Simultaneous determination of baicalin, rhein and berberine in rat plasma by column-switching high-performance liquid chromatography

RP-HPLC METHOD DEVELOPMENT, VALIDATION, AND ITS PHARMACOKINETIC APPLICABILITY IN PRECLINICAL EVALUATION OF RHEIN TREATED WITH NOVEL DIACEREIN EUTECTICS

The current study represents the bio-analytical method for the estimation of Rhein (Rh, an active metabolite of Diacerein (DIA)) in rats treated with novel DIA eutectics to investigate the pharmacokinetics of DIA. A simple protein precipitation technique was used to extract Rh and internal standard (IS), p-aminobenzoic acid, and injected into a Phenomenex Gemini C18 column. The separation was achieved by gradient elution comprising of ammonium acetate (10 mM; pH 3.0) and acetonitrile in 18 min of run time at a flow rate of 0.8 mL/min with the retention time of 11.8 min (Rh) and 5.9 min (IS). The results revealed that the proposed method was linear over the range of 200-20,000 ng/mL (r² > 0.9988) of Rh and proved to be precise and accurate. The method was fully validated as per the USFDA guideline and the pharmacokinetic study in rats was performed for Rh following oral administration of the pure DIA and newly developed eutectics. Therefore, the present method could be used to estimate DIA to illustrate the comparative pharmacokinetic analysis. This can be also applied to its related multi-component formulations for future study.

Pharmacokinetic study of representative anti-oxidative compounds from Denshen-Chuanxiong-Honghua following oral administration in rats

Almost no pharmacokinetic compounds to date have been precisely linked with the activity of their herbal or Traditional Chinese Medicine (TCM) formula. This creates challenges for pharmacokinetic significance and application of the TCM. In our study, a sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to quantitatively or qualitatively determine multiple-components (tanshinol, ferulic acid, protocatechuic acid, rosmarinic acid, salvianolic acid B, baicalin and 9'-methyl lithospermate B) in rat plasma following the oral administration of Denshen-Chuanxiong-Honghua (DCH) extract (20g/kg). Chromatographic separation was carried out on a 300SB-C18 column using a gradient elution with a mobile phase composed of acetonitrile-water (containing 0.1% formic acid) at a flow rate of 1.0mL/min. Determination by mass spectrometry (MS) was conducted in multiple reaction monitoring (MRM) mode with negative electrospray ionization. The validated method exhibited good linearity, with correlation coefficients greater than 0.9949 over a wide concentration range, and the lower limits of quantification were 2.09-12.2ng/mL for the 5 analytes. This assay was successfully applied to investigate the pharmacokinetics of 5 compounds in rat plasma after the oral administration of DCH extracts. In addition, the anti-oxidant capacities of the 5 active ingredients of DCH extract in vitro and the total absorbed DCH extract in vivo were investigated at different concentrations during pharmacokinetic studies.

Validated UPLC-MS/MS method for simultaneous determination of simvastatin, simvastatin hydroxy acid and berberine in rat plasma: Application to the drug-drug pharmacokinetic interaction study of simvastatin combined with berberine after oral administration in rats

A rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) assay method was developed and validated for simultaneous quantification of simvastatin (SV), its metabolite simvastatin hydroxy acid (SVA) and berberine (BBR) in rat plasma. Separation was performed on Poroshell 120 EC-C18 column (4.6×50mm, 2.7μm) using gradient elution by mobile phase containing acetonitrile and 10mM ammonium acetate (pH 4.5). Polarity switch (positive-negative-positive ionization mode) was performed in a total run time of 4.0min. The lower limits of quantification (LLOQ) for SV, SVA and BBR were 0.10, 0.20 and 0.10ng/mL, respectively. The response function was established for concentration range of 0.10-100ng/mL for SV and BBR and 0.20-3000ng/mL for SVA, with a coefficient of correlation of >0.99 for all the compounds. The proposed method was applied to the drug-drug pharmacokinetic interaction study of SV combined with BBR after oral administration in rats.

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.

Comparative pharmacokinetics of puerarin, daidzin, baicalin, glycyrrhizic acid, liquiritin, berberine, palmatine and jateorhizine by liquid chromatography-mass spectrometry after oral administration of Gegenqinlian decoction and active components alignment (ACA) to rats

An LC-MS/MS method was developed for simultaneous analysis of puerarin, daidzin, baicalin, glycyrrhizic acid, liquiritin, berberine, palmatine and jateorhizine of Gegenqinlian Decoction (GQD) and active components alignment (ACA) in rat plasma using hesperidin as the internal standard (I.S.). Chromatography was performed using a C18 column, with gradient elution with 1% acetic acid-0.001 mol/L ammonium acetate and acetonitrile at 0.2 ml/min. All analytes including I.S. were monitored under positive ionization conditions by selected reaction monitoring with an electrospray ionization source. The optimized mass transition ion-pairs (m/z) for quantitation were 471/297 for puerarin, 471/255 for daidzin, 447/271 for baicalin, 823/453 for glycyrrhizic acid, 419/257 for liquiritin, 336/320 for berberine, 352/336 for palmatine, 338/322 for jateorhizine and 611/303 for hesperidin. The calibration curves were linear over the concentration ranges from 0.15-63.0 to 6.3-6340.0 ng/mL. Intra-day and inter-day precisions (RSD%) were within 15.0%, and accuracy (RE%) ranged from -7.4 to 13.2%. The extraction recoveries were ranged from 60.4 to 93.3%. The proposed method was further applied to compare the pharmacokinetics of all analytes following a single oral administration of GQD and ACA. In conclusion, the eight analytes of GQD and ACA had partly similar pharmacokinetics, which were different from single composition (such as puerarin).

Study on the interaction of β-cyclodextrin and berberine hydrochloride and its analytical application

The fluorescence enhancement of berberine hydrochloride (BBH) as a result of complex with β-cyclodextrin (β-CD) is investigated. The mechanism of the inclusion was studied and discussed by spectrofluoremetry and infrared spectrograms. The results showed that a 1∶1 (β-CD: BBH) complex was formed with an apparent association constant of 4.23×10² L/mol. Based on the enhancement of the fluorescent intensity of berberine hydrochloride, a new spectrofluorimetric method for the determination of BBH in the presence of β-CD was developed. The linear range was 1.00∼4.00 µg/mL with the detection limit of 5.54 ng/mL. The proposed method was successfully applied to the determination of BBH in tablets.

New method of screening allergenic components from Shuanghuanglian injection: with RBL-2H3/CMC model online HPLC/MS system

Shuanghuanglian (SHL) injection is a traditional Chinese medicine (TCM) injection widely used in China to treat influenza, tonsillitis, bronchitis, and faucitis. Adverse drug reactions (ADR) of SHL injection, majorly manifested as allergic reactions, were among the leading causes of death from TCM injection. In this study, an RBL-2H3/CMC online LC/MS system was established to screen and identify allergenic components in SHL injection, by which Baicalin was identified as a potential allergenic component. Allergenic activities of baicalin were investigated in RBL-2H3 cell degranulation and β-hexosaminidase release tests in vitro. Our results showed that baicalin dose-dependently induced RBL-2H3 cell degranulation and β-hexosaminidase release in the range of 0-50μg/ml. The RBL-2H3/CMC online LC/MS system developed in this study may potentially be used to screen allergenic components in other TCM injections.

A novel UPLC-MS/MS method for simultaneous quantification of rhein, emodin, berberine and baicalin in rat plasma and its application in a pharmacokinetic study

BACKGROUND

Dahuang Huanglian Xiexin Decoction (DHXD) is a classical formula in traditional Chinese medicines. In this study, a novel UPLC-MS/MS method was developed for the simultaneous quantification of rhein, emodin, berberine and baicalin, the major bioactive compounds of DHXD in rat plasma.

RESULTS

The method possessed high sensitivity and ultrashort analysis time (7 min). Linearity, accuracy, precision and extraction recovery of four analytes were all satisfactory. The method was then successfully applied in a pharmacokinetic study of four bioactive components after a single oral administration of DHXD extract to rats.

CONCLUSION

The method was applicable for simultaneous bioanalysis of rhein, emodin, berberine and baicalin.

Biological analysis of herbal medicines used for the treatment of liver diseases

Herbal medicines have been used to treat liver disorders for thousands of years in the East and have now become a promising therapy internationally for pathological liver conditions. Biological analysis of hepatoprotective herbs is an important issue from the pharmacokinetic perspective in developing new therapeutic managements for liver disease. The biological analysis focuses on the pretreatment methods, separation and quantification of herbal medicines in biological samples. We have compiled and discuss the biological analytical method of six herbal medicines for liver protection containing Silybum marianum(silymarin), Glycyrrhiza glabra, Scutellaria baicalensis, Schisandra chinensis, Salvia miltiorrhiza and Astragalus membranaceus. This review provides a convenient reference for researchers to reduce time-consuming method optimization.

Baicalin, an emerging multi-therapeutic agent: pharmacodynamics, pharmacokinetics, and considerations from drug development perspectives

Baicalin was extensively researched for utility in a number of therapeutic areas owing to its anti-inflammatory, anti-oxidant, anti-bacterial, and anti-cancer properties. A number of preclinical studies, in vitro work, and mechanistic studies were performed to understand the absorption, distribution, metabolism, and excretion profiles of baicalin. The absorption of baicalin involved several complexities: the restriction to two distant sites; the conversion of baicalin to baicalein; the possible role of transporter(s); and enhanced absorption due to breakdown of conjugates by beta-glucuronidase. Limited distribution data suggest that baicalin reached several sites such as the brain, eye lens, thymus, etc. Hepatobiliary recycling also served as a distribution phase for sustained delivery of baicalin. Metabolism data suggest the rapid conversion of baicalin to baicalein, which was extensively subjected to Phase 2 metabolism, conjugates baicalein glucuronide/sulfate have been identified. Limited excretion data suggest involvement of renal and faecal routes--glucuronide and sulfate conjugates were excreted in urine and faeces (via biliary excretion). The published data on baicalin suggest imminent challenges for developing baicalin and/or during co-administration with other agents. These challenges are absorption related (transporter or changes in the microenvironment), metabolism related (CYP2B6 induction and/or CYP2E1 inhibition), and excretion/efflux related (competitive biliary pathway and/or OATP1B1 transport).

Restricted-access media supports for direct high-throughput analysis of biological fluid samples: review of recent applications

This review presents an update on the use of restricted-access materials (RAMs) for direct injection of biological samples. The fundamental improvements in the preparation of tailored RAMs and the diversity of applications with these phases are presented. Insights into diminishing the matrix effect by the use of RAM supports in methods by LC–MS and into the low number of methods for enantiomeric separations by direct injections of biological samples are addressed. The diversity of systems that incorporate RAMs for selective sample clean-up or fractionation in proteome and peptidome analysis is also covered.

Determination of the active metabolites of sibutramine in rat serum using column-switching HPLC

A simple and direct analysis using column-switching HPLC method was developed and validated for the quantification of active metabolites of sibutramine, N-mono-desmethyl metabolite (metabolite 1, M1) and N-di-desmethyl metabolite (metabolite 2, M2) in the serum of rats administered sibutramine HCl (5.0 mg/kg, p.o.). Rat serum was directly injected onto the precolumn without sample prepreparation step following dilution with mobile phase A, i. e., methanol-ACN-20 mM ammonium phosphate buffer (pH 6.0 with phosphoric acid) (8.3:4.5:87.2 by volume). After the endogenous serum components were eluted to waste, the system was switched and the analytes were eluted to the trap column. Active metabolites M1 and M2 were then back-flushed to the analytical column for separation with mobile phase B, i. e., methanol-ACN-20 mM ammonium phosphate buffer (pH 6.0 with phosphoric acid) (35.8:19.2:45 by volume) and detected at 223 nm. The calibration curves of active metabolites M1 and M2 were linear in the range of 0.1-1.0 microg/mL and 0.15-1.8 microg/mL. This method was fully validated and shown to be specific, accurate (10.4-10.7% error), and precise (1.97-8.79% CV). This simple and rapid analytical method using column-switching appears to be useful for the pharmacokinetic study of active metabolites (M1 and M2) of sibutramine.

Development and validation of a sensitive LC-MS/MS method with electrospray ionization for quantitation of rhein in human plasma: application to a pharmacokinetic study

A highly sensitive and specific LC-MS/MS method has been developed and validated for the estimation of rhein with 100 microL human plasma using celecoxib as an internal standard (IS). The API-4,000 Q-Trap LC-MS/MS was operated under multiple reaction-monitoring mode using the electrospray ionization technique. The assay procedure involved extraction of rhein and IS from human plasma with acetonitrile, which yielded consistent recoveries of 36.01 and 65.85% for rhein and IS, respectively. The total chromatographic run time was 5.0 min and the elution of rhein and IS occurred at approximately 1.60 and 3.96 min, respectively. The resolution of peaks was achieved with 0.01 m ammonium acetate (pH 6.0):acetonitrile:methanol (30:58:12, v/v) on an Inertsil ODS-3 column. The method was proved to be accurate and precise at a linearity range of 0.005-5.00 microg/mL with a correlation coefficient (r) of >or=0.995. The lower limit of quantitation was 0.005 microg/mL. The intra- and inter-day precision and accuracy values were found to be within the assay variability limits as per the FDA guidelines. Rhein was found to be stable in the battery of stability studies. The application of the assay to pre-clinical pharmacokinetic studies confirmed the utility of the assay to derive pharmacokinetic parameters.

Simultaneous determination by UPLC-ESI-MS of scoparone, capillarisin, rhein, and emodin in rat urine after oral administration of Yin Chen Hao Tang preparation

A simple, sensitive, and validated method was developed for simultaneous determination of scoparone, capillarisin, rhein, and emodin in rat urine by ultra-performance liquid chromatography/electrospray ionization quadruple time-of-flight mass spectrometry (UPLC-MS). The urinary samples were analyzed on an Acquity UPLC BEH C18 1.7 microm 2.1x50 mm column. Scoparone, capillarisin, rhein, and emodin in rat urine were simultaneously analyzed with good separation. The lower limits of detection were 6.0, 9.0, 7.0, and 3.0 ng/mL, and the lower limits of quantification were 20.0, 33.0, 24.0, and 12.0 ng/mL for scoparone, capillarisin, rhein, and emodin, respectively. The intra- and inter-day precisions (RSD) were less than 9%. The intra- and inter-accuracies were found to be in the range of 94.14-104.54% for scoparone, 101.72-107.34% for capillarisin, 95.24-103.59% for rhein, and 101.32-107.82% for emodin at three concentration levels. The absolute recoveries for scoparone, capillarisin, rhein, and emodin were not less than 77.0%. The developed method has been applied to determine scoparone, capillarisin, rhein, and emodin in rat urine after oral administration of Yin Chen Hao Tang preparation, a traditional Chinese medicine formulation widely used in China for treatment of jaundice and liver disorders.

Simultaneous determination of berberine, palmatine and jatrorrhizine by liquid chromatography-tandem mass spectrometry in rat plasma and its application in a pharmacokinetic study after oral administration of coptis-evodia herb couple

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to simultaneously determine berberine, palmatine and jatrorrhizine in rat plasma. After mixing with the internal standard (IS) tetrahydropalmatine, plasma samples were pretreated by protein precipitation with acetonitrile-methanol (1:2, v/v). Chromatographic separation was carried out on a C18 column using a mixture of water (containing 0.1% formic acid) and acetonitrile (30:70, v/v) as mobile phase. The detection was performed by selected reaction monitoring (SRM) mode via electrospray ionization (ESI) source operating in the positive ionization mode. The method was linear over the concentration range of 1.0-250.0 ng/mL for all components. The intra- and inter-day precision values were less than 14.6% and the deviations were within +/-4.0%. The fully validated LC-MS/MS method has been successfully applied to the pharmacokinetic study of berberine, palmatine and jatrorrhizine in rat plasma after oral administration of coptis-evodia herb couple. Three peaks were observed in both individual and mean plasma-concentration curves of berberine, palmatine and jatrorrhizine, which may be attributed to distribution re-absorption and enterohepatic circulation.

Protective effects of berberine against low-density lipoprotein (LDL) oxidation and oxidized LDL-induced cytotoxicity on endothelial cells

The oxidative modification of low-density lipoprotein (LDL) is thought to have a central role in the pathogenesis of atherogenesis. Berberine, a natural constituent of plants of the genera Coptis and Berberis, has several anti-inflammation and anticancer biological effects. However, its protective effects on LDL oxidation and endothelial injury induced by oxLDL remain unclear. In this study, we evaluated the antioxidative activity of berberine and how berberine rescues human umbilical vein endothelial cells (HUVECs) from oxidized LDL (oxLDL)-mediated dysfunction. The antioxidative activity of berberine was defined by the relative electrophoretic mobility of oxLDL, fragmentation of ApoB, and malondialdehyde production via the Cu(2+)-mediated oxidation of LDL. Berberine also inhibited the generation of ROS and the subsequent mitochondrial membrane potential collapse, chromosome condensation, cytochrome C release, and caspase-3 activation induced by oxLDL in HUVECs. Our results suggest that berberine may protect LDL oxidation and prevent oxLDL-induced cellular dysfunction.

Simultaneous determination of Angiotensin I-converting enzyme inhibitory peptides in tryptic casein hydrolysate by high-performance liquid chromatography combined with a replicate heart-cut column-switching technique

A replicate heart-cut column-switching HPLC method combined with two switching valves was newly developed for the simultaneous determination of three antihypertensive peptides (Ala-Phe, Tyr-Pro, and Trp-Tyr) in tryptic casein hydrolysate in one run-in assay. After a first separation on an octadecyl silane (ODS) column, heart-cuts of each peptide were individually separated on a subsequent analytical ODS column: 26% acetonitrile for Ala-Phe and Tyr-Pro (32% for Trp-Tyr) in 0.1% trifluoroacetic acid containing 10 mM sodium 1-octanesulfonate at 0.8 mL/min. Ala-Phe, Tyr-Pro, and Trp-Tyr in casein hydrolysate were determined within 70 min to be 0.377 +/- 0.037 mg/g, 2.50 +/- 0.26 mg/g, and 0.096 +/- 0.008 mg/g, respectively.