Publications (15)41.45 Total impact
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Article: Metabolite profiling of plasma and urine from rats with TNBS-induced acute colitis using UPLC-ESI-QTOF-MS-based metabonomics--a pilot study.
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ABSTRACT: The incidence of inflammatory bowel disease, a relapsing intestinal condition whose precise etiology is still unclear, has continually increased over recent years. Metabolic profiling is an effective method with high sample throughput that can detect and identify potential biomarkers, and thus may be useful in investigating the pathogenesis of inflammatory bowel disease. In this study, using a metabonomics approach, a pilot study based on ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was performed to characterize the metabolic profile of plasma and urine samples of rats with experimental colitis induced by 2,4,6-trinitrobenzene sulfonic acid. Acquired metabolic profile data were processed by multivariate data analysis for differentiation and screening of potential biomarkers. Five metabolites were identified in urine: two tryptophan metabolites [4-(2-aminophenyl)-2,4-dioxobutanoic acid and 4,6-cihydroxyquinoline], two gut microbial metabolites (phenyl-acetylglycine and p-cresol glucuronide), and the bile acid 12α-hydroxy-3-oxocholadienic acid. Seven metabolites were identified in plasma: three members of the bile acid/alcohol group (cholic acid, 12α-hydroxy-3-oxocholadienic acid and cholestane-3,7,12,24,25-pentol) and four lysophosphatidylcholines [LysoPC(20:4), LysoPC(16:0), LysoPC(18:1) and LysoPC(18:0)]. These metabolites are associated with damage of the intestinal barrier function, microbiota homeostasis, immune modulation and the inflammatory response, and play important roles in the pathogenesis of inflammatory bowel disease. Our results positively support application of the metabonomic approach in study of the pathophysiological mechanism of inflammatory bowel disease.FEBS Journal 04/2012; 279(13):2322-38. · 3.79 Impact Factor -
Article: Analysis of the transcriptome of Panax notoginseng root uncovers putative triterpene saponin-biosynthetic genes and genetic markers.
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ABSTRACT: Panax notoginseng (Burk) F.H. Chen is important medicinal plant of the Araliacease family. Triterpene saponins are the bioactive constituents in P. notoginseng. However, available genomic information regarding this plant is limited. Moreover, details of triterpene saponin biosynthesis in the Panax species are largely unknown. Using the 454 pyrosequencing technology, a one-quarter GS FLX titanium run resulted in 188,185 reads with an average length of 410 bases for P. notoginseng root. These reads were processed and assembled by 454 GS De Novo Assembler software into 30,852 unique sequences. A total of 70.2% of unique sequences were annotated by Basic Local Alignment Search Tool (BLAST) similarity searches against public sequence databases. The Kyoto Encyclopedia of Genes and Genomes (KEGG) assignment discovered 41 unique sequences representing 11 genes involved in triterpene saponin backbone biosynthesis in the 454-EST dataset. In particular, the transcript encoding dammarenediol synthase (DS), which is the first committed enzyme in the biosynthetic pathway of major triterpene saponins, is highly expressed in the root of four-year-old P. notoginseng. It is worth emphasizing that the candidate cytochrome P450 (Pn02132 and Pn00158) and UDP-glycosyltransferase (Pn00082) gene most likely to be involved in hydroxylation or glycosylation of aglycones for triterpene saponin biosynthesis were discovered from 174 cytochrome P450s and 242 glycosyltransferases by phylogenetic analysis, respectively. Putative transcription factors were detected in 906 unique sequences, including Myb, homeobox, WRKY, basic helix-loop-helix (bHLH), and other family proteins. Additionally, a total of 2,772 simple sequence repeat (SSR) were identified from 2,361 unique sequences, of which, di-nucleotide motifs were the most abundant motif. This study is the first to present a large-scale EST dataset for P. notoginseng root acquired by next-generation sequencing (NGS) technology. The candidate genes involved in triterpene saponin biosynthesis, including the putative CYP450s and UGTs, were obtained in this study. Additionally, the identification of SSRs provided plenty of genetic makers for molecular breeding and genetics applications in this species. These data will provide information on gene discovery, transcriptional regulation and marker-assisted selection for P. notoginseng. The dataset establishes an important foundation for the study with the purpose of ensuring adequate drug resources for this species.BMC Genomics 12/2011; 12 Suppl 5:S5. · 4.07 Impact Factor -
Article: Application of microscopy in authentication of valuable Chinese medicine I--Cordyceps sinensis, its counterfeits, and related products.
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ABSTRACT: Light and polarized microscope was applied to authenticate 32 Cordyceps and 6 artificial counterfeits and 8 fermented Cordyceps as well as 7 Cordyceps capsules available in Hong Kong markets. Results showed that transverse sections of stroma and powder of larvae can be used to differentiate C. sinensis from its counterfeits. The fermented Cordyceps are in powder form. Among the eight fermented Cordyceps collected, half of them were pure; three were a mixture of fermented Cordyceps and soya beans; one was a mixture of unknown plant tissues and soya beans. For the seven Cordyceps capsules, the powders of five samples were a mixture of fermented Cordyceps and soya beans; the powders of other two were a mixture of C. sinensis stroma powder and fermented Cordyceps. The study indicated that the microscopy is an unambiguous method that requests fewer sample for the authentication of valuable Chinese medicine-C. sinensis and its related products.Microscopy Research and Technique 05/2011; 75(1):54-64. · 1.79 Impact Factor -
Article: Applying plant DNA barcodes for Rosaceae species identification
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ABSTRACT: © The Willi Hennig Society 2010.AbstractThe Consortium for the Barcode of Life (CBOL) Plant Working Group (PWG) established the use of matK+rbcL as core barcodes and ITS2 as one of the supplementary loci for differentiating plants at the Third International Barcoding Conference. Here, we tested the applicability of four DNA regions (rbcL, matK, rpoC1 and ITS2) as the barcodes for identifying species within Rosaceae. Based on assessments of the success rates of PCR amplifications, the sequence quality, extent of specific genetic divergence, DNA barcoding gap and ability for species discrimination, our results suggest that ITS2 is the best of the four loci tested for barcoding Rosaceae. We further evaluated the effectiveness of ITS2 for identifying a wide range of species within Rosaceae. Of the 1410 plant samples collected from 893 species in 96 diverse genera, ITS2 successfully identified 78 and 100% of them at the species and genus levels, respectively. Therefore, our research indicated that the ITS2 region is a powerful, though not perfect, barcode for Rosaceae identification that also contributes valuable information for identifying closely related species in other plant taxonomic groups.Cladistics 05/2010; 27(2):165 - 170. · 5.25 Impact Factor -
Article: Identification of medicinal plants in the family Fabaceae using a potential DNA barcode ITS2.
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ABSTRACT: To test whether the ITS2 region is an effective marker for use in authenticating of the family Fabaceae which contains many important medicinal plants. The ITS2 regions of 114 samples in Fabaceae were amplified. Sequence assembly was assembled by CodonCode Aligner V3.0. In combination with sequences from public database, the sequences were aligned by Clustal W, and genetic distances were computed using MEGA V4.0. The intra- vs. inter-specific variations were assessed by six metrics, wilcoxon two-sample tests and "barcoding gaps". Species identification was accomplished using TaxonGAP V2.4, BLAST1 and the nearest distance method. ITS2 sequences had considerable variation at the genus and species level. The intra-specific divergence ranged from 0% to 14.4%, with an average of 1.7%, and the inter-specific divergence ranged from 0% to 63.0%, with an average of 8.6%. Twenty-four species found in the Chinese Pharmacopoeia, along with another 66 species including their adulterants, were successfully identified based on ITS2 sequences. In addition, ITS2 worked well, with over 80.0% of species and 100% of genera being correctly differentiated for the 1507 sequences derived from 1126 species belonging to 196 genera. Our findings support the notion that ITS2 can be used as an efficient and powerful marker and a potential barcode to distinguish various species in Fabaceae.Journal of ethnopharmacology 05/2010; 130(1):116-21. · 2.32 Impact Factor -
Article: Use of ITS2 region as the universal DNA barcode for plants and animals.
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ABSTRACT: The internal transcribed spacer 2 (ITS2) region of nuclear ribosomal DNA is regarded as one of the candidate DNA barcodes because it possesses a number of valuable characteristics, such as the availability of conserved regions for designing universal primers, the ease of its amplification, and sufficient variability to distinguish even closely related species. However, a general analysis of its ability to discriminate species in a comprehensive sample set is lacking. In the current study, 50,790 plant and 12,221 animal ITS2 sequences downloaded from GenBank were evaluated according to sequence length, GC content, intra- and inter-specific divergence, and efficiency of identification. The results show that the inter-specific divergence of congeneric species in plants and animals was greater than its corresponding intra-specific variations. The success rates for using the ITS2 region to identify dicotyledons, monocotyledons, gymnosperms, ferns, mosses, and animals were 76.1%, 74.2%, 67.1%, 88.1%, 77.4%, and 91.7% at the species level, respectively. The ITS2 region unveiled a different ability to identify closely related species within different families and genera. The secondary structure of the ITS2 region could provide useful information for species identification and could be considered as a molecular morphological characteristic. As one of the most popular phylogenetic markers for eukaryota, we propose that the ITS2 locus should be used as a universal DNA barcode for identifying plant species and as a complementary locus for CO1 to identify animal species. We have also developed a web application to facilitate ITS2-based cross-kingdom species identification (http://its2-plantidit.dnsalias.org).PLoS ONE 01/2010; 5(10). · 4.09 Impact Factor -
Article: Chemical markers for the quality control of herbal medicines: an overview.
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ABSTRACT: Selection of chemical markers is crucial for the quality control of herbal medicines, including authentication of genuine species, harvesting the best quality raw materials, evaluation of post-harvesting handling, assessment of intermediates and finished products, and detection of harmful or toxic ingredients. Ideal chemical markers should be the therapeutic components of herbal medicines. However, for most herbal medicines, the therapeutic components have not been fully elucidated or easily monitored. Bioactive, characteristic, main, synergistic, correlative, toxic and general components may be selected. This article reviews the effective use of chemical markers in the quality control of herbal medicines including the selection criteria considering the roles and physicochemical factors which may affect the effective use of chemical markers.Chinese Medicine 07/2008; 3:7. · 1.79 Impact Factor -
Article: An optimized high-performance liquid chromatography (HPLC) method for benzoylmesaconine determination in Radix Aconiti Lateralis Preparata (Fuzi, aconite roots) and its products.
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ABSTRACT: Benzoylmesaconine (BMA) is the main Aconitum alkaloid in Radix Aconiti Lateralis Preparata (Fuzi, aconite roots) with potent pharmacological activities, such as analgesia and anti-inflammation. The present study developed a simple and reliable method using BMA as a marker compound for the quality control of processed aconite roots and their products. After extraction, a high-performance liquid chromatography (HPLC) determination of BMA was conducted on a RP-C18 column by gradient elution with acetonitrile and aqueous phase, containing 0.1% phosphoric acid adjusted with triethylamine to pH 3.0. A distinct peak profile was obtained and separation of BMA was achieved. Method validation showed that the relative standard deviations (RSDs) of the precision of BMA in all intra-day and inter-day assays were less than 1.36%, and that the average recovery rate was 96.95%. Quantitative analysis of BMA showed that the content of BMA varied significantly in processed aconite roots and their products. This HPLC method using BMA as a marker compound is applicable to the quality control of processed aconite roots and their products.Chinese Medicine 02/2008; 3:6. · 1.79 Impact Factor -
Article: Alkaloid profiling in crude and processed Strychnos nux-vomica seeds by matrix-assisted laser desorption/ionization-time of flight mass spectrometry.
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ABSTRACT: Direct analysis of alkaloids in the tissues of crude and processed Strychnos nux-vomica seeds by MALDI-TOFMS was described. The alkaloid profiles of the herb drugs were obtained without the need of complicated sample preparation to avoid potential damage or change of the active components. Seed tissues that were optimally sliced to a thickness of 10-20 microm from the crude and processed Strychnos nux-vomica seeds as well as various parts of tissue such as endosperm and epidermis were analyzed on MALDI target plate after the matrix was directly applied onto the tissue surface. The obtained alkaloid profiles provided valuable information for the differentiation of crude and processed Strychnos nux-vomica seeds and for the explanation of the significantly different toxicity. Experimental results indicated that the direct MALDI-TOFMS analysis allowed rapid screening of the alkaloid components in Strychnos nux-vomica seeds.Journal of Pharmaceutical and Biomedical Analysis 12/2007; 45(3):430-6. · 2.97 Impact Factor -
Article: Neonatal maternal separation enhances central sensitivity to noxious colorectal distention in rat.
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ABSTRACT: Psychological stress experienced in early life plays an important role in the development of visceral hyperalgesia in irritable bowel syndrome (IBS). Neonatal maternal separation has been shown to trigger a long-term alternation in stress-induced responses to visceral nociceptive stimuli in rats. The aim of the present study was to show a direct evidence of stress-induced alteration in central neuronal responses to colorectal distention (CRD) in rats by a quantitative study of c-fos expression in relevant brain structures. Male Wistar rat pups were subjected to 180-min daily neonatal maternal separation (NMS) for 13 consecutive days (from PND 2 to PND 14). The expression of c-fos was examined by using immunohistochemistry. Increased c-fos expression was observed, for the first time, in the cingulate cortex (3-fold) in NMS rats in comparison with the control group at basal condition. At noxious CRD (80 mm Hg), c-fos expression was induced in the supraspinal centers and in both the superficial (laminae I-II) and the deeper laminae (laminae V-VI and X) of the spinal cord in rats. Significantly more Fos-IR nuclei were found in the laminae I and II, and laminae V-VI of the lumbarsacral spinal cord, the paraventricular thalamic nucleus, the cingulate cortex, the amygdaloid central nucleus in NMS rats, but not in the solitary tract, the central medial thalamic nucleus, the ventromedial hypothalamic nucleus, and the periaquaductal gray. The present results indicate that NMS has sensitized the cingulate cortex and upregulated the activity of the ascending pathway at spinal level as well as the thalamo-cortico-amydala pathway to CRD. The upregulation and sensitization of these pathways may be responsible for the development of visceral hypersensitivity in IBS.Brain Research 07/2007; 1153:68-77. · 2.73 Impact Factor -
Article: Simultaneous determination of multiple marker constituents in concentrated Gegen Tang granule by high performance liquid chromatography.
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ABSTRACT: Concentrated Gegen Tang (GT) granule is a widely available traditional Chinese medicinal product for the treatment of cold and flu. There was no reliable analytical method available for the quality assessment of GT granules. An HPLC method with an Agilent Zorbax SB-Phenyl Stablebond column (250 x 4.6 mm, 5 microm) was developed and validated. The mobile phase gradient was a mixture of 0.1% trifluoroacetic acid (TFA) in acetonitrile (ACN) and 0.1% TFA in water. The detection with a diode-array detector was set at 207, 230, 250 and 275 nm. Seven components, namely puerarin, daidzein, paeoniflorin, cinnamic acid, glycyrrhizin, ephedrine and pseudoephedrine were selected as marker compounds for the evaluation. The regression equations revealed good linear relationships (correlation coefficients: 0.9994-0.9998) between the peak areas and concentrations. The recovery was between 98.8% and 101.7% with good precision and accuracy. The quality of GT granule from four different manufacturers was evaluated with this newly developed method. Samples from four manufacturers showed similar profiles but contents of the detected markers varied significantly among manufacturers and batches. A new method using high performance liquid chromatography (HPLC) has been developed for simple and reliable quality control of commercial concentrated GT granules. Sensitivity was increased by multi-wavelength detection. The contents of selected marker components in GT granules varied significantly among manufacturers and batches, making it necessary to evaluate the quality of concentrated GT granules in the market.Chinese Medicine 02/2007; 2:7. · 1.79 Impact Factor -
Article: Preparative isolation of hydrolysable tannins chebulagic acid and chebulinic acid from Terminalia chebula by high-speed counter-current chromatography.
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ABSTRACT: As a chromatographic column, the high-speed counter-current chromatography system was equipped with a preparative HPLC series, enabling the successful isolation of hydrolysable tannins from the fruits of Terminalia chebula, a traditional Chinese medicine. The two-phase solvent system was composed of n-hexane-ethyl acetate-methanol-water (1:20:1:20 v/v). As a result, 33.2 mg chebulagic and 15.8 mg chebulinic acids were obtained in one step from 300 mg of crude extract. Their purities were determined by HPLC to be 95.3 and 96.1%, respectively. The chemical structures were identified by their MS and 1H NMR spectra.Journal of Separation Science 08/2006; 29(11):1653-7. · 2.73 Impact Factor -
Article: Puerarin induces angiogenesis in myocardium of rat with myocardial infarction.
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ABSTRACT: Puerarin is a major effective ingredient extracted from the traditional Chinese medicine ge-gen (radix puerariae, RP). Recently, puerarin has been used to treat patients with coronary artery diseases (CAD). However, the mechanisms of puerarin on coronary artery diseases are still not very clear. In this study, we investigated the role of puerarin on angiogenesis in the non-ischemic and ischemic myocardium. We found that puerarin (120, 60 mg/kg, i.p.) could reduce infarct area in the heart of rat with myocardial infarction (MI). Puerarin (120 mg/kg) induced angiogenesis in the non-ischemic and ischemic myocardium, which was one of the mechanisms of curing coronary artery diseases. The gene expression or activation of vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1alpha (HIF-1alpha) and endothelial nitric oxide synthase (eNOS) that correlated with angiogenesis were also induced by puerarin. From these results, we suggested that puerarin may induce therapeutic angiogenesis in myocardium of rat with MI. The mechanism may be that puerarin can induce VEGF and eNOS expression.Biological & Pharmaceutical Bulletin 06/2006; 29(5):945-50. · 1.66 Impact Factor -
Article: Gambogic acid and epigambogic acid, C-2 epimers with novel anticancer effects from Garcinia hanburyi.
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ABSTRACT: Gambogic acid, usually isolated as an inseparable stereomeric mixture of C-2 epimers, was newly separated into two epimers (1 and 2) from the gamboges of Garcinia hanburyi. The stereochemistry at C-2 was clearly defined by extensive spectroscopic analysis and direct comparison of NMR and HPLC data with those of the known R-epimer. Both epimers were examined for their cytotoxicities against human leukemia K562 (K562/S) and doxorubicin-resistant K562 (K562/R) cell lines. Different from doxorubicin (IC (50) = 10.78 microM for K562/R and 0.66 microM for K562/S), epimers 1 and 2 exhibited similar activities against both cell lines (IC(50) = 1.32 and 0.89 microM for 1, IC(50) = 1.11 and 0.86 microM for 2). These results suggested that both epimers were not multidrug resistance (MDR) substrates. Furthermore, epimers 1 and 2 were tested for their inhibitory effects against six human cytochrome P-450 enzymes. Epimers 1 and 2 showed little inhibitory effects toward five of the enzymes except CYP2C9. Interestingly, when tested against CYP2C9, S-epimer 2 had an inhibitory effect 20-fold stronger than that of R-epimer 1.Planta Medica 03/2006; 72(3):281-4. · 2.15 Impact Factor -
Article: Attenuated endothelium-mediated relaxation by acteoside in rat aorta: Role of endothelial [Ca2+]i and nitric oxide/cyclic GMP pathway.
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ABSTRACT: Acteoside and other phenylethanoid glycoside are contained in many plants that are widely used in traditional Chinese herbal medicine. Acteoside possesses multiple biological actions. Its effect on the vascular system is, however, incompletely understood. This study was aimed to investigate the role of endothelial [Ca2+]i, nitric oxide (NO), and cyclic GMP in acteoside-induced inhibition of endothelial NO-mediated relaxation in rat aorta. Acteoside reduced endothelial NO-dependent relaxation induced by acetylcholine (Ach) or A23187. Acteoside inhibited Ach-stimulated increase in tissue content of cyclic GMP in endothelium-intact rings. L-NNA abolished the stimulatory effect of Ach. Treatment with acteoside significantly suppressed bradykinin-induced increase in [Ca2+]i of cultured rat aortic endothelial cells. Acute exposure to acteoside (30 microM) did not affect the expression of eNOS mRNA in endothelium-intact rings. In summary, acteoside impairs endothelial NO-mediated aortic relaxation partially through inhibition of agonist-induced endothelial Ca2+ mobilization and Ca2+-dependent NO production and subsequent suppression of cyclic GMP formation. This novel pharmacological action if occurring in small vessels in vivo, may contribute to the reported anti-inflammatory effect of acteoside against NO-mediated vascular permeability-related acute edema.Life Sciences 08/2004; 75(10):1149-57. · 2.53 Impact Factor
Top co-authors
Top Journals
Institutions
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2011
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The Hong Kong Polytechnic University
- Department of Applied Biology and Chemical Technology
Hong Kong, Hong Kong
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2010–2011
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Peking Union Medical College Hospital
Beijing, Beijing Shi, China
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2006–2010
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Racing Laboratory of the Hong Kong Jockey Club
Hong Kong, Hong Kong -
State Key Laboratory of Medical Genetics of China
Changsha, Hunan, China
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