Identification of prototypes from Ligustri Lucidi Fructus in rat plasma based on a data-dependent acquisition and multicomponent pharmacokinetic study.

The identification and quantization of traditional Chinese medicine (TCM) are a challenge for researchers and industry. Using untargeted analytical methods, the in vivo detection and identification of TCM compounds are difficult because of the significant interference of endogenous substances. Fortunately, the ongoing development of new analytical technologies, especially Q-Orbitrap-MS, offers some solutions. Our team developed a holistic MS method, combining untargeted data-dependent MS2 (dd-MS2 ) modes to extensively identify TCM prototypes in vivo. The method was successfully applied to the analysis of Ligustri Lucidi Fructus (LLF). LLF is a widely used TCM with a remarkable nourishing effect on the liver and kidney. In the study, we aimed to identify the prototypes in rat plasma after oral administration of LLF extract. Following separation on an HSS T3 column, LLF extract and rat plasma were performed in untargeted dd-MS2 mode. Forty-seven compounds were characterized in rats plasma as prototypes of LLF extract. Furthermore, seven major prototypes were chosen as pharmacokinetic markers to investigate LLF's pharmacokinetic properties. The results provides comprehensive determination of compounds in LLF both in vitro and in vivo, which is important for quality control, pharmacology studies and clinical use of LLF.

LC-electrolyte switch in a contiguous time segments to analyze multi-components: Simultaneous determination of phenolic acids and iridoids in rat plasma after inhalation administration of Reduning aerosol.

The optimization of electrolytes, kinds and concentrations, in mobile phase for multiple constituents analyzing using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS) was usually compromised to ensure good LC separation of partial components. However, the compromised electrolytes could lead to ionization suppression of some of the analytes. To solve the compromise of electrolytes within various components, taking phenolic acids and iridoids as a case, we used electrolyte switch in contiguous running time segments of UPLC-ESI-MS/MS to ensure chromatographic separation of chlorogenic acid, neochlorogenic acid and cryptochlorogenic acid and improve the response of geniposide. Then the method was applied for pharmacokinetic study of the four components in rat after inhaling Reduning aerosol for the first time. The complete separation of the three chlorogenic acid isomers was achieved and the LLOQs of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, and geniposide were 1, 1, 3, and 0.2 ng/mL, respectively. In conclusion, we developed a sensitive and time-saving LC-MS/MS method for the quantitative analysis of chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, and geniposide in rat plasma, and this method appears to be useful for pharmacokinetic studies of Reduning aerosol. The method provided a sight to alleviate compromise of electrolytes in mobile phase for HPLC-ESI-MS in analyzing multi-components.

Comparative pharmacokinetic study of four major bioactive components after oral administration of Zhi-Zi-Hou-Po decoction in normal and corticosterone-induced depressive rats.

A highly selective and efficient LC-MS/MS method was developed to determine the plasma concentration of magnolol, hesperidin, neohesperidin and geniposide following oral administration of Zhi-Zi-Hou-Po decoction in normal and depressed rats. Plasma samples were pretreated by protein precipitation with methanol. Chromatographic separation was performed on an XTerra® MS C18 column using a gradient elution with a mobile phase composed of acetonitrile-0.1% aqueous formic acid. The proposed method was validated to be specific, accurate and precise for the analytes determination in plasma samples. The calibration curves displayed good linearity over definite concentration ranges for the analytes. The intra- and inter-day precision of the proposed method at three different levels were all within <11.13% and the relative errors ranged from -8.46 to 8.93%. The recovery of the four compounds ranged from 82.72 to 89.08% and no apparent matrix effect was observed during sample analysis. After full validation, the established method was successfully applied for comparing the pharmacokinetics of four components between normal and depressed rats. The results showed that the AUC and Cmax of four analytes in depressed rats were significantly different from those in normal rats and might provide helpful information to guide the clinical use of Zhi-Zi-Hou-Po to treat depression.

Rapid characterization of the absorbed constituents in rat serum after oral administration and action mechanism of Naozhenning granule using LC-MS and network pharmacology.

Naozhenning granule is a Chinese herbal formula, which is mainly used in the treatment of concussion, cerebral post-traumatic syndrome. Although its effectiveness has been certified in the clinical use, the mechanism of action and bioactive components of Naozhenning remain unknown. In this study, the ultrahigh performance liquid chromatography coupled with hybrid quadrupole-orbitrap mass spectrometry was applied to identify the absorbed constituents of Naozhenning in the rat serum. A total of 60 compounds, including 30 prototype components and 30 metabolites were identified. Then the absorbed constituents were subjected to the network pharmacology analysis. The compound-target-disease (CTD) and KEGG pathway analysis revealed that 40 absorbed constituents, 56 target genes and three key pathways such as RAS, PI3K/Akt, MAPK, TGFß were probably related with the efficacy of Naozhenning against cerebral trauma and cerebral concussion. The results provided a scientific basis for understanding the bioactive compounds and the pharmacological mechanism of Naozhenning granule.

Established UPLC-MS/MS procedure for multicomponent quantitative analysis in rat plasma: A contrastive pharmacokinetics study of Qiangshen tablet in normal and kidney yang deficiency syndrome models.

Qiangshen tablet, an important prescription consisting of 14 kinds of Chinese herbal medicines, has been used for decades to treat kidney yang deficiency syndrome (KYDS) in China. Qiangshen tablet has been recorded in ChP (2015 edition) and possesses the effect of strengthening yang, invigorating qi and tonifying kidneys. In this research, a simple, reliable and specific method was established for simultaneous determination of stachydrine, psoralen, isopsoralen, morroniside, paeoniflorin and loganin in normal and KYDS rat plasma after intragastric administration of a Qiangshen tablet suspension by UPLC-MS/MS. Protein precipitation (PP) by acetonitrile and liquid-liquid extraction (LLE) by ethyl acetate - n-butanol (1: 1, v/v) were used for pretreatment of plasma samples. Chromatographic separation of two IS (Internal Standard) and six analytes was achieved using an ACQUITY UPLC® BEH C18 column (2.1 × 100 mm, 1.7 µm). The mobile phase consisted of 0.1% formic acid aqueous solution (solvent A) and acetonitrile (solvent B) with a gradient scheme. Multiple reaction monitoring (MRM) mode with positive and negative ion source switching was applied to perform the mass spectrometric analyses. This method has been validated with good linearity (r ≥ 0.9942) and acceptable precision and accuracy (RSD ≤ 11%, RE from -4.8% to 7.7%). The mean recovery values of the analytes and IS were all ≥68.28%, and the matrix effects ranged from 94.4% to 101.7%. The stability of the IS and analytes was measured throughout the experiment. The results showed significant differences between the pharmacokinetic traits of the analytes in the normal and KYDS groups, suggesting that pharmacokinetic procedures involving these analytes could be modified in cases of KYDS.

UPLC-Q-TOF/MS-based metabolic profiling comparison of four major bioactive components in normal and CKD rat plasma, urine and feces following oral administration of Cornus officinalis Sieb and Rehmannia glutinosa Libosch herb couple extract.

Cornus officinalis-Rehmannia glutinosa herb couple is widely used herb medicine in clinical practice to treat chronic kidney disease (CKD). However, the in vivo integrated metabolism of its main bioactive components in CKD rats remains unknown. In this study, UPLC-Q-TOF/MS technique combined with Metabolynx™ software, was developed and successfully applied for analysis of metabolic profiles of the bioactive components of the herb couple in normal and CKD rat biological samples. Main parent components of the herb couple extract such as loganin, morroniside and catalpol were absorbed into the blood circulation of the normal and CKD rats. Another parent component acteoside was almost completely degraded. Seventeen metabolites involved in the in vivo metabolism processes were tentatively identified. These metabolites indicated that loganin was mainly metabolized to the demethylated product, and morroniside was firstly deglycosylated to the aglycone and the latter was subsequently demethylated and acetylated. Additionally, hydrogenation and deglycosylation were the principal metabolic reactions of catalpol; while O-glucuronide and O-sulphate conjugates were observed as major metabolites for methylated caffeic acid and hydroxytyrosol released from acteoside. Compared with the normal group, the CKD rat showed lower conversion capability. Few kinds and minor amounts of the metabolites appeared in the CKD rat samples. While considerable amounts of the parent compounds were detected in the CKD plasma. This will help maintain a high blood drug concentration which might be beneficial for the treatment of CKD. The proposed method could develop an integrated template approach to analyze screening and identification of the bioactive components in plasma, urine and feces after oral administration of herb medicines. Additionally, this investigation might provide helpful chemical information for further pharmacology and active mechanism research on herb medicines.

Synthesis and Characterization of pH-Sensitive Genipin Cross-Linked Chitosan/Eudragit® L100 Hydrogel for Metformin Release Study Using Response Surface Methodology.

BACKGROUND: In this study, central composite design was utilized for the optimization of genipin cross-linked chitosan/Eudragit®-L 100 interpenetrating hydrogel network films fabricated through solvent evaporation technique. METHODS: Hydrogel formulations were studied using response surface methodology; regression analysis and the surface plots were used to evaluate the effect of variables on T50% (the time for 50% of drug release) and dynamic swelling with optimum formulation selection. Initial burst release of drug was observed from the formulated hydrogels during the first 2 hours of dissolution at simulated gastric pH 1.2 and then slow release during the next 10 hours in the simulated intestinal fluid at pH 7.4. Different polymer ratios in formulation showed significant influence on T50% and dynamic swelling of hydrogel. The highest T50% was observed at 9.89 hour and dynamic swelling at 7.86 h. RESULT: It was observed that by changing the polymer ratio with cross-linker, release rate of metformin could be modified. Cross-linker also affects drug release rate, i.e. the release rate is decreased with the increase in its concentration. The physical state of hydrogel was investigated by scanning electron microscope. CONCLUSION: It indicated the uniform distribution of drug in hydrogel matrix system. Moreover, the presence of hydrogen and ionic bonds between polymers and crosslinking agent formed interpenetrating hydrogel network, likely responsible for increased value of T50%, as confirmed by FTIR. Acute oral toxicity study was performed to investigate the toxic effect of crosslinking agent and polymer used in formulations.

Comprehensive investigation of in-vivo ingredients and action mechanism of iridoid extract from Gardeniae Fructus by liquid chromatography combined with mass spectrometry, microdialysis sampling and network pharmacology.

Gardeniae Fructus is a widely used Traditional Chinese Medicines in treating various diseases. However, the absorbed components and metabolites of its main bioactive iridoid ingredients from iridoid extract of the fruits of Gardeniae Fructus in rat plasma need further study. In this study, a systematic method based on ultra-performance liquid chromatography-quadrupole-time-of-flight/mass spectrometry (UPLC-Q-TOF/MS) technique was developed to speculate the absorbed components and metabolites of iridoid extract in rat plasma after oral administration. A total of 19 compounds, including 9 prototype components and 10 metabolites were identified in plasma. 5 metabolites containing 4 new metabolites (M1, M2, M7, M10) were tentatively determined in rat plasma. Besides, Microdialysis-intensity-fading mass spectrometry (MD-IF-MS) method was originally employed to reveal the binding affinities with α-glucosidase for in-vivo prototype components and their metabolites. Finally, the absorbed constituents and the corresponding target proteins were used to generate compound-target network to find the related diseases and action pathways by a network pharmacology method. The results provide useful information for further study of pharmacology and in vivo mechanism of action of iridoid extract from the fruits of Gardeniae Fructus.

High Resolution Mass Spectrometric Analysis of Secoiridoids and Metabolites as Biomarkers of Acute Olive Oil Intake-An Approach to Study Interindividual Variability in Humans.

SCOPE: Phenolic compounds are minor components of extra virgin olive oil (EVOO). Secoiridoids are the major components contributing to the phenolic content of EVOO. Information is lacking regarding their potential as biomarkers for EVOO intake. METHODS AND RESULTS: Healthy volunteers (n = 9) ingested 50 mL of EVOO in a single dose containing 322 mg kg-1 total phenolic content (caffeic acid equivalents) and 6 mg 20 g-1 hydroxytyrosol and its derivatives. Plasma is collected before (0 h) and at 0.5, 1, 2, 4, and 6 h after ingestion. Urine samples are collected prior to ingestion (0 h) and at 0-4, 4-8, 8-15, and 15-24 h. Samples are analyzed by UPLC coupled with an Exactive Orbitrap MS. Partial least squares discriminant analysis with orthogonal signal correction is applied to screen for metabolites that allow sample discrimination. Plasma biomarkers and urine biomarkers are selected although individual variability is observed among volunteers. Results are in accordance with in vitro experiments performed (in vitro digestion and hepatic microsomal activity assays). CONCLUSIONS: Plasma (elenolic acid + H2 ; p-HPEA-EA + H2 + glucuronide) and urinary (3,4-DHPEA-EA, 3,4-DHPEA-EA + H2 +glucuronide, methyl 3,4-DHPEA-EA + H2 +glucuronide) secoiridoid compounds are selected as biomarkers to monitor EVOO intake showing good predictive ability according to multivariate analysis.

A sensitive LC-MS/MS method for simultaneous quantification of geniposide and its active metabolite genipin in rat plasma and its application to a pharmacokinetic study.

Genipin (GP), an active metabolite of geniposide (GE), exhibits more potent pharmacological effects than its parent compound. In this paper, a sensitive LC-MS/MS method was developed and fully validated for the simultaneous determination of GE and GP in rat plasma. We found that GP degraded rapidly in rat plasma at room temperature as a result of irreversible binding with the endogenous nucleophiles in plasma. GP was stable when the sample's pH was ≤4.0. The degradation of GP in rat plasma was well prevented by immediate addition of 5% glacial acetic acid to the freshly collected plasma. The detection was performed on a tandem mass spectrometer coupled with electrospray ionization source in negative mode. Quantification was conducted by multiple reaction monitoring of the transitions [M + CH3 COO]- m/z 447.3 → 225.3 for GE and [M - H]- m/z 225.2 → 123.1 for GP. The method exhibited high sensitivity (LLOQ 1 ng/mL for GE and 0.2 ng/mL for GP) by selecting the acetate adduct ions as the precursor ions for GE. The robust developed method was successfully applied to a pharmacokinetic study in rats after oral administration of GE.

Simultaneous quantification method for comparative pharmacokinetics studies of two major metabolites from geniposide and genipin by online mircrodialysis-UPLC-MS/MS.

Genipin-1-o-glucuronic acid and genipin-monosulfate are two major metabolites from geniposide and genipin. Based on diabetic rat model, we developed a simultaneous quantification method to investigate their comparative pharmacokinetics by online mircrodialysis-ultra performance liquid chromatography-mass spectrometry (MD-UPLC-MS/MS) without their standard compounds. Online microdialysis sampling could avoid unexpected contamination or degradation of the analytes during the storage and transfer steps. Combined with good sensitivity, selectivity and selectivity of UPLC-MS/MS, online MD-UPLC-MS/MS method could real-timely monitor metabolites in rat blood for quantitative analysis. Our research found that AUC0→t of genipin-1-o-glucuronic acid and genipin-monosulfate in blood of diabetic group were 17.68 and 7.58 times than those in normal group, respectively, and AUC0→t of genipin-1-o-glucuronic acid was 2.28 times than that of genipin-monosulfate in blood of diabetic group, which revealed the effect of diabetes on the pharmacokinetic properties of the two metabolites. This study not only provides an approach for pharmacokinetic studies for various metabolites from herb medicines, but also can predict druggability of their bioactive metabolites. The insight obtained should facilitate drug development and toxicity research.

Comparative pharmacokinetic analysis of extracts of crude and wine-processed Dipsacus asper in rats by a sensitive ultra performance liquid chromatography-tandem mass spectrometry approach.

The purpose of this study is to establish and validate an UPLC-MS/MS approach to determine 4-caffeoylquinic acid, chlorogenic acid, 3,5-dicaffeoylquinic acid, loganic acid, loganin, sweroside, dipsacoside B and asperosaponin VI from extracts of crude and wine-processed Dipsacus asper in biological samples and apply the approach to a comparative pharmacokinetic study. A Waters BEH C18 UPLC column was employed with acetonitrile/0.2% formic acid-water as mobile phases. The mass analysis was carried out in a triple quadrupole mass spectrometer using multiple reaction monitoring (MRM) with negative scan mode. A one-step protein precipitation by acetonitrile was performed to extract the eight analytes from plasma. Our results revealed that all of the calibration curves displayed good linear regression (r2>0.9990). The lower limits of quantification (LLOQ) were determined as 10.0, 9.6, 8.9, 9.1, 9.2, 9.8, 10.1 and 9.8ng/mL. The intra-day and inter-day precisions (RSD) of the eight compounds at high, medium and low levels were less than 4.94% and the bias of the accuracies ranged from -3.89% to 3.95%.The extraction recoveries of the eight compounds were from 90.4% to 100.2% and the matrix effects ranged from 89.3% to 100.1%. The stabilities of these compounds were investigated by analyzing six replicates of QC samples at three different concentrations following storage at 25°C for 4h, -80°C for 30days, three-freeze-thaw cycles, and 4°C for 24h. All the samples showed satisfactory precision and accuracy after various stability tests. Pharmacokinetic parameters were estimated using a non-compartment model. Compared with the crude group, the parameters of Cmax and AUC0-t of 4-caffeoylquinic acid, loganic acid, loganin and asperosaponin VI increased remarkably (p<0.05) after oral administration of the aqueous extract of wine-processed Dipsacus asper, indicating that wine-processing could enhance bioavailability of 4-caffeoylquinic acid, loganic acid, loganin and asperosaponin VI.

Pharmacokinetics and Disposition of Circulating Iridoids and Organic Acids in Rats Intravenously Receiving ReDuNing Injection.

ReDuNing injection, prepared from a combination of Gardenia Jasminoides fruits, Lonicera japonica flower buds, and the Artemisia annua aerial part, is extensively used for treatment of viral upper respiratory tract infections in China. Iridoids, organic acids, and flavonoids are likely important compounds of the herbal injection because of their reported pharmacological properties. This study was designed to characterize pharmacokinetics and disposition of the major circulating herbal compounds in rats that received the injection intravenously. ReDuNing injection was found to contain 19 iridoids (content levels 0.01-27.93 mM), 16 organic acids (0.04-19.06 mM), and 11 flavonoids (<0.08 mM). After dosing the injection, the iridoids geniposide, secologanic acid, secoxyloganin, genipin-1-ß-gentiobioside, geniposidic acid, sweroside, and shanzhiside and the organic acids chlorogenic acid, quinic acid, cryptochlorogenic acid, and neochlorogenic acid were found to be the major circulating compounds, with mean elimination half-lives of 0.2-0.9 hour; the other plasma compounds were at low exposure levels. These major circulating compounds exhibited small apparent volumes of distribution (0.03-0.34 l/kg). Most of the iridoids were eliminated predominantly via renal excretion of the unchanged compounds, whereas the organic acids were eliminated via methylation and sulfation and were excreted into urine as the unchanged and metabolized compounds. The methylated metabolites also underwent subsequent conjugations before hepatobiliary and renal excretion. In vitro data suggested that the metabolism of the organic acids in rats also occurred in humans. The current pharmacokinetic research could serve as a crucial step in identifying the chemical basis responsible for the therapeutic action of ReDuNing injection.

A novel bioanalytical method based on UHPLC-HRMS/MS for the quantification of oleuropein in human serum. Application to a pharmacokinetic study.

A highly sensitive, rapid and specific ultrahigh-performance liquid chromatography, coupled to negative electrospray ionization high-resolution tandem mass spectrometry, method was developed and validated in order to investigate the absorption of dietary oleuropein (OE) in human subjects. Serum samples were collected at predefined time points, after oral administration of an olive leaf extract enriched in OE (204.4 mg OE per capsule) to two subjects. Subsequently, samples were analyzed by the developed method after a simple solid-phase extraction step. Chromatographic separation was operated with aqueous formic acid, 0.1% (v/v), and acetonitrile following a gradient program at a flow rate of 0.45 mL/min in an RP-C18 (50 × 2.1 mm, 1.9 µm) column with a total run time of 2.7 min. The method was validated and successfully applied to the determination of OE in human serum, with the pharmacokinetic analysis of the data revealing a biphasic response.

Simultaneous determination of loganin, morroniside, catalpol and acteoside in normal and chronic kidney disease rat plasma by UPLC-MS for investigating the pharmacokinetics of Rehmannia glutinosa and Cornus officinalis Sieb drug pair extract.

A sensitive and rapid method for determination of loganin, morroniside, catalpol and acteoside in rat plasma after oral administration of Rehmannia glutinosa Libosch and Cornus officinalis Sieb drug pair based on ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS). Chromatographic separation was achieved using an Acquity UPLC BEH C18 column (100mm×2.1mm, 1.7µm) at a flow rate of 0.4mL/min, using gradient mode containing 0.1% formic acid in water and acetonitrile were used as the mobile phase A and B. Loganin, morroniside, catalpol, acteoside and the internal standard (chloramphenicol) were detected by selected reaction monitoring in the negative ion mode with the mass transition of m/z 451.0→179.0 (morroniside), m/z 435.0→227.0 (loganin), m/z 407.1→199.1 (catalpol), m/z 623.2→161.0 (acteoside) and m/z 320.8→151.9 (chloramphenicol), respectively. All calibration curves showed good linearity (r>0.991). The precision was evaluated by intra-day and inter-day assays and the RSD% were all within 9.58%. The recovery ranged from 67.62 to 80.14%. The method was successfully applied to pharmacokinetic study of the analytes in normal and doxorubicin-induced chronic kidney disease rat plasma.

Targeted and Untargeted Metabolomics to Explore the Bioavailability of the Secoiridoids from a Seed/Fruit Extract (Fraxinus angustifolia Vahl) in Human Healthy Volunteers: A Preliminary Study.

The bark, seeds, fruits and leaves of the genus Fraxinus (Oleaceae) which contain a wide range of phytochemicals, mostly secoiridoid glucosides, have been widely used in folk medicine against a number of ailments, yet little is known about the metabolism and uptake of the major Fraxinus components. The aim of this work was to advance in the knowledge on the bioavailability of the secoiridoids present in a Fraxinus angustifolia Vahl seed/fruit extract using both targeted and untargeted metabolomic analyses. Plasma and urine samples from nine healthy volunteers were taken at specific time intervals following the intake of the extract and analyzed by UPLC-ESI-QTOF. Predicted metabolites such as tyrosol and ligstroside-aglycone glucuronides and sulfates were detected at low intensity. These compounds reached peak plasma levels 2 h after the intake and exhibited high variability among the participants. The ligstroside-aglycone conjugates may be considered as potential biomarkers of the Fraxinus secoiridoids intake. Using the untargeted approach we additionally detected phenolic conjugates identified as ferulic acid and caffeic acid sulfates, as well as hydroxybenzyl and hydroxyphenylacetaldehyde sulfate derivatives which support further metabolism of the secoiridoids by phase I and (or) microbial enzymes. Overall, the results of this study suggest low uptake of intact secoiridoids from a Fraxinus angustifolia Vahl extract in healthy human volunteers and metabolic conversion by esterases, glycosidases, and phase II sulfo- and glucuronosyl transferases to form smaller conjugated derivatives.

[Pharmacokinetics of loganin, ferulic acid and stilbene glucoside in Bushen Tongluo formula in vivo].

To study the pharmacokinetics characteristic of loganin, ferulic acid and stilbene glucoside in rat plasma after oral administration of Bushen Tongluo formula. The plasma samples were treated by using liquid-liquid extraction technique, the concentrations were determined by HPLC-UV. Johnson spherigel C18 column (4.6 mm x 250 mm, 5 µm) was adopted and eluted with the of mobile phase of methanol-water containing 0.01% glacial acetic acid in a gradient mode, with the flow rate at 1.0 mL x min(-1), column temperature at 30 degrees C and injection volume of 10 µL. According to the findings, loganin was determined at 235 nm, ferulic acid and stilbene glucoside were determined at 320 nm, with the sample size of 10 µL. The pharmacokinetic parameters of loganin, ferulic acid and stilbene glucoside were calculated by DAS 2. 0 software as follows: C(max) was (0.369 ± 0.042), (0.387 ± 0.071), (0.233 ± 0.044) mg x L(-1); t(max) was (0.226 ± 0.022), (0.282 ± 0.031), (0.233 ± 0.044) h; t(½ß) was (6.89 ± 0.20), (10.73 ± 0.11), (6.93 ± 0.09) h; AUC(0-∞) was (1.91 ± 0.36), (3.22 ± 0.52), (1.52 ± 0.33) mg x h x L(-1); AUCO(0-t) was (1.62 ± 0.33), (2.58 ± 0.43), (1.30 ± 0.30) mg x h x L(-1); CL was (20.2 ± 4.0), (1.39 ± 0.23), (31.7 ± 6.9) L x h(-1) x kg(-1), respectively. The results showed that after the oral administration with Bushen Tongluo formula, loganin, ferulic acid and stilbene glucoside showed concentration-time curves in conformity with the two compartment model, with a rapid absorption, loganin and stilbene glucoside was excreted at a moderate speed, and ferulic acid was excreted slowly (but with the highest bioavailability). Bushen Tongluo formula can main maintain plasma concentration with three administrations everyday and so is suitable to be made into common oral preparation.

Synergistic effects of rhubarb-gardenia herb pair in cholestatic rats at pharmacodynamic and pharmacokinetic levels.

ETHNOPHARMACOLOGICAL RELEVANCE: Herb pair serves as the basic building block of a traditional Chinese medicine (TCM) formula. The rhubarb-gardenia herb pair (RGHP), composed of rhubarb and gardenia, has meaningful clinical effects to cure cholestasis diseases. This study was designed to confirm the expected synergistic effects of RGHP at pharmacodynamic and pharmacokinetic levels. MATERIALS AND METHODS: Thirty male Sprague-Dawley rats were divided into control, model and drug-treated groups. After intragastrically administrated with α-naphthylisothiocyanate (ANIT) to induce cholestasis, rats were treated with rhubarb, gardenia or RGHP. For pharmacodynamic study, biochemical and histopathological tests were performed to assess the hepatoprotective effects. While for pharmacokinetic study, a LC-MS method was developed for determination of five main chemical markers, namely genipin, rhein, aloe emodin, emodin and chrysophanol in rat plasma. RESULTS: The biochemical and histopathological tests suggested that RGHP exerted enhanced hepatoprotective effects against the ANIT-induced cholestasis compared with single herbs. The pharmacokinetic study indicated RGHP could significantly elevate systemic exposure level and prolong retention time of five markers in comparison with rhubarb or gardenia alone. CONCLUSIONS: The present study demonstrated the synergistic effects of RGHP in ANIT-induced cholestatic rats at pharmacodynamic and pharmacokinetic levels, and has significant enlightenments for the rational use of the related TCM formulas containing RGHP.

Comparative pharmacokinetics of the main compounds of Shanzhuyu extract after oral administration in normal and chronic kidney disease rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Pharmacokinetic studies on traditional Chinese medicine are useful to evaluate and predict the drug efficacy and safety. The renal impairment may affect drug clearance and other pharmacokinetic processes which can increase toxicity and drug to drug interactions or cause ineffective therapy. Pharmacokinetic studies in pathological status rats might be meaningful for revealing the action mechanism and improving clinical medication of the herb medicine. MATERIALS AND METHODS: A highly sensitive and rapid ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) method with multiple-reaction monitoring (MRM) mode was developed and validated for simultaneous quantitation of morroniside and loganin in normal and doxorubicin-induced chronic kidney disease (CKD) rat plasma after oral administration of Shanzhuyu (fruit of Cornus officinalis) extract. RESULTS: Both calibration curves gave satisfactory linearity (r>0.99) at linear range of 1.96-1962.5ngmL(-1) for morroniside, 1.53-1531.25ngmL(-1) for loganin. The precision and accuracy of the in vivo study were assessed by intra-day and inter-day assays. The percentages of relative standard deviation (RSD) were all within 9.58% and the accuracy (RE) was in the -6.02% to 8.11% range. The extraction recoveries of morroniside, loganin and internal standard (IS) were all >67.62% and the matrix effects ranged from 95.07% to 102.75%. CONCLUSIONS: The pharmacokinetic behavior of morroniside and loganin in normal and CKD rat plasma was determined in this paper. The significant different pharmacokinetic parameters might partly result from the changes of P-glycoprotein and metabolic enzymes in the pathological state. The pharmacokinetic research in the pathological state might provide more useful information to guide the clinical usage of the herb medicine.

Development of a LC-MS-MS Method for Quantification of Valtrate and Its Application to Pharmacokinetic Study.

A simple and selective liquid chromatography-tandem mass spectrometric method for determination of valtrate in rat plasma was developed in this study. Chromatographic separation was achieved on a Thermo BDS HYPERSIL C18 column using acetonitrile-water-formic acid (75 : 25 : 0.1, v/v/v) as mobile phase in an isocratic mode of elution at a flow rate of 300 µL/min. MS-MS detection was performed in a positive ion electrospray ionization mode with the ion transitions 445.2 → 219.2 for valtrate and 355.2 → 135.1 for internal standard (sesamin). The developed method exhibited a linear dynamic range over 5.65-1695 ng/mL for valtrate in rat plasma. The overall extraction recovery of valtrate from plasma was 86.13-88.32%. The intra- and inter-day accuracy and precision were within the pre-defined limits of ≤15% at all concentrations. The method was successfully applied to pharmacokinetic studies of valtrate in rats.