Metabolomic study of corticosterone-induced cytotoxicity in PC12 cells by ultra performance liquid chromatography-quadrupole/time-of-flight mass spectrometry

Metabolic response of Lactobacillus acidophilus exposed to amoxicillin

Drug-induced diarrhea is a common adverse drug reaction, especially the one caused by the widespread use of antibiotics. The reduction of probiotics is one reason for intestinal disorders induced by an oral antibiotic. However, the intrinsic mechanism of drug-induced diarrhea is still unknown. In this study, we used metabolomics methods to explore the effects of the classic oral antibiotic, amoxicillin, on the growth and metabolism of Lactobacillus acidophilus, while scanning electron microscopy (SEM) and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were employed to evaluate changes in cell activity and morphology. The results showed that cell viability gradually decreased, while the degree of cell wall rupture increased, with increasing amoxicillin concentrations. A non-targeted metabolomics analysis identified 13 potential biomarkers associated with 9 metabolic pathways. The data showed that arginine and proline metabolism, nicotinate and nicotinamide metabolism, pyrimidine metabolism, glycine, serine and threonine metabolism, beta-alanine metabolism, glycerolipid metabolism, tryptophan metabolism, steroid hormone biosynthesis, and histidine metabolism may be involved in the different effects exerted by amoxicillin on L. acidophilus. This study provides potential targets for screening probiotics regulators and lays a theoretical foundation for the elucidation of their mechanisms.

Metabolomic analysis of spontaneous neutrophil apoptosis reveals the potential involvement of glutathione depletion

Spontaneous apoptosis of neutrophils plays a key role in maintaining immune homeostasis and resolving inflammation. However, the mechanism triggering this apoptosis remains obscure. In the present study, we performed a global metabolomics analysis of neutrophils undergoing spontaneous apoptosis by using hydrophilic interaction chromatography ultra-high-performance liquid chromatography-tandem quadrupole/time-of-flight mass spectrometry and found 23 metabolites and 42 related pathways that were altered in these cells. Among them, glutathione, which is known to be involved in apoptosis, was particularly interesting. We found that L-pyroglutamic acid, glutamate, and their glutathione-mediated embolic pathways were all changed. Our findings confirmed the glutathione levels decreased in apoptotic neutrophils. Exogenous glutathione and LPS treatment delayed neutrophil apoptosis and decreased the levels of pro-apoptotic protein caspase-3. γ-glutamylcyclotransferase, 5-oxoprolinase, and ChaC1, which participated in glutathione degradation, were all activated. At the same time, the down-regulation of ATP production suggested the activity of glutathione biosynthesis may be attenuated even if glutamate-cysteine ligase and glutathione synthase, which are two ATP-dependent enzymes participating in glutathione biosynthesis, were enhanced. To our knowledge, this is the first report highlighting a global metabolomics analysis using hydrophilic interaction chromatography ultra-high-performance liquid chromatography-tandem quadrupole/time-of-flight mass spectrometry and the potential involvement of glutathione depletion in spontaneous apoptosis of neutrophils demonstrating that LPS could delay this process.

Serum metabolomics reveals the intervention mechanism and compatible regularity of Chaihu Shu Gan San on chronic unpredictable mild stress-induced depression rat model

OBJECTIVES

To provide a comprehensive study of the intervention mechanism and compatible regularity of Chaihu Shu Gan San (CSGS) in a chronic unpredictable mild stress (CUMS)-induced depression model.

METHODS

Ethological study and ELISA assay were applied to measure the phenotypes of depression after CUMS stimulate and assess the antidepressant activity of fluoxetine, CSGS and its compatibilities. The serum metabolic profile changes were revealed by untargeted Q/TOF MS-based metabolomics followed by multivariate statistical analysis.

KEY FINDINGS

CSGS exhibits an significant intervention effect on CUMS-induced depression. After the multivariate statistical analysis, 17 potential serum biomarkers were identified and 16 of them could be regulated by CSGS. The intervention of CSGS on CUMS-induced depression involved five key pathways. Moreover, each functional unit (monarch, minister, assistant and guide medicine) in CSGS regulates different metabolites and metabolic pathways to achieve different effects on antidepressant; however, their intervention efficacies are inferior to the holistic formula, which may be due to the synergism of bioactive ingredients in the seven herbs of CSGS.

CONCLUSIONS

CSGS produced an obvious antidepressant activity. The comprehensive and holistic metabolomics approach could be a powerful tool to study the intervention mechanism and the compatibility rule of traditional Chinese medicine.

Protective Effect of Resveratrol Against Corticosterone-induced Neurotoxicity in PC12 Cells

Objective

Resveratrol(RES) is a natural polyphenol which possesses an anti-depressant effect. However, the mechanisms of its anti-depressant effect remain unclear. The aim of the study is to investigate the potential mechanisms in the neuro-protective efficiency in the corticosterone-induced pheochromacytoma 12 (PC12) cells.

Methods

PC12 cells were treated with 200 μM of corticosterone in the absence or presence of different concentrations of RES for 24 h. Then, cell viability was measured by Cell Counting Kit-8 assay. Apoptosis of PC12 cells was measured by Annexin V-FITC and Propidium iodide (PI) labelling. The expression of apoptosis-related proteins including Bax, Bcl-2, caspase-3 was determined by western blotting.

Results

The results showed that treatment with 200 μM of corticosterone induced cytotoxicity in PC12 cells. However, different concentrations of RES (2.5μmol/L, 5μmol/L and 10 μmol/L) significantly increased the cell viability, suppressed the apoptosis of PC12 cells, down-regulated Bax and caspase-3 protein expression, and up-regulated Bcl-2 protein expression, compared to the model group (p<0.05).

Conclusion

Resveratrol has a protective effect on corticosterone-induced neurotoxicity in PC12 cells, which may be related to the apoptosis via inhibition of apoptosis-related proteins and displays the antidepressant-like effect.

Acute and short-term administrations of delta-9-tetrahydrocannabinol modulate major gut metabolomic regulatory pathways in C57BL/6 mice

Delta-9-tetrahydrocannabinol (THC) is the primary psychoactive compound in Cannabis, which is studied extensively for its medicinal value. A central gap in the science is the underlying mechanisms surrounding THC's therapeutic effects and the role of gut metabolite profiles. Using a mass-spectrometry based metabolomics, we show here that intraperitoneal injection of THC in C57BL/6 mice modulates metabolic profiles that have previously been identified as integral to health. Specifically, we investigated the effects of acute (single THC injection denoted here as '1X') and short -term (five THC injections on alternate days denoted as '5X') THC administration on fecal and intestinal tissue metabolite profiles. Results are consistent with the hypothesis that THC administration alters host metabolism by targeting two prominent lipid metabolism pathways: glycerophospholipid metabolism and fatty acid biosynthesis.

Uncovering the anti-proliferation mechanism and bioactive compounds in red kidney bean coat against B16-F10 melanoma cells by metabolomics and network pharmacology analysis

In this study, coat (RKBC) and kernel (RKBK) extracts of red kidney bean were prepared, and their chemical compositions and potential anti-cancer activity against B16-F10 cells were evaluated.

Metabolomic study of natrin-induced apoptosis in SMMC-7721 hepatocellular carcinoma cells by ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry

Natrin, a new member of the cysteine-rich secretory protein (CRISP) family purified from the snake venom of Naja naja atra, has been demonstrated to have anticancer activity. However, the underlying molecular mechanisms need further elucidation. In this study, MTT was used to evaluate cell viability. Apoptotic cells were analyzed by employing a transmission electron microscope (TEM). Metabolomic study of the metabolic perturbations caused by natrin-induced apoptosis in differentiated SMMC-7721 cells was performed for the first time by using integrative ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF MS). To investigate the possible mechanism in the mitochondrial pathway of natrin-induced apoptosis, we measured apoptosis-related mRNA changes using real-time fluorescent quantitative PCR (FQ-PCR). Cell proliferation was significantly inhibited after treatment with natrin in a dose-dependent manner. Principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) clearly demonstrated that metabolic profiles were affected by natrin. The results of multivariate statistical analysis showed that a total of 13 metabolites were characterized as potential biomarkers highly implicated in natrin-induced apoptosis, which corresponded to fluctuations of five pathways, including sphingolipid metabolism, fatty acid biosynthesis, fatty acid metabolism, glycerophospholipid metabolism and glycosphingolipid biosynthesis. Furthermore, natrin-induced apoptosis showed an increase in the Bax/Bcl-2 ratio in the mitochondrial pathway compared with controls. This study illustrated that rapid and holistic cell metabolomics combining molecular biological approaches might be a powerful tool for evaluating the underlying mechanisms of natrin-induced apoptosis, which would help to deepen specific insights into the anti-hepatoma mechanisms of natrin and facilitate the clinical application of natrin in the future.

Serum metabolomics of laryngeal cancer based on liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

The discovery of new laryngeal cancer-related metabolite biomarkers could help to facilitate early diagnosis. A serum metabolomics study from laryngeal cancer patients and healthy individuals was conducted using liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Univariate and multivariate statistics were used to discriminate laryngeal cancer patients and healthy individuals. 1-Palmitoyl-sn-glycero-3-phosphocholine (LysoPC 16:0), 1-o-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (PAF) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine were found to be significantly different between the laryngeal cancer group and the healthy group. They are mainly involved in phospholipids catabolism, linoleic acid metabolism, α-linoleic acid metabolism and arachidonic acid metabolism. The area under the curve of the biomarker combined by two metabolites (LysoPC 16:0 and PAF) was 0.935, the sensitivity was 0.962 and the specificity was 0.825. LysoPC 16:0 and PAF may show diagnostic potential for laryngeal carcinoma.

Protective effect of isoliquiritin against corticosterone-induced neurotoxicity in PC12 cells

Isoliquiritin, a flavonoid glycoside compound from licorice, possesses a broad spectrum of pharmacological activities including antioxidant, anti-inflammatory and anti-depression activities. However, the neuroprotective mechanisms of antidepressant effects remain unclear. In this study, the aim was to investigate the cytoprotective efficiency and potential mechanisms of isoliquiritin in corticosterone-damaged PC12 cells. The results of this study showed that pretreatment of PC12 cells with isoliquiritin significantly prevented corticosterone-induced cell apoptosis. In addition, isoliquiritin increased the activity of dismutase (SOD) and catalase (CAT), decreased the contents of reactive oxygen species (ROS) and malondialdehyde (MDA). These findings suggest that isoliquiritin provides protective action against corticosterone-induced cell damage by reducing oxidative stress. Furthermore, pretreatment with isoliquiritin reduced corticosterone-induced mitochondrial dysfunction by preventing mitochondrial membrane potential dissipation. Our findings indicate that isoliquiritin might exert its therapeutic effects via regulating mitochondrial dysfunction. Moreover, isoliquiritin strongly attenuated intracellular calcium ([Ca²⁺]i) overload and down-regulation of Bax, caspase-3 and cytochrome C (Cyt-C) protein expression, and up-regulation of Bcl protein expression. In conclusion, isoliquiritin has a cytoprotective effect on corticosterone-induced neurotoxicity in PC12 cells, which may be related to its antioxidant action, inhibition of [Ca²⁺]i overload and inhibition of the mitochondrial apoptotic pathway.

Effects of phenolic constituents of daylily flowers on corticosterone- and glutamate-treated PC12 cells

Background

Daylily flowers, the flower and bud parts of Hemerocallis citrina or H. fulva, are well known as Wang-You-Cao in Chinese, meaning forget-one’s sadness plant. However, the major types of active constituents responsible for the neurological effects remain unclear. This study was to examine the protective effects of hydroalcoholic extract and fractions and to identify the active fractions.

Methods

The extract of daylily flowers was separated with AB-8 resin into different fractions containing non-phenolic compounds, phenolic acid derivatives and flavonoids as determined using UPLC-DAD chromatograms. The neuroprotective activity was measured by evaluating the cell viability and lactate dehydrogenase release using PC12 cell damage models induced by corticosterone and glutamate. The neurological mechanisms were explored by determining their effect on the levels of dopamine (DA), 5-hydroxy tryptamine (5-HT), γ-aminobutyric acid (GABA), noradrenaline (NE) and acetylcholine (ACh) in the cell culture medium measured using an LC-MS/MS method.

Results

Pretreatment of PC12 cells with the extract and phenolic fractions of daylily flowers at concentrations ranging from 0.63 to 5 mg raw material/mL significantly reversed corticosterone- and glutamate-induced neurotoxicity in a dose-dependent manner. The fractions containing phenolic acid derivatives (0.59% w/w in the flowers) and/or flavonoids (0.60% w/w) exerted similar dose-dependent neuroprotective effect whereas the fractions with non-phenolic compounds exhibited no activity. The presence of phenolic acid derivatives in the corticosterone- and glutamate-treated PC12 cells elevated the DA level in the cell culture medium whereas flavonoids resulted in increased ACH and 5-HT levels.

Conclusion

Phenolic acid derivatives and flavonoids were likely the active constituents of daylily flowers and they conferred a similar extent of neuroprotection, but affected the release of neurotransmitters in a different manner.