Metabonomics Approach to Assessing the Modulatory Effects of St John’s Wort, Ginsenosides, and Clomipramine in Experimental Depression

Widely targeted quantitative lipidomics and prognostic model reveal plasma lipid predictors for nasopharyngeal carcinoma

BACKGROUND

Dysregulation of lipid metabolism is closely associated with cancer progression. The study aimed to establish a prognostic model to predict distant metastasis-free survival (DMFS) in patients with nasopharyngeal carcinoma (NPC), based on lipidomics.

METHODS

The plasma lipid profiles of 179 patients with locoregionally advanced NPC (LANPC) were measured and quantified using widely targeted quantitative lipidomics. Then, patients were randomly split into the training (125 patients, 69.8%) and validation (54 patients, 30.2%) sets. To identify distant metastasis-associated lipids, univariate Cox regression was applied to the training set (P < 0.05). A deep survival method called DeepSurv was employed to develop a proposed model based on significant lipid species (P < 0.01) and clinical biomarkers to predict DMFS. Concordance index and receiver operating curve analyses were performed to assess model effectiveness. The study also explored the potential role of lipid alterations in the prognosis of NPC.

RESULTS

Forty lipids were recognized as distant metastasis-associated (P < 0.05) by univariate Cox regression. The concordance indices of the proposed model were 0.764 (95% confidence interval (CI), 0.682-0.846) and 0.760 (95% CI, 0.649-0.871) in the training and validation sets, respectively. High-risk patients had poorer 5-year DMFS compared with low-risk patients (Hazard ratio, 26.18; 95% CI, 3.52-194.80; P < 0.0001). Moreover, the six lipids were significantly correlated with immunity- and inflammation-associated biomarkers and were mainly enriched in metabolic pathways.

CONCLUSIONS

Widely targeted quantitative lipidomics reveals plasma lipid predictors for LANPC, the prognostic model based on that demonstrated superior performance in predicting metastasis in LANPC patients.

Ginseng total saponins and Fuzi total alkaloids exert antidepressant-like effects in ovariectomized mice through BDNF-mTORC1, autophagy and peripheral metabolic pathways

BACKGROUND

Shenfu decoction (SFD) is a classic Chinese medicine prescription that has a strong cardiotonic effect. The combination of ginseng (the dried root of Panax ginseng C. A. Meyer) and Fuzi (processed product of sub-root of Aconitum carmichaeli Debx), the main constituents of SFD, has been reported to improve the pharmacological effect of each other. Moreover, research has shown that the main active components of SFD, ginseng total saponins (GTS) and Fuzi total alkaloids (FTA), have antidepressant activity. However, the effects of these ingredients on depressive-like behavior induced by ovariectomy, a model of menopausal depression, have not been studied.

PURPOSE

Our research aims to elucidate the antidepressant-like effects of GTS and FTA compatibility (GF) in ovariectomized mice and the potential mechanisms.

METHODS

To elucidate the antidepressant-like effects of GF in mice in ovariectomy condition, behavioral tests were performed after 7 days of intragastric administration of different doses of GF. Underlying molecular mechanisms of CREB-BDNF, BDNF-mTORC1 and autophagy signaling were detected by western blotting, serum metabolites were examined by UPLC-QE plus-MS and dendritic spine density was determined by Golgi-Cox staining.

RESULTS

GF remarkably decreased the immobility time in the forced swim test. GF also increased levels of pCREB/CREB, BDNF, Akt, mTORC1 and p62 in the prefrontal cortex and hippocampus, as well as decreased LC3-II/LC3-I in the prefrontal cortex and hippocampus of ovariectomized mice. Furthermore, 15 serum differential metabolites (9 of which are lipids and lipid molecules) were identified by metabonomics. Next, the antidepressant-like effects of GF was blocked by rapamycin, an inhibitor of mTORC1. The antidepressant actions of GF on levels of pCREB, mTORC1, LC3-Ⅱ/LC3-Ⅰ and p62 in the prefrontal cortex and the levels of BDNF, Akt, mTORC1 and p62 in the hippocampus were inhibited by rapamycin, and the dendritic spines density was also regulated.

CONCLUSION

GF has antidepressant effects in ovariectomized mice, and like other antidepressants, these effects involve activation of BDNF-mTORC1, autophagy regulation and consequent effects on hippocampal synaptic plasticity. Moreover, metabolomic results suggest that GF also has effects on peripheral lipid profiles that may provide potential biomarkers for these antidepressant-like effects. These results indicate that GF is worthy of further exploration as a promising pharmaceutical treatment for depression. This study provides a new direction for the development of new indications for traditional Chinese medicine compounds.

Antidepressant Active Ingredients From Chinese Traditional Herb Panax Notoginseng: A Pharmacological Mechanism Review

Depression is one of the most common mental illnesses in the world and is highly disabling, lethal, and seriously endangers social stability. The side effects of clinical drugs used to treat depression are obvious, and the onset time is longer. Therefore, there is a great demand for antidepressant drugs with better curative effects, fewer side effects, and shorter onset time. Panax notoginseng, a Chinese herbal medication, has been used to treat depression for thousands of years and shown to have a therapeutic effect on depression. This review surveyed PubMed’s most recent 20 years of research on Panax notoginseng’s use for treating depression. We mainly highlight animal model research and outlined the pathways influenced by medicines. We provide a narrative review of recent empirical evidence of the anti-depressive effects of Panax Notoginseng and novel ideas for developing innovative clinical antidepressants with fewer side effects.

Pithecellobium clypearia: Amelioration Effect on Imiquimod-Induced Psoriasis in Mice Based on a Tissue Metabonomic Analysis

Pithecellobium clypearia Benth. (accepted name: Archidendron clypearia (Jack) I.C.Nielsen; Mimosaceae), a popular traditional Chinese medicine, has a significant anti-inflammatory effect. The crude water extract of the aerial part of P. clypearia has been clinically applied to treat upper respiratory tract infections, acute gastroenteritis, laryngitis, and pharyngitis. However, the therapeutic mechanism of ethanol fraction of water extract (ESW) of P. clypearia to treat psoriasis should be complemented. The aim of our research was to clarify the protective effects of ESW from P. clypearia against psoriasis-like skin inflammation induced by imiquimod (IMQ) in mice with efficacy indexes and target tissue (spleen and serum) metabolomics. The ingredient of ESW was analyzed by ultrahigh-performance liquid chromatography combined with tandem mass spectrometry (UHPLC-MS/MS) method. The imiquimod-induced psoriatic mouse model was employed to investigate the effect of ESW against psoriasis, where the treatment method was implemented for 6 days both topically (Gel at 5%) and orally (at 2.4 g/kg p.o.). Traditional pharmacodynamic indicators (phenotypic characteristics, psoriasis area and severity index (PASI) score, H&E staining, immunohistochemical staining, the thickness of epidermis, body weight change, and spleen index) were conducted to appraise the efficacy of ESW. Furthermore, a gas chromatography-mass spectrometer (GC-MS) coupled with multivariate analysis was integrated and applied to obtain serum and spleen metabolic profiles for clarifying metabolic regulatory mechanisms of ESW. The current study illustrated that ESW is composed mainly of gallic acid, ethyl gallate, quercitin, 7-O-galloyltricetiflavan, quercetin, and myricetin by UHPLC-MS/MS analysis. ESW could distinctly improve IMQ-induced psoriasis in mouse through reducing PASI score, alleviating tissue damage, restoring spleen index, and inhibiting proliferating cell nuclear antigen (PCNA) expression in psoriasis-like skin tissue. From the metabolomics study, 23 markers with significant changes are involved in eight main pathways in spleen and serum samples, including linoleic acid metabolism and glycine, serine, and threonine metabolism. The current study showed that ESW had obvious antipsoriasis effects on IMQ-induced psoriasis in mice, which might be attributed to regulating the dysfunction of differential biomarkers and related pathways. In summary, ESW of P. clypearia showed a favourable therapeutic effect on IMQ-induced psoriasis, and metabolomics provided insights into the mechanisms of ESW to the treatment of psoriasis.

Emerging application of metabolomics on Chinese herbal medicine for depressive disorder

Depressive disorder is a kind of emotional disorder that is mainly manifested with spontaneous and persistent low mood. Its etiology is complex and still not fully understood. Metabolomics, an important part of system biology characterized by its integrity and systematicness, analyzes endogenous metabolites of small molecules in vivo and examines the metabolic status of the organism. It is widely used in the field of disease research for its unique advantage in the disease molecular marker discovering Due to fewer adverse reactions and high safety, Chinese herbal medicine (CHM) has great advantages in the treatment of chronic diseases including depression. Metabolomics has been gradually applied to the efficacy evaluation of CHM in treatment of depression and the metabolomics analysis exhibits a systemic metabolic shift in amino acids (such as alanine, glutamic acid, valine, etc.), organic acids (lactic acid, citric acid, stearic acid, palmitic acid, etc.), and sugars, amines, etc. These differential metabolites are mainly involved in energy metabolism, amino acid metabolism, lipid metabolism, etc. In this review, we have exemplified the study of CHM in animals or clinics on the depression, and revealed that CHM treatment has significantly changed the metabolic disorders associated with depression, promoting metabolic network reorganization through restoring of key metabolites, and metabolic pathways, which may be the main mechanism basis of CHM's treatment on depression. Besides, we further envisioned the future application of metabolomics in the study of CHM treatment of depression.

Assessment of Phytochemicals and Herbal Formula for the Treatment of Depression through Metabolomics

Depression is a widespread and persistent psychiatric disease. Due to various side effects and no curative treatments of conventional antidepressant drugs, botanical medicines have attracted considerable attention as a complementary and alternative approach. The pathogenesis of depression is quite complicated and unclear. Metabolomics is a promising new technique for the discovery of novel biomarkers for exploring the potential mechanisms of diverse diseases and assessing the therapeutic effects of drugs. In this article, we systematically reviewed the study of botanical medicine for the treatment of depression using metabolomics over a period from 2010 to 2019. Additionally, we summarized the potential biomarkers and metabolic pathways associated with herbal medicine treatment for depression. Through a comprehensive evaluation of herbal medicine as novel antidepressants and understanding of their pharmacomechanisms, a new perspective on expanding the application of botanical medicines for the treatment of depression is provided.

Lipids and cancer: Emerging roles in pathogenesis, diagnosis and therapeutic intervention

With the advent of effective tools to study lipids, including mass spectrometry-based lipidomics, lipids are emerging as central players in cancer biology. Lipids function as essential building blocks for membranes, serve as fuel to drive energy-demanding processes and play a key role as signaling molecules and as regulators of numerous cellular functions. Not unexpectedly, cancer cells, as well as other cell types in the tumor microenvironment, exploit various ways to acquire lipids and extensively rewire their metabolism as part of a plastic and context-dependent metabolic reprogramming that is driven by both oncogenic and environmental cues. The resulting changes in the fate and composition of lipids help cancer cells to thrive in a changing microenvironment by supporting key oncogenic functions and cancer hallmarks, including cellular energetics, promoting feedforward oncogenic signaling, resisting oxidative and other stresses, regulating intercellular communication and immune responses. Supported by the close connection between altered lipid metabolism and the pathogenic process, specific lipid profiles are emerging as unique disease biomarkers, with diagnostic, prognostic and predictive potential. Multiple preclinical studies illustrate the translational promise of exploiting lipid metabolism in cancer, and critically, have shown context dependent actionable vulnerabilities that can be rationally targeted, particularly in combinatorial approaches. Moreover, lipids themselves can be used as membrane disrupting agents or as key components of nanocarriers of various therapeutics. With a number of preclinical compounds and strategies that are approaching clinical trials, we are at the doorstep of exploiting a hitherto underappreciated hallmark of cancer and promising target in the oncologist's strategy to combat cancer.

Beneficial Effects of Crocin against Depression via Pituitary Adenylate Cyclase-Activating Polypeptide

Depression is one of the foremost psychological illness, and the exact mechanism is unclear. Recent studies have reported that the pituitary adenylate cyclase-activating polypeptide (PACAP) signaling pathway is involved in the progression of depression. In the present study, we extracted crocin from the traditional Chinese medicine (TCM), Gardenia jasminoides Ellis, to evaluate its antidepressant effect and clarify the underlying mechanism. Here, we established a chronic unpredictable mild stress (CUMS) mouse model to assess whether crocin can improve depression-like behavior in an open field test (OFT), tail suspension test (TST), forced swimming test (FST), and sucrose preference test (SPT). A corticosterone (CORT) model of PC12 was set up to explore the antidepressant mechanism of crocin. We pretreated PC12 cells with crocin for 1 hour and then stimulated the cells with CORT for 24 hours. Cell survival was detected by Hoechst staining and MTT assay. The expression of PACAP, cyclic adenosine monophosphate (cAMP) response element binding protein (CREB), and extracellular regulated protein kinases (ERK) were analyzed by western blotting. PACAP RNAi was used to interfere with PC12 cells to downregulate the content of PACAP. The results showed that crocin (30 mg/kg) significantly reversed the decrease of body weight and elevation of serum CORT, mitigated CUMS induced depression-like behaviors of mice, and crocin (12.5 μmol/L) protected PC12 cells against CORT (200 μmol/L)-induced injury. Furthermore, crocin greatly increased the protein expression of PACAP and phosphorylation of ERK and CREB in the CORT model. PACAP RNAi cancelled the neuroprotective effect of crocin. In conclusion, these results indicated that crocin exerted an antidepressant effect via upregulating PACAP and its downstream ERK and CREB signaling pathways.

Mechanisms of Panax ginseng action as an antidepressant

OBJECTIVES

Panax ginseng, a well-known traditional Chinese medicine with multiple pharmacological activities, plays a crucial role in modulating mood disorders. Several recent studies have identified an underlying role of Panax ginseng in the prevention and treatment of depression. However, the cellular and molecular mechanisms remain unclear.

MATERIALS AND METHODS

In this review, we summarized the recent progress of antidepressant effects and underlying mechanisms of Panax ginseng and its representative herbal formulae.

RESULTS

The molecular and cellular mechanisms of Panax ginseng and its herbal formulae include modulating monoamine neurotransmitter system, upregulating the expression of neurotrophic factors, regulating the function of HPA axis, and anti-inflammatory action.

CONCLUSIONS

Therefore, this review may provide theoretical bases and clinical applications for the treatment of depression by Panax ginseng and its representative herbal formulae.

Chronic paradoxical sleep deprivation-induced depression-like behavior, energy metabolism and microbial changes in rats

AIMS

Given the lasting impact of chronic paradoxical sleep deprivation (PSD) on behavior and organism metabolic alternations, along with the role of the microbiome in neurobehavioral development and metabolism, we sought to examine the relationship between the microbiota and chronic PSD-induced behavioral and metabolic changes.

MATERIALS AND METHODS

Psychological status of 7-day PSD (7d-PSD) male rats was tested by behavioral method, serum inflammatory cytokines and hypothalamic-pituitary-adrenal (HPA) axis-related hormones. In addition, GC-MS based urine metabolomics and 16S rRNA gene sequencing approaches were applied to estimate the influences of chronic PSD on host metabolism and gut-microbiota. Furtherly, microbial functional prediction and Spearman's correlation analysis were implemented to manifest the relations between the differential urinary metabolites and gut microbiota.

KEY FINDINGS

7d-PSD rats displayed depression-like behavior, metabolic and microbial changes. By integrating differential gut bacteria with indicators of depression and differential metabolites, we found that the alterations of Akkermansia, Oscillospira, Ruminococcus, Parabacteroides, Aggregatibacter and Phascolarctobacterium were closely related to abnormalities of depression symptoms and inflammatory cytokines. These bacteria also had close connections with host energy metabolism concerning arginine and proline metabolism, glycine, serine and threonine metabolism, and glyoxylate and dicarboxylate metabolism, pyruvate metabolism, which overlapped with the results of 16S rRNA gene function annotation.

SIGNIFICANCE

These data suggest that a specific situation of circadian disturbance, chronic PSD-induced alterations in gut microbiota and related host changes in metabolism may be the pathogenesis of depression.

Panax ginseng components and the pathogenesis of Alzheimer's disease (Review)

Ginseng is one of the main representatives of traditional Chinese medicine and presents a wide range of pharmacological actions. Ginsenosides are the main class of active compounds found in ginseng. They demonstrate unique biological activity and medicinal value, namely anti-tumour, anti-inflammatory and antioxidant properties, as well as anti-apoptotic properties. Increasing levels of stress in life are responsible for the increased incidence of nervous system diseases. Neurological diseases create a huge burden on the lives and health of individuals. In recent years, studies have indicated that ginsenosides play a pronounced positive role in the prevention and treatment of neurological diseases. Nevertheless, research is still at an early stage of development, and the complex mechanisms of action involved remain largely unknown. This review aimed to shed light into what is currently known about the mechanisms of action of ginsenosides in relation to Alzheimer's disease. Scientific material and theoretical bases for the treatment of nervous system diseases with purified Panax ginseng extracts are also discussed.

Metabolomics studies on corticosterone-induced PC12 cells: A strategy for evaluating an in vitro depression model and revealing the metabolic regulation mechanism

There are three types of differentiated (un-, poorly- and well-differentiated) PC12 cells, which have been widely used as a model system for depression studies after the administration of corticosterone (CORT). In order to investigate the underlying metabolic profiles of CORT-induced PC12 cells and evaluate the suitable differentiated types of PC12 cells for use in depressive studies, proton nuclear magnetic resonance (¹H NMR) metabolomics coupled with network analysis approaches were employed. The results showed that CORT induced metabolic alterations in PC12 cells. There were 8 and 13 common differential metabolites in intracellular and extracellular extracts, respectively, of the three types of differentiated PC12 cells in response to CORT treatment, and the perturbed metabolic pathways were involved in amino acid metabolism, glutathione metabolism, pyruvate metabolism and inositol phosphate metabolism. Eighteen protein targets of depression were identified from the five different metabolic pathways from metabolomics and network analysis among the three types of CORT-induced differentiated PC12 cells, and these proteins were all found in the pathways that were perturbed by CORT treatment of poorly-differentiated PC12 cells. These results may indicate that the metabolism of CORT-induced PC12 cells is similar to the pathogenesis of depression, and poorly-differentiated PC12 cells are the most suitable cells for depressive research among the distinct types of differentiated PC12 cells. Thus, an effective predicative strategy to evaluate the in vitro disease models could be referenced.

Ginsenosides: A Potential Neuroprotective Agent

Ginseng is a traditional Chinese medicine with a wide range of pharmacological activities. Ginsenosides are the major constituents of ginseng. Ginsenosides have the unique biological activity and medicinal value, such as antitumor, anti-inflammatory, antioxidation, and inhibition of cell apoptosis. With the increase of stress in life, the incidence of nervous system diseases is also increasing. Neurological diseases pose a huge burden on people's life and health. In recent years, some studies have shown that ginsenosides have a certain role in the prevention and treatment of neurological diseases. However, the research is still in its infancy, and the relevant mechanisms are complex. In the paper, we review the effects and mechanisms of ginsenosides on epilepsy, depression, cerebral ischemia reperfusion injury, Alzheimer's disease, and Parkinson's disease. We hope to provide a theoretical basis for the treatment of nervous system diseases by ginsenosides.

Urinary Metabolomic Study of Chlorogenic Acid in a Rat Model of Chronic Sleep Deprivation Using Gas Chromatography-Mass Spectrometry

The urinary metabolomic study based on gas chromatography-mass spectrometry (GC-MS) had been developed to investigate the possible antidepressant mechanism of chlorogenic acid (CGA) in a rat model of sleep deprivation (SD). According to pattern recognition analysis, there was a clear separation among big platform group (BP), sleep deprivation group (SD), and the CGA (model + CGA), and CGA group was much closer to the BP group by showing a tendency of recovering towards BP group. Thirty-six significantly changed metabolites related to antidepressant by CGA were identified and used to explore the potential mechanism. Combined with the result of the classic behavioral tests and biochemical indices, CGA has significant antidepressant effects in a rat model of SD, suggesting that the mechanism of action of CGA might be involved in regulating the abnormal pathway of nicotinate and nicotinamide metabolism; glyoxylate and dicarboxylate metabolism; glycine, serine, and threonine metabolism; and arginine and proline metabolism. Our results also show that metabolomics analysis based on GC-MS is a useful tool for exploring biomarkers involved in depression and elucidating the potential therapeutic mechanisms of Chinese medicine.

Metabonomics Approach To Comparing the Antistress Effects of Four Panax ginseng Components in Rats

Different components of Panax ginseng have different properties and medicinal effects. Metabonomics was a prospective approach to analyze the global response of endogenous metabolites to physiological and pathological processes. In this study, an untargeted metabonomics method using GC/TOFMS combined with multivariate statistical techniques was applied to compare entire metabolite differences and the antistress variations among four components of P. ginseng, namely, total ginsenosides (TG), panaxadiol (PD), panaxatriol (PT), and ginseng polysaccharide (PS), in Wistar rats. The results of metabolite analysis showed that numerous urine metabolites involving neurotransmitters, amino acids, organic acids, and gut microbiota metabolites were changed after administration of the four components of P. ginseng, with TG having the least impact on urinary metabolites. The urinary metabolite profiling of these rats exposed to acute combined stress (forced swimming and behavior restriction) demonstrated that the four ginseng components attenuated urine metabolite changes involving gut microbiota metabolites, tricarboxylic acid (TCA) cycle and energy metabolites, and organic acids to different degrees, with TG improving most of the metabolites altered by stress.

A urinary metabolomics (GC-MS) strategy to evaluate the antidepressant-like effect of chlorogenic acid in adrenocorticotropic hormone-treated rats

Major depressive disorder (MDD) is a chronic recurring illness that seriously affects human health. Chlorogenic acid (CGA), an important polyphenol extracted from Eucommia ulmoides Oliver bark, has been reported to have anti-depression, neuroprotection, memory improvement and other pharmacological effects. However, little is known about the underlying mechanisms of CGA on the treatment of depression. Here, we investigated the antidepressant-like effects of CGA on an adrenocorticotropic hormone (ACTH)-treated rat model. Thirty-two male Wistar rats were randomly divided into four groups: normal diet group (N), ACTH-treated model group (M), memantine positive control group (M + Mem) and CGA intervened group (M + CGA). Sucrose preference tests (SPTs) and open-field tests (OFTs) were performed to evaluate depressive-like behaviors. Memantine (30 mg kg⁻¹) and CGA (500 mg kg⁻¹) administration dramatically increased hedonic behaviors of the rats in SPT. The scores of crossing and rearing were significantly increased in the M + Mem group and M + CGA group. These results of the behaviour tests might be suggestive of antidepressant-like effects. Moreover, memantine and CGA reversed the levels of serum 5-hydroxytryptamine (5-HT), ACTH, corticotropin-releasing hormone (CRH), and dopamine (DA) that were altered in ACTH-treated rats. Based on a GC-MS metabolomic approach, significant differences in the metabolic profile were observed in ACTH-treated rats compared with the control group, as well as the M + CGA group and M + Mem group compared with the ACTH-treated group. A total of 19 metabolites were identified for the discrimination of normal rats and ACTH-treated rats, and 12 out of 19 differential metabolites were reversed with CGA intervention. Combined with pattern recognition and bioinformatics, nine perturbed metabolic pathways, including energy metabolism, neurotransmitter metabolism, and amino acid metabolism, were identified based on these metabolites. These integrative studies might give a holistic insight into the pathophysiological mechanism of the ACTH-treated depressive rat model, and also showed that CGA has antidepressant-like activities in ACTH-treated rats, providing an important drug candidate for the prevention and treatment of tricyclic anti-depressant treatment-resistant depression.

Chlorogenic acid showed antidepressant-like activity in chronic ACTH-treated rats, providing a potential drug candidate for prevention and treatment of tricyclic antidepressant treatment-resistant depression. Related metabolic pathways were shown.

Serum and Brain Metabolomic Variations Reveal Perturbation of Sleep Deprivation on Rats and Ameliorate Effect of Total Ginsenoside Treatment

Sleep loss or sleep deprivation (SD) refers to shorter sleep than average baseline need, and SD has been a serious problem of modern societies which affects health and well-being. Panax ginseng is a well-known traditional Chinese medicine (TCM). Our previous study has demonstrated that total ginsenosides (GS), the extracts from Panax ginseng, could effectively improve cognition and behavior on SD rats. However, little is known about its metabolomic study. In this study, serum and brain metabolomic method based on gas chromatography coupled with mass spectrometry (GC/MS) was employed to evaluate the efficacy and study the mechanism of GS on a rat model of SD. With pattern recognition analysis of serum and brain tissue metabolite profile, a clear separation of the model group and control group was acquired for serum and brain tissue samples; the MGS (model + GS) group showed a tendency of recovering when compared to control group, which was consistent with behavioral and biochemical parameters. 39 and 40 potential biomarkers of brain tissues and serum samples, respectively, were identified and employed to explore the possible mechanism. Our work revealed that GS has significant protective effects on SD, and metabolomics is a useful tool for evaluating efficacy and elucidating mechanism in TCM.

The effects of kisspeptin-10 on serum metabolism and myocardium in rats

Kisspeptin is a peptide encoded by the Kiss 1 gene and is also called metastin. Previous studies have generally focused on several functions of this peptide, including metastasis, puberty, vasoconstriction and reproduction. However, few studies have focused on the cardiac functions of kisspeptin. In the present study, cardiac histomorphology was observed via TEM (transmission electron microscope) and HE and Masson staining to observe instinctive changes. Serum metabolites levels were also measured and analyzed using GC/TOF-MS after injection with kisspeptin-10. A gene chip was employed to screen the potential genes and pathways in the myocardium at the transcriptional leve, while RT-PCR and Western Blot were conducted to verify the relevant mRNA and protein expression, respectively. Histopathological findings demonstrated that there were many irregular wavy contractions through HE staining and increased fibrosis around the heart cells through Masson staining after treatment with kisspeptin-10. Additionally, the main changes in ultrastructure, including changes in mitochondrial and broken mitochondrial cristae, could be observed with TEM after treatment with kisspeptin-10. The PCA scores plot of the serum metabolites was in the apparent partition after injection of kisspeptin-10. Twenty-six obviously changed metabolites were detected and classified as amino acids, carbohydrate metabolites, organic acids and other metabolites. Furthermore, gene chip analysis showed 1112 differentially expressed genes after treatment with kisspeptin-10, including 330 up-regulated genes and 782 down-regulated genes. These genes were enriched in several signaling pathways related to heart diseases. The RT-PCR result for ITGB8, ITGA4, ITGB7, MYL7, HIF1-α and BNP corresponded with the gene chip assay. Moreover, the upregulated genes ITGB8, ITGA4 and BNP also displayed consistent protein levels in Western Blot results. In summary, these findings suggest that kisspeptin-10 could alter the morphology and structure of myocardial cells, serum metabolite levels, and expression of genes and proteins in heart tissues. Our work determined the profound effects of kisspeptin-10 on the heart, which could further lead to the development of therapeutics related to kisspeptin-10, including antagonists and analogs.

Anti-stress effects of ginseng total saponins on hindlimb-unloaded rats assessed by a metabolomics study

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng, the roots and rhizomes of Panax ginseng C.A. Mey. (Araliaceae), is used as a tonic herb for thousands of years in Asian countries. Saponins are recognized as its major active ingredients and reportedly can ease disorders caused by various adverse stimuli. Nevertheless, it is unclear whether ginseng saponins have beneficial effects on stress caused by microgravity.

AIM OF THE STUDY

This study aimed to assess the anti-stress effects and corresponding mechanisms of ginseng total saponins (GTSs) on simulated microgravity (SM) hindlimb-unloaded rats using a metabolomics method.

MATERIALS AND METHODS

The stressed rats were induced by hindlimb unloading for 7 continuous days. Levels of plasma corticosterone (CORT) and weights of immune organs including the thymuses, spleens, and adrenal glands were determined. Urinary metabolic profiles of the rats under the simulated microgravity condition with and without GTSs intervention were compared using an ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF-MS) based metabolomics method. Multivariate statistical analysis including Principal Component Analysis (PCA) and Partial Least Squares project to latent structures-Discriminant Analysis (PLS-DA) were performed.

RESULTS

Compared with control (66.22±10.40ng/mL), the plasma CORT level of the SM rats (82.67±13.64ng/mL) were significantly (p<0.05) elevated, and GTSs could restore this elevation to a lower level (77.75±14.35ng/mL). GTSs could also significantly alleviate the atrophy of the thymuses and the spleens, as well as the hypertrophy of the adrenal glands of the SM rats. Urinary metabolic profiling showed comprehensive metabolic variation among the three groups. A series of metabolic pathways including taurine and hypotaurine, purine and pyridine, and amino acid were affected. Eleven potential biomarkers such as taurine, adenine, and valine were identified. GTSs could correct the disturbed metabolic pathways and restore the variation of these potential markers.

CONCLUSION

GTSs can exert anti-stress effects by reducing the secretion of plasma CORT, enhancing the immune function, and restoring an array of disturbed metabolic pathways and metabolites. The findings of this study provide crucial evidence of a link between metabolic imbalance and microgravity, and reveal a molecular basis for the anti-stress benefits of GTSs in the management of microgravity-related disorders.

Metabolomics studies in brain tissue: A review

Brain is still an organ with a composition to be discovered but beyond that, mental disorders and especially all diseases that curse with dementia are devastating for the patient, the family and the society. Metabolomics can offer an alternative tool for unveiling new insights in the discovery of new treatments and biomarkers of mental disorders. Until now, most of metabolomic studies have been based on biofluids: serum/plasma or urine, because brain tissue accessibility is limited to animal models or post mortem studies, but even so it is crucial for understanding the pathological processes. Metabolomics studies of brain tissue imply several challenges due to sample extraction, along with brain heterogeneity, sample storage, and sample treatment for a wide coverage of metabolites with a wide range of concentrations of many lipophilic and some polar compounds. In this review, the current analytical practices for target and non-targeted metabolomics are described and discussed with emphasis on critical aspects: sample treatment (quenching, homogenization, filtration, centrifugation and extraction), analytical methods, as well as findings considering the used strategies. Besides that, the altered analytes in the different brain regions have been associated with their corresponding pathways to obtain a global overview of their dysregulation, trying to establish the link between altered biological pathways and pathophysiological conditions.

The Current Situation on Major Depressive Disorder in China: Research on Mechanisms and Clinical Practice

Depression is the most disabling disorder worldwide that accounts for the highest proportion of global burden attributable to mental disorders. Major depressive disorder (MDD) is characterized by deep sadness, reduced energy, vegetative nervous system dysregulation, cognitive dysfunction, and even a high suicidal tendency. Although other treatment choices are available, antidepressant medication is the front-line treatment option for MDD. Regarding clinical efficacy, only ~50% of patients respond to frontline antidepressants, and <33% obtain remission. Currently, objective indexes to guide clinical decisions are still lacking. Furthermore, knowledge about the neurobiological mechanisms underlying discrepant antidepressant outcomes is still also fragmentary. In the present review, we discuss the current research progress and clinical opinions on MDD in China.

Gastrointestinal Symptoms and Altered Intestinal Permeability Induced by Combat Training Are Associated with Distinct Metabotypic Changes

Physical and psychological stress have been shown to modulate multiple aspects of gastrointestinal (GI) physiology, but its molecular basis remains elusive. We therefore characterized the stress-induced metabolic phenotype (metabotype) in soldiers during high-intensity combat training and correlated the metabotype with changes in GI symptoms and permeability. In a prospective, longitudinal study, urinary metabotyping was conducted on 38 male healthy soldiers during combat training and a rest period using gas chromatography-mass spectrometry. The urinary metabotype during combat training was clearly distinct from the rest period (partial least-squares discriminant analysis (PLSDA) Q(2) = 0.581), confirming the presence of a unique stress-induced metabotype. Differential metabolites related to combat stress were further uncovered, including elevated pyroglutamate and fructose, and reduced gut microbial metabolites, namely, hippurate and m-hydroxyphenylacetate (p < 0.05). The extent of pyroglutamate upregulation exhibited a positive correlation with an increase in IBS-SSS in soldiers during combat training (r = 0.5, p < 0.05). Additionally, the rise in fructose levels was positively correlated with an increase in intestinal permeability (r = 0.6, p < 0.005). In summary, protracted and mixed psychological and physical combat-training stress yielded unique metabolic changes that corresponded with the incidence and severity of GI symptoms and alteration in intestinal permeability. Our study provided novel molecular insights into stress-induced GI perturbations, which could be exploited for future biomarker research or development of therapeutic strategies.

Analytical protocols based on LC-MS, GC-MS and CE-MS for nontargeted metabolomics of biological tissues

Invasive, site-specific metabolite information could be better obtained from tissues. Hence, highly sensitive mass spectrometry-based metabolomics coupled with separation techniques are increasingly in demand in clinical research for tissue metabolomics application. Applying these techniques to nontargeted tissue metabolomics provides identification of distinct metabolites. These findings could help us to understand alterations at the molecular level, which can also be applied in clinical practice as screening markers for early disease diagnosis. However, tissues as solid and heterogeneous samples pose an additional analytical challenge that should be considered in obtaining broad, reproducible and representative analytical profiles. This manuscript summarizes the state of the art in tissue (human and animal) treatment (quenching, homogenization and extraction) for nontargeted metabolomics with mass spectrometry.

Metabolomic identification of biochemical changes induced by fluoxetine and imipramine in a chronic mild stress mouse model of depression

Metabolomics was applied to a C57BL/6N mouse model of chronic unpredictable mild stress (CMS). Such mice were treated with two antidepressants from different categories: fluoxetine and imipramine. Metabolic profiling of the hippocampus was performed using gas chromatography-mass spectrometry analysis on samples prepared under optimized conditions, followed by principal component analysis, partial least squares-discriminant analysis, and pair-wise orthogonal projections to latent structures discriminant analyses. Body weight measurement and behavior tests including an open field test and the forced swimming test were completed with the mice as a measure of the phenotypes of depression and antidepressive effects. As a result, 23 metabolites that had been differentially expressed among the control, CMS, and antidepressant-treated groups demonstrated that amino acid metabolism, energy metabolism, adenosine receptors, and neurotransmitters are commonly perturbed by drug treatment. Potential predictive markers for treatment effect were identified: myo-inositol for fluoxetine and lysine and oleic acid for imipramine. Collectively, the current study provides insights into the molecular mechanisms of the antidepressant effects of two widely used medications.

Urinary metabolomics study on an induced-stress rat model using UPLC-QTOF/MS

An integrated application of multivariable analysis and artificial intelligence was used for the first time to find potential biomarkers relating to the occurrence and development of liver-Qi syndrome PMS induced by electric stimulation in rats.

Proteomics, metabolomics, and protein interactomics in the characterization of the molecular features of major depressive disorder

Omics technologies emerged as complementary strategies to genomics in the attempt to understand human illnesses. In general, proteomics technologies emerged earlier than those of metabolomics for major depressive disorder (MDD) research, but both are driven by the identification of proteins and/or metabolites that can delineate a comprehensive characterization of MDD's molecular mechanisms, as well as lead to the identification of biomarker candidates of all types—prognosis, diagnosis, treatment, and patient stratification. Also, one can explore protein and metabolite interactomes in order to pinpoint additional molecules associated with the disease that had not been picked up initially. Here, results and methodological aspects of MDD research using proteomics, metabolomics, and protein interactomics are reviewed, focusing on human samples.

Amino acid metabolic dysfunction revealed in the prefrontal cortex of a rat model of depression

Major depressive disorder (MDD) is a debilitating mood disorder. However, the molecular mechanism(s) underlying depression remain largely unknown. Here, we applied a GC-MS-based metabonomic approach in the chronic unpredictable mild stress (CUMS) model, a well-established rodent model of depression, to investigate significant metabolic changes in the rat prefrontal cortex (PFC). Multivariate statistical analysis - including principal component analysis, partial least squares-discriminate analysis, and pair-wise orthogonal projections to latent structures discriminant - was applied to identify differential PFC metabolites between CUMS rats and healthy controls. As compared to healthy control rats, CUMS rats were characterized by lower levels of isoleucine and glycerol in combination with higher levels of N-acetylaspartate and β-alanine. These findings should provide insight into the pathophysiological mechanism(s) underlying MDD and preliminary leads relevant to diagnostic biomarker discovery for depression.

Effect of bisphenol A on rat metabolic profiling studied by using capillary electrophoresis time-of-flight mass spectrometry

Bisphenol A (BPA), a chemical widely used in the manufacture of polycarbonate plastics, has raised considerable concern in recent decades because of its hormone-like properties. Whether BPA exposure is a health risk remains controversial in many countries. A metabolomics study based on capillary electrophoresis time-of-flight mass spectrometry (CE-TOF/MS) was performed to study the urine metabolic profiles of Sprague-Dawley rats fed with four dose levels of BPA (0, 1, 10, and 100 μg/kg body weight) for 45 days. Multivariate pattern recognition directly reflected the metabolic perturbations caused by BPA. On the basis of univariate analysis, 42 metabolites including amino acids, polyamines, nucleosides, organic acids, carbohydrates, pterins, polyphenols, and sugar phosphates were found as the most significantly differential metabolites. The marked perturbations were related with valine, leucine and isoleucine biosynthesis, D-glutamine and D-glutamate metabolism, etc. Significant alterations of neurotransmitters (glutamate, gamma-aminobutyric acid, and noradrenaline) and neurotransmitter-related metabolites (tyrosine, histamine, valine, and taurine) suggested that the toxic effects of small-dose BPA (below 50 mg/kg/day) may contribute to its interactions with the neuromediating system. Our study demonstrated that metabolomics may offer more specific insights into the molecular changes underlying the physiological effects of BPA.