-
[show abstract]
[hide abstract]
ABSTRACT: NAD(P)H:quinone oxidoreductase 1 (NQO1, DT-diaphorase) is a prognostic biomarker and a potential therapeutic target for various tumors. Therefore, it is of significance to develop a robust method for the absolute quantification of NQO1. This study aimed to develop and validate a LC-MS/MS based method and to test the appropriateness of using non-isotopic analog peptide as the internal standard (IS) by comparing with a stable isotope labeled (SIL) peptide. The chromatographic performance and mass spectra between the selected signature peptide of NQO1 and the non-isotopic peptide were observed to be very similar. The use of the two internal standards was validated appropriate for the absolute quantification of NQO1, as evidenced by satisfactory validation results over a concentration range of 1.62-162fmolμL(-1). This method has been successfully applied to the absolute quantification of NQO1 expression in various tumor cell lines and tissues. NQO1 expression in human tumor tissues is much higher than that in the neighboring normal tissues in both the cases of lung and colon cancer. The quantitative results obtained from the isotopic and non-isotopic methods are quite similar, further supporting that the use of non-isotopic analog peptide as internal standard is appropriate and feasible for the quantification of NQO1. By comparing with a classical isotopic IS, the present study indicates that the use of a non-isotopic peptide analog to the proteotypic peptide as the internal standard can get equal accuracy and preciseness in measuring NQO1. The universal applicability of the non-isotopic IS approach for the quantification of proteins warrants further research.
Analytica chimica acta 04/2013; 772:59-67. · 4.31 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Diabetes mellitus is a chronic disease of complex metabolic disorder and associated with various types of complications. UDP-glucuronosyltransferases (UGTs), the major phase II conjugation enzymes, mediate the metabolism of both drugs and endogenous metabolites that may raise great concerns in the condition of diabetes. The aim of this study was to determine whether diabetes could affect UGTs at the intestinal and colonic tract. High-fat diet combined with a low-dose streptozotocin was used to induce type II diabetic model in rat. The mRNA levels and enzymatic activities of UGT1A1, -1A6, and -1A7 in diabetic intestine and colon were higher than those in nondiabetic rats. In contrast, both the activity and mRNA level of UGT2B1 in diabetic rats were lower than that in nondiabetic rats. Notably, the diabetic intestine and colon exhibited an inflammatory state with increased pro-inflammatory cytokines. Various transcriptional factors involved in UGT regulation were unanimously upregulated in diabetic intestine and colon. These findings strongly suggest that the regulating pathways of UGT1 family are adaptively upregulated in the diabetic gastrointestinal tract. Given the essential regulatory role of the gastrointestinal site in drug disposition, such changes in UGTs may have a dynamic and complex impact on therapeutic drugs and endogenous metabolomes.
Drug Metabolism and Pharmacokinetics 04/2013; · 2.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The dopamine, serotonin, and kynurenine metabolic pathways play pivotal roles on brain function and their disturbances are closely related to various neurological diseases. Comprehensive measurement of these metabolites is thus essential for monitoring the global neurochemical responses to pathological challenges or drug intervention. However, simultaneous measurement of various neurochemcial metabolites represents a great challenge. We developed herein an original and feasible method using high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). A chemical derivatization approach using benzoyl chloride (benzoylation) was developed to achieve better chromatographic behavior and mass detecting sensitivity. The developed method enables a rapid quantification of 11 metabolites spanning dopamine, serotonin, and kynurenine metabolic pathways within 10.5 min. With this method, we were able to simultaneously monitor inflammation induced alternations of all these metabolites in rat brain and in particular their dynamics in plasma matrix. The balance between the serotonin and kynurenine branches of tryptophan metabolism was disrupted by lipopolysaccharide (LPS)-induced inflammation, characterized with the overproduction of neurotoxic metabolite 3-hydroxykynurenine and decreased levels of serotonine. The measured levels of this panel of neurotransimtters ranged from 4.3 ng to 10.6 μg per gram brain tissues. All these results support that the presently developed method is sufficiently sensitive and robust to simultaneously monitor a large panel of metabolites with diverse properties and large range of concentration differences. Therefore, this method will be expected highly useful for comprehensive studies of the pathophysiological roles and mechanisms of these critical neurotransmitters.
Analytical Chemistry 10/2012; · 5.86 Impact Factor
-
Tong Xie,
Yan Liang,
Jiye A,
Haiping Hao,
Linsheng Liu, Xiao Zheng,
Chen Dai,
Yuanyuan Zhou,
Tianye Guan,
Yanna Liu,
Lin Xie,
Guangji Wang
[show abstract]
[hide abstract]
ABSTRACT: This study describes the effectiveness of post-acquisition data processing techniques in detecting the lipid species rapidly from the massive data generated by high resolution mass spectrometry. The filtering approaches by product ions or neutral losses enabled glycerophospholipids and sterol conjugates to be identified based on the investigation of their fragmentation patterns, and the filtration by mass defect facilitated the detection of fatty acyl residues and bile acids by limiting the range of mass defect values. After application of these filtering techniques to mass spectra, the background noise was significantly filtered out and characteristic peaks of lipid species were efficiently sorted out. Totally 145 individual lipids were identified and structurally elucidated. Validation results of the LCMS-Q-TOF-based quantitative performance for all the peaks showed that the accuracy, expressed as relative errors (RE%), was lower than ±15%, and values (RSD%) of the inter-batch and intra-batch precision were lower than 15% in the assay. The developed method was integrated to the evaluation of plasma lipid profile from high fat diet versus energy restricted diet fed rats. A unique discrimination of the groups was successfully achieved through a principal component analysis (PCA).
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 08/2012; 905:43-53. · 2.78 Impact Factor
-
Tong Xie,
Yan Liang,
Haiping Hao,
Jiye A,
Lin Xie,
Ping Gong,
Chen Dai,
Linsheng Liu,
An Kang, Xiao Zheng,
Guangji Wang
[show abstract]
[hide abstract]
ABSTRACT: This study was to develop and evaluate a practical approach of mass defect filtering (MDF), a post-acquisition data processing technique, for the rapid classification of complicated peaks into well-known chemical families based on the exact mass acquired by high resolution mass spectrometry. The full-scan LC-MS/MS data of the Ophiopogon japonicus extract was acquired using high performance liquid chromatography coupled with hybrid quadrupole-time of flight (LCMS-Q-TOF) system which features high resolution, mass accuracy, and sensitivity. To remove the interferences of the complex matrix, MDF approach was developed and employed to rapidly pick out the peaks of ophiopogonins and ophiopogonones from full-scan mass chromatograms. The accuracy of MDF was evaluated in reference to the result of structural identification. After the MDF based classification, both target and non-target components in Ophiopogon japonicus extract were characterized based on the detailed fragment ions analysis in the hybrid ion trap and time-of-flight mass spectrometry (LCMS-IT-TOF). By this approach, more than 50 ophiopogonins and 27 ophiopogonones were structurally characterized. The present results of rapid detection and identification of ophiopogonins and ophiopogonones suggest that the proposed MDF approach based on the high-resolution mass spectrometry data would be expected adaptable to the analysis of other herbal components.
Journal of chromatography. A 03/2012; 1227:234-44. · 4.19 Impact Factor
-
An Kang,
Haiping Hao, Xiao Zheng,
Yan Liang,
Yuan Xie,
Tong Xie,
Chen Dai,
Qijin Zhao,
Xiaolan Wu,
Lin Xie,
Guangji Wang
[show abstract]
[hide abstract]
ABSTRACT: The effectiveness of ginseng in preventing and treating various central nervous system (CNS) diseases has been widely confirmed. However, ginsenosides, the principal components of ginseng, are characterized by poor accessibility to the brain, and this pharmacokinetic-pharmacological paradox remains poorly explained. Anti-inflammatory approaches are becoming promising therapeutic strategies for depression and other CNS diseases; however, previous studies have focused largely on anti-inflammatory therapies directed at the central nervous system. It is thus of interest to determine whether ginsenosides, characterized by poor brain distribution, are also effective in treating lipopolysaccharide- (LPS) induced depression-like behavior and neuroinflammation.
In an LPS-induced depression-like behavior model, the antidepressant effects of ginseng total saponins (GTS) were assessed using a forced swimming test, a tail suspension test, and a sucrose preference test. The anti-inflammatory efficacies of GTS in brain, plasma, and LPS-challenged RAW264.7 cells were validated using ELISA and quantitative real-time PCR. Moreover, indoleamine 2,3-dioxygenase (IDO) activity in the periphery and brain were also determined by measuring levels of kynurenine/tryptophan.
GTS significantly attenuated LPS-induced depression-like behavior. Moreover, LPS-induced increases in 5-HT and tryptophane turnover in the brain were significantly reduced by GTS. IDO activities in brain and periphery were also suppressed after pretreatment with GTS. Furthermore, GTS-associated recovery from LPS-induced depression-like behavior was paralleled with reduced mRNA levels for IL-1β, IL-6, TNF-α, and IDO in hippocampus. Poor brain distribution of ginsenosides was confirmed in LPS-challenged mice. GTS treatment significantly decreased production of various proinflammatory cytokines in both LPS-challenged mice and RAW264.7 cells.
This study suggests that the anti-depression efficacy of GTS may be largely attributable to its peripheral anti-inflammatory activity. Our study also strengthens an important notion that peripheral anti-inflammation strategies may be useful in the therapy of inflammation-related depression and possibly other CNS diseases.
Journal of Neuroinflammation 08/2011; 8:100. · 3.83 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A sensitive and simple liquid chromatography-mass spectrometry (LC-MS) method has been developed and validated for the quantification of solamargine, a steroidal glycoalkaloid, in rat plasma. Vincristine was selected as the internal standard. Sample preparation involved simple liquid-liquid extraction by ethyl acetate with high efficiency. The chromatographical separation was performed on a Shimadzu C(18) column (150mm×2.0mm, 5μm) with a gradient elution of acetonitrile and 0.02% (v/v) formic acid. The elutes were detected under positive electrospray ionization (ESI) and the target analytes quantified by selected ion monitoring (SIM) mode. The method was sensitive with the lowest limit of quantitation (LLOQ) at 0.5ng/mL in 50μL of rat plasma. Good linearity (r(2)=0.9996) was obtained covering the concentration of 0.5-2000.0ng/mL. The intra- and inter-day assay precision ranged from 2.87 to 3.60% and 0.52 to 6.81%, respectively. In addition, the stability, extraction recovery and matrix effect involved in the method were also validated. The practical utility of the aforementioned method was successfully confirmed in the pharmacokinetic evaluation of solamargine in Sprague-Dawley rats after intravenous administration.
Journal of pharmaceutical and biomedical analysis 07/2011; 55(5):1157-62. · 2.45 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Translational research is an emerging discipline that aims to fill the gap through the whole pipeline from bench to bedside. This review highlights the importance and urgency of incorporating translational research into the study of pharmacokinetic herb drug interactions (PHDI), based on an intensive discussion on the controversial and inconsistent reports from preclinical to clinical, in vitro to in vivo, and across different studies concerning PHDI. Current controversial and dispersed reports confer poor translational capacity of experimental research data to guiding the clinical practices. We propose that the herbal complexities in their chemical compositions, biphasic and tissue-specific effects of enzymes, and the present incomplete understanding of the disposition properties of herbal medicines themselves; and the enzymatic complexities in the species differences, individual genotype and phenotype, differential regulation during healthy and pathological conditions, substrate dependent modulations, and their interplay with transporters, collectively constitute the major translational blocks in PHDI from experimental research to daily clinical practice. In clinical considerations, this review indicates that PHDI are far from clear based on the isolated preclinical findings, and that the intestine is a much more susceptible site than liver when subjected to herbal regulations, and that enzymatic induction could be more predominant than inhibition upon chronic ingestion of herbal medicines. Hopefully, this review would be helpful for better understanding the nature of hurdles in PHDI research, and for igniting the future translational research initiatives.
Current Drug Metabolism 05/2011; 12(9):850-70. · 5.11 Impact Factor
-
Chen Dai,
Wei Xiao,
Yan Liang,
Lin Xie,
Guangji Wang,
Gang Ding,
Zhaoqing Meng,
Juan Zhang,
Tianye Guan,
An Kang, Xiao Zheng,
Tong Xie,
Chunzhu Li,
Qijin Zhao,
Wenjun Liu,
Li Zhao,
Jia Xu
[show abstract]
[hide abstract]
ABSTRACT: A simple, sensitive and specific high-performance liquid chromatography mass spectrometry (LC-MS) method was developed and validated for the quantification of strictosamide in dog plasma. Strictosamide and internal standard (IS, ranolazine) extracted by liquid-liquid extraction with ethyl acetate were separated on a C(18) column using a gradient elution program. The detection was performed by selected ion monitoring mode via a positive electrospray ionization interface. The LLOQ was 1.0 ng/mL and the method exhibited acceptable precision, extraction efficiency and matrix effect. Finally, this proposed method was successfully applied to dog pharmacokinetic study and yielded the most comprehensive data on systemic exposure of strictosamide to date.
Biomedical Chromatography 03/2011; 25(12):1338-42. · 1.97 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Metabolic research for herbal medicine (HM) is a formidable task, which is still in its infancy due to complicated components in HM, complex metabolic pathways, and lack of authentic standards. The present work contributes to the development of a powerful technical platform to rapidly identify and classify metabolites of herbal components based on a liquid chromatography hybrid ion trap time-of-flight mass spectrometry. Taking Schisandra lignans extract as an example, the metabolic studies were completed both in vitro and in vivo. In the in vitro study, metabolites for five representative Schisandra lignans were identified and structurally characterized. The major metabolic pathways were summed as demethylation, hydroxylation, and demethylation and hydroxylation. In the in vivo study, 44 metabolites were detected in rat urine. These metabolites were identified and classified rapidly according to the metabolic rules obtained in the in vitro studies, and hydroxylation was confirmed as the primacy metabolic pathway for lignans in rat urine. In addition, "relative cumulative excretion" (RCE) for the metabolites in female and male rats were calculated according to their relative intensities in the urine samples collected at 0 to 12, 12 to 24, and 24 to 36 h. As a result, great gender-related difference on RCE was observed. For most metabolites, RCE in female rats was significantly lower than that in male rats. In conclusion, the presently developed methodology and approach on metabolic research for Schisandra lignans will find its wide use in metabolic studies for herbal medicines.
Drug metabolism and disposition: the biological fate of chemicals 10/2010; 38(10):1747-59. · 3.74 Impact Factor
-
Yuan Xie,
Haiping Hao,
An Kang,
Yan Liang,
Tong Xie,
Shiqing Sun,
Chen Dai, Xiao Zheng,
Lin Xie,
Juan Li,
Guangji Wang
[show abstract]
[hide abstract]
ABSTRACT: Although pharmacokinetic alternations by hepatic injury have been extensively studied, little is known about the potential influence of hepatoprotective agent's treatment. This study was aimed to investigate the holistic pharmacokinetics of multiple lignans, CYP3A regulations, and their correlations with hepatic injury biomarkers, in hepatic injured rats pretreated with or without schisandra lignan extract (SLE) and dimethyl-diphenyl-bicarboxylate (DDB). Integral pharmacokinetics of multiple lignans based on an AUC-weighting approach was determined in normal, CCl4 induced hepatic injury rats pretreated with or without SLE and DDB. Protein expression and activities of CYP3A were determined. Pharmacokinetic parameters and CYP3A activities were correlated with serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. CCl4 induced acute hepatic injury resulted in a nearly 8-fold enhancement of integral plasma exposures of multiple lignans, which was caused by the significant down-regulation of CYP3A. SLE and DDB pretreatment exhibited potent hepatoprotective effects, accompanied with the restored expression and activity of CYP3A, and the recovery of the respective and integral pharmacokinetics of lignans components. The integral AUC(0-tn) and CYP3A activities correlated well with ALT and AST. This study suggested that the pharmacokinetic regulating effects of hepatoprotective agent's on themselves and co-prescribed drugs should be of concern, and hepatic injury biomarkers may serve as good predictors.
Journal of ethnopharmacology 09/2010; 131(2):290-9. · 2.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To date, the pharmacokinetic research of herbal medicines (HMs) is still in its infancy and is facing critical technical challenges on the qualitative and quantitative analysis of complicated components from biological matrices. Additionally, the lack of authentic standards constitutes another bottleneck on assessing herbal pharmacokinetics. This present work contributes to the development of a powerful technical platform for both qualitative and quantitative pharmacokinetic analysis of herbal components, and a strategy of relative exposure that provides a practicable pharmacokinetic assessment independent of authentic standards, based on the use of liquid chromatography hybrid ion trap time-of-flight mass spectrometry (LC-IT-TOF/MS). Taking schisandra lignans extract (SLE) as an example, the LC-IT-TOF/MS assay was initially applied to the global qualitative analysis of components contained in SLE per se and in the rat plasma post SLE dosing. Afterwards, this study focused on validating the quantitative performance of LC-IT-TOF/MS assay by comparison with a well-established LC-Q/MS assay. For the absolute quantification of five lignans components with authentic standards, both assays showed very similar analytical figures of merit such as linearity, precision, accuracy, and pharmacokinetic parameters. Compared with LC-Q/MS, the prominent advantage of LC-IT-TOF/MS assay is its much higher sensitivity. Moreover, a 'relative exposure approach' (REA) that entails the use of sequentially diluted original herbal preparations to prepare the 'mixed calibration curves' was developed to assessing herbal pharmacokinetics independent of specific authentic compounds for each component. Such an approach was found capable of providing virtually identical pharmacokinetic parameters as that from the typical pharmacokinetic assay calibrated by authentic standards, except for the absolute plasma concentrations. The presently developed methodology and approach will find its wide use in, but not limited to, the qualitative and quantitative pharmacokinetic analysis of herbal medicines.
Journal of chromatography. A 07/2010; 1217(30):4971-9. · 4.19 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Quadrupole (Q) mass spectrometers are the most popular analytical tools due to their reliability, effectiveness, and low cost. However, they are not suitable for quantitative analysis of multi-component since the sensitivity will get worse rapidly with the increasing number of m/z detected. The present work, for the first time, attempted to analyze of 16 saponins simultaneously using an approach of segmental and selected ion monitoring (SSIM) based on LC-Q/MS, and systematically investigated the influence of different SSIM modes on signal level/noise level (S/N), lower limits of quantification (LLOQ), upper limits of quantification (ULOQs), etc. Our results showed that a proper SSIM mode could not only provide much higher sensitivity for all the targeting analytes, but also dramatically broadened their dynamic ranges. The developed methodology could effectively break the application bottleneck on the quantitative analysis of multi-component with LC-Q/MS, and would be applied widely in related fields for multi-component analysis, such as environmental monitoring, metabonomics, Chinese herbal medicine research.
Journal of chromatography. A 06/2010; 1217(26):4501-6. · 4.19 Impact Factor
