Yan-xu Chang

A sensitive LC-MS/MS method for simultaneous determination of six flavonoids in rat plasma: Application to a pharmacokinetic study of total flavonoids from mulberry leaves

A simple and sensitive LC-MS/MS method has been developed and validated for the determination of rutin, isoquercitrin, astragalin, quercetin, kaempferol and isorhamnetin in rat plasma using naringin as the internal standard (IS). The plasma samples were pretreated and extracted by liquid-liquid extraction. Chromatographic separation was accomplished on a C18 column with a 10 min gradient elution using acetonitrile and 0.1% formic acid aqueous solution as mobile phase at a flow rate of 0.3 mL min(-1). A tandem mass spectrometric detection was conducted using multiple reaction monitoring (MRM) via an electrospray ionization (ESI) source and operating in the negative ionization mode. The lower limit of quantitation (LLOQ) of each analyte was lower than 1 ng mL(-1). Intra-day and inter-day precisions were less than 11.9%. The relative errors of accuracy were in the range of -9.2% to 6.1%. The mean recoveries of flavonoids and IS were higher than 53.8%. The proposed method was further applied to investigate the pharmacokinetics of all analytes after a single oral administration of total flavonoids from mulberry leaves to rats.

Simultaneous determination of stilbenes, phenolic acids, flavonoids and anthraquinones in Radix polygoni multiflori by LC–MS/MS

A simple and sensitive method was developed for the simultaneous determination of stilbenes, phenolic acid, flavonoids and anthraquinones in Radix polygoni multiflori by liquid chromatography tandem mass spectrometry (LC-MS/MS). The separation was completed on an Eclipse Plus C(18) (50 mm × 3.0 mm, 1.8 μm) column using 0.05% (v/v) formic acid and acetonitrile as mobile phases. The correlation coefficients of all the calibration curves were higher than 0.9990. The recoveries ranged from 95.9% to 106%. Relative standard deviations of intra and inter-day precisions were lower than 6.51%. The validated method was successfully applied to quantify stilbenes, phenolic acid, flavonoids and anthraquinones, which provided a new basis for overall assessment on quality of Radix polygoni multiflori.

Simultaneous determination of scopoletin, psoralen, bergapten, xanthotoxin, columbianetin acetate, imperatorin, osthole and isoimperatorin in rat plasma by LC–MS/MS for pharmacokinetic studies following oral administration of Radix Angelicae Pubescentis extract

A rapid and sensitive bioassay based on liquid chromatography tandem mass spectrometry (LC-MS/MS) has been developed and validated for the simultaneous determination of eight coumarins in rat plasma. The liquid-liquid extraction method with ethyl acetate was used to prepare the plasma samples after addition of warfarin as an internal standard (IS). Chromatographic separation was performed on an Eclipse plus C18 column (100mm×4.6mm, 1.8μm) using gradient elution when 1mM ammonium acetate aqueous solution - acetonitrile was used as the mobile phase. The lower limit of quantitation (LLOQ) of each coumarin was lower than 2.16ngmL(-1). Intra-day and inter-day precisions were less than 15%. The accuracies were in the range of 88.9-117%. The mean recoveries of coumarins and IS were higher than 84%. The method was successfully applied to a pharmacokinetic study of eight coumarins in rats after oral administration of radix angelicae pubescentis.

Cuscuta chinensis Lam.: A systematic review on ethnopharmacology, phytochemistry and pharmacology of an important traditional herbal medicine.

ETHNOPHARMACOLOGICAL RELEVANCE Cuscuta chinensis Lam. has found its use as a traditional medicine in China, Korea, Pakistan, Vietnam, India and Thailand. It is commonly used as an anti-aging agent, anti-inflammatory agent, pain reliever and aphrodisiac. To provide an overview of the ethnopharmacology, phytochemistry, pharmacokinetics, pharmacology and clinical applications of Cuscuta chinensis, as well as being an evidence base for further research works of the plant. MATERIALS AND METHODS The present review covers the literature available from 1985 to 2014. The information was collected from journals, books, theses and electronic search (Google Scholar, PubMed, ScienceDirect, ESBCO, Springerlink and CNKI). Literature abstracts and full-text articles were analyzed and included in the review. RESULTS Many phytochemicals have been isolated, identified and published to date, including: at least 18 flavonoids; 13 phenolic acids; 2 steroids; 1 hydroquinone; 10 volatile oils; 22 lignans; 9 polysaccharides; 2 resin glycosides; 16 fatty acids. These phytochemicals and plant extracts exhibit a range of pharmacological activities that include hepatoprotective, renoprotective, antiosteoporotic, antioxidant, anti-aging, antimutagenic, antidepressant, improve sexual function, abortifacient effects, etc. CONCLUSION This present review offers primary information for further studies of Cuscuta chinensis. The in vitro studies and in vivo models have provided a bioscientific explanation for its various ethnopharmacological uses and pharmacological activities (most notably antioxidant effects) especially in the prevention of hepatic disease and renal failure. It is necessary and important to do more pharmacokinetic and toxicological research works on human subjects in order to inform the possible active compounds in the body and validate its safety in clinical uses.

Simultaneous determination of catechin, epicatechin and epicatechin gallate in rat plasma by LC–ESI-MS/MS for pharmacokinetic studies after oral administration of Cynomorium songaricum extract

A rapid and valid method was developed for simultaneous determination catechin, epicatechin and epicatechin gallate in rat plasmas using scopoletin (103 ng mL(-1)) as an internal standard (IS). The separation was performed on Eclipse plus C18 column (100 mm × 4.6 mm, 1.8 μm) at a flow rate of 0.3 mL min(-1), and acetonitrile-0.1% formic acid was used as mobile phase. The recoveries of three analytes and IS were more than 78.9%. The lower limits of quantitation (LLOQ) in rat plasma were 2.14, 2.38 and 2.08 ng mL(-1) respectively for catechin, epicatechin and epicatechin gallate. Intra-day and inter-day precisions were within 12%. The accuracies were more than 85%. After single oral administration of 15.25 g kg(-1) Cynomorium songaricum extract, C(max) of catechin, epicatechin and epicatechin gallate in rat plasma were respectively 86.69±38.65, 32.57±15.00 and 36.93±12.62 ng mL(-1) while T(max) values were respectively 0.15±0.09, 0.20±0.10 and 0.20±0.13 h. The results demonstrated that the present LC-MS/MS method was sensitive enough for pharmacokinetic study of catichins following oral administration of C. songaricum extract.

Danhong injection attenuates isoproterenol-induced cardiac hypertrophy by regulating p38 and NF-κb pathway.

ETHNOPHARMACOLOGICAL RELEVANCE Danhong injection (DHI), derived from Rhizoma Salviae Miltiorrhizae (Salvia miltiorrhiza Bge., Labiatae, Danshen in Chinese) and Flos Carthami (Carthamus tinctorius L., Compositae, Salvia militiorrhiza Bunge), is an extensively-used Chinese material standardized clinical product for treatment of cardiovascular diseases. AIM OF THE STUDY Cardiac hypertrophy (CH) is an adaptive response of cardiomyocytes. Long-lasting cardiac hypertrophy results in the loss of compensation by cardiomyocytes which could ultimately develop into heart failure. In the present study, we aimed to investigate the effect and exact mechanisms of DHI on isoproterenol (ISO)-induced CH. MATERIALS AND METHODS H9c2 cells and male Wistar rats were stimulated by ISO in the present study to establish CH models in vitro and in vivo. CCk-8 assay, Western blot, real time-polymerase chain reaction (RT-PCR), electrophoretic mobility shift assay (EMSA) and Echocardiography were used in the present study. RESULTS DHI significantly attenuated ISO-induced CH of H9c2 cells (p<0.01). DHI decreased ISO-induced atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) elevation both at the mRNA and protein levels (p<0.05 and p<0.01, respectively). Western blot showed that DHI down-regulated the phosphorylation of p38. Furthermore, we found that DHI inhibited the nuclear translocation and activation of NF-κb. Echocardiography from ISO-induced CH rats showed that DHI significantly decreased left ventricle (LV) mass, the thickness of the LV end-systolic posterior wall (LVPWs), and the LV end-diastolic posterior wall (LVPWd) elevated by ISO (p<0.01 and p<0.05, respectively). CONCLUSION These data demonstrate that DHI might exert anti-cardiac hypertrophic effects by regulating p38 and NF-κb pathway.

A randomized double-blind placebo-controlled trial of a Chinese herbal medicine preparation (Jiawei Qing'e Fang) for hot flashes and quality of life in perimenopausal women.

ObjectiveThis study aimed to evaluate the effectiveness and safety of a Chinese herbal medicine preparation, Jiawei Qing’e Fang (JQF), on menopausal symptoms in perimenopausal women. MethodsA randomized double-blind placebo-controlled trial was performed over 12 weeks in 72 perimenopausal women who reported 14 or more hot flashes per week. The participants were randomly allocated to receive JQF or placebo for 8 weeks. Posttreatment follow-up was performed 4 weeks after intervention. The primary outcome was the Menopause-Specific Quality of Life. Secondary outcomes included hot flash and plasma lipids. ResultsThere was greater improvement in hot flash score in the JQF group compared with the placebo group, and the difference between the two groups was statistically significant (P = 0.048). There were between-group differences in vasomotor (P = 0.011) and physical (P = 0.034) domains. The triglyceride (TG) level in the JQF group showed a significant reduction (P = 0.036) in women with a baseline TG greater than 150 mg/dL (1.7 mmol/L). ConclusionsThe Chinese herbal medicine preparation JQF was found to be superior to placebo in reducing hot flashes and improving menopausal symptoms in the vasomotor and physical aspects and might have a potential benefit in reducing TG levels. The herbal medicine preparation was well tolerated, with no serious adverse events noted during the study period.

An activity-integrated strategy involving ultra-high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry and fraction collector for rapid screening and characterization of the α-glucosidase inhibitors in Coptis chinensis Franch. (Huanglian).

An activity integrated strategy was established and validated to screen α-glucosidase inhibitors by ultra-high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry and fraction collector (UHPLC/Q-TOF-MS-FC). UHPLC was used to separate the components in Coptis chinensis Franch. (Huanglian in Chinese) extract, which was identified by UHPLC-Q-TOF-MS to acquire structural information and collected by the fraction collector. Finally, the collected fractions were tested for inhibitory activity of α-glucosidase. The results showed that Huanglian extract had the α-glucosidase inhibitory activity with the IC50 value at 3.528mg mL(-1), which could be used for the treatment of diabetes. Alkaloids were the main components that had inhibitory activity of α-glucosidase in Huanglian extract, while the inhibitory activity of phenolic acids against α-glucosidase was relatively weaker. Coptisine, epiberberine, jatrorrhizin and berberine were screened and identified as α-glucosidase inhibitors from Huanglian extract in vitro. Compared with conventional methods, the integrated UHPLC/Q-TOF-MS-FC method could quantitatively analyze α-glucosidase inhibitory activity of individual constituent and provide the total α-glucosidase inhibitory activity of the samples. The results demonstrated that the activity integrated UHPLC/Q-TOF-MS-FC method was an effective and powerful tool for screening and identifying active ingredients from Traditional Chinese medicines.

Simultaneous determination of four phenolic acids and seven alkaloids in rat plasma after oral administration of traditional Chinese medicinal preparation Jinqi Jiangtang Tablet by LC-ESI–MS/MS

A rapid, sensitive and selective high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of four phenolic acids (neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and ferulic acid) and seven alkaloids (berberine, epiberberine, coptisine, magnoflorine, berberubine, palmatine and jatrorrhizine) in rat plasma. After mixing with the internal standards tetrahydropalmatine (IS1) and rosmarinic acid (IS2), plasma samples were pretreated by protein precipitation using acetonitrile. The HPLC analysis was performed on an Agilent Eclipse plus C18 (4.6 mm×100 mm, 1.8 μm) column with mobile phase consisting of 0.1% formic acid aqueous solution and acetonitrile at a flow rate of 0.3 mL min(-1). The detection was accomplished for the analytes and internal standards using positive electrospray ionization for the alkaloids and negative electrospray ionization for the phenolic acids in multiple-reaction monitoring mode. The method showed a good linearity over a wide concentration range (r(2)>0.99). The lower limit of quantification of seven alkaloids was lower than 2 ng mL(-1) and that of four phenolic acids was less than 20 ng mL(-1). The developed method was applied to the pharmacokinetic study of 11 components after oral administration of traditional Chinese medicinal preparation Jinqi Jiangtang Tablet in rats.

The experimental study of Astragalus membranaceus on meridian tropsim: The distribution study of astragaloside IV in rat tissues

According to Traditional Chinese Medicine (TCM) theories, TCM with different meridian tropism have different therapeutic effects. In view of the meridian tropism of Astragalus membranaceus (Huangqi), astragaloside IV, one of the effective phytochemicals of Huangqi, was appointed and observed its distribution in rat tissues following a single intravenous (i.v.) dose. A simple and accurate LC-ESI-MS/MS method was developed and validated for astragaloside IV quantification in heart, liver, spleen, lung and kidney using warfarin as an internal standard (IS). Chromatographic separation was performed on a Eclipse plus C18 (4.6mm×100mm, 1.8μm) when the flow rate was set at 0.300mLmin(-1) and ammonium acetate aqueous solution - acetonitrile was used as mobile phase. The intra- and inter-day precisions of the quality control samples were within 15% and accuracies were within 90.0-110%. The recoveries were more than 90.0% at high, medium and low concentrations, respectively. This method was successfully applied for distribution of astragaloside IV after intravenous (i.v.) dose of 4mgkg(-1) astragaloside IV in rats. Astragaloside IV concentration was highest in liver and kidney and remained much higher than that in other tissues over the experiment course. Lung, heart and spleen were also detected to contain astragaloside IV. The results clearly demonstrated that astragaloside IV was one of the material bases of the meridian tropism of Huangqi.