LC-MS Metabolomic Analysis Research Articles

Abdominal obesity in youth: the associations of plasma Lysophophatidylcholine concentrations with insulin resistance.

This study aimed to explore the associations of lysophosphatidylcholines (LPCs) with insulin resistance (IR) and abdominal obesity among children and adolescents. A cross-sectional study was conducted on 612 young individuals, aged 7 to 18 years in Tianjin City, China. LC-MS metabolomic analysis was used to measure LPCs levels. The Homeostasis Model Assessment was used to estimate IR. Waist circumference measurements were used to assess abdominal obesity. Logistic regression models were employed to explore the relationships between LPCs and IR and abdominal obesity. Mediation analyses were performed to analyze whether LPCs affected IR through abdominal obesity. Compared to their counterparts, five specific LPCs were significantly different in youth with IR. The levels of LPC 24:0 and 26:0 were significantly associated with IR after adjustment. Both decreased levels of LPC 24:0 and 26:0 associated with the increased risks of IR (OR: 0.64, 95%CI: 0.38-0.95; OR: 0.66, 95%CI: 0.40-1.00), and the ORs for abdominal obesity were 0.68 (95%CI: 0.38-1.00) and 0.51 (95%CI: 0.28-0.90), respectively. Mediation analysis indicated that abdominal obesity mediated the association between LPC 26:0 and IR, with a total effect (c) of -0.109 (P < 0.05), a direct effect (c') of -0.055 (P > 0.05), and an indirect effect through obesity (a × b) path with "a" of -0.125 (P < 0.05) and "b" of 0.426 (P < 0.05). Overall findings suggest that decreased levels of LPC 24:0 and 26:0 were associated with increased risks of IR and abdominal obesity. Importantly, addressing abdominal obesity may mediate the impact of IR driven by LPC 26:0.

Comparison of behavioral responses, respiratory metabolism-related enzyme activities, and metabolomics of the juvenile Chinese mitten crab Eriocheir sinensis with different tolerance to air exposure

Air exposure is a common stressor for Chinese mitten crab (Eriocheir sinensis) during rearing and transport, and air exposure tolerance can serve as a crucial indicator for assessing the quality of juvenile E. sinensis. In this study, juvenile E. sinensis were divided into two groups based on their behavioral responses: Group S, which exhibited strong tolerance to air exposure, and Group W, which exhibited weak tolerance. Immersed crabs, not exposed to air, served as a control group (Group C). Whole body morphological characteristics and enzyme activities related to respiratory metabolism in the hemolymph and anterior gills were compared among the three groups. Non-targeted LC-MS metabolomic analysis was conducted on anterior gills. The results showed that, independent of developmental stage, crabs that were larger and had higher condition factor were more tolerant to air exposure. Additionally, compared to Group W, air exposure had a relatively small effect on glycolysis and anaerobic respiratory metabolic processes in the hemolymph and anterior gills of Group S. In response to air exposure, E. sinensis experienced increased energy demand, and switched from aerobic to anaerobic respiration to increase energy supply. Simultaneously, air exposure induced oxidative stress in the hemolymph and anterior gills. This study enhances our understanding of the response mechanism of E. sinensis to air exposure and provides a theoretical reference for the identification of high-quality juvenile E. sinensis.

Investigating the modulatory effects of lactoferrin on depressed rats through 16S rDNA gene sequencing and LC-MS metabolomics analysis.

Lactoferrin is a natural multifunctional glycoprotein with potential antidepressant-like effects. However, the mechanism of its antidepressant effect has not been explored from the perspective of gut flora metabolism. Therefore, we employed both 16S rDNA gene sequencing and LC-MS metabolomics analysis to investigate the regulatory effects and mechanisms of lactoferrin in a rat model of depression. After one week of acclimatization, twenty-four 7-week-old male Sprague-Dawley rats were randomly and equally assigned into three groups: the control group, the model group, and the lactoferrin intervention group. The control group rats were housed under standard conditions, while the rats in the model and lactoferrin intervention groups were individually housed and exposed to chronic unpredictable mild stress for 44days simultaneously. The lactoferrin intervention group was provided with water containing 2% lactoferrin (2g/100ml). Behavioural tests were conducted at week 7. Upon completion of the behavioral tests, the rats were anesthetized with isoflurane, humanely euthanized using a rat guillotine, and tissue samples were collected for further experiments. The results indicated that lactoferrin intervention led to an increase in sucrose solution consumption, horizontal movement distance, number of cross platforms, and residence time in the target quadrant. Additionally, it resulted in an increase in jejunal tight junction protein ZO-1 expression and a suppression of serum expression of inflammatory factors, Lipopolysaccharide and Diamine oxidase. In summary, lactoferrin can regulate the metabolic disorder of intestinal flora, reduce intestinal permeability, and further regulate the metabolic balance of hippocampal tissues through the microbiota-gut-brain axis. This process ultimately alleviates the depression-like behavior in rats.

Low-frequency ultrasound assisted contact-electro-catalysis for efficient inactivation of Microcystis aeruginosa

Frequent cyanobacterial blooms pose a serious threat to the aquatic ecosystem and human health, so developing an efficient algae removal method is a long-term goal for bloom management. Current technologies for algal bloom control need urgent improvement in terms of algicide recovery, eco-friendliness and cost. Here we propose a contact-electro-catalytic method, using polytetrafluoroethylene (PTFE) film as a reusable catalyst. This contact-electro-catalytic approach involves the generation of reactive oxygen species (e.g., O2•–, HO•, 1O2 and H2O2) through water-PTFE contact electrification under the low-frequency ultrasonic waves, facilitating the inactivation of algae. The removal rate of the cyanobacterium Microcystis aeruginosa (M. aeruginosa) exposured to the water-PTFE contact-electro-catalytic system is almost five times greater than that of ultrasound alone after 5 h. A mechanistic investigation revealed that the contact-electro-catalytic system damaged the photosynthetic activity, antioxidant system and membrane integrity of the cells. Additionally, LC-MS metabolomic analysis indicated that this system caused substantial significant disruptions in the TCA cycle, amino acid metabolism, purine metabolism and phospholipid metabolism. Three-dimensional fluorescence spectroscopy suggested contact-electro-catalysis could further availably degrade the organic matter. We anticipate that this method can provide an eco-friendly, highly efficient and economic approach for effective control of harmful algal blooms.

Nutrient and metabolite characteristics of the husk, bran and millet isolated from the foxtail millet (Setaria italica L.) during polishing

The utilization of byproducts from foxtail millet polishing can reduce food loss and waste. Thus, it is necessary to know the chemical compounds from the millet and the segregation of the layers. The nutrients including minerals were compared among the husk, bran, and millet, and a LC-MS metabolomics analysis was also performed among them. The results showed that the protein, crude fat and 4 fatty acids, seven minerals, the nitrogen-containing compounds and phenolic acids were at much higher levels in the bran part than the husk and millet, whereas the husk only contained higher levels of dietary fibre, and some minerals. The millet section, as the edible part, contained the lowest level of chemical constituents. It illustrated that the bran part contained more functional and nutritional components than the millet and husk part. Therefore, the bran of the foxtail millet should be a food resources instead of wasting.

Dietary succinate reduces fat deposition through gut microbiota and lipid metabolism in broilers

Succinate has been shown to be a potentially beneficial nutritional supplement with a diverse range of physiological functions. However, it remains unknown whether succinate supplementation regulates lipid metabolism in chickens. The aim of this study was to explore how succinate affects fat deposition and the underlying mechanism involved in broilers and to determine the most appropriate level of succinate supplementation in the diet. A total of 640 one-day-old male yellow-feathered broilers were randomly divided into 4 groups with 8 replicates and 20 broilers per replicate. A basal diet was provided to the control group (CON). The experimental broilers were fed diets containing 0.2% (L), 0.4% (M), or 0.6% (H) succinate and the study was lasted for 21 d. The linear (l) and quadratic (q) effects of succinate addition were determined. The results indicated that supplementation with 0.4% succinate reduced ADFI, serum triglycerides (l, q; P < 0.05), glucose (q; P < 0.05), and increased high-density lipidprotein cholesterol (l, q; P < 0.05) concentrations in broilers. Moreover, 0.4% succinate affects lipid metabolism by decreasing the abdominal fat percentage and adipocyte surface area, the expression of genes that promote liposynthesis in the abdominal fat and liver, as well as increasing the expression of genes that promote lipolysis in the abdominal fat and liver. In addition, increased cecal propionic acid content (q, P < 0.05) was found in the M group compared to the CON group. The 16S rRNA sequence analysis showed that group M altered cecum microbial composition by increasing the abundance of genera such as Blautia and Sellimonas (P < 0.05). LC-MS metabolomic analysis revealed that the differential metabolites between the M and CON groups were enriched in amino acid-related pathways. In conclusion, the optimum level of succinate added to broiler diets in the present study was 0.4%. Succinate can potentially reduce fat accumulation in broilers by modulating the composition of the gut flora and amino acid metabolism related to lipid metabolism.

LCMS-Metabolomic Profiling and Genome Mining of Delftia lacustris DSM 21246 Revealed Lipophilic Delftibactin Metallophores.

Bacteria have evolved various strategies to combat heavy metal stress, including the secretion of small molecules, known as metallophores. These molecules hold a potential role in the mitigation of toxic metal contamination from the environment (bioremediation). Herein, we employed combined comparative metabolomic and genomic analyses to study the metallophores excreted by Delftia lacustris DSM 21246. LCMS-metabolomic analysis of this bacterium cultured under iron limitation led to a suite of lipophilic metallophores exclusively secreted in response to iron starvation. Additionally, we conducted genome sequencing of the DSM 21246 strain using nanopore sequencing technology and employed antiSMASH to mine the genome, leading to the identification of a biosynthetic gene cluster (BGC) matching the known BGC responsible for delftibactin A production. The isolated suite of amphiphilic metallophores, termed delftibactins C-F (1-4), was characterized using various chromatographic, spectroscopic, and bioinformatic techniques. The planar structure of these compounds was elucidated through 1D and 2D NMR analyses, as well as LCMS/MS-based fragmentation studies. Notably, their structures differed from previously known delftibactins due to the presence of a lipid tail. Marfey's and bioinformatic analyses were employed to determine the absolute configuration of the peptide scaffold. Delftibactin A, a previously identified metallophore, has exhibited a gold biomineralizing property; compound 1 was tested for and also demonstrated this property.

PSVI-18 Low and high feed efficiency grower-finisher pigs fed three different levels of dietary crude protein showed no immediate difference in blood metabolomics profile

Abstract Improving feed efficiency (FE) of grower-finisher pigs is of great importance considering its impact on production economy, nutrient excretions as well as carbon-footprint. The biological background describing variation in FE between pen mates, is difficult to establish as feed intake (FI) and FE are not estimated on an individual level. In this study advanced feeding stations were used to estimate FI and further calculate feed conversion ratio (FCR) on individual level. The study aimed to investigate the possible difference in the blood metabolic profile between low and high FE grower-finisher pigs fed three different levels of dietary crude protein (CP). The study included 60 newly weaned gilts divided in two series, housed as 10 pigs/pen. The 30 pigs per series were distributed between three pens (10 pigs/pen) and were balanced by body weight and litter. Throughout the entire weaner period all pigs had ad libitum access to the same diet. Pigs were redistributed among the grower-finisher pens to balance FCR levels between dietary treatments (CP levels) and to reduce any carry over effect from the weaner to the grower-finisher pens. From 30-115 kg body weight (BW), pigs were fed either a low (L; 14.8% CP), standard (15.2% CP) or high (H; 15.8% CP) CP diet equal in energy, where BW, average weekly gain (AWG), and FCR were determined on weekly basis, while FI was estimated on daily basis. Three low FE (20% least) and three high FE (20% greatest) pigs were selected based on the final 4 wk of growth within station and CP level. On the final day of the experimental period all low-FE and high-FE pigs within each dietary treatment were euthanized and blood plasma was sampled and subjected to a nontargeted LC-MS metabolomics analysis. Growth performance and metabolite data were, respectively, analyzed in R and MetaboAnalyst 5.0 with FE and CP as fixed effects. High-FE and H-CP pigs continuously displayed numerically greater BW, while AWG and FCR were, respectively, numerically greater, and less in L-CP than H-CP group during last 2 wk of the experimental period. Principal Component Analysis (PCA) showed no grouping (P &amp;gt; 0.05) of metabolites and no specific pattern of the metabolic profile from either the two FE categories or the three dietary CP levels. Furthermore, no correlation (P &amp;gt;0.05) of metabolites to any other observation was found, and only little variation, measured by distance to model showing deviation of each pig to overall model, was observed. In conclusion, at first glance the metabolomics profile did not appear to present any specific pattern between low and high feed efficiency grower-finisher pigs or between pigs exposed to different levels of dietary CP in the grower finisher period.

Comparative metabolomics reveals serum metabolites changes in goats during different developmental stages

Goats can provide meat, milk and skins for humans and are livestock with high economic benefits. However, despite their economic significance, the comprehensive analysis of goats’ serum metabolic profile and its intricate alterations throughout their developmental journey remains conspicuously absent. To investigate the stage-specificity and dynamic change characteristics of metabolites during the growth and development of goats, this study compared the alterations in serum hormone levels and serum biochemical markers across different developmental stages of female goats (1, 60, 120 and 180 days old; n = 5). Additionally, a serum untargeted LC–MS metabolomics analysis was conducted. A total of 504 DAMs were identified with age. The results indicated that PE, PC, Lyso-PE, Lyso-PC and FAFHA may play important roles in lipid metabolism in goats after birth. Weighted gene co-expression network analysis (WGCNA) identified two metabolite modules (Turquoise and Yellow) and key metabolites within these modules that were significantly associated with phenotypic features. l-carnitine may be a metabolite related to muscle development in goats. The findings of this study demonstrate notable variations in serum metabolites across distinct developmental phases in goats. Lipids and organic acids play important roles in different developmental stages of goats.

Mechanistic study of C5F10O-induced lung toxicity in rats: An eco-friendly insulating gas alternative to SF6

The global warming and other environmental problems caused by SF6 emissions can be reduced due to the widespread use of eco-friendly insulating gas, perfluoropentanone (C5F10O). However, there is an exposure risk to populations in areas near C5F10O equipment, so it is important to clarify its biosafety and pathogenesis before large-scale application. In this paper, histopathology, transcriptomics, 4D-DIA proteomics, and LC-MS metabolomics of rats exposed to 2000 ppm and 6000 ppm C5F10O are analyzed to reveal the mechanisms of toxicity and health risks. Histopathological shows that inflammatory cell infiltration, epithelial cell hyperplasia, and alveolar atrophy accompanied by alveolar wall thickening are present in both low-dose and high-dose groups. Analysis of transcriptomic and 4D-DIA proteomic show that Cell cycle and DNA replication can be activated by both 2000 ppm and 6000 ppm C5F10O to induce cell proliferation. In addition, it also leads to the activation of pathways such as Antigen processing and presentation, Cell adhesion molecules and Complement and coagulation cascades, T cell receptor signal path, Th1 and T cell receptor signal path, Th1 and Th2 cell differentiation, complement and coagulation cascades. Finally, LC-MS metabolomics analysis confirms that the metabolic pathways associated with glycerophospholipids, arachidonic acid, and linoleic acid are disrupted and become more severe with increasing doses. The mechanism of lung toxicity caused by C5F10O is systematically expounded based on the multi-omics analysis and provided biosafety references for further promotion and application of C5F10O.

Environmentally relevant concentrations of chemically complex shale gas wastewater led to reduced fitness of water fleas (Daphnia carinata): Multiple lines of evidence approach

Shale gas hydraulic fracturing generates flowback waters that pose a threat to aquatic organisms if released into the environment. In order to prevent adverse effects on aquatic ecosystems, multiple lines of evidence are needed to guide better decisions and management actions. This study employed a multi-disciplinary approach, combining direct toxicity assessment (DTA) on the water flea Daphnia carinata and LC-MS metabolomics analysis to determine the impact of a major ion salinity control (SC) and a cumulative flowback shale gas wastewater (SGW) from a well in the Beetaloo Sub-basin, Northern Territory, Australia. The exposures included a culture water control, simply further referred to as ‘control’, SC at 1% and 2% (v/v) and SGW at 0.125, 0.25, 0.5, 1% and 2% (v/v). The results showed that reproduction was significantly increased at SGW 0.5%, and significantly decreased when exposed to SC 2%. SGW 2% was found to be acutely toxic for the D. carinata (< 48-h). Second generation (F1) of D. carinata exposed to 0.125–1% SGW generally saw reduced activity in four oxidative biomarkers: glutathione S-transferase, lipid peroxidation, reactive oxygen species, and superoxide dismutase. At the metabolomics level, we observed significant changes in 103 metabolites in Daphnia exposed to both SGW and elevated salinity, in comparison to the control group. These changes indicate a range of metabolic disturbances induced by SGW and salinity, such as lipid metabolism, amino acid metabolism, nucleotide synthesis, energy production, and the biosynthesis of crucial molecules like hormones and pigments. These multiple lines of evidence approach not only highlights the complexities of SGW's impact on aquatic ecosystems but also underscores the importance of informed decision-making and management practices to safeguard the environment and its inhabitants.

From the perspective of rumen microbiome and host metabolome, revealing the effects of feeding strategies on Jersey Cows on the Tibetan Plateau.

Previous studies have discussed the effects of grazing and house feeding on yaks during the cold season when forage is in short supply, but there is limited information on the effects of these feeding strategies on Jersey cows introduced to the Tibetan Plateau. The objective of this study was to use genomics and metabolomics analyses to examine changes in rumen microbiology and organism metabolism of Jersey cows with different feeding strategies. We selected 12 Jersey cows with similar body conditions and kept them for 60 days under grazing (n=6) and house-feeding (n=6) conditions. At the end of the experiment, samples of rumen fluid and serum were collected from Jersey cows that had been fed using different feeding strategies. The samples were analyzed for rumen fermentation parameters, rumen bacterial communities, serum antioxidant and immunological indices, and serum metabolomics. The results of the study were examined to find appropriate feeding strategies for Jersey cows during the cold season on the Tibetan plateau. The results of rumen fermentation parameters showed that concentrations of acetic acid, propionic acid, and ammonia nitrogen in the house-feeding group (Group B) were significantly higher than in the grazing group (Group G) (P<0.05). In terms of the rumen bacterial community 16S rRNA gene, the Chao1 index was significantly higher in Group G than in Group B (P=0.038), while observed species, Shannon and Simpson indices were not significantly different from the above-mentioned groups (P>0.05). Beta diversity analysis revealed no significant differences in the composition of the rumen microbiota between the two groups. Analysis of serum antioxidant and immune indices showed no significant differences in total antioxidant capacity between Group G and Group B (P>0.05), while IL-6, Ig-M , and TNF-α were significantly higher in Group G than in Group B (P<0.05). LC-MS metabolomics analysis of serum showed that a total of 149 major serum differential metabolites were found in Group G and Group B. The differential metabolites were enriched in the metabolic pathways of biosynthesis of amino acids, protein digestion and absorption, ABC transporters, aminoacyl-tRNA biosynthesis, mineral absorption, and biosynthesis of unsaturated fatty acids. These data suggest that the house-feeding strategy is more beneficial to improve the physiological state of Jersey cows on the Tibetan Plateau during the cold season when forages are in short supply.

LC/MS-based discrimination between plasma and urine metabolomic changes following exposure to ultraviolet radiation by using data modelling

IntroductionThis study sought to compare between metabolomic changes of human urine and plasma to investigate which one can be used as best tool to identify metabolomic profiling and novel biomarkers associated to the potential effects of ultraviolet (UV) radiation.MethodA pilot study of metabolomic patterns of human plasma and urine samples from four adult healthy individuals at before (S1) and after (S2) exposure (UV) and non-exposure (UC) were carried out by using liquid chromatography-mass spectrometry (LC–MS).ResultsThe best results which were obtained by normalizing the metabolites to their mean output underwent to principal components analysis (PCA) and Orthogonal Partial least squares-discriminant analysis (OPLS-DA) to separate pre-from post-of exposure and non-exposure of UV. This separation by data modeling was clear in urine samples unlike plasma samples. In addition to overview of the scores plots, the variance predicted-Q2 (Cum), variance explained-R2X (Cum) and p-value of the cross-validated ANOVA score of PCA and OPLS-DA models indicated to this clear separation. Q2 (Cum) and R2X (Cum) values of PCA model for urine samples were 0.908 and 0.982, respectively, and OPLS-DA model values were 1.0 and 0.914, respectively. While these values in plasma samples were Q2 = 0.429 and R2X = 0.660 for PCA model and Q2 = 0.983 and R2X = 0.944 for OPLS-DA model. LC–MS metabolomic analysis showed the changes in numerous metabolic pathways including: amino acid, lipids, peptides, xenobiotics biodegradation, carbohydrates, nucleotides, Co-factors and vitamins which may contribute to the evaluation of the effects associated with UV sunlight exposure.ConclusionsThe results of pilot study indicate that pre and post-exposure UV metabolomics screening of urine samples may be the best tool than plasma samples and a potential approach to predict the metabolomic changes due to UV exposure. Additional future work may shed light on the application of available metabolomic approaches to explore potential predictive markers to determine the impacts of UV sunlight.

Higher niacin intakes improve the lean meat rate of Ningxiang pigs by regulating lipid metabolism and gut microbiota.

As one of the local pig breeds in China with a high fat rate, improving the lean meat rate of Ningxiang pigs through nutritional intervention is an urgent issue to be solved. As an important feed additive, niacin plays an important role in lipid metabolism. The purpose of this study was to investigate the regulation and mechanism of niacin on fat deposition in Ningxiang pigs. Thirty-four Ningxiang pigs (53.34 ± 2.78 kg) were randomly divided into two groups with five replicates each, with three to four Ningxiang pigs per replicate. The control group was fed a basal diet (contained 22 mg/kg niacin), and the experimental group was fed the same diet supplemented with an additional 100 mg/kg of niacin. The experimental period lasted 60 days. One Ningxiang pig was selected for slaughter sampling for each replicate. This study found that lean meat percentage of Ningxiang pigs in the experimental group was significantly increased (P < 0.05), accompanied by a significant decrease in fat percentage (P < 0.05). 16S rRNA sequencing analysis found an abundance of Streptococcus in the experimental group (P < 0.05), along with significantly decreased levels of Lactobacillus (P < 0.05). The changes in some OTUs belonging to Firmicutes, Bacteroidota, and Actinobacteriota were closely related to the changes in the fat rate and lean meat rate of Ningxiang pigs (P < 0.05). LC–MS metabolomics analysis found that about 43.75% of the differential metabolites were related to lipids and lipid-like molecules in the liver (P < 0.05). Spearman's correlation analysis showed correlations between the carcass traits, microbiota, and liver metabolites. In conclusion, niacin improves lean meat percentage and reduces fat deposition by regulating lipid metabolism and gut microbiota composition in Ningxiang pigs.

Enhancement of denitrifying anaerobic methane oxidation via applied electric potential.

In this study, single-chamber three-electrode electrochemical sequencing batch reactor (ESBR) was set up to investigate the impact of applying potential on denitrifying anaerobic methane oxidation (DAMO) process. When the applied potential was +0.8V, the conversion rate of nitrite to nitrogen was superior to those of other potentials. With the optimal potential of +0.8V for 60 days, the nitrite removal rate of ESBR could reach 3.34±0.28mgN/L/d, which was 4.5 times more than that of the non-current control (0.74±0.16mgN/L/d). The DAMO functional bacteria Candidatus Methylomirabilis exhibited noticeable enrichment under applying potential, and its functional gene of pmoA was significantly expressed. Through untargeted LC-MS metabolomics analysis, applied potential was shown to affect the regulation of prior metabolites including spermidine, spermine and glycerophosphocholine that were related to the metabolic pathways of glycerophospholipid metabolism and arginine and proline metabolism, which had positive effects on DAMO process. These results show that applying electric potential could be a useful strategy in DAMO process used for methane and nitrogen removal.

An LC–MS-based metabolomic approach provides insights into the metabolite profiles of Ginkgo biloba L. at different developmental stages and in various organs

Ginkgo (Ginkgo biloba L.) is a tree valued for the high medicinal and nutritional value of its leaves and seeds. However, the metabolite profiles of ginkgo leaves and seeds and their changes during development have not been comprehensively analyzed, which hinders improvements in the utilization of ginkgo. A comprehensive and systematic untargeted LC–MS metabolomics analysis of the metabolites in ginkgo leaves (male and female) and seeds at two developmental stages identified 8146 known metabolites, which mainly included lipids and lipid-like molecules, phenylpropanoids and polyketides, organoheterocyclic compounds, organic acids and derivatives, organic oxygen compounds, and benzenoids. Some of the identified metabolites have known healthcare and food value, and some of the others are newly discovered metabolites with potential for new drug development. The small number of differential Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways between leaves of male and female gingko trees indicated that the developmental stage affected the metabolic pathways more significantly than sex. Among the flavonoid constituents of ginkgo, 653 flavonoid metabolites were identified, and these included some new flavonoid components, which confirmed that the developmental stage is a critical factor in secondary metabolite variations. This study illuminated the metabolites and medicinal and edible values of ginkgo leaves and seeds at different developmental stages and thus supports further effective utilization of ginkgo leaves and seeds.

Evaluation of nanospray capillary LC-MS performance for metabolomic analysis in complex biological matrices

LC-MS metabolomic analysis in complex biological matrices may be complicated by degeneracy when using large-bore columns. Degeneracy is the detection of multiple mass spectral peaks from the same analyte due to adduction of salts to the metabolite, dimerization, or loss of neutrals. This introduces interferences to the MS spectra, diminishes quantification, and increases the rate of false identifications. Analysis using 2.1 mm inner diameter (i.d.) columns typically leads to degenerate peaks whereas nanospray using capillary columns (25, 50, and 75 µm i.d.) reduces degeneracy. Optimization of chromatographic parameters of capillary LC for amino acid standards showed the lowest HETP at 1.25 mm/sec across all capillary i.d. columns. Results suggest mass-sensitive detection below the optimum velocity. At faster velocities, concentration-dependent detection occurred across all capillaries. The 2.1 mm i.d. analytical scale column showed the greatest level of degeneracy, particularly in the low signal intensity range. 25 µm i.d. columns showed higher levels of metabolite annotation for the same signal intensity range. It also provided the lowest level of degeneracy, making it best suited for untargeted analysis. The 25 µm i.d. column achieved a peak capacity (nc) of 144 in a 30-minute gradient method with nc decreasing as the column i.d. increased. 75 µm i.d. capillary columns showed the highest signal intensity, which is beneficial for targeted analysis. These effects of chromatographic performance, resolution, and degeneracy profile of capillary and analytical scale columns were compared for metabolomic analyses in complex serum and cell lysate matrices.

Circulating metabolome does not predict development of aortic stenosis

Abstract Background Calcific aortic valve disease (CAVD) is the most common valvular heart disease in Western world. CAVD is ranging from mild aortic valve sclerosis to severe obstructive aortic stenosis (AS). The development of AS has been associated with several risk factors including age, sex and hypertension. However, there is limited knowledge about factors that predict the development of aortic stenosis. Purpose We investigated if the circulating metabolite profile can predict the development of aortic stenosis in Finnish males. Methods We did a non-targeted LC-MS metabolomics analysis to baseline (1984–1989) serum samples from a prospective population-based Kuopio Ischemic Heart Disease risk factor study (KIHD) cohort of 2682 random Finnish males aged from 42 to 60 years. During the follow-up (until year 2020), 53 subjects developed either moderate (peak flow gradient 36–64mmHg or mean flow gradient 20–40mmHg) or severe aortic valvular stenosis (peak flow gradient over 64mmHg or mean gradient over 40mmHg). The AS patients were collected from the KIHD database using appropriate ICD-10 -codes for aortic valvular disease (from baseline to the end of the year 2017) and the diagnosis was checked manually using hospital medical records of the individuals. Results The AS patients seemed to have altered lipid metabolism and possibly altered composition of gut microbiota, since several acylcarnitines (e.g. octanoylcarnitine [Cohen's d=−0.40], decanoylcarnitine [d=−0.43], layroylcarnitine [d=−0.41], and oleoylcarnitine [d=−0.40]), and branched chain amino acids (BCAA, e.g. leucine [d=0.39], and isoleucine [d=0.49]) had p-values below 0.05. However, after correction for multiple testing, there were no significant differences between the cases and controls. Conclusions The present preliminary results, in need of verification with a larger set of samples, suggest that subjects, who will later develop AS might have reduced levels of acylcarnitines and increased levels of BCAA when compared to matched controls. However, these changes do not have large effects sizes and are likely not good candidates for biomarkers to predict future diagnosis of AS. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): The Finnish Cultural Foundation, The Finnish Foundation for Cardiovascular Research.

LC-MS metabolomics analysis of Stevia rebaudiana Bertoni leaves cultivated in Malaysia in relation to different developmental stages.

Stevia is known for its sweet taste, attributed to the presence of steviol glycosides. Although reports on the dynamic changes of steviol glycosides during development of stevia are available, the data are mainly focused on stevioside and rebaudioside A. Information concerning the comprehensive metabolite profile of stevia in relation to different developmental stages is still lacking. This study investigated the metabolite changes along the developmental stages of a local stevia cultivar. Stevia leaves were harvested at 4 different developmental stages (early vegetative, late vegetative, budding, and flowering). Samples were then subjected to LC-MS metabolomics analysis to determine the metabolite variations. A total of 55 metabolites, comprising phenolic acids, flavonoids, and terpenoids were identified by MS/MS analysis of the stevia leaf extracts, revealing a metabolite profile which was comparatively similar with those of cultivars grown in other countries. PLS-DA differentiated the early vegetative stage stevia leaf samples from those of the later stages by higher content of phenolic acids. The leaf metabolomes of the later 3 stages (late vegetative, budding, and flowering) were collectively richer in flavonoids. Meanwhile, the content of steviol glycosides is highest during the late vegetative and budding stages. The present study provided, for the first time, a general overview of the metabolite variations with regard to the different developmental stages of stevia. The information may facilitate decision making of suitable harvesting times for higher yields of steviol glycosides or a more balanced metabolite profile in terms of pharmacologically useful metabolites.

Comparison of the preventive effects of Murraya exotica and Murraya paniculata on alcohol-induced gastric lesions by pharmacodynamics and metabolomics

Ethnopharmacological relevanceMulti-source phenomenon is very common for traditional Chinese medicine (TCM). Both Murraya exotica L. (ME) and Murraya paniculata (L.) Jack (MP) are used as the source plants of Murrayae Folium et Cacumen (MFC), a traditional Chinese medicine recorded in Chinese Pharmacopoeia for promoting qi and relieving pain, mainly for the treatment of stomach pain, rheumatism and arthralgia. However, up to now, there has been no comparative study of these two plants on their efficacies and mechanisms, thus, further research is needed to evaluate their similarity and difference in order to judge the reasonability for their common usage.Aim of the study: This study aims to compare the effects and potential mechanisms of ME and MP, the two source plants of MFC on gastric lesions in rats by pharmacodynamics and metabolomics. Materials and methodsA rat model of gastric lesions induced by 70% aqueous ethanol and 150 mmol/L HCl was established and adopted to evaluate the gastric protective effects of ME and MP by analysis of the lesion index, histopathological changes (observed by H&E staining and TUNEL staining) and cytokine levels (IL-1β, IL-6, TNF-α, MTL, and GAS). The potential mechanisms were investigated by LC-MS metabolomic analysis of the rat plasma. ResultsME and MP showed the similar effects on improving the lesions of rat stomachs and reducing the cytokine levels related to inflammation and digestion of rats. The metabolomics results showed that the metabolism of rats with gastric lesions was abnormal mainly in lipid metabolism, energy metabolism, and amino acid metabolism. ME and MP demonstrated a similar metabolic modulation for gastric lesions by acting on the similar pathways and metabolites. Also, PLA2 pathway was proved as an important pathway for ME and MP modulation of glycerophospholipid metabolism in gastric lesions. ConclusionsOur results proved that it is feasible and reasonable to use both of ME and MP as the source plants of MFC, at least for the treatment of gastric lesions, due to their similar pharmacodynamics and metabolic modulation ability. Moreover, the combination of pharmacodynamics and metabolomics is an efficient means for multi-source TCM study.