Brain metabolomics study for the protective effects of Rhodiola crenulata extract on Alzheimer's disease by HPLC coupled with Fourier transform-ion cyclotron resonance mass spectrometry.

In order to investigate the protective effects of Rhodiola crenulata extract on Alzheimer's disease, a brain metabolomics study in rats was conducted by high performance liquid chromatography coupled with Fourier transform ion cyclotron resonance mass spectrometry. Rat model was constructed by bilateral hippocampal injection of amyloid-ß peptide and immunohistochemistry was performed to evaluate the pharmacological effect of Rhodiola crenulata extract. Multivariate statistical analysis was used to discover potential biomarkers in rat brain and related metabolic pathways analysis was conducted to elucidate the action mechanism of Rhodiola crenulata extract. As a result, a total of 19 metabolites contributing to Alzheimer's disease progress were identified and nine of them were restored to the normal levels after drug administration. Pathway analysis revealed that the protective effects of Rhodiola crenulata extract are related to the regulation of glutathione metabolism and arachidonic acid metabolism in rat brain. In conclusion, this work demonstrates that the developed metabolomics method is useful to investigate the protective effects of Rhodiola crenulata extract against Alzheimer's disease. These outcomes may further provide reliable evidence to illuminate the intervention mechanism of other traditional Chinese medicines on Alzheimer's disease.

Species Differences of Bile Acid Redox Metabolism: Tertiary Oxidation of Deoxycholate is Conserved in Preclinical Animals.

It was recently disclosed that CYP3A is responsible for the tertiary stereoselective oxidations of deoxycholic acid (DCA), which becomes a continuum mechanism of the host-gut microbial cometabolism of bile acids (BAs) in humans. This work aims to investigate the species differences of BA redox metabolism and clarify whether the tertiary metabolism of DCA is a conserved pathway in preclinical animals. With quantitative determination of the total unconjugated BAs in urine and fecal samples of humans, dogs, rats, and mice, it was confirmed that the tertiary oxidized metabolites of DCA were found in all tested animals, whereas DCA and its oxidized metabolites disappeared in germ-free mice. The in vitro metabolism data of DCA and the other unconjugated BAs in liver microsomes of humans, monkeys, dogs, rats, and mice showed consistencies with the BA-profiling data, confirming that the tertiary oxidation of DCA is a conserved pathway. In liver microsomes of all tested animals, however, the oxidation activities toward DCA were far below the murine-specific 6ß-oxidation activities toward chenodeoxycholic acid (CDCA), ursodeoxycholic acid, and lithocholic acid (LCA), and 7-oxidation activities toward murideoxycholic acid and hyodeoxycholic acid came from the 6-hydroxylation of LCA. These findings provided further explanations for why murine animals have significantly enhanced downstream metabolism of CDCA compared with humans. In conclusion, the species differences of BA redox metabolism disclosed in this work will be useful for the interspecies extrapolation of BA biology and toxicology in translational researches. SIGNIFICANCE STATEMENT: It is important to understand the species differences of bile acid metabolism when deciphering biological and hepatotoxicology findings from preclinical studies. However, the species differences of tertiary bile acids are poorly understood compared with primary and secondary bile acids. This work confirms that the tertiary oxidation of deoxycholic acid is conserved among preclinical animals and provides deeper understanding of how and why the downstream metabolism of chenodeoxycholic acid dominates that of cholic acid in murine animals compared with humans.

Bioavailability of polyphenols from peanut skin extract associated with plasma lipid lowering function.

Peanut skin is a rich source of polyphenols including procyanidins and is shown to have hypolipidemic properties. This study investigated the bioavailability of peanut skin polyphenols using a rat model. First, the bioavailability of peanut skin polyphenols in rat plasma was evaluated. Our results showed procyanidin A2 levels in plasma peaked within 30 min of ingestion. The results of a second study show that peanut skin extract supplemented in addition to oil gavage resulted in significant decrease in plasma triglyceride and VLDL within 5h. In the third study, rats were given a Western type diet for 5 weeks with peanut skin extract at a dose of 150 and 300 mg/kg body weight. The main effects observed were lowering of total blood lipid and reduction of the plasma fatty acids profile. Our results suggest that procyanidin A may impart a key role of hypolipidemic effect seen in peanut skin polyphenols.

Metabonomics approach to assessing the modulatory effects of St John's wort, ginsenosides, and clomipramine in experimental depression.

The protective effects of St John's Wort extract (SJ), ginsenosides (GS), and clomipramine (CPM) on chronic unpredictable mild stress (CUMS)-induced depression in rats were investigated by using a combination of behavioral assessments and metabonomics. Metabonomic analyses were performed using gas chromatography/mass spectrometry in conjunction with multivariate and univariate statistical analyses. During and at the end point of the chronic stress experiment, food consumption, body weight, adrenal gland, thymus and spleen indices, behavior scores, sucrose consumption, and stress hormone levels were measured. Changes in these parameters reflected characteristic phenotypes of depression in rats. Metabonomic analysis of serum, urine, and brain tissue revealed that CPM and SJ mainly attenuated the alteration of monoamine neurotransmitter metabolites, while GS affected both excitatory/inhibitory amino acids and monoamine neurotransmitter metabolites. GS also attenuated the stress-induced alterations in cerebrum and peripheral metabolites to a greater extent than CPM and SJ. These results provide important mechanistic insights into the protective effects of GS against CUMS-induced depression and metabolic dysfunction.

Chia seed supplementation and disease risk factors in overweight women: a metabolomics investigation.

OBJECTIVE/SETTING: This study assessed the effectiveness of milled and whole chia seed in altering disease risk factors in overweight, postmenopausal women using a metabolomics approach. DESIGN/INTERVENTION: Subjects were randomized to chia seed (whole or milled) and placebo (poppy seed) groups, and under double-blinded procedures ingested 25 g chia seed or placebo supplements each day for 10 weeks. SUBJECTS: Subjects included 62 overweight (body-mass index 25 kg/m(2) and higher), nondiseased, nonsmoking, postmenopausal women, ages 49-75 years, with analysis based on the 56 subjects who completed all phases of the study. OUTCOME MEASURES: Pre- and poststudy measures included body mass and composition, blood pressure and augmentation index, serum lipid profile, inflammation markers from fasting blood samples, plasma fatty acids, and metabolic profiling using gas chromatography-mass spectrometry with multivariate statistical methods including principal component analysis and partial least-square discriminant analysis (PLS-DA). RESULTS: Plasma α-linolenic acid (N=ALA) increased 58% (interaction effect, p=0.002) and eicosapentaenoic acid (EPA) 39% (p=0.016) in the milled chia seed group (N=14) compared to nonsignificant changes in the whole chia seed (N=16) and placebo (N=26) groups. Pre-to-post measures of body composition, inflammation, blood pressure, augmentation index, and lipoproteins did not differ between chia seed (whole or milled) and placebo groups (all interaction effects, p>0.05). Global metabolic difference scores for each group calculated through PLS-DA models were nonsignificant (Q(2)Y<0.40), and fold-changes for 28 targeted metabolites associated with inflammation and disease risk factors did not differ between groups. CONCLUSIONS: Ingestion of 25 g/day milled chia seed compared to whole chia seed or placebo for 10 weeks by overweight women increased plasma ALA and EPA, but had no influence on inflammation or disease risk factors using both traditional and metabolomics-based measures.

Rapid and sensitive DNA target detection using enzyme amplified electrochemical detection based on microchip.

A rapid and sensitive DNA targets detection using enzyme amplified electrochemical detection (ED) based on microchip was described. We employed a biotin-modified DNA, which reacted with avidin-conjugated horseradish peroxidase (avidin-HRP) to obtain the HRP-labeled DNA probe and hybridized with its complementary target. After hybridization, the mixture containing dsDNA-HRP, excess ssDNA-HRP, and remaining avidin-HRP was separated by MCE. The separations were performed at a separation voltage of +1.6 kV and were completed in less than 100 s. The HRP was used as catalytic labels to catalyze H(2)O(2)/o-aminophenol reaction. Target DNA could be detected by the HRP-catalyzed reduction with ED. With this protocol, the limits of quantification for the hybridization assay of 21- and 39-mer DNA fragments were of 8 x 10(-12) M and 1.2 x 10(-11) M, respectively. The proposed method has been applied satisfactorily in the analysis of Escherichia coli genomic DNA. We selected the detection of PCR amplifications from the gene of E. coli to test the real applicability of our method. By using an asymmetric PCR protocol, we obtained ssDNA targets of 148 bp that could be directly hybridized by the single-stranded probe and detected with ED.

[Functional genomic approaches to explore secondary metabolites in medicinal plants].

Extensive genomic data concerning medicinal plants are rather scarce and insights of the secondary metabolic pathways and their regulatory mechanism are insufficient, hampering the broad application of cell or tissue cultivation and metabolic engineering to producing high-value secondary metabolites. The integration of cDNA-AFLP based transcript profiling and metabolomics, a new development of functional genomic approaches could establish correlations between the changes of secondary metabolites and expressions of related genes. It has manifested widely applicative prospects in seeking genes involved in biosynthesis of secondary metabolites and exploring secondary metabolic pathways. Functional genomic approaches are promising trends in the field of medicinal plants secondary metabolites research and will lead to better utilization of natural medicinal resources.

Characterization of pu-erh tea using chemical and metabolic profiling approaches.

In this study, the chemical constituents of pu-erh tea, black tea, and green tea, as well as those of pu-erh tea products of different ages, were analyzed and compared using a chemical profiling approach. Differences in tea processing resulted in differences in the chemical constituents and the color of tea infusions. Human biological responses to pu-erh tea ingestion were also studied by using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS) in conjunction with multivariate statistical techniques. Metabolic alterations during and after pu-erh tea ingestion were characterized by increased urinary excretion of 5-hydroxytryptophan, inositol, and 4-methoxyphenylacetic acid, along with reduced excretion of 3-chlorotyrosine and creatinine. This study highlights the potential for metabonomic technology to assess nutritional interventions and is an important step toward a full understanding of pu-erh tea and its influence on human metabolism.

Multiparametric analysis of amino acids and organic acids in rat brain tissues using GC/MS.

Using design of experiment (DOE) theory coupled with multivariate statistical analysis, we have developed a simple and reliable GC/MS-based analytical assay for simultaneous analysis of amino acids and organic acids in rat brain tissue samples. The process of water extraction (pH 10.0) was extensively evaluated using brain tissue samples and a set of 21 reference standards. Acceptable calibration curves were obtained over a wide concentration range, 0.2-35.0 microg/mL for standards and 15.0-2.4 mL/g (tissue) for brain tissue samples. The precision was mostly better than 10% for both the mixed standards and the brain tissue samples. The brain tissue samples exhibited good stability within 48 h with RSD generally less than 15%. Furthermore, the developed analytical method was successfully applied in distinguishing the subtle variation among different parts of the brain tissues, such as cerebral cortex, hippocampus, and thalamus.

Metabolite profiling of Panax notoginseng using UPLC-ESI-MS.

The metabolite profiling of different parts of Panax notoginseng was carried out using rapid ultra-performance liquid chromatography-electrospray ionization mass spectrometry (UPLC-ESI-MS) and multivariate statistical analysis. Principal component analysis (PCA) of the UPLC-ESI-MS data showed a clear separation of compositions among the flower buds, roots and rhizomes of P. notoginseng. The saponins accounting for such variations were identified through the corresponding loadings weights and were further verified by accurate mass, tandem mass and retention times of available standard saponins using UPLC quadrupole time-of-flight mass spectrometer (UPLC-QtofMS). Finally, the influential factors of different metabolic phenotypes of P. notoginseng was elucidated. The currently proposed UPLC-ESI-MS/MS analytical method coupled with multivariate statistical analysis can be further utilized to evaluate chemical components obtained from different parts of the plant and/or the plant of different geographical locations, thereby classifying the medicinal plant resources and potentially elucidating the mechanism of inherent phytochemical diversity.

Ultra-performance LC/TOF MS analysis of medicinal Panax herbs for metabolomic research.

In this study, metabolite profiling of five medicinal Panax herbs including Panax ginseng (Chinese ginseng), Panax notoginseng (Sanchi), Panax japonicus (Rhizoma Panacis Majoris), Panax quinquefolium L. (American ginseng), and P. ginseng (Korean ginseng) were performed using ultra-performance LC-quadrupole TOF MS (UPLC-QTOFMS) and multivariate statistical analysis technique. Principal component analysis (PCA) of the analytical data showed that the five Panax herbs could be separated into five different groups of phytochemicals. The chemical markers such as ginsenoside Rf, 20(S)-pseudoginsenoside F11, malonyl gisenoside Rb1, and gisenoside Rb2 accountable for such variations were identified through the loadings plot of PCA, and were identified tentatively by the accurate mass of TOFMS and partially verified by the available reference standards. Results from this study indicate that the proposed method is reliable for the rapid analysis of a group of metabolites present in herbal medicines and other natural products and applicable in the differentiation of complex samples that share similar chemical ingredients.

Mass spectrometry-based metabolic profiling of rat urine associated with general toxicity induced by the multiglycoside of Tripterygium wilfordii Hook. f.

We propose here a combined gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) metabolic profiling strategy to elucidate the toxicity in rats induced by orally administered multiglycosides of Tripterygium wilfordii Hook. f. (GTW) in multiple organs including the kidney, liver, and testis. Overnight 12-h urine samples were collected from Sprague-Dawley male rats exposed to GTW (100 mg/kg/day, n = 6) and healthy controls ( n = 6) at predose and at the 1st, 3rd, 6th, 10th, and 14th day postdose for both GC/MS and LC/MS analyses. The integrated urinary MS data were analyzed via multivariate statistical techniques such as principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) to identify the differential metabolites and pertinent altered biological pathways in response to the herbal toxin. The liver, kidney, and testis were also assessed using conventional histopathological examinations at the end point of the experiment. This work indicates that GTW caused a time-dependent toxic effect at a high dose as revealed by the perturbed metabolic regulatory network involving disorders in energy metabolism, elevated amino acid and choline metabolism pathways, as well as altered structure of gut flora. This integrated MS-based metabolic profiling approach has been able to capture and probe the metabolic alterations associated with the onset and progression of multiorgan toxicity induced by GTW, thereby permitting a comprehensive understanding of systemic toxicity for phytochemicals and other types of xenobiotic agents.

[Effect of jinfu kang to experimental precancerous colon lesions and urinary metabolites in rat].

OBJECTIVE: : To profile urinary metabolite variations from 1, 2-dimethylhydrazine (DMH)-induced precancerous colon rats, Jinfu Kang treated rats and healthy controls. METHOD: We used ethyl chloroformate derivatization and gas chromatography-mass spectrometry (GC-MS) based metabonomic method to analyze rat urines. RESULT: The time-dependent variations of metabolite profile showed a progressive deviation of the metabolism in the model group from the initial pattern over time and a systemic recovery of the metabolism in the treatment group, which is consistent with the histological results. The in-depth analysis indicated that the disorder of tricarboxylic acid cycle (TCA), tryptophan metabolism, polyamine metabolism and gut flora structure were associated with DMH intervention. CONCLUSION: Metabolic study revealed that Jinfu Kang can effectively reverse metabolic departures in DMH-induced precancerous colon rat, which is consistent with pathological results.

Pharmacometabonomic phenotyping reveals different responses to xenobiotic intervention in rats.

In conventional pharmacological studies, intersubject differences within an animal strain are normally neglected, leading to variations in pharmacological outcomes in response to the same stimulus. Using two classical experimental models, the Streptozotocin (STZ)-induced diabetic model of Wistar rats and the high-energy, diet-induced obesity model of Sprague-Dawley rats, we demonstrate that the different outcomes of STZ or diet intervention are closely associated with variation in predose (baseline) urinary metabolic profiles of the rats. The pharmacometabonomic analysis of predose metabolic profiles indicates that the intersubject difference is, to a great extent, associated with gut-microbiota, which predisposes different pathophysiological outcomes upon diet alteration or chemical stimulus. We hypothesize that there may exist an important association between observations from these two models and the obese/diabetic human population in that subtle variations in metabolic phenotype may predetermine different systems' responses to xenobiotic perturbation, ultimately leading to varied pathophysiological processes. Results from two independent models also suggest that the pharmacometabonomics approach is of great importance in the study of pharmacology and clinical drug evaluations, where endogenous metabolite signatures of predose individuals should be taken into consideration to minimize intersubject difference and the resulting variation in the postdose pharmacological outcomes.

Metabonomic study of aristolochic acid-induced nephrotoxicity in rats.

This paper describes a metabonomic study characterizing the nephrotoxicity induced by aristolochic acid (AA), a suspected kidney toxicant. For these studies, we examined the biochemical compositions of AA-treated rat urine using LC-MS and pattern recognition methods. The biochemical and histological patterns of rat groups treated with different AA sources showed distinct differences from those of the control group. Certain metabolic pathways, such as homocysteine formation and the folate cycle were significantly accelerated, while others, including arachidonic acid biosynthesis, were decreased. A subset-validation procedure using linear discriminant analysis (LDA) and selected predictive variables indicated that approximately 95% of the treated and nontreated rat urine samples were classified correctly into their respective treatment groups. The results suggested that this metabonomic approach is a promising methodology for the rapid in vivo screening of nephrotoxicity associated with ingesting multi-ingredient medicinal herb supplements, and provides a valid method for comprehending the chemical-induced perturbations in the metabolic network and the networked lesions.