Determination and Comparison of Short-Chain Fatty Acids in Serum and Colon Content Samples: Alzheimer's Disease Rat as a Case Study

Short-chain fatty acids (SCFAs) are the main microbial fermentation products from dietary fibers in the colon, and it has been speculated that they play a key role in keeping healthy in the whole-body. However, differences in SCFAs concentration in the serum and colon samples had attracted little attention. In this study, we have optimized the extract and analysis methods for the determination of ten SCFAs in both serum and colon content samples. Methanol and acetonitrile were chosen for extraction of SCFAs from serum and colon content samples, respectively. Biological samples were collected from Alzheimer's disease rats treated by extract of Schisandra chinensis (Turcz.) Baill (SC-extract) were taken as research objects. The results showed that, the relative peak intensities of SCFAs in the colon content from all groups were quite similar, and the trend was identical in the serum samples. Compared with the values in humans, the ratio of ten SCFAs in rat's colon was similar, while the percent of acetate in rat's serum was significantly higher. For therapy of Alzheimer's disease (AD), SC-extract decreased the concentration of butyrate, 3-Methyvalerate, and caproate in the serum samples towards the trend of normal rats. This study may help our understanding of how SCFAs are transported across colonic epithelium in healthy and diseased organisms.

Time-dependent metabolomics study of cerebral ischemia-reperfusion and its treatment: focus on the combination of traditional Chinese medicine and Western medicine

Cerebral ischemia is a common cerebrovascular disease with high mortality, and thrombolysis can cause more severe reperfusion injury. In clinical practice, Ginkgo biloba dispersible tablets combined with nimodipine have been widely used to reduce cerebral ischemia-reperfusion injury, but the mechanism has not been clearly elucidated. To explore this relationship, the change in metabolism between a sham operation group, a model group and an administration group was analyzed for the period after cerebral ischemia. Biochemical assays were used to assess injury extent and the therapeutic effects of different dosing regimens. A metabolomics method based on ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was developed to screen biomarkers in plasma of rats and analyze abnormal metabolic pathways. Using statistical analysis, corticosterone, glutamine, oleic acid, isoleucine, phenylalanine and sphingomyelin (d18:1/16:0) were screened as diagnostic biomarkers. The metabolic pathways perturbed by cerebral ischemia-reperfusion involved phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, alpha-linolenic acid metabolism, retinol metabolism, alanine, aspartate and glutamate metabolism, and glycerophospholipid metabolism. Analysis of the adjustment of biomarkers at different time points showed that the best time to evaluate the efficacy of combined administration is about 6 h after administration. Both pathological characteristics and metabolomics confirmed the better effect of the combined group than the individual groups. In this study, a non-targeted metabolomics method was developed to explore the mechanism of action of the combination of traditional Chinese and Western medicine in cerebral ischemia-reperfusion treatment, providing a theoretical basis for disease prognosis and treatment options. Graphical abstract.

Bioactive flavonoids in medicinal plants: Structure, activity and biological fate

Flavonoids, a class of polyphenol secondary metabolites, are presented broadly in plants and diets. They are believed to have various bioactive effects including anti-viral, anti-inflammatory, cardioprotective, anti-diabetic, anti-cancer, anti-aging, etc. Their basic structures consist of C₆-C₃-C₆ rings with different substitution patterns to produce a series of subclass compounds, and correlations between chemical structures and bioactivities have been studied before. Given their poor bioavailability, however, information about associations between structure and biological fate is limited and urgently needed. This review therefore attempts to bring some order into relationships between structure, activity as well as pharmacokinetics of bioactive flavonoids.

Simultaneous Determination of Five Specific and Sensitive Nephrotoxicity Biomarkers in Serum and Urine Samples of Four Drug-Induced Kidney Injury Models

In clinical diagnosis, serum creatinine (CR) was commonly used as the routine markers for the evaluation of kidney injury. To investigate the specific and sensitive nephrotoxicity biomarkers in different drug-induced kidney injury (DKI) models, receiver operating characteristic (ROC) analysis was applied in this study. The quantification data were acquired by the LC-MS determination. Histopathology results showed that different kinds of kidney injuries were observed in different DKI models (gentamycin, cisplatin, methotrexate and amphotericin B models), indicating the injuries might be caused by different mechanisms. Then, five typical biomarkers were simultaneously determined by a newly developed and validated LC-MS method. Uric acid, CR, hippuric acid, 3-indoxyl sulfate and phenaceturic acid were separated by an Apollo C₁₈ column and a methanol/water (5 mM ammonium acetate) gradient program. The prepared calibration curves showed good linearity with regression coefficients all above 0.9927. Of all the analytes, the precision were below 9.9% and the accuracy were from -10.3% to 9.2%. ROC results showed that different nephrotoxicity biomarkers were specific in different DKI models. The changes of different biomarkers might be induced by different nephrotoxic mechanisms in the DKI models. These specific and sensitive biomarkers in combination with serum CR are promising in the clinical diagnosis of DKI.

Use of a semi-physiological pharmacokinetic model to investigate the influence of itraconazole on tacrolimus absorption, distribution and metabolism in mice

1. The aim of this study was to investigate the influence of itraconazole (ITCZ) on tacrolimus absorption, distribution and metabolism by developing a semi-physiological pharmacokinetic model of tacrolimus in mice. 2. Mice were randomly divided into four groups, namely control group (CG, taking 3 mg kg^-1 tacrolimus only), low-dose group (LDG, taking tacrolimus with 12.5 mg kg^-1 ITCZ), medium-dose group (MDG, taking tacrolimus with 25 mg kg^-1 ITCZ) and high-dose group (HDG, taking tacrolimus with 50 mg kg^-1 ITCZ). 3. Liver clearance (CL_li) decreased significantly (**p < 0.01) in LDG (35.3%), MDG (45.2%) and HDG (58.7%) mice compared to CG mice. With respect to gut clearance (CL_gu), significant (**p < 0.01) decrease was also revealed in LDG (35.9%), MDG (50.2%) and HDG (64.6%) mice. A significant (**p < 0.01) higher tacrolimus brain-to-blood partition coefficient (K_t,br) was found in MDG (25.3%) and HDG (55.9%) mice than in CG mice. Moreover, a significant (*p < 0.05) increase (16.3%) was found in the absorption rate constant (K_a) in HDG mice compared to CG mice. There was a significant (**p < 0.01) association between ITCZ dose and the change in CL_gu (ΔCL_gu, r= -0.790), the change in CL_li (ΔCL_li, r= -0.787) and the change in K_t,br (ΔK_t,br, r = 0.727), while the association between ITCZ dose and the change in K_a (ΔK_a) was not significant (p > 0.05). 4. These findings could be useful in predicting the efficacy and toxicity of tacrolimus, and drug-drug interaction of ITCZ and tarcolimus in human.

Mixed effects of OATP1B1, BCRP and NTCP polymorphisms on the population pharmacokinetics of pravastatin in healthy volunteers

1. Pravastatin is a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor used for the treatment of hyperlipidaemia. This study aims to investigate the effects of genetic polymorphisms in OATP1B1, BCRP and NTCP on pravastatin population pharmacokinetics in healthy Chinese volunteers using a non-linear mixed-effect modelling (NONMEM) approach. A two-compartment model with a first-order absorption and elimination described plasma pravastatin concentrations well. 2. Genetic polymorphisms of rs4149056 (OATP1B1) and rs2306283 (OATP1B1) were found to be associated with a significant (p < 0.01) decrease in the apparent clearance from the central compartment (CL/F), while rs2296651 (NTCP) increased CL/F to a significant degree (p < 0.01). The combination of these three polymorphisms reduced the inter-individual variability of CL/F by 78.8%. 3. There was minimal effect of rs2231137 (BCRP) and rs2231142 (BCRP) on pravastatin pharmacokinetics (0.01 < p < 0.05), whereas rs11045819 (OATP1B1), rs1061018 (BCRP) and rs61745930 (NTCP) genotypes do not appear to be associated with pravastatin pharmacokinetics based on the population model (p > 0.05). 4. The current data suggest that the combination of rs4149056, rs2306283 and rs2296651 polymorphisms is an important determinant of pravastatin pharmacokinetics.

Evaluation of the protective effect of Zhi-Zi-da-Huang decoction on acute liver injury with cholestasis induced by α-naphthylisothiocyanate in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Zhi-Zi-Da-Huang decoction (ZZDHD), a classic traditional Chinese medicine (TCM) formula composed of four herbal medicines, has been widely used to treat various hepatobiliary disorders for a long time in China. However, the pharmacological effect of ZZDHD on liver injury with cholestasis is unrevealed.

AIM OF THE STUDY

To investigate the hepatoprotective effect of ZZDHD against α-naphthylisothiocyanate (ANIT)-induced liver injury with cholestasis in rats.

MATERIALS AND METHODS

The rats were intragastrically (i.g.) given ZZDHD at doses of 1, 2 and 4 g/kg (crude drug/body weight) once a day for seven days and treated with ANIT (75 mg/kg via i.g.) to cause liver injury at 12h after the fifth administration. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltranspeptidase (γ-GTP), total bilirubin (TBIL), direct bilirubin (DBIL) and total bile acid (TBA), as well as bile flow were measured at 48 h after ANIT treatment to evaluate the protective effect of ZZDHD. Moreover, the possible protective mechanisms were elucidated by assays of liver enzyme activities and component contents including malondialdehyde (MDA), myeloperoxidase (MPO), lipid peroxide (LPO), superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). The biochemical observations were supplemented by histopathological examination. Ultra fast liquid chromatography-mass spectrometry (UFLC-MS) was used for the phytochemical analysis of ZZDHD.

RESULTS

The high dose (4 g/kg) and middle dose (2g/kg) of ZZDHD exhibited significant and dose-dependent protective effect on ANIT-induced liver injury with cholestasis by reversing the changes in bile flow, the serum and hepatic enzymes, and histopathology of the liver tissue. Meanwhile, it was found that the low dose (1g/kg) of ZZDHD did not improve the biochemical indexes except serum TBIL, DBIL and TBA, which showed little protective effect. Phytochemical analysis revealed the presence of sixteen compounds in ZZDHD.

CONCLUSIONS

This study indicates that ZZDHD exerted a hepatoprotective effect on ANIT-induced liver injury with cholestasis in rats, and the mechanism of this activity is possibly related to its antioxidant properties.

Simultaneous determination of four active components in Alisma orientale (Sam.) Juz. by HPLC-DAD using a single reference standard

A rapid, simple and practical high-performance liquid chromatography method coupled with diode array detector (HPLC-DAD) was developed to evaluate the quality of Alisma orientale (Sam.) Juz. through a simultaneous determination of four major active triterpenes using a single standard to determine the multi-components (SSDMCs). Alisol B 23-acetate was selected as the reference compound for calculating the relative response factors. All calibration curves showed good linearity (R2>0.9998) within test ranges. RSDs for intra- and inter-day of four analytes were less than 3.6% and 2.3%; the overall recovery was 92.1-110.2% (SSDMC). The proposed method was successfully applied to quantify the four components in 20 samples from different localities in China. Moreover, significant variations were demonstrated in the content of these compounds. In addition, hierarchical clustering analysis (HCA) and principal components analysis (PCA) were performed to differentiate and classify the samples based on the contents of Alisol C 23-acetate, Alisol A, Alisol A 24-acetate and Alisol B 23-acetate. This simple, rapid, low-cost and reliable HPLC-DAD method using SSDMC is suitable for routine quantitative analysis and quality control of A. orientale (Sam.) Juz.

¹H-NMR and MS based metabolomics study of the intervention effect of curcumin on hyperlipidemia mice induced by high-fat diet

Curcumin, a principle bioactive component of Curcuma longa L, is well known for its anti-hyperlipidemia effect. However, no holistic metabolic information of curcumin on hyperlipidemia models has been revealed, which may provide us an insight into the underlying mechanism. In the present work, NMR and MS based metabolomics was conducted to investigate the intervention effect of curcumin on hyperlipidemia mice induced by high-fat diet (HFD) feeding for 12 weeks. The HFD induced animals were orally administered with curcumin (40, 80 mg/kg) or lovastatin (30 mg/kg, positive control) once a day during the inducing period. Serum biochemistry assay of TC, TG, LDL-c, and HDL-c was conducted and proved that treatment of curcumin or lovastatin can significantly improve the lipid profiles. Subsequently, metabolomics analysis was carried out for urine samples. Orthogonal Partial Least Squares-Discriminant analysis (OPLS-DA) was employed to investigate the anti-hyperlipidemia effect of curcumin and to detect related potential biomarkers. Totally, 35 biomarkers were identified, including 31 by NMR and nine by MS (five by both). It turned out that curcumin treatment can partially recover the metabolism disorders induced by HFD, with the following metabolic pathways involved: TCA cycle, glycolysis and gluconeogenesis, synthesis of ketone bodies and cholesterol, ketogenesis of branched chain amino acid, choline metabolism, and fatty acid metabolism. Besides, NMR and MS based metabolomics proved to be powerful tools in investigating pharmacodynamics effect of natural products and underlying mechanisms.

[Analysis on influential factors in China's exports of primary and semi-finished products of traditional Chinese medicine to ASEAN]

Two regression models, based on panel data over the period of 2000-2011, are built and used to analyze what factors determine China's exports of primary and semi-finished products of traditional Chinese medicine to ASEAN. The results indicate that, China GDP, the ratio of ASEAN to China GDP per capita, average export price, the ratio of state-owned assets to total assets, have a significant positive influence on the export volumes of primary products of Chinese medicine. At the same time, RMB appreciation, the ratio of three kinds of foreign-invested assets to total assets, China-ASEAN Early Harvest Program, ASEAN-China Free Trade Area have a significant negative influence. In respect of the export volumes of semi-finished products of Chinese medicine, the significant influential factors are ASEAN GDP and the ratio of ASEAN to China GDP per capita. The former is positive and the latter is negative. In order to optimize the commodity composition of experts, it is needed to increase export volumes of both primary and semi-finished products of Chinese medicine. According to the analysis above, some proposals are put forward, such as, improving the performance of foreign capital, playing an exemplary and leading role in technological innovation by state-owned enterprises, taking advantage of bargaining power of suppliers, increasing outward foreign direct investment.

Phenanthrenes, 9,10-dihydrophenanthrenes, bibenzyls with their derivatives, and malate or tartrate benzyl ester glucosides from tubers of Cremastra appendiculata

Eleven previously unknown compounds and 23 known compounds, including 20 phenanthrene or 9,10-dihydrophenanthrene derivatives, five bibenzyls, seven malate or tartrate benzyl ester glucosides, adenosine and gastrodin were isolated from tubers of Cremastra appendiculata. Among the obtained compounds, two are the first isolated dimers with one phenanthrene or bibenzyl unit connected to C-3 of 2,3,4,5-tetrahydro-phenanthro[2,1-b]furan moiety. In addition, 33 of these compounds were evaluated in vitro for their cytotoxic activity against two cancer cell lines. Among the compounds examined, one compound showed moderate cytotoxic activity, while five showed weak cytotoxic activity against the A549 cell line.

[Analysis on influential factors of Chinese medicinal herb growers' willingness to use green pesticides: evidence on Panax notoginseng production areas in Wenshan, Yunnan province]

The purpose of the article is to apply a binary logistic model to analyze the major factors, which influence Chinese medicinal herb growers' willingness to use green pesticides by using survey data collected in Wenshan, Yunnan Province. The results indicate that, output per capita, average pesticide cost per mu, cognition of pesticide residues, expectations on Panax notoginseng prices, cognition of pesticides' effect of pests control, cognition of P. notoginseng prices of low pesticide residues have a significant influence on growers' willingness to use green pesticides. According to the analysis above, some proposals for enhancing Chinese medicinal herb growers' willingness to use green pesticides are put forward, such as, moving toward the intensive planting systems, fetching down the pieces of green pesticides, emphasizing and propagating the advantages of green pesticides, keeping the prices of Chinese medicinal herb running at steady rates.

Validation of HPLC method for the determination of polydatin in giant knotweed rhizome

An HPLC method has been developed to determine polydatin in giant knotweed rhizome. In order to systematically validate the method, specificity, precision, linearity of reference solution and test solution, repeatability, reproducibility, accuracy, stability and robustness were measured. In the robustness test, a one-variable-at-a-time procedure was applied to evaluate the influence of slight variations in method factors, including the flow rate, the column temperature, the extraction time, and etc., on the assay result of polydatin. No significant differences were found when the process parameters changed during the experimental domain. And system suitability test limits were defined based on the robustness test. Results showed that the developed method was accurate, reproducible and robust.

[Comparative study on pharmacokinetics of senkyunolide I after administration of simple recipe and compound recipe in rats]

OBJECTIVE

To develop a LC-MS method for the determination of senkyunolide I (SI) in rat plasma, in order to observe whether there is significant change in the pharmacokinetics parameters of complex prescriptions of Huoluoxiaolingdan (HLXL) and single herbal extracts from Ligusticum chuanxiong Hort. in rats, and assess the effect of other components in HLXL on the pharmacokinetics of SI.

METHOD

Twelve male Sprague-Dawley (SD) rats were randomly divided into two groups, and orally administered with extract from HLXL and L. chuanxiong (both equal to SI 4.53 mg x kg(-1)). Their blood was collected at different time points for LC-MS, in order to detect the plasma concentration of SI. The pharmacokinetic parameters of SI were calculated by DAS 2.0 software. SPSS 16.0 software was used for independent-sample T-test and Nonparametric T-test.

RESULT

A linear relationship of SI ranged from 6.750 to 675.0 microg x L(-1), and with the lowest limit of detection being 6.750 microg L(-1). Both of the plasma concentration-time curves of SI were fitted with the two-compartment model for extract of HLXL and L. chuanxiong. The detected AUC and Cmax of SI showed significant difference, with no significant difference in other parameters.

CONCLUSION

The LC-MS determination method established in this experiment was so exclusive, accurate and sensitive that it is suitable for pharmacokinetic studies on extracts of HLXL and SI from L. chuanxion. The experiment results show that other ingredients of HLXL have noticeable effect on the absorption of SI in rat plasma.

Neolignanamides, lignanamides, and other phenolic compounds from the root bark of Lycium chinense

Seven new neolignanamides (1-7), including two pairs of cis- and trans-isomers, and a new lignanamide (8) were isolated from the EtOAc-soluble fraction of an EtOH extract of the root bark of Lycium chinense, together with 22 known phenolic compounds (9-30), four of which were obtained from the genus Lycium for the first time. Compounds 5, 6, and 7 are unusual dimers having a rare connection mode between the two cinnamic acid amide units, while compounds 6, 7, and 8 are the first naturally occurring dimers derived from two dissimilar cinnamic acid amides. The cinnamic acid amides, neolignanamides, and lignanamides possess moderate radical-scavenging activity against the DPPH (2,2-diphenyl-1-picrylhydrazyl) and superoxide radicals.

[Screening of hepatotoxicity fraction of Genkwa Flos and study on UPLC fingerprint of hepatotoxicity fraction]

OBJECTIVE

To look for the active fraction of ethanol extract of Genkwa Flos (EGF) induced hepatotoxicity and develop an UPLC fingerprint of the active fraction.

METHOD

Target fraction of EGF induced hepatotoxicity was guided by the serum biochemical and histopathology methods. The UPLC method was applied to establish the chromatographic fingerprint. The separation was achieved on a BEH C18 column (2.1 mm x 50 mm, 1.7 microm) with a mobile phase consisting of acetonitrile and water containing 0.05% phosphate acid running gradient elution. The detection was carried out at 210 nm and the analysis was finished within 10 min.

RESULT

The chloroform phase of EGF could be responsible for the hepatotoxicity of this herb. The common mode of the UPLC fingerprint was set up under the established condition. There were 17 common peaks in fourteen batches of herbs, eight of which were identified, and the similar degrees of the fourteen batches to the common mode were between 0.890-0.999.

CONCLUSION

It is easy to locate the chloroform extraction of EGF with hepatotoxicity. And the UPLC fingerprint was developed for the above fraction, which could provide valuable references for safe and effective clinical use of EGF.

[Identification of metabolites of arbidol by ultra-high performance liquid chromatography tandem mass spectrometry]

UPLC-MS-MS system was used for the identification of arbidol metabolites in the rat feces, urine and plasma samples. The system was so powerful a way with high ability of separation and analysis, based on both chromatography and mass properties. The isotope of Br was also a good indicator for metabolites finding. There were altogether 9 metabolites detected and identified, including 2 phase I biotransformation products and 7 phase II ones. It is concluded that arbidol mainly undergo metabolic reactions such as N-demethylation, S-oxidation, glucuronidation and sulfation in rats.

[Mass spectrometry technology and its application in analysis of biological samples]

With the excellent merits of wide analytical range, high sensitivity, small sample size, fast analysis speed, good repeatability, simple operation, low mobile phase consumption, as well as its capability of simultaneous isolation and identification, etc, mass spectrometry techniques have become widely used in the area of environmental science, energy chemical industry, biological medicine, and so on. This article reviews the application of mass spectrometry technology in biological sample analysis in the latest three years with the focus on the new applications in pharmacokinetics and bioequivalence, toxicokinetics, pharmacokinetic-pharmacodynamic, population pharmacokinetics, identification and fragmentation pathways of drugs and their metabolites and metabonomics to provide references for further study of biological sample analysis.

Development of the fingerprints for the quality evaluation of Viscum coloratum by high Performance liquid chromatography

A high-Performance liquid chromatography coupled ultraviolet (HPLC-UV) method was developed for a chemical fingerprint analysis of Viscum coloratum. Eighteen peaks were selected as the common peaks and Homoeriodictyol-7-0-β-D-apiosiyl-(1→2)-β-D-glucoside was used as a reference. The relative areas of common peaks were used for hierarchical clustering analysis and similarity calculation. Thirty-seven samples collected from different sources were classified into five groups. The similarities of 21 batches Viscum coloratum samples were beyond 0.90. The results obtained suggest that the Chromatographie fingerprint can efficiently identify Viscum coloratum. Additionally, the fingerprints can then be used to evaluate the correlation between Viscum coloratum and hosts.

Pharmacokinetic analysis of alpha and beta epimers of glycyrrhetinic acid in rat plasma: differences in singly and combined administrations

An HPLC method for the determination of 18alpha-glycyrrhetinic acid and 18beta-glycyrrhetinic acid in rat plasma was established, which was used subsequently to determine the pharmacokinetic profiles of both epimers of glycyrrhetinic acid in rats. alpha-glycyrrhetinic acid, beta-glycyrrhetinic acid, and a mixture of alpha-glycyrrhetinic and beta-glycyrrhetinic acids were administered to rats via gastric infusion. Blood samples were collected at different time intervals and extracted by liquid-liquid extraction. Separation was achieved by using a Kromasil C18 column (150 mm x 4.6 mm, 5 microm) with the mobile phase composed of acetonitrile--4 mmol x L(-1) ammonium acetate solution (46 : 54, v/v) at a flow rate of 1.0 mL x min(-1), and the detection wavelength was set at 250 nm. The pharmacokinetic parameters were calculated using the software DAS 2.0. In a combined administration, the main pharmacokinetic parameters of beta-glycyrrhetinic acid are significantly different from that of alpha-glycyrrhetinic acid (P < 0.05), while no significant difference was obtained when administrated individually. Compared to the single administration, significant differences (P < 0.05) on the values of AUC(0-t) and AUC(0-infinity) of beta-glycyrrhetinic acid were observed when this chemical was administrated together with alpha-glycyrrhetinic acid. In contrast, the pharmacokinetic parameters of alpha-glycyrrhetinic acid were not affected even under the co-administration. Here, a sensitive, specific, rapid and reproducible HPLC method was developed for the pharmacokinetic studies of alpha-glycyrrhetinic acid and beta-glycyrrhetinic acid in rat plasma.

Simultaneous quantification of three iridoids in rat plasma after oral administration of Zhi-zi-chi decoction using LC-MS

A sensitive and efficient liquid chromatography-mass spectrometry (LC-MS) method was developed and validated for the simultaneous determination of geniposide, 6α-hydroxygeniposide, and genipin gentiobioside in rat plasma. After the addition of internal standard (I.S.) salidroside and acidification (formic acid, 0.1%), plasma samples were carried out by protein precipitation with acetonitrile and separated on a Kromasil C(18) column (200 mm × 4.6 mm, 5 μm) within a runtime of 15.0 min. The linear ranges were 2-250 ng/mL for both 6α-hydroxygeniposide and genipin gentiobioside and 2-2000 ng/mL for geniposide, respectively. The lower limit of quantification (LLOQ) was 2 ng/mL for all the analytes. The validated method was successfully applied to the pharmacokinetics study of geniposide, 6α-hydroxygeniposide, and genipin gentiobioside in rats after oral administration of Zhi-zi-chi decoction.

LC-MS determination and pharmacokinetic study of salidroside in rat plasma after oral administration of suspensions of traditional Chinese medicine Erzhi Wan and Fructus Ligustri lucidi

A simple, rapid and sensitive liquid chromatography-mass spectrometry (LC-MS) method was developed for the determination of salidroside in rat plasma and study of its pharmacokinetics after oral administration of suspension of Erzhi Wan and Fructus Ligustri lucidi into Wistar rats. Plasma sample of 200 μL was extracted with acetic ether-isopropanol (2:1) and the extraction was performed on a Kromasil C₁₈ column (150 mm × 4. 6 mm, 5 μm) with the mobile phase of methanol-water (41:59, v/v) within a run time of 6.0 min. The analyte was monitored with positive electrospray ionization (ESI) by selected ion monitoring (SIM) mode. The target ions were m/z 323.05 for salidroside and m/z 411.05 for internal Standard (IS) geniposide. A good linear relationship was obtained over the range of 5.0–500.0 ng/mL and the lower limit of quantification was 5.0 ng/mL. The validated method was successfully applied to the pharmacokinetic study of salidroside in rat plasma after oral administration of suspension of Erzhi Wan and Fructus Ligustri lucidi.

[RP-HPLC simultaneous determination of five triterpenoid acids in different parts of Poria cocos by UV wavelengths switch]

To establish a method for simultaneous determination of dehydrotumulosic acid, polyporenic acid C, 3-epi-dehydrotumulosic acid, dehydropachymic acid and pachymic acid in Poria, a RP-HPLC method detected by UV wavelengths switch had been developed, including 210 nm (48-55 min) for pachymic acid and 241 nm (0-48 min) for dehydrotumulosic acid, polyporenic acid C, 3-epi-dehydrotumulosic acid, dehydropachymic acid, separately. The system consisting of a Kromasil C18 column (250 mm x 4.6 mm, 5 microm) and a mixture of acetonitrile and 0.05% phosphate acid as the mobile phase was adopted; The flow rate was 1.0 mL x min(-1). The linear response range was 30.5-610.0 microg x mL(-1) (r = 0.999 6) for dehydrotumulosic acid, 12.66-253.2 microg x mL(-1) (r = 0.999 5) for polyporenic acid C, 2.99-59.7 microg x mL(-1) (r = 0.999 7) for 3-epi-dehydrotumulosic acid, 6.13-122.5 microg x mL(-1) (r = 0.999 5) for dehydropachymic acid and 11.3-226.0 microg x mL(-1) (r = 0.9995) for pachymic acid. The average recoveries of these compounds were 98.5% (RSD = 1.9%), 99.4% (RSD = 1.7%), 97.9% (RSD = 1.2%), 96.7% (RSD = 2.5%) and 97.9% (RSD = 2.3%), respectively. The method is simple, accurate and reproducible for quality control of Poria.

[Analysis of monosaccharide compositions in Heterosmilax japonica polysaccharide by precolumn derivation HPLC]

OBJECTIVE

To establish precolumn derivation HPLC method to determine the monosaccharides in Heterosmilax japonica polysaccharide.

METHODS

Heterosmilax japonica sample was hydrolyzed with trifluoroacetic (TFA)and derivated by 1-phenyl-3-methyl-5-pyrazolone (PMP). The monosaccharide composition of Heterosmilax japonica polysaccharide was carried out by reversed-phase technique on a Kromasil C18 column with a mobile phase composed of 100 mmol/L ammonium acetate buffer (pH5.5) and acetonitrile in the ratio of 77: 23. The detection was carried out at 245 nm.

RESULTS

The Heterosmilax japonica polysaccharide composed of mannose, rhamnose, glucose, galactose and xylose with amolar ratio of 66: 1:7590: 452: 528.

CONCLUSION

The HPLC method with precolumn derivatization is appropriate for the analysis of monosaccharide composition of Heterosmilax japonica polysaccharide and the method is simple, quick and accurate.

[Simultaneous determination of anthraquinones in Liuwei'anxiao capsules by HPLC]

OBJECTIVE

To establish an RP-HPLC method for measuring the contents of aloe-emodin, rhein, emodin, chrysophanol and physion in Liuwei'anxiao Capsules (traditional Chinese medicine).

METHODS

The analysis was carried out with a Diamonsil-C18 column (200 mm x 4.6 mm, 5 microm) and a mobile phase of methanol-0.05% phosphoric acid solution with gradient elution. The flow rate was 1.0 mL/min and the column temperature was 35 degrees C. The detection wavelength was 254 nm.

RESULTS

The calibration curve was linear within the range of 1.622 - 16.22 microg/mL (r1 = 0.9998), 0.6960 - 6.960 microg/mL (r2 = 0.9998), 2.448 - 24.48 microg/mL (r3 = 0.9995), 2.752 - 27.52 microg/mL (r4 = 0.9997), 2.702 -27.02 microg/mL (r = 0.9997) for aloe-emodin, rhein, emodin, chrysophanol and physion, respectively.

CONCLUSION

This method is convenient, accurate and reproducible for the quality control of Liuwei'anxiao Capsules.

[Effects of ligustrazine on extracellular acetylcholine levels in rat brain dialysate]

Using brain microdialysis and LC-MS/MS to detect acetylcholine in rat brain to investigate the effects of ligustrazine. A liquid chromatography-tandem mass spectrometry method has been developed and validated for the determination of acetylcholine in rat brain dialysate sampling by microdialysis. The results indicated that ligustrazine administration by subcutaneous injection significantly increased Ach release in rat medial prefrontal cortex and nucleus accumbens in a dose-related manner. The drug' s effect on Ach release in rat brain could be directly detected by microdialysis combined with HPLC-MS/MS and this method is selective and sensitive.

Proteomic analysis of differential protein expression in rat platelets treated with notoginsengnosides

Sanqi, the root of Panax notoginseng, is a popularly used traditional Chinese medicine with cardiovascular effects. Notoginsengnosides (NG) isolated from Sanqi could inhibit ADP-induced platelet aggregation of rat washed platelets. To identify the possible target proteins of NG in platelets, two-dimensional gel electrophoresis (2-DE)-based comparative proteomics was performed and proteins altered in expressional level after NG treatment were identified by MALDI-TOF MS/MS. Treatment of 200 microg/ml NG caused regulation of the levels of 12 proteins, which play important roles in platelet activation, oxidative stress and cytoskeleton. In the NG-treated platelets, there were increase in the levels of growth factor receptor-bound protein 2 (Grb2), thrombospondin 1, tubulin alpha 6 and decrease in the levels of thioredoxin, Cu-Zn superoxide dismutase, DJ-1 protein, peroxiredoxin 3, thioredoxin-like protein 2, ribonuclease inhibitor, potassium channel subfamily V member 2, myosin regulatory light chain 9 and laminin receptor 1. The change in the levels of these proteins caused by NG treatment might contribute to the inhibitive effect of NG on platelet aggregation. Furthermore, analysis of the reactive oxygen species (ROS) level indicated that NG could decrease the ROS level in platelets. The regulation of ROS level might play important role in the effect of NG on platelets.

Interaction of salvianolic acids and notoginsengnosides in inhibition of ADP-induced platelet aggregation

Salvia miltiorrhiza and Panax notoginseng were both considered to be beneficial to cardiovascular diseases in traditional Chinese medicine and often used in combination. To examine the possible interaction between them, the effects of the active fractions of these two herbs, salvianolic acids (SA) and notoginsengnosides (NG), on platelet aggregation were checked respectively or in combination in vitro and in vivo. Both the platelet aggregation of platelet rich plasma (PRP) and washed platelet after ADP induction were checked. In vitro study showed that both SA and NG had an inhibitory effect on platelet aggregation. However, there is no synergistic effect of the combination of SA and NG in vitro. In vivo study showed that i.g. 550 mg/kg/day SA or NG for 5 days could significantly inhibit ADP-induced platelet aggregation of PRP. Moreover, combination of SA and NG at a ratio of 5:1 had a synergistic effect on platelet aggregation of PRP. The mechanism for the synergism of SA and NG in vivo was not clear. High performance liquid chromatography analysis of the plasma of rats received SA, NG or combination of SA and NG showed that co-administration of NG caused change in the plasma distribution profile of SA. The influence of combination on the absorption and/or metabolism of SA may be one of the reasons for the synergism of SA and NG in vivo.

[Simultaneous determination of matrine, oxysophocarpin and oxymatrine in rat plasma by HPLC-MS and its application in the pharmacokinetic study]

To establish an HPLC-MS method for simultaneous determination of matrine, oxymatrine and oxysophocarpine in rat plasma after oral administration of herbal preparation, namely Sanwu Huangqin decoction, and the pharmacokinetic porameters were calculated as well. Matrine, oxymatrine, oxysophocarpine, and internal standard pseudoephedrine were extracted from plasma with liquid-liquid extraction, then separated on a Kromasil C18 column by using acetonitrile-0.1% aqueous formic acid (10 : 90) as mobile phase. Electrospray ionization (ESI) source was applied and operated in positive ion mode. The linear calibration curve was obtained in the concentration range of 10 -5 000 ng x mL(-1) for matrine, 2 - 1 000 ng x mL(-1) for oxymatrine, and 2 - 1 000 ng x mL(-1) for oxysophocarpine. The extraction recovery was 89.1% - 93.5%, 83.9% - 91.3%, and 85.4% - 88.0% accordingly. The inter- and intra- day precision (RSD) was below 15.0% calculated from quality control (QC) samples. Matrine, oxymatrine and oxysophocarpine concentration time profile conformed to a two-compartment pharmacokinetic model. The method was shown to be effective, convenient, and suitable for simultaneous pharmacokinetic study of matrine, oxymatrine, and oxysophocarpine in rat.

[Analysis of the main components of coptis-evodia herb couple by HPLC-DAD-MS]

A comprehensive HPLC-DAD-MS method was developed to study the chemical components of semi-bionic extract of Coptis-Evodia herb couple. The extract was isolated on a Hypersil BDS C18 column (4.6 mm x 200 mm, 5 microm) using acetonitrile-ammonium formic buffer as mobile phase by gradient elution. Detection was performed on DAD and MS equipped with an electrospray ionization (ESI) source by full scan and product full scan on positive mode. The chromatogram of Coptis-Evodia showed seventeen main peaks, eight of which were from Evodia while the others were from Coptis. By comparison of the retention time, the on-line UV spectra and MS spectra, four peaks were identified as jatrorrhizine, hydroxevodiamine, palmatine and berberine, and three peaks were deduced as epiberberine, columbamine and coptisine. In addition, berberine and palmatine were quantitatively determined. No new component was created in the semi-bionic extract of the herb couple, yet the solubilities of berberine and palmatine decreased.

[Determination of macrozamin in Rhizoma Heterosmilacis Japonicae by RP-HPLC]

OBJECTIVE

To develop a RP-HPLC method for the determination of the content of macrozamin in Rhizoma Heterosmilacis Japonicae.

METHOD

A Century C18 AQ column (4.6 mm x 250 mm, 5 microm) was used with the mobile phase consisted of water (4:96). The flow rate was 1.0 mL x min(-1). The detection wavelength was set at 215 nm, and the column temperature was 35 degrees C.

RESULT

The calibration curve was linear (r = 0.999 8) in the range of 19.12 - 382.4 microg x mL(-1) for macrozamin, the average recovery of the method was 99.5%, with RSD 2.1% (n = 9).

CONCLUSION

This method can be used for the quality study of Rhizoma Heterosmilacis Japonicae.

Determination of arbidol in rat plasma by HPLC-UV using cloud-point extraction

A method based on cloud-point extraction (CPE) was developed to determine arbidol in rat plasma by high performance liquid chromatography separation and ultraviolet detection (HPLC-UV). The non-ionic surfactant Triton X-114 was chosen as the extract solvent. Variable parameters affecting the CPE efficiency were evaluated and optimized. A Zorbax SB-C(18) column (4.6 mm i.d. x 150 mm, 5 microm particle size) was used for isocratic elution separation at 40 degrees C with detection wavelength at 316 nm. Under the optimum conditions, the method was shown to be reproducible and reliable with intraday precision below 6.6%, interday precision below 8.8%, accuracy within +/-5.0% and mean extraction recovery more than 89.7%, which were all calculated using a range of spiked samples at three concentrations of 0.2, 2 and 16 microg/ml for arbidol in plasma. The linear range was from 0.08 to 20 microg/ml. After strict validation, the method was successfully applied to the pharmacokinetic study of arbidol in rats after oral and intravenous administration, respectively.

Determination of mildronate in human plasma and urine by liquid chromatography–tandem mass spectrometry

A sensitive and selective analytical method based on liquid chromatography-triple-quadrupole mass spectrometer has been developed to determine mildronate in human plasma and urine. The aim of this work was to find a valid method to study the pharmacokinetic profiles of mildronate in humans. Mildronate is a heart protection medicine, a carnitine's structural analogue, so levocarnitine was used as an internal standard for quantification. Under the electrospray ionization source positive ion mode, calibration curves with good linearities (r=0.9998 for plasma sample and r=0.9999 for urine sample) were obtained in the range of 1.0-20,000 ng ml(-1) for mildronate. The detection limit was 1 ng ml(-1). Recoveries were around 90% for the extraction from human plasma, and good precision and accuracy were achieved. This method is feasible for the evaluation of pharmacokinetic profiles of mildronate in humans, and to the best of our knowledge, this is the first report on LC-MS-MS analysis of mildronate in plasma and urine.

Survey of heavy metal pollution and assessment of agricultural soil in Yangzhong district, Jiangsu Province, China

We investigated concentrations of Hg, Cd, Pb, Zn, Cu, As, Ni, and Cr in samples of soil, cereal, and vegetables from Yangzhong district, China. Compared to subsoils, the sampled topsoils are enriched in Hg, Cd, Cu, Pb, Zn, and As. High levels of Cd and Hg are observed in most agricultural soils. Concentrations of Cr and Ni show little spatial variation, and high Cu, Pb, and Zn contents correspond well to areas of urban development. High As contents are primarily recorded at the two ends of the sampled alluvion. The contents of Cd, Hg, and total organic carbon (TOC) increase gradually to maximum values in the upper parts of soil profiles, while Cr and Ni occur in low concentrations within sampled profiles. As, Pb, Cu, and Zn show patterns of slight enrichment within the surface layer. Compared to data obtained in 1990, Cd and Hg show increased concentrations in 2005; this is attributed to the long-term use of agrochemicals. Cr and Ni contents remained steady over this interval because they are derived from the weathering of parent material and subsequent pedogenesis. The measured As, Cu, Pb, and Zn contents show slight increases over time due to atmospheric deposition of material sourced from urban anthropogenic activity. Low concentrations of heavy metals are recorded in vegetables and cereals because the subalkaline environment of the soil limits their mobility. Although the heavy metal concentrations measured in this study do not pose a serious health risk, they do affect the quality of agricultural products.

Characterization of flavonoids in the extract of Sophora flavescens Ait. by high-performance liquid chromatography coupled with diode-array detector and electrospray ionization mass spectrometry

A method coupling high-performance liquid chromatography (HPLC) with diode-array detector (DAD) and electrospray ionization mass spectrometry (ESI) was established for the separation and characterization of flavonoids in Sophora flavescens Ait. Based on the chromatographic separation of most flavonoids present in S. flavescens Ait., a total of 24 flavonoids were identified. Fourteen compounds were unambiguously identified comparing experimental data for retention time (t(R)), UV and MS spectra with those of the authentic compounds: 3',7-dihydroxy-4'-methoxy-isoflavone (13), trifolirhizin (14), kurarinol (18), formononetin (19), 7,4'-dihydroxy-5-methoxy-8-(gamma,gamma-dimethylallyl)-flavanone (22), maackiain (21), isoxanthohumol (23), kuraridine (26), kuraridinol (27), sophoraflavanone G (30), xanthohumol (31), isokurarinone (33), kurarinone (35) and kushenol D (38), and additional 10 compounds were tentatively identified as kushenol O (10), trifolirhizin-6''-malonate (15), sophoraisoflavanone A (20), norkurarinol/kosamol Q (24), kushenol I/N (25), kushenol C (28), 2'-methoxykurarinone (29), kosamol R (32), kushecarpin A (34) and kushenol A (37) by comparing experimental data for UV and MS spectra with those of literature. Furthermore, fragmentation pathways in positive ions mode of 24 flavonoid compounds of types of flavanone, flavanonol, flavonol, chalcone, isoflavone, isoflavanone and ptercocarpane were summarized. Some common features, such as CH(3)., H(2)O, CO, CO(2), C(3)O(2) and C(2)H(2)O losses, together with Retro-Diels-Alder fragmentations were observed in the prenylated flavonoids in S. flavescens Ait. The loss of the lanandulyl chain was their characteristic fragmentation, which might help deducing the structure of unknown flavonoid compounds. The present study provided an approach to rapidly characterize bioactive constituents in S. flavescens Ait.