Screening of differential components of Gegenqinlian decoction and their comparative pharmacokinetics in normal and pyrexia rats using UHPLC-FT-ICR-MS and UHPLC-MS/MS.

UHPLC combined with Fourier-transform ion cyclotron resonance MS metabonomic approach was employed to screen the differential components between normal rats and yeast-induced pyrexia rats after an oral administration of Gegenqinlian decoction (GQLD). Nine compounds, namely puerarin, daidzein, baicalin, wogonoside, wogonin, berberine, palmatine, jateorhizine, and coptisine, were identified as differential components in the plasma. A rapid, sensitive, selective, and accurate UHPLC-MS method was developed and fully validated for the simultaneous determination of the screened components in rat plasma after an oral administration of GQLD. The values for the limit of quantification ranged from 0.025 to 5.0 ng/mL. The inter- and intra-day precision of all analytes was ≤10.7%, with an accuracy of ≤10.5%. Good extraction recovery and matrix effects were also obtained. The method was successfully applied to a comparative pharmacokinetic study of GQLD in normal and pyrexia rats. The results showed that the pharmacokinetic behavior of the analytes was changed in pyrexia rats compared to normal rats. These results could provide beneficial guidance for clinical applications of GQLD.

Pharmacokinetic Effects of l-Tetrahydropalmatine on Ketamine in Rat Plasma by Ultraperformance Liquid Chromatography Tandem Mass Spectrometry.

Male Sprague-Dawley rats (n = 18) were randomly divided into three groups: a saline group (20 mL/kg by gavage), a ketamine (KET) group (100 mg/kg by gavage), and a KET (the same routes and doses) combined with levo-tetrahydropalmatine (l-THP; 40 mg/kg by gavage) group (n = 6). Blood samples were acquired at different time points after drug administration. A simple and sensitive ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established to determine the concentrations of KET and its metabolite, norketamine (NK), in rat plasma. Chromatographic separation was achieved using a BEH C18 column (2.1 mm × 50 mm, 1.7 µm) with chlorpheniramine maleate (Chlor-Trimeton) as an internal standard (IS). The initial mobile phase consisted of acetonitrile-water with 0.1% methanoic acid (80 : 20, v/v). The multiple reaction monitoring (MRM) modes of m/z 238.1→m/z 179.1 for KET, m/z 224.1→m/z 207.1 for NK, and m/z 275→m/z 230 for Chlor-Trimeton (IS) were utilized to conduct a quantitative analysis. Calibration curves of KET and NK in rat plasma demonstrated good linearity in the range of 2.5-500 ng/mL (r > 0.9994), and the lower limit of quantification (LLOQ) was 2.5 ng/mL for both. Moreover, the intra- and interday precision relative standard deviation (RSD) of KET and NK were less than 4.31% and 6.53%, respectively. The accuracies (relative error) of KET and NK were below -1.41% and -6.07%, respectively. The extraction recoveries of KET and NK were more than 81.23 ± 3.45% and 80.42 ± 4.57%, respectively. This sensitive, rapid, and selective UPLC-MS/MS method was successfully applied to study the pharmacokinetic effects of l-THP on KET after gastric gavage. The results demonstrated that l-THP could increase the bioavailability of KET and promote the metabolism of KET. The results showed that l-THP has pharmacokinetics effects on KET in rat plasma.

UPLC-MS/MS simultaneous determination of seven active ingredients of Yaobitong capsule in rat plasma and its integrated pharmacokinetic application.

A reliable and sensitive UPLC-MS/MS method was first established and validated for the simultaneous determination of seven active ingredients of Yaobitong capsule in rat plasma: ginsenoside Rg1, ginsenoside Rb1, osthole, tetrahydropalmatine, paeoniflorin, albiflorin, and ferulic acid. And this method was further applied for the integrated pharmacokinetic study of Yaobitong capsule in rats after oral administration. Plasma samples (100 µL) were precipitated with 300 µL of methanol using carbamazepine as internal standard. Chromatographic separation was achieved using an Aquity UPLC BEH C18 column (100 × 2.1 mm, 1.7 µm), with the mobile phase consisting of 0.1% formic acid and acetonitrile. The method was validated using a good linear relationship (r ≥ 0.991), and the lower limit of quantification of the analytes ranged from 0.5 to 40 ng/mL. In the integrated pharmacokinetic study, the weight coefficient was calculated by the ratio of AUC0-∞ of each component to the total AUC0-∞ of the seven active ingredients. The integrated pharmacokinetic parameters Cmax , Tmax , and t1/2 were 81.54 ± 9.62 ng/mL, 1.00 ± 0.21 h, and 3.26 ± 1.14 h, respectively. The integration of pharmacokinetic parameters showed a shorter t1/2 because of fully considering the contribution of the characteristics of each active ingredient to the overall pharmacokinetics.

Simultaneous determination of eight bioactive components in rat plasma after oral administration of Yan-Ke-Ning-Tablet by liquid chromatography coupled with Q-Exactive Orbitrap tandem mass spectrometry.

A rapid, sensitive and reliable quantitative method based on ultra-high performance liquid chromatography coupled with Q-Exactive Orbitrap tandem mass spectrometry was developed for simultaneous determination of berberine, berberrubine, palmatine, jatrorrhizine, columbamine, baicalin, baicalein and wogonin in rat plasma after oral administration with Yan-Ke-Ning-Tablet (YKNT). After precipitation with acetonitrile, the plasma samples were separated on a reverse-phase C18 column with 1 mm ammonium acetate containing 0.2% acetic acid-acetonitrile as mobile phase. Calibration curves showed good linearity (r > 0.9983) over the tested concentration ranges of 0.5-200 ng/mL for berberine, berberrubine, palmatine, jatrorrhizine and columbamine, and 1-300 ng/mL for baicalin, baicalein and wogonin. The precision (relative standard deviation) at three different concentration levels was <12.15% and the accuracy (relative error) ranged from -8.24 to 10.85%. No matrix effects were observed with matrix effect value ranging from 89.23 to 107.68%. The extraction recovery was in the range of 82.34-92.31%. The validated assay was further successfully applied to the pharmacokinetic study of these components after oral administration of YKNT. The present study provides the pharmacokinetic profiles of major bioactive components found in YKNT, and provides valuable information regarding the chemical components that were absorbed into plasma, which will be helpful for understanding the therapeutic effects of YKNT.

Poly-pharmacokinetic strategy-delineated metabolic fate of bioactive compounds in a traditional Chinese medicine formula, Yuanhu Zhitong tablets, using parallel reaction monitoring mode.

OBJECTIVE: To evaluate the pharmacokinetics of eight constituents in Yuanhu Zhitong tablets, which may provide a method for the poly-pharmacokinetic study of traditional Chinese medicine. METHODS: A robust platform using Thermo Scientific™ Dionex™ UltiMate™ 3000 rapid separation LC, integrated with Thermo Scientific™ Q Exactive™ MS, was developed and validated to acquire, in a high-resolution full-scan mode, a global profile of all ionized components in rat plasma after oral administration of a suspension of Yuanhu Zhitong tablets. RESULTS: This robust UPLC-HRMS method was successfully applied for pharmacokinetic evaluation after oral administration of Yuanhu Zhitong tablets. The MS response showed a good linear relationship, with a coefficient of determination (r2) of >0.99. The levels of detection were in the range of 0.088-0.414 ng·ml-g for the different constituents. The recoveries ranged from 92.23% to 104.47%, and the matrix effect ranged from 85.24% to 101.02%. The intra- and inter-day accuracy was in the range of 0.00-12.54%, while the intra- and inter-day precision ranged from 0.44% to 7.63%. Short-term stability, long-term stability, freeze-thaw stability, and post-preparative stability ranged from -recision rangedThe time to reach peak plasma concentration (tmax) values for the analytes was less than 10 h, except that for tetrahydropalmatine, which was quickly absorbed into the bloodstream. The large area under the concentration-time curve (AUC) values (≥105 ng·h·l-g) for the eight compounds indicated good absorption and utility in rat plasma. The mean residence time was more than 6 h, indicating slow elimination. CONCLUSION: UPLC-HRMS was shown to be a very promising and powerful tool for the kinetic screening and characterization of compounds in medicinal herbs and traditional Chinese medicine formulas. Pharmacokinetic profiling of multiple compounds enables the clarification of metabolic processes and fates of the selected medicinal herbs or traditional Chinese medicine formula. This allows us to better understand the actions and associated therapeutic mechanisms of the traditional Chinese medicine.

Biotransformation and tissue distribution of protopine and allocryptopine and effects of Plume Poppy Total Alkaloid on liver drug-metabolizing enzymes.

In this study, the biotransformation in the plasma, urine and feces of rats following oral administration of protopine (PRO) and allocryptopine (ALL)were explored using HPLC-QqTOF MS. An HPLC-MS/MS method for the determination of tissues was developed and applied to the tissue distribution study in rats following intragastric administration of Plume Poppy Total Alkaloid for 3 weeks. A total of ten PRO metabolites and ten ALL metabolites were characterized in rats in vivo. Among these metabolites, six PRO metabolites and five ALL metabolites were reported for the first time. The predicated metabolic pathways including ring cleavage, demethylation following ring cleavage, and glucuronidation were proposed. The low-concentration residue of PRO and ALL in various tissues was detected at 24 h and 48 h after dosing, which indicated that both compounds could be widely distributed in tissues and exist as low levels of residue. The activities of erythromycin N-demethylase, aminopyrine N-demethylase and NAD (P)H quinone oxidoreductase in female rats can be induced post-dose, but these activities were inhibited in male rats. The proposed biotransformation and residues of PRO and ALL and their effects on enzymes may provide a basis for clarifying the metabolism and interpreting pharmacokinetics.

Comparative pharmacokinetics study of five alkaloids in rat plasma and related compound-herb interactions mechanism after oral administration of Shuanghua Baihe tablets.

Shuanghua Baihe tablet is a traditional Chinese patent medicine which showed special advantages in the treatment of recurrent aphthous stomatitis. Scientists have improved and implemented the LC-MS/MS method, which is specific and sensitive, for comparative pharmacokinetics study of five alkaloids, including palmatine, berberine, epiberberine, jatrorrhizine and coptisine in rat plasma after oral administration of Rhizoma Coptidis extract and Shuanghua Baihe tablets. The results showed that Shuanghua Baihe tablets could promote the absorption of these five alkaloids and improved their bioavailability compared with R. Coptidis extract. To further investigate the related mechanism, everted intestinal sac model in vitro was used to indicate that alteration of in vivo pharmacokinetics of five alkaloids could be attributed to, at least in part, the absorption changes by coadministration of other herbs. These discoveries served as a theoretical basis for clinical use of Shuanghua Baihe tables.

Pharmacokinetics study of Erhuang decoction extracts in rats by HPLC-MS/MS.

To study the pharmacokinetics of Erhuang decoction extracts, a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established for the determination of effective substances in rat plasma. The extracts prepared by water extraction (WE) method were given to rats by oral administration. After collected from the orbital venous plexus, plasma was treated by protein precipitation method. Then, the concentration of index components, including baicalin, liquiritin, berberine, palmatine and glycyrrhetinic acid, were determined by HPLC-MS/MS. Gradient elution mode was used to the chromatographic separation with an Inertsil ODS-SP column (100 mm×2.1mm, 5µm), with acetonitrile and 0.1% formic acid containing 10mmolL-1 ammonium acetate as the mobile phase. MS analysis was conducted by multiple reactions monitoring (MRM) with Electrospray Ionization (ESI). The extraction recoveries of the five active ingredients from plasma were greater than 86.04%, and the intra- and inter-day precisions were less than 16.57%. Results indicated that active ingredients in plasma of rats with oral administration of extracts showed certain difference in the pharmacokinetic parameters, which proved that the active ingredients were effectively absorbed. The established HPLC-MS/MS analytical method was sensitive and accurate, suitable for the pharmacokinetic study of active ingredients in Erhuang decoction.

Highly sensitive electrochemical detection of palmatine using a biocompatible multiwalled carbon nanotube/poly-l-lysine composite.

To date, the natural alkaloids are mostly used in the field of pharmacological applications and the active substance of palmatine was extensively used in cancer therapy and other biomedical applications. Hence, in this study we report a simple preparation of poly-l-lysine (PLL) electro-polymerized on the surface of functionalized multiwalled carbon nanotubes (f-MWCNT) for electrochemical detection of palmatine content in human serum and urine samples. The active amino group of PLL plays a vital role towards the oxidation palmatine and exhibits superior electrocatalytic activity. Under optimum conditions, the prepared f-MWCNT/PLL composite shows a wide linear response range over the palmatine concentration ranging from 0.5µM to 425µM, and a detection limit (LOD) of 0.12µM based on S/N =3 (signal to noise ratio). The real time monitoring of palmatine content in serum and urine samples displays an appropriate recoveries and excellent performance for the practical analysis. The advantage of this developed system was simple, higher electrocatalytic activity, long-term stability and low cost. We hope that the prepared composite opens a new way for the fabrication of different biosensors in the field of biomedical application.

Identification of metabolites of palmatine in rats after oral administration using ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

RATIONALE: Palmatine (PAL), a protopalmatine alkaloid, is an active constituent in a number of medicinal plants. In order to obtain a comprehensive and systematic metabolic profile of PAL, we investigated its metabolites in plasma, liver tissue, bile, urine, and feces samples after intragastrical administration to Sprague-Dawley rats with a dose of 100 mg/kg/day. METHODS: In this study, a rapid and sensitive method by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/QTOF-MS), and Metabolynx™ software with the mass defect filter (MDF) technique was developed for screening and identification of the metabolites. The structural elucidation of the metabolites was performed by comparing their molecular weights and fragment ions with those of the parent drug. RESULTS: As a result, a total of 58 metabolites were identified in rat biological samples including 46 metabolites in urine, 18 metabolites in plasma, 34 metabolites in bile, 26 metabolites in liver tissue, and 10 metabolites in feces. Among them, six major metabolites were fully confirmed using reference standards and others were identified by retention time, accurate mass and fragment ions. CONCLUSIONS: These results indicated that phase I reactions (demethylation and hydroxylation) and phase II reaction (glucuronidation and sulfation) were the main metabolic pathways of PAL in vivo. This research enhances our understanding of metabolism of PAL in rats, and provides useful information on the action mechanism of PAL. Copyright © 2017 John Wiley & Sons, Ltd.

Simultaneous determination of anemoside B4, phellodendrine, berberine, palmatine, obakunone, esculin, esculetin in rat plasma by UPLC-ESI-MS/MS and its application to a comparative pharmacokinetic study in normal and ulcerative colitis rats.

A sensitive and rapid ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS/MS) method was developed for the simultaneous analysis of anemoside B4, phellodendrine, berberine, palmatine, obakunone, esculin, esculetin, toosendanin (IS1 of anemoside B4), tetrahydropalmatine (IS2 of phellodendrine, berberine, palmatine and obakunone) and scopoletin (IS3 of esculin and esculetin) and to compare the pharmacokinetics of these active ingredients in normal and ulcerative colitis rats. After methanol deproteinization, solvents were evaporated at 40°C under a gentle stream of nitrogen. Chromatography was performed using a C18 column with a gradient elution of 0.1% aqueous formic acid and acetonitrile at 0.4ml/min. Detection and measurement were performed on a 4000 QTRAP UPLC-MS/MS system from AB Sciex in the multiple reaction monitoring (MRM) mode. Phellodendrine, berberine, palmatine, obakunone, esculin, esculetin, tetrahydropalmatine (IS2) and scopoletin (IS3) were monitored under positive ionization conditions. Anemoside B4, and toosendanin (IS1) were monitored under negative ionization conditions. The optimized mass transition ion-pairs (m/z) were 1221.1/750.7 for anemoside B4, 343.2/193.2 for phellodendrine, 337.1/321.0 for berberine, 353.0/336.9 for palmatine, 455.1/161.1 for obakunone, 341.2/179.2 for esculin, 179.1/123.0 for esculetin, 573.4/531.4 for toosendanin (IS1), 356.2/192.2 for tetrahydropalmatine (IS2) and 193.0/133.1 for scopoletin (IS3).

Development and validation of a high performance liquid chromatography quantification method of levo-tetrahydropalmatine and its metabolites in plasma and brain tissues: application to a pharmacokinetic study.

Levo-tetrahydropalmatine (l-THP) is an alkaloid isolated from Chinese medicinal herbs of the Corydalis and Stephania genera. It has been used in China for more than 40 years mainly as an analgesic with sedative/hypnotic effects. Despite its extensive use, its metabolism has not been quantitatively studied, nor there a sensitive reliable bioanalytical method for its quantification simultaneously with its metabolites. As such, the objective of this study was to develop and validate a sensitive and selective HPLC method for simultaneous quantification of l-THP and its desmethyl metabolites l-corydalmine (l-CD) and l-corypalmine (l-CP) in rat plasma and brain tissues. Rat plasma and brain samples were processed by liquid-liquid extraction using ethyl acetate. Chromatographic separation was achieved on a reversed-phase Symmetry® C18 column (4.6 × 150 mm, 5 µm) at 25°C. The mobile phase consisted of acetonitrile-methanol-10 mm ammonium phosphate (pH 3) (10:30:60, v/v) and was used at a flow rate of 0.8 mL/min. The column eluent was monitored at excitation and emission wavelengths of 230 and 315 nm, respectively. The calibration curves were linear over the concentration range of 1-10,000 ng/mL. The intra- and interday reproducibility studies demonstrated accuracy and precision within the acceptance criteria of bioanalytical guidelines. The validated HPLC method was successfully applied to analyze samples from a pharmacokinetic study of l-THP in rats. Taken together, the developed method can be applied for bioanalysis of l-THP and its metabolites in rodents and potentially can be transferred for bioanalysis of human samples.

Simultaneous determination of l-tetrahydropalmatine and its active metabolites in rat plasma by a sensitive ultra-high-performance liquid chromatography with tandem mass spectrometry method and its application in a pharmacokinetic study.

A sensitive and reliable ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for simultaneous determination of l-tetrahydropalmatine (l-THP) and its active metabolites l-isocorypalmine (l-ICP) and L-corydalmine (l-CD) in rat plasma. The analytes were extracted by liquid-liquid extraction and separated on a Bonshell ASB C18 column (2.1 × 100 mm; 2.7 µm; Agela) using acetonitrile-formic acid aqueous as mobile phase at a flow rate of 0.2 mL/min in gradient mode. The method was validated over the concentration range of 4.00-2500 ng/mL for l-THP, 0.400-250 ng/mL for l-ICP and 1.00-625 ng/mL for l-CD. Intra- and inter-day accuracy and precision were within the acceptable limits of <15% at all concentrations. Correlation coefficients (r) for the calibration curves were >0.99 for all analytes. The quantitative method was successfully applied for simultaneous determination of l-THP and its active metabolites in a pharmacokinetic study after oral administration with l-THP at a dose of 15 mg/kg to rats.

Characterization of human metabolism and disposition of levo-tetrahydropalmatine: Qualitative and quantitative determination of oxidative and conjugated metabolites.

Levo-tetrahydropalmatine (l-THP) is a tetrahydroprotoberberine isoquinoline alkaloid and has been used as an analgesic agent in China for over 50 years. Recent studies revealed that l-THP was effective in the treatment of drug addiction. However, the plasma metabolic profile, mass balance and clearance pathways of l-THP in human remain unknown. In the present study, an analytical strategy was developed for qualitative and quantitative investigation of metabolism and disposition of l-THP in human. Detection and structural characterization of l-THP metabolites were performed using liquid chromatography-quadrupole time-of-flight mass spectrometry. Selected major metabolites in plasma, urine and feces determined by liquid chromatography with UV detection were further quantified using a triple quadruple mass spectrometry and reference standards. A total of 20 metabolites were identified, most of which were formed via demethylation, mono-hydroxylation, and glucuronidation and sulfonation of desmethyl metabolites. Five major metabolites accounted for over 10% of the parent drug concentration in plasma. Major urinary and fecal metabolites and the parent drug that were monitored for 72h accounted for 46.3% of the dose, while only 0.16% of the dose was the unchanged drug. Multiple demethylations followed by glucuronide and sulfate conjugations and renal excretion were the major drug clearance pathways of l-THP in human.

Pharmacokinetic analysis of levo-tetrahydropalmatine in rabbit plasma by rapid sample preparation and liquid chromatography-tandem mass spectrometry.

A rapid extraction method was developed and validated for levo-tetrahydropalmatine (l-THP) determination in rabbit plasma by liquid chromatography tandem-mass spectrometry (LC-MS/MS). The sample preparation included a single-step acetonitrile extraction and salting out liquid-liquid partitioning from the water in plasma with MgSO4. Berberine was used as internal standard. The mass spectrometry source was negative electrospray ionization. The method showed good performance in the concentration range from 5 to 200ngmL(-1). The limit of quantification (LOQ) was 1ngmL(-1). The method was successfully applied to a pharmacokinetic study in rabbit comparing the two drug formulation of l-THP including the raw material and the self-microemulsifying drug delivery system pellet.

Pharmacokinetics of a multicomponent herbal preparation in healthy Chinese and African volunteers.

K-601 is an herbal formulation for influenza consisting of Lonicera japonica, Isatis indigotica, Rheum palmatum, Phellodendron chinense, and Scutellaria baicalensis. In this work, we characterized the chemical constituents in K-601, identified the absorbed compounds and determined their pharmacokinetics in 6 Chinese and African volunteers by liquid chromatography with time-of-flight mass spectrometry. Similarity evaluation for chromatographic fingerprint of nine different batches showed values above 0.983. Totally, 50 components were identified in K-601. Then, 15 major prototype compounds and 17 metabolites were identified in human plasma. Major metabolic pathways included glucuronidation, sulfation, methylation, demethylation, and reduction. The pharmacokinetics of the most abundant prototype compounds, berberine, jatrorrhizine, palmatine and magnoflorine were determined. Significant pharmacokinetic differences were observed between the African and Chinese subjects. The AUCs of the African is about 4-10 fold higher than that of the Chinese for the three benzylisoquinoline alkaloids. Magnoflorine, an aporphine alkaloid, was absorbed better in the Chinese than in the African. The biotransformation of K-601 by human intestinal microflora was also investigated. The major reactions included hydroxylation, methylation, demethylation, acetylation and reduction. Glucuronidation and sulfation were not observed with fecal flora. These results may be important and useful in linking data from pharmacological assays and clinical effects.

A UPLC-MS/MS method for simultaneous quantitation of three monoterpene glycosides and four alkaloids in rat plasma: application to a comparative pharmacokinetic study of Huo Luo Xiao Ling Dan and single herb extract.

The objective of this study was to develop a sensitive and reliable ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneous quantitation of three monoterpene glycosides (paeoniflorin, alibiflorin and oxypaeoniflorin) and four alkaloids (tetrahydropalmatine, corydaline, dehydrocorydaline and berberine), the main active ingredients of Radix Paeoniae Rubra extract (RPE) and Corydalis yanhusuo extract (CYE) in Huo Luo Xiao Ling Dan (HLXLD), and to compare the pharmacokinetics of these active ingredients in normal and arthritic rats orally administrated with HLXLD or RPE/CYE alone. The analytes and internal standard (IS) (geniposide) were separated on a XBridge C18 column (150 × 4.6 mm, 3.5 µm) using gradient elution with the mobile phase consisting of methanol and 0.01% formic acid in water at a flow rate of 0.6 ml/min. The detection of the analytes was performed on Acquity UPLC-MS/MS system with an electrospray ionization and multiple reaction monitoring mode via polarity switching between negative (for monoterpene glycosides) and positive (for alkaloids) ionization mode. The lower limits of quantification were 2.5, 1, 0.5, 0.2, 0.2, 0.02 and 0.01 ng/ml for paeoniflorin, alibiflorin, oxypaeoniflorin, tetrahydropalmatine, corydaline, dehydrocorydaline and berberine, respectively. Intra-day and inter-day precision and accuracy of analytes were well within acceptance criteria (15%). The mean extraction recoveries of analytes and IS from rat plasma were all more than 83.1%. The validated method has been successfully applied to determination of the analytes. Results showed that there were remarkable differences in pharmacokinetic properties of the analytes between herbal formula and single herb group, normal and arthritic group.

Pharmacokinetics and brain distribution of tetrahydropalmatine and tetrahydroberberine after oral administration of DA-9701, a new botanical gastroprokinetic agent, in rats.

DA-9701, a new botanical gastroprokinetic agent, has potential for the management of delayed gastric emptying in Parkinson's disease if it has no central anti-dopaminergic activity. Therefore, we examined the pharmacokinetics of DA-9701 components having dopamine D2 receptor antagonizing activity, tetrahydropalmatine (THP) and tetrahydroberberine (THB), following various oral doses (80-328 mg/kg) of DA-9701. The distribution of THP and THB to the brain and/or other tissues was also evaluated after single or multiple oral administrations of DA-9701. Oral administration of DA-9701 yielded dose-proportional area under the plasma concentration-time curve (AUC0-8 h) and maximum plasma concentration (Cmax) values for THP and THB, indicating linear pharmacokinetics (except for THB at the lowest dose). THP and THB's large tissue-to-plasma concentration ratios indicated considerable tissue distribution. High concentrations of THP and THB in the stomach and small intestine suggest an explanation for DA-9701's potent gastroprokinetic activity. The maximum concentrations of THP and THB in brain following multiple oral DA-9701 for 7 d (150 mg/kg/d) was observed at 30 min after the last oral DA-9701 treatment: 131±67.7 ng/g for THP and 6.97±4.03 ng/g for THB. Although both THP and THB pass through the blood-brain barrier, as indicated by brain-to-plasma concentration ratios greater than unity (approximately 2-4), oral administration of DA-9701 at the effective dose in humans is not expected to lead to sufficient brain concentrations to exert central dopamine D2 receptor antagonism.

Gender differences in corydaline pharmacokinetics in rats.

1. Corydaline, an isoquinoline alkaloid, is one of the major active constituents in a new prokinetic botanical agent, DA-9701. It has been recommended that preclinical pharmacokinetic studies of natural medicines include both genders. Therefore, in this study, the pharmacokinetics of corydaline in male and female rats was evaluated following intravenous and oral administration of pure corydaline or DA-9701. 2. After intravenous administration of corydaline, the area under the plasma concentration-time curve (AUC) was significantly greater (by 46.4%) in female rats compared to male rats due to a 29.3% reduction in non-renal clearance in female rats. The gender difference in corydaline hepatic metabolic clearance was supported by a significantly slower metabolism of corydaline in hepatic microsomes of female rats mediated via male-specific (CYP2C11 and CYP3A2) or male-dominant (CYP3A1) CYP isozymes. 3. Following oral administration of pure corydaline or DA-9701, the AUC and Cmax values of corydaline in female rats were significantly greater (by 793% and 466% increase for corydaline administration or by 501% and 143% increase for DA-9701 administration) than in male rats. Greater F values of corydaline in female rats could be due to smaller hepatic first-pass extraction as a result of slower hepatic metabolism of corydaline. 4. However, we observed a comparable disappearance of corydaline in male and female human liver microsomes, consistent with little gender difference in CYP2C9 and CYP3A activities in humans compared to that in rats. Thus, gender differences in corydaline metabolism are not expected to occur in humans.

Comparative pharmacokinetics of active alkaloids after oral administration of Rhizoma Coptidis extract and Wuji Wan formulas in rat using a UPLC-MS/MS method.

Wuji Wan (WJW), containing Rhizoma Coptidis (Huanglian in Chinese, HL), Frutus Evodiae Rutaecarpae (Wuzhuyu, WZY) and Radix Paeoniae Alba (Baishao, BS), is a classical traditional Chinese medical formula employed in treating intestinal disorders. Berberine (BBR) and palmatine (PMT) are the major active alkaloids in HL and have analgesic and anti-microbial effects. A sensitive, specific and validated ultra-performance liquid chromatography-tandem mass spectrometric method was developed to investigate the pharmacokinetic profiles of BBR and PMT in rat plasma and in situ intestinal perfusion solution. In comparison with the pharmacokinetic parameters of BBR and PMT, t(1/2), C(max), T(max), AUC, CL and MRT after intragastric (i.g.) administration with HL extract alone, those remarkably changed after i.g. administration with WJW formulas 1 and 2 (herb proportions are 12:2:3 and 12:1:12). Particularly, the oral bioavailability of PMT in WJW formula 1 was significantly increased. In rat intestinal perfusion experiments, the apparent permeability coefficient value of PMT was (1.45 ± 0.72) × 10(-5) cm/s when perfusion with HL was performed, and the value was significantly increased to (3.92 ± 0.52) × 10(-5) cm/s on perfusion with WJW formula 1. These results indicate that the pharmacokinetic parameters and absorption of BBR and PMT are affected by the other herbs or ingredients from WJW formulas.