[RUNX3 regulates trastuzumab resistance of gastric cancer cells: a metabolomic analysis based on UPLC-Q Exactive Focus Orbitrap mass spectrometry]

OBJECTIVE

To explore the role of Runt-related transcription factor 3 (RUNX3) in metabolic regulation of trastuzumab-resistant gastric cancer cells and investigate the mechanism of RUNX3 knockdown-mediated reversal of trastuzumab resistance.

METHODS

We performed a metabolomic analysis of trastuzumab-resistant gastric cancer cells (NCI N87R) and RUNX3 knockdown cells (NCI N87R/RUNX3) using ultra performance liquid chromatography (UPLC) coupled with Q Exactive Focus Orbitrap mass spectrometry (MS). Multivariate combined with univariate analyses and MS/MS ion spectrums were used to screen the differential variables. MetaboAnalyst 5.0 database was employed for pathway enrichment analysis. Differential metabolites-genes regulatory relationships were constructed based on OmicsNet database. The changes in GSH/GSSG and NADPH/NADP ratios in NCI N87R/RUNX3 cells were measured using detection kits.

RESULTS

The metabolic profile of NCI N87R cells was significantly altered after RUNX3 knockdown, with 81 differential metabolites identified to contribute significantly to the classification, among which 43 metabolites were increased and 38 were decreased (P < 0.01). In NCI N87R cells, RUNX3 knockdown resulted in noticeable alterations in 8 pathways involving glutamine metabolism, glycolysis, glycerophospholipid, nicotinate-nicotinamide and glutathione metabolism, causing also significant reduction of intracellular GSH/GSSG and NADPH/NADP ratios (P < 0.01). The differential metabolites-genes network revealed a regulatory relationship between the metabolic molecules and genes.

CONCLUSION

RUNX3 reverses trastuzumab resistance in gastric cancer cells by regulating energy metabolism and oxidation-reduction homeostasis and may serve as a potential therapeutic target for trastuzumab-resistant gastric cancer.

An updated toolkit for exploring bacterial cell wall structure and dynamics

The bacterial cell wall is made primarily from peptidoglycan, a complex biomolecule which forms a bag-like exoskeleton that envelops the cell. As it is unique to bacteria and typically essential for their growth and survival, it represents one of the most successful targets for antibiotics. Although peptidoglycan has been studied intensively for over 50 years, the past decade has seen major steps in our understanding of this molecule because of the advent of new analytical and imaging methods. Here, we outline the most recent developments in tools that have helped to elucidate peptidoglycan structure and dynamics.

Effect of Elicitors on Morpho-Physiological Performance and Metabolites Enrichment in Valeriana jatamansi Cultivated Under Aeroponic Conditions

The use of new agricultural technologies such as soilless and aeroponic cultivation systems is a valuable approach to medicinal plant production. The present study investigated the prospects of enhancing yield and secondary metabolite production in Valeriana jatamansi under aeroponic cultivation using elicitors, such as yeast extract and methyl jasmonate. Plants were evaluated by measuring growth parameters, photosynthetic rate, and secondary metabolites contents (on a dry weight basis). Maximum plant height (36.83 cm), leaf number (17.67), rootlet number (37.33), and rootlet length (6.90 cm) were observed at 0.5 mg/L yeast extract treatment; whereas treatment levels of 1.5 mg/L yeast extract and 150 µM methyl jasmonate resulted in maximum leaf length (6.95 cm) and leaf width (5.43 cm), respectively. Maximum photosynthetic rate (5.4053 µmol m^-2s^-1) and stomatal conductance (0.0656 mmol m^-2s^-1) were recorded at treatment levels of 0.5 mg/L and 1.5 mg/L yeast extract respectively, whereas at 150 µM methyl jasmonate treatment, transpiration rate was 0.9046 mmol m^-2s^-1. In aeroponic cultivation, the maximum content of valerenic acid and hydroxy valerenic acid was detected in leaf (2.47 and 8.37 mg/g) and root (1.78 and 7.89 mg/g) at treatment levels of 100 µM and 150 µM methyl jasmonate, respectively. Acetoxy valerenic acid was highest in leaf (1.02 mg/g) at 1.5 mg/L yeast extract, and in the root (2.38 mg/g) at 150 µM methyl jasmonate. Gas chromatography-mass spectrometry analysis identified twenty-eight volatile compounds in roots, of which three-isovaleric acid (6.72-50.81%), patchouli alcohol (13.48-25.31%) and baldrinal (0.74-25.26%)-were the major constituents. The results revealed that, besides roots, leaves could also be utilized as a prominent alternative source for targeted secondary metabolites. In conclusion, aeroponic cultivation offers year-round quality biomass production and ease to access subsequent roots harvest in V. jatamansi, to meet the demand of the pharmaceutical industries.

[UPLC characteristic fingerprint and chemical pattern recognition of Angong Niuhuang Pills]

To establish the UPLC fingerprint of Zhongyi Angong Niuhuang Pills, in order to evaluate its quality by chemical pattern recognition. The method was developed on a column of Poroshell 120 EC-C_(18), with methanol-0.1% formic acid solution as the mobile phase for gradient elution at a flow rate of 0.4 mL·min~(-1). The column temperature was 30 ℃,and the detective wavelength was 254 nm. The similarity of 24 batches of Angong Niuhuang Pills was compared by using Traditional Chinese Medicine Chromatographic Fingerprint Similarity Evaluation System(2004 A). Hydrophobic cluster analysis,principal components analysis and partial least squares discriminant analysis were conducted by using SIMCA 13.0 software to investigate different components among these products. The UPLC characteristic fingerprint was established in this study. And 17 common peaks were identified by standard reference and UPLC-MS. The similarity of 24 batches samples were above 0.980,which can be classified into three categories for pattern recognition. Baicalin,berberine,jatrorrhizine,wogonin and wogonoside were identified as the main markers that cause differences of various batches. The method is simple,rapid,accurate and reproducible,and can provide scientific basis for improving the quality standard of Zhongyi Angong Niuhuang Pills.

Quantification of microdosed oral yohimbine and its major metabolite in human plasma in the picogram range

Aim: Pharmacokinetics after oral microdosing of the anticipated CYP2D6 substrate yohimbine and its metabolite 11-OH-yohimbine is potentially useful for drug-drug interaction trials and profiling of CYP2D6 enzyme activity. Materials & methods: We developed an ultrasensitive ultra performance liquid chromatography coupled to tandem mass spectrometry assay for quantification of yohimbine and its main metabolite 11-OH-yohimbine in plasma with a linear calibration range of 5-2500 pg/ml and validated it according to US FDA's and EMA's guidelines. Sample preparation was performed using fast liquid-liquid extraction. The assay was applied for the determination of concentrations of yohimbine and 11-OH-yohimbine in plasma after oral administration of 50 μg yohimbine to two subjects. Conclusion: Ultrasensitive quantification of yohimbine and its metabolite enables the determination of their concentrations in plasma after microdosing which would be applicable to use in CYP2D6 phenotyping.

A Validated Reverse Phase-Ultra-Performance Liquid Chromatography Method for the Determination of Gemifloxacin Mesylate in Bulk and its Pharmaceutical Preparation

Objectives

Gemifloxacin Mesylate is a fourth generation fluoroquinolone antibacterial agent. A simple, accurate, and precise reversed phase (RP)-ultra performance liquid chromatography (UPLC) method was developed and validated for short time analysis of Gemifloxacin Mesylate in its bulk and pharmaceutical preparation.

Materials and Methods

The optimum separation was achieved at 0.5±0.03 min using an Acclaim^TM RSLC 120 C18 column 2.2 μm (2.1×100 mm) at 30°C by isocratic mobile phase at pH 3.0 composed of acetonitrile:phosphate buffer (25 mM) in a ratio of 75:25 (v/v). The column effluents were monitored at 276 nm using a photodiode array detector at a flow rate of 0.5 mL/min. The method was validated according to International Conference on Harmonization guidelines.

Results

The linearity of the calibration curve ranged from 0.5 μg/mL to 10 μg/mL and the square of the regression coefficient (r²) was 0.9991. The % relative standard deviation (RSD) of inter-day precision ranged from 0.081% to 1.233%, while for intra-day it ranged from 0.364% to 1.018%. The method was accurate with % recovery ranging from 93.71% to 100.29% and % RSD ranging from 1.054 to 2.722. The limit of detection and the limit of quantification were 0.066 and 0.2 μg/mL, respectively.

Conclusion

The validated method proved its ability for the assay of Gemifloxacin Mesylate in its bulk and dosage form in a short time (less than 1 min). To the best of our knowledge, this is the first RP-UPLC method for the determination of Gemifloxacin Mesylate.

Untargeted Metabolomics Reveals the Protective Effect of Fufang Zhenshu Tiaozhi (FTZ) on Aging-Induced Osteoporosis in Mice

Fufang Zhenzhu Tiaozhi (FTZ), as an effective traditional Chinese medicine, has been prescribed for more than 20 years. It has proven clinical efficacy as a prescription for patients with dyslipidemia, glucocorticoid- and high-fat-induced osteoporosis, but its effect on osteoporosis induced by aging is still unclear. The aim of this study was to investigate the anti-osteoporosis effect of FTZ in aging mice and revealed its biochemical action mechanism using metabolomics. Model of primary osteoporosis induced by aging was established. The mice in treatment group received a therapeutic dose of oral FTZ extract once daily during the experiment. The model and control groups received the corresponding volume of oral normal saline solution. Plasma samples of all three groups were collected after 12 weeks. Clinical biochemical parameters and biomechanics were determined in the osteoporosis model induced by normal aging to evaluate anti-osteoporosis effect of FTZ. Ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) was used to analyze metabolic changes. The changes of histomorphometric and biomechanic parameters of femurs, as well as osteoblast and osteoclast activity indicated that FTZ administration reduced the risk of osteoporosis. Partial least squares discriminant analysis (PLS-DA) score plot revealed a clear separation trend between model and controls. Moreover, PLS-DA score plot indicated the anti-osteoporosis effect of FTZ with sphingosine 1-phosphate, LPA (16:0) and arachidonic acid (AA) among key biomarkers. The pivotal pathways revealed by pathway analysis including sphingolipid metabolism, glycerophospholipid metabolism, and AA metabolism. The mechanism by which FTZ reduces the risk of primary age-related osteoporosis in mice might be related to disorders of the above-mentioned pathways. FTZ has a protective effect against osteoporosis induced by aging, which may be mediated via interference with sphingolipid, glycerophospholipid, and AA metabolisms in mice.

Systematic study on metabolism and activity evaluation of Radix Scutellaria extract in rat plasma using UHPLC with quadrupole time-of-flight mass spectrometry and microdialysis intensity-fading mass spectrometry

Radix Scutellaria is a widely used traditional Chinese medicine in the treatment of various diseases. However, the activities of the absorbed components and metabolites of its main flavones in rat plasma need further investigation. In this study, a systematic method based on ultra-high performance liquid chromatography with quadruple time-of-flight mass spectrometry was developed to speculate the absorbed components and metabolites of the main flavonoids in Radix Scutellaria extract in rat plasma sample after oral administration of the extract. Twelve compounds, including four prototype components and eight metabolites, were confirmed in drug-containing plasma. In these metabolites, five were originally detected in rat plasma. The possible metabolic pathways of these polyhydroxy flavones in vivo were described and clarified. Microdialysis with intensity-fading mass spectrometry was originally employed to investigate the binding affinities of the absorbed components and metabolites with α-glucosidase. The order of their binding affinities was P4 > P3 > P2 > P1≥M5 > M3 > M1. The research result is helpful to deepen the understanding of the absorbed components and metabolic pathways of main flavones from Radix Scutellaria, and provide a new approach to screen potential inhibitors from in vivo components originated from Chinese herb.

Glycosylation engineering of therapeutic IgG antibodies: challenges for the safety, functionality and efficacy

Glycosylation of the Fc region of IgG has a profound impact on the safety and clinical efficacy of therapeutic antibodies. While the biantennary complex-type oligosaccharide attached to Asn297 of the Fc is essential for antibody effector functions, fucose and outer-arm sugars attached to the core heptasaccharide that generate structural heterogeneity (glycoforms) exhibit unique biological activities. Hence, efficient and quantitative glycan analysis techniques have been increasingly important for the development and quality control of therapeutic antibodies, and glycan profiles of the Fc are recognized as critical quality attributes. In the past decade our understanding of the influence of glycosylation on the structure/function of IgG-Fc has grown rapidly through X-ray crystallographic and nuclear magnetic resonance studies, which provides possibilities for the design of novel antibody therapeutics. Furthermore, the chemoenzymatic glycoengineering approach using endoglycosidase-based glycosynthases may facilitate the development of homogeneous IgG glycoforms with desirable functionality as next-generation therapeutic antibodies. Thus, the Fc glycans are fertile ground for the improvement of the safety, functionality, and efficacy of therapeutic IgG antibodies in the era of precision medicine.

Analysis of Chemical Constituents of Melastoma dodecandrum Lour. by UPLC-ESI-Q-Exactive Focus-MS/MS

The ethnic drug Melastoma dodecandrum Lour. (MDL) is widely distributed throughout South China, and is the major component of Gong Yan Ping Tablets/Capsules and Zi Di Ning Xue San. Although the pharmacological effects of MDL have been well documented, its chemical profile has not been fully determined. In this study, we have developed a rapid and sensitive UPLC-ESI-Q-Exactive Focus-MS/MS method to characterize the chemical constituents of MDL in the positive and negative ionization modes. A comparison of the chromatographic and spectrometric data obtained using this method with data from databases, the literature and reference standards allowed us to identify or tentatively characterize 109 compounds, including 26 fatty acids, 26 organic acids, 33 flavonoids, six tannins, 10 triterpenoids, two steroids and six other compounds. Notably, 55 of the compounds characterized in this study have never been detected before in this plant. The information obtained in this study therefore enriches our understanding of the chemical composition of MDL and could be used in quality control, pharmacological research and the development of drugs based on MDL. In addition, this study represents the first reported comprehensive analysis of the chemical constituents of MDL.

Antioxidant, Antinociceptive and CNS Activities of Viscum orientale and High Sensitive Quantification of Bioactive Polyphenols by UPLC

Viscum orientale Willd. (Loranthaceae) has long been used in traditional medicine to treat pain, neuropharmacological disorders and various forms of tumor but not yet been reported. The aim of this study is to rationalize the traditional medicinal use of this plant by evaluating the methanol extract of V. orientale leaves (MEVOL) for anti-nociceptive, CNS depressant and antioxidant activities and to quantify the bioactive polyphenols present in this plant. Five polyphenolic compounds namely gallic acid, vanillic acid, caffeic acid, ellagic acid, and quercetin (17.54, 8.99, 99.61, 4523.31, and 100.15 mg/100 g of dry weight, respectively) have been identified in MEVOL using Ultra Performance Liquid Chromatography. Qualitative antioxidant activity determined by Thin Layer Chromatography indicated the presence of antioxidants. In quantitative antioxidant test using 2,2-diphenyl 1-picrylhydrazyl, MEVOL exhibited strong free antioxidant activity in a dose dependant manner (IC₅₀ = 6.63 μg/ml) compared with ascorbic acid (IC₅₀ = 1.91 μg/ml) and butylatedhydroxyanisole (IC₅₀ = 2.27 μg/ml) controls. Total phenolic content determined using Folin Ciocaltu reagent was found to be 73.4 mg gallic acid equivalent/g of extract, while flavonoid content estimated using aluminum chloride colorimetric method was 170.7 mg quercetin equivalent/g of extract. Anti-nociceptive activity of MEVOL measured using acetic acid and formalin induced pain models in mice was significant (p < 0.001). MEVOL showed 65.6 and 88.8% writhing inhibition at 300 and 500 mg/kg body weight, respectively, comparing with standard diclofenac-Na (75.2% inhibition) at 25 mg/kg body weight in acetic acid induced pain model. In formalin induced pain model, paw licking was inhibited 45.93 and 56.4% in early phase and 55.66 and 72.64% in late phase at 300 and 500 mg/kg body weight, respectively, while diclofenac-Na inhibited 60.47 and 61.32% in early and late phase at 10 mg/kg body weight, respectively. In neuropharmacological activity test, overall behavioral test significantly reinforced CNS depressant activity. Spontaneous motor activities were reduced (p < 0.05) in both hole cross and open field tests compared with diazepam. Antioxidant activity of MEVOL is likely due to the phenolic and flavonoid compounds present within the leaf tissues. This study reveals significant in vivo anti-nociceptive and CNS depressant activities which justifies traditional medicinal applications of V. orientale.

Biochemical Characterization and Antimicrobial and Antifungal Activity of Two Endemic Varieties of Garlic (Allium sativum L.) of the Campania Region, Southern Italy

Extracts of the bulbs of the two endemic varieties "Rosato" and "Caposele" of Allium sativum of the Campania region, Southern Italy, were analyzed. The phenolic content, ascorbic acid, allicin content, and in vitro antimicrobial and antifungal activity were determined. Ultra performance liquid chromatography with diode array detector performed polyphenol profile. The polyphenolic extracts showed antioxidant activity (EC50) lower than 120 mg. The amount of ascorbic acid and allicin in the two extracts was similar. Polyphenol extract exhibited antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and (only by the extract of Rosato) against Bacillus cereus. The extract of Caposele was more effective in inhibiting the growth of Aspergillus versicolor and Penicillum citrinum. On the other hand, the extract of Rosato was effective against Penicillium expansum.

Online antioxidant activity and ultra-performance LC-electrospray ionisation-quadrupole time-of-fight mass spectrometry for chemical fingerprinting of Indian polyherbal formulations

A HPLC-DAD-DPPH method was developed for evaluating the 1, 1-diphenyl-2-picryl hydrazyl free radical scavenging activity of ethylacetate extracts of different polyherbal formulations (draksarista, draksava, lohasava and arvindasava) by using RP-18e column. The ethylacetate extract from polyherbal, 'draksarista' exhibited maximum free radical scavenging activity (99.9 ± 0.38%) followed by draksava (99.8 ± 0.34%), lohasava (98.5 ± 0.30%) and arvindasava (42.3 ± 0.34%) at 100 μg mL(-1). Simultaneously, ultra-performance liquid chromatography coupled with electrospray ionisation-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study chemical composition of the ethylacetate extracts of formulations. The characteristic electrospray mass ionisation reveals the dominance of polyphenols and their glycosides in the four polyherbal formulations.

Development and validation of sensitive LC-MS/MS assays for quantification of HP-β-CD in human plasma and CSF

2-Hydroxypropyl-β-cyclodextrin (HP-β-CD), a widely used excipient for drug formulation, has emerged as an investigational new drug for the treatment of Niemann-Pick type C1 (NPC1) disease, a neurodegenerative cholesterol storage disorder. Development of a sensitive quantitative LC-MS/MS assay to monitor the pharmacokinetics (PKs) of HP-β-CD required for clinical trials has been challenging owing to the dispersity of the HP-β-CD. To support a phase 1 clinical trial for ICV delivery of HP-β-CD in NPC1 patients, novel methods for quantification of HP-β-CD in human plasma and cerebrospinal fluid (CSF) using LC-MS/MS were developed and validated: a 2D-LC-in-source fragmentation-MS/MS (2D-LC-IF-MS/MS) assay and a reversed phase ultra performance LC-MS/MS (RP-UPLC-MS/MS) assay. In both assays, protein precipitation and "dilute and shoot" procedures were used to process plasma and CSF, respectively. The assays were fully validated and in close agreement, and allowed determination of PK parameters for HP-β-CD. The LC-MS/MS methods are ∼100-fold more sensitive than the current HPLC assay, and were successfully employed to analyze HP-β-CD in human plasma and CSF samples to support the phase 1 clinical trial of HP-β-CD in NPC1 patients.

Eucommia ulmoides Oliv.: ethnopharmacology, phytochemistry and pharmacology of an important traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Eucommia ulmoides Oliv. (Family Eucommiaceae), also known as Dù-zhòng (Chinese: ), Tuchong (in Japanese), is the sole species of the genus Eucommia. The leaf, stem, and bark as well as staminate flower of Eucommia ulmoides have been traditionally used to cure many diseases in China, Japan, Korea, among others. The aim of this review is to comprehensively outline the botanical description, ethnopharmacology, phytochemistry, biological activities, and toxicology of Eucommia ulmoides and to discuss possible trends for further study of Eucommia ulmoides.

MATERIALS AND METHODS

Information on Eucommia ulmoides was gathered via the internet (using Pub Med, Elsevier, Baidu Scholar, Google Scholar, Medline Plus, ACS, CNKI, and Web of Science) and from books in local libraries.

RESULTS

One-hundred twelve compounds of Eucommia ulmoides, including the main active constituents, lignans and iridoids, have been isolated and identified. In vitro and in vivo studies indicated that monomer compounds and extracts from Eucommia ulmoides possess wide-ranging pharmacological actions, especially in treating hypertension, hyperlipemia, diabetes, obesity, sexual dysfunction, osteoporosis, Alzheimer's disease, aging, lupus-like syndrome, and immunoregulation.

CONCLUSIONS

Eucommia ulmoides has been used as a source of traditional medicine and as a beneficial health food. Phytochemical and pharmacological studies of Eucommia ulmoides have received much interest, and extracts and active compounds continue to be isolated and proven to exert various effects. Further toxicity and clinical studies are warranted to establish more detailed data on crude extracts and pure compounds, enabling more convenient preparations for patients. Therefore, this review on the ethnopharmacology, phytochemistry, biological activities, and toxicity of Eucommia ulmoides will provide helpful data for further studies as well as the commercial exploitation of this traditional medicine.

UPLC-PDA determination of paeoniflorin in rat plasma following the oral administration of Radix Paeoniae Alba and its effects on rats with collagen-induced arthritis

Rheumatoid arthritis (RA) is a chronic disabling autoimmune disease with characteristics of chronic, progressive inflammatory joint synovial damage, which mainly encroaches upon the synovium of the joint. The use of traditional medicine to treat RA slows the development of RA to a certain extent; however, it often has numerous side-effects. Therefore, the focus of RA research is the identification of a new, safe and effective medicine. The aim of the present study was to use an ultra performance liquid chromatography and photo diode array (UPLC-PDA) method to detect the paeoniflorin component in a Radix Paeoniae Alba decoction and in rat plasma following the oral administration of Radix Paeoniae Alba decoction. In addition, the effects of paeoniflorin on collagen-induced arthritis (CIA) in rats were investigated. The results indicate that a UPLC-PDA method for determining the presence of paeoniflorin in the Radix Paeoniae Alba decoction was successfully established. The method was fast, simple, sensitive, precise and valid. Paeoniflorin was shown to be a bioactive component of the Radix Paeoniae Alba decoction that was absorbed into rat plasma. Paeoniflorin significantly improved the disease resistant ability of RA rats and reduced the levels of the inflammatory cytokines, IL-1β and TNF-α, thereby inhibiting inflammation and bone erosion in the rats with CIA. The observations are likely to lay the foundation for further study of the mechanism of paeoniflorin in the treatment of RA.

The toxicity of 3-chloropropane-1,2-dipalmitate in Wistar rats and a metabonomics analysis of rat urine by ultra-performance liquid chromatography-mass spectrometry

3-Monochloropropane-1,2-diol(3-MCPD) fatty acid esters can release free 3-MCPD in a certain condition. Free 3-MCPD is a well-known food contaminant and is toxicological well characterized, however, in contrast to free 3-MCPD, the toxicological characterization of 3-MCPD fatty acid esters is puzzling. In this study, toxicological and metabonomics studies of 3-chloropropane-1,2-dipalmitate(3-MCPD dipalmitate) were carried out based on an acute oral toxicity test, a 90-day feeding test and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) analysis. The LD50 value of 3-MCPD dipalmitate was determined to be 1780 mg/kg body weight (bw) for Wistar rats. The results of the 90-day feeding test in male Wistar rats showed that 3-MCPD dipalmitate caused a significant increase in blood urea nitrogen and creatinine in the high-dose group (267 mg/kg bw/day) compared to control rats. Renal tubular epithelium cell degeneration and renal tubular hyaline cast accumulation were the major histopathological changes in rats administered 3-MCPD dipalmitate. Urine samples obtained after the 90-day feeding test and analyzed by UPLC-MS showed that the differences in metabolic profiles between control and treated rats were clearly distinguished by partial least squares-discriminant analysis (PLS-DA) of the chromatographic data. Five metabolite biomarkers which had earlier and significant variations had been identified, they were first considered to be the early, sensitive biomarkers in evaluating the effect of 3-MCPD dipalmitate exposure, and the possible mechanism of these biomarkers variation was elucidated. The combination of histopathological examination, clinical chemistry and metabolomics analyses in rats resulted in a systematic and comprehensive assessment of the long-term toxicity of 3-MCPD dipalmitate.

Antioxidant and phenolic acid profiles of tissue cultured and acclimatized Merwilla plumbea plantlets in relation to the applied cytokinins

Merwilla plumbea (Lindl.) Speta is an important medicinal plant widely used in traditional medicine. We evaluated the effect of five cytokinins [benzyladenine (BA), 2-isopentenyladenine (2iP), meta-topolin (mT), meta-topolin riboside (mTR), and meta-methoxy-9-tetrahydropyran-2-yl-topolin (MemTTHP)] on the level of phenolic acids and antioxidant activity of M. plumbea during the tissue culture and acclimatization stages. Two cytokinins (mT and mTR) significantly improved the antioxidant activity of tissue culture plantlets while the control plantlets were better after acclimatization. Using UPLC-MS/MS, the levels of hydroxybenzoic and hydroxycinnamic acid derivatives (phenolic acids) varied significantly during tissue culture and acclimatization, depending on the cytokinin and plant part analyzed. Vanillic acid (24.9 μg g⁻¹) detected in underground parts of tissue culture plants supplemented with BA was the most abundant phenolic acid detected. The current findings indicate that the phytochemicals together with the bioactivity during in vitro propagation of M. plumbea is influenced by the cytokinin type used and the stage of plant material collection.

Absolute quantification of UGT1A1 in various tissues and cell lines using isotope label-free UPLC-MS/MS method determines its turnover number and correlates with its glucuronidation activities

Uridine 5'-diphosphate-glucuronosyltransferase (UGT)1A1 is a major phase II metabolism enzyme responsible for glucuronidation of drugs and endogenous compounds. The purpose of this study was to determine the expression level of UGT1A1 in human liver microsomes and human cell lines by using an isotope label-free LC-MS/MS method. A Waters Ultra performance liquid chromatography (UPLC) system coupled with an API 5500Qtrap mass spectrometer was used for the analysis. Two signature peptides (Pep-1, and Pep-2) were employed to quantify UGT1A1 by multiple reaction monitoring (MRM) approach. Standard addition method was used to validate the assay to account for the matrix effect. 17β-Estradiol was used as the marker substrate to determine UGT1A1 activities. The validated method has a linear range of 200-0.0195nM for both signature peptides. The precision, accuracy, and matrix effect were in acceptable ranges. UGT1A1 expression levels were then determined using 8 individual human liver microsomes, a pooled human liver microsomes, three UGT1A1 genotyped human liver microsomes, and four cell lines (Caco-2, MCF-7, Hela, and HepG2). The correlations study showed that the UGT1A1 protein levels were strongly correlated with its glucuronidation activities in human liver microsomes (R(2)=0.85) and in microsomes prepared from cell lines (R(2)=0.95). Isotope-labeled peptides were not necessary for LC-MS/MS quantitation of proteins. The isotope label-free absolute quantification method used here had good accuracy, sensitivity, linear range, and reproducibility, and were used successfully for the accurate determination of UGT1A1 from tissues and cell lines.

Elevated dimethylglycine in blood of children with congenital heart defects and their mothers

OBJECTIVE

Congenital Heart Defects (CHD) may be related to nutritional deficiencies affecting the methylation cycle. We aimed to study the metabolic markers of the betaine homocysteine methyl transferase (BHMT) pathway in children with CHD and their mothers compared to children without CHD and their mothers.

MATERIALS AND METHODS

Children with CHD (n=105, age < 3 years) and mothers of 80 of the affected children were studied. The controls were non-CHDs children of comparable age as the CHD group (n=52) and their mothers (n=50). We measured serum or plasma concentrations of the metabolites of the methylation cycle homocysteine (HCY), methylmalonic acid (MMA), cystathionine, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), betaine, choline, and dimethylglycine (DMG).

RESULTS

Children with CHD had higher plasma SAM (131 vs. 100 nmol/L) and DMG (8.7 vs. 6.0 μmol/L) and lower betaine/DMG ratio (7.5 vs. 10.2) compared to the controls. Mothers of CHD children showed also higher DMG (6.1 vs. 4.1 µmol/L) and lower betaine/DMG ratio compared with the mothers of the controls. Higher SAM levels were related to higher cystathionine, MMA, betaine, choline, and DMG. MMA elevation in the patients was related to higher HCY, SAM, betaine and DMG.

CONCLUSIONS

Elevated DMG in CHD children and their mothers compared to the controls can indicate upregulation of the BHMT pathway in this disease group. Nutritional factors are related to metabolic imbalance during pregnancy that may be related to worse birth outcome.

Extraction, chemical characterization and biological activity determination of broccoli health promoting compounds

Broccoli (Brassica oleracea L. var. Italica) contains substantial amount of health-promoting compounds such as vitamins, glucosinolates, phenolic compounds, and dietary essential minerals; thus, it benefits health beyond providing just basic nutrition, and consumption of broccoli has been increasing over the years. This review gives an overview on the extraction and separation techniques, as well as the biological activity of some of the above mentioned compounds which have been published in the period January 2008 to January 2013. The work has been distributed according to the different families of health promoting compounds discussing the extraction procedures and the analytical techniques employed for their characterization. Finally, information about the different biological activities of these compounds has been also provided.

Organic anion-transporting polypeptide 1a4 (Oatp1a4) is important for secondary bile acid metabolism

Organic anion transporting polypeptides (human: OATPs; rodent: Oatps) were thought to have important functions in bile acid (BA) transport. Oatp1a1, 1a4, and 1b2 are the three major Oatp1 family members in rodent liver. Our previous studies have characterized the BA homeostasis in Oatp1a1-null and Oatp1b2-null mice. The present study investigated the physiological role of Oatp1a4 in BA homeostasis by using Oatp1a4-null mice. Oatp1a4 expression is female-predominant in livers of mice, and thereby it was expected that female Oatp1a4-null mice will have more prominent changes than males. Interestingly, the present study demonstrated that female Oatp1a4-null mice had no significant alterations in BA concentrations in serum or liver, though they had increased mRNA of hepatic BA efflux transporters (Mrp4 and Ostα/β) and ileal BA transporters (Asbt and Ostα/β). In contrast, male Oatp1a4-null mice showed significantly altered BA homeostasis, including increased concentrations of deoxycholic acid (DCA) in serum, liver and intestinal contents. After feeding a DCA-supplemented diet, male but not female Oatp1a4-null mice had higher concentrations of DCA in serum and livers than their WT controls. This suggested that Oatp1a4 is important for intestinal absorption of secondary BAs in male mice. Furthermore, loss of Oatp1a4 function did not decrease BA accumulation in serum or livers of bile-duct-ligated mice, suggesting that Oatp1a4 is not likely a BA uptake transporter. In summary, the present study for the first time demonstrates that Oatp1a4 does not appear to mediate the hepatic uptake of BAs, but plays an important male-predominant role in secondary BA metabolism in mice.

Development and validation of ultra-performance liquid chromatographic method with tandem mass spectrometry for determination of lenalidomide in rabbit and human plasma

BACKGROUND

Lenalidomide (LND) is a potent novel thalidomide analog which demonstrated remarkable clinical activity in treatment of multiple myeloma disease via a multiple-pathways mechanism. Validated sensitive method with high throughput is required for the determination of lenalidomide for pharmacokinetics and toxicokinetic studies. Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) is a preeminent analytical tool for rapid biomedical analysis.

RESULTS

A simple, highly sensitive UPLC-MS/MS method was developed and validated for the determination of LND in rabbit and human plasma. After a simple protein precipitation using methanol, LND and carbamazepine (IS) were separated on Acquity UPLC BEH™ C18 column (50 × 2.1 mm, i.d. 1.7 μm, Waters, USA) using a mobile phase consisted of acetonitrile:water:formic acid (65:35:0.1%, v/v/v) pumped at a flow rate of 0.2 mL/min. LND and IS were eluted at 0.71 and 1.92 min, respectively. The mass spectrometric determination was carried out using an electrospray interface operated in the positive mode with multiple reaction monitoring (MRM) mode. The precursor to product ion transitions of m/z 260.1 > 149.0 and m/z 237.0 > 179.0 were used to quantify LND and IS, respectively. The method was linear in the concentration range of 0.23-1000 ng/mL with a limit of quantitation of 0.23 ng/mL. All the validation parameters were in the ranges acceptable by the guidelines of analytical method validation.

CONCLUSION

The proposed UPLC-MS/MS method is simple, rapid and highly sensitive, and hence it could be reliable for pharmacokinetic and toxicokinetic study in both animals and humans.

Disulfiram metabolite S-methyl-N,N-diethylthiocarbamate quantitation in human plasma with reverse phase ultra performance liquid chromatography and mass spectrometry

Disulfiram has been used extensively for alcohol abuse and may have a role in treatment for cocaine addiction. Recent data suggest that disulfiram may also reactivate latent HIV in reservoirs. Disulfiram has complex pharmacokinetics with rapid metabolism to active metabolites, including S-methyl-N,N-diethylthiocarbamate (DET-Me) which is formed from cytochrome P450 (CYP450). Assessing disulfiram in HIV-infected individuals with a CYP450 inducing drug (e.g., efavirenz) or a CYP450 inhibiting drug (e.g., HIV-1 protease inhibitors) requires an assay that can measure a metabolite that is formed directly via CYP450 oxidation. Therefore, an assay to measure concentrations of DET-Me in human plasma was validated. DET-Me and the internal standard, S-ethyldipropylthiocarbamate (EPTC) were separated by isocratic ultra performance liquid chromatography using a Waters Acquity HSS T3 column (2.1 mm × 100 mm, 1.8 μm) and detection via electrospray coupled to a triple quadrupole mass spectrometer. Multiple reaction monitoring in positive mode was used with DET-Me at 148/100 and the internal standard at 190/128 with a linear range of 0.500-50.0 ng/mL with a 5 min run time. Human plasma (500 μL) was extracted using a solid phase procedure. The interassay variation ranged from 1.86 to 7.74% while the intra assay variation ranged from 3.38 to 5.94% over three days. Representative results are provided from samples collected from subjects receiving daily doses of disulfiram 62.5mg or 250 mg.

Ultra performance liquid chromatography and high resolution mass spectrometry for the analysis of plant lipids

Holistic analysis of lipids is becoming increasingly popular in the life sciences. Recently, several interesting, mass spectrometry-based studies have been conducted, especially in plant biology. However, while great advancements have been made we are still far from detecting all the lipids species in an organism. In this study we developed an ultra performance liquid chromatography-based method using a high resolution, accurate mass, mass spectrometer for the comprehensive profiling of more than 260 polar and non-polar Arabidopsis thaliana leaf lipids. The method is fully compatible to the commonly used lipid extraction protocols and provides a viable alternative to the commonly used direct infusion-based shotgun lipidomics approaches. The whole process is described in detail and compared to alternative lipidomic approaches. Next to the developed method we also introduce an in-house developed database search software (GoBioSpace), which allows one to perform targeted or un-targeted lipidomic and metabolomic analysis on mass spectrometric data of every kind.

A Chromatographic Determination of Aripiprazole using HPLC and UPLC: A Comparative Validation Study

A simple, precise, and accurate isocratic reversed-phase (RP) stability-indicating HPLC assay method was developed and validated for determination of Aripiprazole in bulk and solid pharmaceutical dosage form. A reversed-phase C8 (250×4.0 mm, 5 μm particle size) column for HPLC and C8 (50×2.1mm, 1.7 μm particle size) for UPLC method in isocratic mode was used. The mobile phase consists of acetonitrile: 20 mM ammonium acetate (90:10, v/v), flow rate was set at 1.0 ml/min and 0.250 ml/min for HPLC and UPLC, respectively and the detection was performed for both methods were at 240 nm. Further the validation of both developed method was performed and subsequently compared to prove its better applicability.