mass spectrometry platform for both small neurotransmitters and neuropeptides in blood, with automatic and robust solid phase extraction

Neurons communicate via chemical signals called neurotransmitters (NTs). The numerous identified NTs can have very different physiochemical properties (solubility, charge, size etc.), so quantification of the various NT classes traditionally requires several analytical platforms/methodologies. We here report that a diverse range of NTs, e.g. peptides oxytocin and vasopressin, monoamines adrenaline and serotonin, and amino acid GABA, can be simultaneously identified/measured in small samples, using an analytical platform based on liquid chromatography and high-resolution mass spectrometry (LC-MS). The automated platform is cost-efficient as manual sample preparation steps and one-time-use equipment are kept to a minimum. Zwitter-ionic HILIC stationary phases were used for both on-line solid phase extraction (SPE) and liquid chromatography (capillary format, cLC). This approach enabled compounds from all NT classes to elute in small volumes producing sharp and symmetric signals, and allowing precise quantifications of small samples, demonstrated with whole blood (100 microliters per sample). An additional robustness-enhancing feature is automatic filtration/filter back-flushing (AFFL), allowing hundreds of samples to be analyzed without any parts needing replacement. The platform can be installed by simple modification of a conventional LC-MS system.

Comparative studies on polyphenolic composition, antioxidant and antimicrobial activities of Schisandra chinensis leaves and fruits

The aim of this paper was to evaluate the antioxidant and antimicrobial activities and the polyphenolic content of Schisandra chinensis (Turcz.) Baill. leaves and fruits. The leaves are an important source of flavonoids (35.10 ± 1.23 mg RE/g plant material). Qualitative and quantitative analyses of the polyphenolic compounds were achieved using a HPLC-UV-MS method. The main flavonoid from the leaves was isoquercitrin (2486.18 ± 5.72 μg/g plant material), followed by quercitrin (1645.14 ± 2.12 μg/g plant material). Regarding the fruit composition, the dominant compound there was rutin (13.02 ± 0.21 μg/g plant material), but comparing with the leaves, fruits can be considered a poor source of phenolic compounds. The antioxidant activity was evaluated by DPPH, TEAC, hemoglobin ascorbate peroxidase activity inhibition (HAPX), inhibition of lipid peroxidation catalyzed by cytochrome c and EPR spectroscopic assays, revealing a better antioxidant activity for the S. chinensis leaves extract. In the antimicrobial assay, S. chinensis leaves extract showed efficient activities against the targeted bacteria, being more active than the fruits extract. The results suggest the leaves of S. chinensis as a valuable source of antioxidant compounds with significant antioxidant activity.