Screening and verification of CYP3A4 inhibitors from Bushen-Yizhi formula to enhance the bioavailability of osthole in rat plasma.

ETHNOPHARMACOLOGICAL RELEVANCE: With the features of multiple-components and targets as well as multifunction, traditional Chinese medicine (TCM) has been widely used in the prevention and treatment of various diseases for a long time. During the application of TCM, the researches about bioavailability enhancement of the bioactive constituents in formula are flourishing. Bushen-Yizhi formula (BSYZ), a TCM prescription with osthole (OST) as one of the main bioactive ingredients, have been widely used to treat kidney deficiency, mental retardation and Alzheimer's disease. However, the underlying biological mechanism and compound-enzyme interaction mediated bioavailability enhancement of OST are still not clearly illuminated. AIM OF THE STUDY: The aim of this study is to explore the material basis and molecular mechanism from BSYZ in the bioavailability enhancement of OST. Screening the potential CYP3A4 inhibitors using theoretical prediction and then verifying them in vitro, and pharmacokinetics study of OST in rat plasma under co-administrated of screened CYP3A4 inhibitors and BSYZ were also scarcely reported. MATERIALS AND METHODS: Screening of CYP3A4 inhibitors from BSYZ was performed with molecular docking simulation from systems pharmacology database. The screened compounds were verified by using P450-Glo Screening Systems. A multiple reaction monitoring (MRM) mass spectrometry method was established for OST quantification. Male Sprague-Dawley rats divided into four groups and six rats in each group were employed in the pharmacokinetics study of OST. The administrated conditions were group I, OST (20 mg/kg); group II, BSYZ (containing OST 1 mg/mL, at the dose of 20 mg/kg OST in BSYZ); group III, co-administration of ketoconazole (Ket, 75 mg/kg) and OST (20 mg/kg); group IV, co-administration of CYP3A4 inhibitor (10 mg/kg) and OST (20 mg/kg). They were determined by using HPLC-MS/MS (MRM) and statistical analysis was performed using student's t-test with p < 0.05 as the level of significance. RESULTS: 21 potential CYP3A4 inhibitors were screened from BSYZ compounds library. From the results of verification in vitro, we found 4 compounds with better CYP3A4 inhibition efficiency including Oleic acid, 1,2,3,4,6-O-Pentagalloylglucose, Rutin, and Schisantherin B. Under further verification, Schisantherin B exhibited the best inhibitory effect on CYP3A4 (IC50 = 0.339 µM), and even better than the clinically used drug (Ket) at the concentration of 5 µM. In the study of pharmacokinetics, the area under the curve (AUC, ng/L*h) of OST after oral administration of BSYZ, Ket and Schisantherin B (2196.23 ± 581.33, 462.90 ± 92.30 and 1053.03 ± 263.62, respectively) were significantly higher than that of pure OST treatment (227.89 ± 107.90, p < 0.01). CONCLUSIONS: Schisantherin B, a profoundly effective CYP3A4 inhibitor screened from BSYZ antagonized the metabolism of CYP3A4 on OST via activity inhibition, therefore significantly enhanced the bioavailability of OST in rat plasma. The results of this study will be helpful to explain the rationality of the compatibility in TCM formula, and also to develop new TCM formula with more reasonable drug compatibility.

Pharmacokinetic study of Ninjin'yoeito: Absorption and brain distribution of Ninjin'yoeito ingredients in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Ninjin'yoeito (NYT), a Japanese traditional Kampo medicine, has been reported to exert various clinical benefits such as relief from fatigue, malaise, anorexia, frailty, sarcopenia, and cognitive dysfunction. Recently, some review articles described the pharmacological effects of NYT and additionally indicated the possibility that multiple ingredients in NYT contribute to these effects. However, pharmacokinetic data on the ingredients are essential in addition to data on their pharmacological activities to accurately determine the active ingredients in NYT. AIM OF THE STUDY: This study assessed the in vivo pharmacokinetics of NYT using mice. MATERIALS AND METHODS: Target liquid chromatography-mass spectrometry (LC-MS) and wide target LC-MS or LC-tandem MS of NYT ingredients in plasma and the brain after oral administration of NYT were performed. Imaging MS was performed to investigate the detailed brain distributions of NYT ingredients. RESULTS: The concentrations of 13 ingredients in plasma and schizandrin in the brain were quantified via target LC-MS, and the wide target analysis illustrated that several ingredients are absorbed into blood and transported into the brain. Imaging MS revealed that schizandrin was homogenously dispersed in the NYT-treated mouse brain. CONCLUSION: These results should be useful for clarifying the active ingredients of NYT and their mechanisms of actions.

Efficacy of human-simulated bronchopulmonary exposures of cefepime, zidebactam and the combination (WCK 5222) against MDR Pseudomonas aeruginosa in a neutropenic murine pneumonia model.

OBJECTIVES: WCK 5222 combines cefepime with zidebactam, a ß-lactam enhancer that binds PBP2 and inhibits class A and C ß-lactamases. The efficacy of human-simulated bronchopulmonary exposures of WCK 5222 against MDR Pseudomonas aeruginosa was investigated in a neutropenic murine pneumonia model. METHODS: Nineteen MDR isolates of P. aeruginosa (cefepime MICs ≥64 mg/L) were studied. MICs of zidebactam and WCK 5222 ranged from 4 to 512 mg/L and from 4 to 32 mg/L, respectively. Dosing regimens of cefepime and zidebactam alone and in combination that achieved epithelial lining fluid (ELF) exposures in mice approximating human ELF exposures after doses of 2 g of cefepime/1 g of zidebactam every 8 h (1 h infusion) were utilized; controls were vehicle-dosed. Lungs were intranasally inoculated with 107-108 cfu/mL bacterial suspensions. Mice were dosed subcutaneously 2 h after inoculation for 24 h, then lungs were harvested. RESULTS: In vitro MIC was predictive of in vivo response to WCK 5222 treatment. Mean±SD changes in bacterial density at 24 h compared with 0 h controls (6.72±0.50 log10 cfu/lungs) for 13 isolates with WCK 5222 MICs ≤16 mg/L were 1.17±1.00, -0.99±1.45 and -2.21±0.79 log10 cfu/lungs for cefepime, zidebactam and WCK 5222, respectively. Against these isolates, zidebactam yielded >1 log10 cfu/lungs reductions in 8/13, while activity was enhanced with WCK 5222, producing >2 log10 cfu/lungs reductions in 10/13 and >1 log10 cfu/lungs reductions in 12/13. Among isolates with WCK 5222 MICs of 32 mg/L, five out of six showed a bacteriostatic response. CONCLUSIONS: Human-simulated bronchopulmonary exposure of WCK 5222 is effective against MDR P. aeruginosa at MIC ≤16 mg/L in a murine pneumonia model. These data support the clinical development of WCK 5222 for pseudomonal lung infections.

Pharmacokinetics and liver uptake of three Schisandra lignans in rats after oral administration of liposome encapsulating ß-cyclodextrin inclusion compound of Schisandra extract.

Schisandra chinensis fructus (SCF) is widely used traditional Chinese medicine, which possesses hepato-protective potential. Schisandrin (SD), schisantherin (ST), and γ-schizandrin (SZ) are the major bioactive lignans. The main problem associated with the major bioactive lignans oral administration is low oral bioavailability due to the lignans' poor aqueous solubility and taste. The aim of the present research work was to develop liposome (SCL) encapsulated ß-cyclodextrin (ß-CD) inclusion complex loaded with SCF extract (SCF-E). The SD, ST, and SZ were selected as effective candidates to perform comparisons of liver targeting among the solution (SES), ß-cyclodextrin inclusion compound (SCF-E-ß-CD), liposome (SEL), and SCL of SCF-E to characterize the pharmacokinetic behaviors and liver targeting in rats. The ß-CD inclusion complex (SCF-E-ß-CD) was used to improve the solubility. The concentrations were determined using high-performance liquid chromatography (HPLC) and analyzed by DAS3.0. The pharmacokinetic results indicate that the plasma concentration-time courses were fitted well to the one-compartment model with the first weighing factor. The half-life period (t1/2) and area under the concentration-time curve (AUC) of the three components in SCL were the largest. The SCL exhibit a relatively high liver targeting effect. The results would be helpful for guiding the clinical application of this herbal medicine.

Pharmacokinetics and distribution of schisandrol A and its major metabolites in rats.

1. Schizandrol A is an active component in schisandra, also the representative component for the identification of schisandra. 2. A rapid resolution liquid chromatography coupled with quadruple-time-of-flight mass spectrometry (RRLC-QTOF/MS) was developed to investigate the pharmacokinetics of schizandrol A after its intragastric administration (50 mg/kg) in rats. 3. Schizandrol A was rapidly absorbed (T max = 2.07 h), with a longer duration (t 1/2 = 9.48 h) and larger apparent volume of distribution (Vz/F = 111.81 l/kg) in rats. Schizandrol A can be detected in main organs and the order of its distribution was in the liver > kidney > heart > spleen > brain, particularly higher in the liver. 4. Five schizandrol A metabolites were identified, including 2-demethyl-8(R)-hydroxyl-schizandrin, 3-demethyl-8(R)-hydroxyl-schizandrin, hydroxyl-schizandrin, demethoxy-schizandrin, 2, 3-demethyl-8(R)-hydroxyl-schizandrin, indicating that the hydroxylation and demethylation may be the major metabolic way of schizandrol A. 5. This study defined the pharmacokinetic characteristics of schizandrol A in vivo, and the RRLC-QTOF/MS is more sensitive and less limited by conditions, and needs less samples, which may be a useful resource for the further research and development of schisandrol A.

Simultaneous UPLC-MS/MS determination of four components of Socheongryong-tang tablet in human plasma: Application to pharmacokinetic study.

The purpose of this study was to develop a method for simultaneous analysis of schizandrin, ephedrine, paeoniflorin, and cinnamic acid as constituents of Socheongryong-tang tablet in human plasma using UPLC-MS/MS. These four components were separated using water containing 0.01% formic acid and methanol as a mobile phase by gradient elution at a flow rate of 0.3 mL/min with a HALO-C18 column (2.1 mm × 100 mm, 2.7 µm particle size). Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization technique operated in multiple reaction monitoring mode. Mass transitions were m/z 432.9 → 384.1 for schizandrin, 165.8 → 148.1 for ephedrine, 525.0 → 449.2 for paeoniflorin, 146.8 → 102.9 for cinnamic acid, and 340.0 → 324.0 for papaverine as internal standard. Liquid-liquid extraction and protein precipitation with ethyl acetate-methanol (1:2, v/v) were used to obtain these four components. Chromatograms showed high resolution, sensitivity, and selectivity without interference by plasma constituents. Calibration curves of schizandrin, ephedrine, paeoniflorin, and cinnamic acid in human plasma ranged from 0.02 to 8 ng/mL, 0.5 to 200 ng/mL, 0.2 to 80 ng/mL, and 1 to 400 ng/mL, respectively. Calibration curves of each analyte displayed excellent linearity, with correlation coefficients > 0.99. For all four components, both intra- and inter-day precisions (CV%) were <5.99%. The accuracy was 99.35-103.30% for schizandrin, 98.48-104.38% for ephedrine, 97.06-103.34% for paeoniflorin, and 99.97-104.36% for cinnamic acid. This analytical method developed in this study satisfied the criteria of international guidance. It could be successfully applied to pharmacokinetic studies of schizandrin, ephedrine, paeoniflorin, and cinnamic acid after oral administration of Socheongryong-tang tablet to humans.

Simultaneous quantification of Schisandrin B enantiomers in rat plasma by chiral LC-MS/MS: Application in a stereoselective pharmacokinetic study.

Schisandrin B (Sch B) has received much attention owing to its various biological activities. Schisandrin B exists as a racemate in "wuweizi", a traditional Chinese medicine in China. In the present study, a novel chiral LC-MS/MS method was developed for enantioselective separation and determination of Schisandrin B in rat plasma. The plasma samples were prepared by liquid-liquid extraction (LLE). Schisandrol B was used as internal standard. Chiral separation was obtained on a Chiralpak IC column using 0.1% (v/v) formic acid in mixture of methanol and water (90:10, v/v) as a mobile phase. Parameters including the selectivity, linearity, precision, accuracy, extraction recovery, matrix effect and stability were evaluated. The method described here is simple and reproducible. The lower limit of quantification of 5.0 ng/mL for each Sch B enantiomer permits the use of the method in investigating the stereoselective pharmacokinetics of Sch B. Following racemic Sch B and "wuweizi" extracts, the area under the curve of (8R, 8'S)-Sch B was statistically higher than the one of (8S, 8' R)-Sch B, with a ratio of 1.16-1.40 in three cases. This study firstly reports the development and validation of enantioselective behavior of Sch B in vivo, and provides a reference for clinical practice and encourages further research into Sch B enantioselective metabolism and drug interactions.

Pharmacokinetics of Schizandrin and Its Pharmaceutical Products Assessed Using a Validated LC-MS/MS Method.

Schisandra chinensis has been used as an important component in various prescriptions in traditional Chinese medicine and, more recently, in Western-based medicine for its anti-hepatotoxic effect. The aim of this study was to develop a selective, rapid, and sensitive ultra-performance liquid chromatography-tandem mass spectrometry method for pharmacokinetic studies of schizandrin in rats. Liquid-liquid extraction was used for plasma sample preparation. A UHPLC reverse-phase C18e column (100 mm × 2.1 mm, 2 µm) coupled with a mobile phase of methanol-0.1% formic acid (85:15, v/v) was used for sample separation. A triple quadrupole tandem mass spectrometer was used to detect the analytes in the selected reaction monitoring mode. The linear range of schizandrin in rat plasma was 5.0-1000 ng/mL (r² > 0.999), with a lower limit of quantification of 5 ng/mL. The method was validated with regard to accuracy, intra-day and inter-day precision, linearity, stability, recovery, and matrix effects in rat plasma, which were acceptable according to the biological method validation guidelines developed by the FDA. This method was successfully applied to a pharmacokinetic study after oral administration of 3 g/kg and 10 g/kg of Schisandra chinensis products, which yielded a maximum concentration of schizandrin of 0.08 ± 0.07 and 0.15 ± 0.09 µg/mL, respectively. A parallel study design was used to investigate the oral bioavailability of single compound of schizandrin and the herbal extract, the single compound of pure schizandrin (10 mg/kg, i.v.), pure schizandrin (10 mg/kg, p.o.), and the herbal extract of Schisandra chinensis (3 g/kg and 10 g/kg, p.o.) were given individually. The dose of Schisandra chinensis (3 g/kg) equivalent to schizandrin (5.2 mg/kg); the dose of Schisandra chinensis (10 g/kg) equivalent to schizandrin (17.3 mg/kg). The result demonstrated that the oral bioavailability of schizandrin was approximately 15.56 ± 10.47% in rats, however the oral bioavailability of herbal extract was higher than single compound. The method was successfully applied to the pharmacokinetic study of pure schizandrin after oral administration of its pharmaceutical industry products in rats.

Prediction of Drug-Drug Interaction between Tacrolimus and Principal Ingredients of Wuzhi Capsule in Chinese Healthy Volunteers Using Physiologically-Based Pharmacokinetic Modelling.

Schisantherin A and schisandrin A, the most abundant active ingredients of Wuzhi capsule, are known to inhibit tacrolimus metabolism by inhibiting CYP3A4/5. We aimed to predict the contribution of schisantherin A and schisandrin A to drug-drug interaction (DDI) between Wuzhi capsule and tacrolimus using physiologically-based pharmacokinetic (PBPK) modelling. Firstly, the inhibition mechanism of schisantherin A and schisandrin A on CYP3A4/5 was investigated. Thereafter, PBPK models of schisantherin A, schisandrin A and tacrolimus were established. Finally, tacrolimus pharmacokinetics were evaluated after the combined use with schisantherin A or schisandrin A. The blood area under the curve (AUC) of tacrolimus increased 1.77- and 2.61-fold after a single dose and multiple doses of schisantherin A, respectively. Meanwhile, schisandrin A inhibited tacrolimus metabolism to a smaller extent. Also, it showed that mechanism-based inhibition (MBI) played a more important role in DDI than reversible inhibition after long-term administration, while reversible inhibition was comparable to MBI after single-dose administration. In conclusion, we utilized PBPK modelling to quantify the contribution of schisantherin A and schisandrin A to DDI between tacrolimus and Wuzhi capsule. This may provide more insights for the rational use of this drug combination.

Study on the pharmacokinetics of deoxyschizandrin and schizandrin in combination with epigallocatechin gallate, a component of green tea, in rats.

1. Green tea is commonly used worldwide due to its potential positive health benefits. We have examined the effects of epigallocatechin gallate (EGCG), the most abundant catechin in green tea, on the pharmacokinetics of deoxyschizandrin (DSD) and schizandrin (SD), which are the representative lignans in popular traditional Chinese medicines Fructus schisandrae, in rats. 2. The effects on the transport in Caco-2 cells and metabolism in human liver microsomes (HLMs) of DSD and SD by EGCG were determined to analyze their interactions thoroughly. 3. In pharmacokinetic studies, rats were divided into four groups. Each group was orally treated with DSD alone (Group 1), DSD combined with EGCG (Group 2), SD alone (Group 3) and SD combined with EGCG (Group 4). The pharmacokinetic parameters of DSD and SD in rats were determined by UPLC-MS/MS. 4. The in vivo results indicated that EGCG had no significant influence on the pharmacokinetic behaviors of DSD or SD in rats, which were in accordance with the in vitro transport and metabolism studies. However, there were marked differences between male and female rats among Cmax, AUC0-t, AUC0-∞ of DSD and SD. This disparity suggested that gender differences might exist in the pharmacokinetic processes of DSD or SD in rats.

Development and validation of an LC-MS/MS method for the simultaneous quantification of seven constituents in rat plasma and application in a pharmacokinetic study of the Zaoren Anshen prescription.

A sensitive, specific and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of seven constituents of the Zaoren Anshen prescription (ZAP) in rat plasma after oral administration of the ZAP: spinosin, salvianic acid A, 6'''-feruloylspinosin, protocatechualdehyde, salvianolic acid B, schisandrin and deoxyschisandrin. The plasma samples and the internal standard (IS) sulfamethoxazole were extracted using acetonitrile. Chromatographic separation was performed with an Agilent HC-C18 column using a gradient elution profile and a mobile phase consisting of 0.01% formic acid in water (A) and acetonitrile (B). The analytes were quantified simultaneously in a single run using an ion trap mass spectrometer operated in the multiple reaction monitoring mode and electrospray ion-source polarity in the positive and negative modes. The calibration curves for spinosin, salvianic acid A, 6'''-feruloylspinosin, protocatechualdehyde, salvianolic acid B, schisandrin and deoxyschisandrin were linear over the concentration ranges of 2.90-1160, 2.50-1000, 1.80-720, 0.65-260, 2.50-1000, 8.00-1600 and 1.30-520 ng/mL, respectively. The intra- and inter-day precisions in terms of relative standard deviation were <18.9%, and the accuracies in terms of relative error were within ±14.2%. Consequently, the proposed method was successfully applied to the pharmacokinetic analysis of these seven major active compounds in rats administered ZAP. These results will facilitate research aiming to predict the effectiveness of the optimal dose of ZAP and might be beneficial for the therapeutic use of ZAP in the clinical setting.

Time- and NADPH-Dependent Inhibition on CYP3A by Gomisin A and the Pharmacokinetic Interactions between Gomisin A and Cyclophosphamide in Rats.

The traditional Chinese medicine Schisandra chinensis has remarkable protective effects against chemical-induced toxicity. Cyclophosphamide (CTX), in spite advances in chemotherapy and immunosuppressive regimes, is prone to cause severe toxicity due to its chloroacetaldehyde (CAA) metabolite produced by CYP3A. Our previous study identified that S. chinensis extract (SCE) co-administration potently decreased CAA production and attenuated liver, kidney and brain injuries in CTX-treated rats. Gomisin A (Gom A) is proved to be one of the most abundant bioactive lignans in S. chinensis with a significant CYP3A inhibitory effect. To find out whether and how Gom A participated in the chemoprevention of SCE against CTX toxicity, the Gom A-caused CYP3A inhibition in vitro as well as the pharmacokinetic interactions between Gom A and CTX in vivo were examined in this study. Using human liver microsomes, a reversible inhibition assay revealed that Gom A was a competitive inhibitor with a KI value of 1.10 µM, and the time- and NADPH-dependent CYP3A inhibition of Gom A was observed in a time-dependent inhibition assay (KI = 0.35 µM, kinact = 1.96 min-1). Hepatic CYP3A mRNA expression experienced a significant increase in our rat model with Gom A administration. This explained why CAA production decreased in the 0.5 h- and 6 h-pretreatment rat groups while it increased in the 24 h- and 72 h-pretreatment groups, indicating a bidirectional effect of Gom A on CYP3A-mediated CTX metabolism. The present study suggested that Gom A participates like SCE in the pharmacokinetic intervention of CTX by blocking CYP3A-mediated metabolism and reducing CAA production, and thus plays an important role in the chemopreventive activity of S. chinensis against CTX toxicity, in addition to the previously recognized protective effects. Also, the combined use of S. chinensis preparation or other drugs containing Gom A as the main component with CTX needed to be addressed for better clinical intervention.

Simultaneous determination of wogonin, oroxylin a, schisandrin, paeoniflorin and emodin in rat serum by HPLC-MS/MS and application to pharmacokinetic studies.

Wogonin and oroxylin A in Scutellariae Radix, schisandrin in Chinensis Fructus, paeoniflorin in Moutan Cortex and emodin in Polygoni Cuspidate Rhizome et Radix are anti-inflammatory active compounds. A method for simultaneous determination of the five compounds in rat was developed and validated using high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). The separation was performed on a Symmetry C18 column (4.6 × 50 mm, 3.5 µm) with acetonitrile and 0.1% formic acid aqueous solution as the mobile phases. The detection was performed using multiple-reaction monitoring with electrospray ionization source in positive-negative ion mode. The calibration curves showed good linearity (r ≥ 0.9955). The lower limit of quantification (LLOQ) was 5 ng/mL for wogonin and schisandrin, 10 ng/mL for oroxylin A and emodin, and 15 ng/mL for paeoniflorin, respectively. The relative standard deviations of intraday and interday precisions were <11.49 and 14.28%, respectively. The extraction recoveries and matrix effects were acceptable. The analytes were stable under the experiment conditions. The validated method has been successfully applied to pharmacokinetic studies of the five compounds in rats after oral administration of Hu-gan-kan-kang-yuan capsule. This paper would be a valuable reference for pharmacokinetic studies of Chinese medicine preparations containing the five compounds.

Comparative pharmacokinetics and tissue distribution profiles of lignan components in normal and hepatic fibrosis rats after oral administration of Fuzheng Huayu recipe.

ETHNOPHARMACOLOGICAL RELEVANCE: Fuzheng Huayu recipe (FZHY) is formulated on the basis of Chinese medicine theory in treating liver fibrosis. AIM OF THE STUDY: To illuminate the influence of the pathological state of liver fibrosis on the pharmacokinetics and tissue distribution profiles of lignan components from FZHY. MATERIALS AND METHODS: Male Wistar rats were randomly divided into normal group and Hepatic fibrosis group (induced by dimethylnitrosamine). Six lignan components were detected and quantified by ultrahigh performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in the plasma and tissue of normal and hepatic fibrosis rats. RESULTS: A rapid, sensitive and convenient UHPLC-MS/MS method has been developed for the simultaneous determination of six lignan components in different rat biological samples successfully. After oral administration of FZHY at a dose of 15g/kg, the pharmacokinetic behaviors of schizandrin A (SIA), schizandrin B (SIB), schizandrin C (SIC), schisandrol A (SOA), Schisandrol B (SOB) and schisantherin A (STA) have been significantly changed in hepatic fibrosis rats compared with the normal rats, and their AUC(0-t) values were increased by 235.09%, 388.44%, 223.30%, 669.30%, 295.08% and 267.63% orderly (P<0.05). Tissue distribution results showed the amount of SIA, SIB, SOA and SOB were significant increased in heart, lung, spleen and kidney of hepatic fibrosis rats compared with normal rats at most of the time point (P<0.05). Meanwhile, the result also reveals that the hepatic fibrosis could delay the peak time of lignans in liver. CONCLUSION: The results proved that the established UHPLC-MS/MS method could be applied to the comparative study on pharmacokinetics and tissue distribution of lignan components in normal and hepatic fibrosis rats. The hepatic fibrosis could alter the pharmacokinetics and tissue distribution properties of lignan components in rats after administration of FZHY. The results might be helpful for guide the clinical application of this medicine.

Simultaneous determination of calycosin-7-O-ß-d-glucoside, calycosin, formononetin, astragaloside IV and schisandrin in rat plasma by LC-MS/MS: application to a pharmacokinetic study after oral administration of Shenqi Wuwei chewable tablets.

A rapid, sensitive and reliable high-performance liquid chromatography-mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous quantification of the five main bioactive components, calycosin, calycosin-7-O-ß-d-glucoside, formononetin, astragaloside IV and schisandrin in rat plasma after oral administration of Shenqi Wuwei chewable tablets. Plasma samples were extracted using solid-phase extraction separated on a CEC18 column and detected by MS with an electrospray ionization interface in multiple-reaction monitoring mode. Calibration curves offered linear ranges of two orders of magnitude with r > 0.995. The method had a lower limit of quantitation of 0.1, 0.02, 0.1, 1 and 0.1 ng/mL for calycosin, calycosin-7-O-ß-d-glucoside, formononetin, astragaloside IV and schisandrin, respectively. Intra- and inter-day precisions (relative standard deviation) for all analytes ranged from 0.97 to 7.63% and from 3.45 to 10.89%, respectively. This method was successfully applied to the pharmacokinetic study of the five compounds in rats after oral administration of Shenqi Wuwei chewable tablets.

A pharmacokinetic and pharmacodynamic study of drug-drug interaction between ginsenoside Rg1, ginsenoside Rb1 and schizandrin after intravenous administration to rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginsenoside Rg1, ginsenoside Rb1 and schizandrin are main bioactive components from Panax ginseng and Schisandra chinensis. They have been found in many prescriptions of Traditional Chinese Medicines (TCM) and proven to be effective for prevention and treatment of cardiovascular disease. It is valuable to investigate their pharmacokinetic and pharmacodynamic behavior and potential synergistic effect for better drug development and clinical application. MATERIALS AND METHODS: Pharmacokinetic and nitric oxide (NO) release pharmacodynamic drug-drug interactions of ginsenoside Rg1, ginsenoside Rb1 and schisandrin were studied after intravenous administration of each compound with the dose of 10 mg/kg and their mixture with the total dose of 10 mg/kg to isoproterenol (ISO)-induced myocardial ischemia rats. Drug concentrations in serum were determined using LC-MS method. Nitrite and nitrate (NOx(-)), the predominant oxidation product of NO in serum was used as an effective marker and quantitated by the method of high-performance liquid chromatography coupled with fluorescence detection (HPLC-FL). The main pharmacokinetic parameters of T(1/2ß), MRT(0-∞), Vd, Cl, and AUC, and the main pharmacodynamic parameters of Cmax, Tmax and AUEC were calculated by non-compartment model. RESULTS: The results indicated ginsenoside Rb1 and (or) schisandrin in mixture could significantly postpone the elimination of ginsenoside Rg1 in rat serum. Co-administration of three compounds markedly increased the systemic exposure level of each compound in vivo. Ginsenoside Rg1 and ginsenoside Rb1 had the effect of inducing real-time NO release in rats concentration dependently. Schisandrin had no effect of inducing real-time NO release in this study. The mixture of ginsenoside Rg1, Rb1 and schisandrin administration exhibited synergistic effect of inducing NO release in ISO treated rats. CONCLUSIONS: The result obtained from this study suggested pharmacokinetic and pharmacodynamic drug-drug interactions between ginsenoside Rg1, Rb1 and schisandrin. The study provided valuable information for drug development and clinical application of TCM.

Comparative pharmacokinetics and tissue distribution of schisandrin, deoxyschisandrin and schisandrin B in rats after combining acupuncture and herb medicine (schisandra chinensis).

Recently, combination therapy with acupuncture and medicine as a practical strategy to treat diseases has gained increasing attention. The present study aimed to investigate whether acupuncture stimulation at ST.36 had a potential impact on the pharmacokinetics and tissue distribution of lignans. An HPLC-ESI/MS analytical method was established and successfully applied to a comparative study of drug concentration in plasma and tissues of three lignans. The parameters area under the plasma concentration-time curve from time zero to the final measurable point and from time zero to infinity, and peak concentration were significantly increased, with a prolonged mean residence time and a corresponding decrease in clearance in comparision with the Schisandra-alone group. Additionally, tissue concentrations of three lignans were improved in the group with acupuncture, especially in liver. The results indicated that acupuncture has a synergistic effect on the pharmacokinetics and tissue distribution of the three lignans, which could postpone their elimination, resulting in a longer blood circulating time in rat plasma and prolonged residence time in target tissues, leading to higher tissue concentration. The findings provide some scientific evidence for the mechanism of the combined use of acupuncture and herbal medicine. Furthermore, we suggest that acupuncture and its combination with herbal medicine should be investigated further as a possible adjuvant therapy in clinical treatment for liver injury.

Ultra-performance liquid-chromatography with tandem mass spectrometry for rapid analysis of pharmacokinetics, biodistribution and excretion of schisandrin after oral administration of Shengmaisan.

This study aimed to investigate the in vivo behaviors of the main components in traditional Chinese medicine (TCM) fomulae. The plasma pharmacokinetics, tissue distribution and excretion of the main component-schisandrin in rats after oral administration of a classical TCM prescription, shengmaisan (SMS), were studied by a developed and validated UPLC-MS/MS method. The separation of schisandrin was achieved on a UPLC HSS T3 column with a mobile phase consisting of acetonitrile and water at a flow rate of 0.5 mL/min by linear gradient elution. The MS/MS detection was carried out by monitoring the fragmentation of m/z 415.22 → 384.26 for schisandrin on a triple quadrupole mass spectrometer. The result showed that the method was suitable for the quantification of schisandrin in plasma, tissue and excreta samples with satisfactory selectivity, precision, accuracy, sensitivity, linearity and recovery. Pharmacokinetic results showed a rapid absorption phase with the mean Tmax of 0.17 h and a relatively slow elimination proceeding with a half-life (T1/2 ) of 5.24 ± 1.28 h. The tissue distribution showed the maximum concentration distributions of schisandrin after oral administration of SMS were in the order of small intestine > large intestine > lung > liver > kidney > spleen > heart > brain. Only 0.005-0.006% of schisandrin was recovered in feces and was not detected in urine.

Chemical-pharmacokinetic-pharmacodynamic fingerprints of Schisandra chinensis alcoholic extract.

It is valuable to establish a chemical-pharmacokinetic (PK)-pharmacodynamics (PD) fingerprint of traditional Chinese medicine (TCM) for comprehensively understanding the TCM integrated conception and revealing the material foundation. The chemical, metabolic in vitro, and PK/PD in vivo fingerprints of Schisandra chinensis (SC) alcoholic extract were established and comparatively analyzed using HPLC-UV-MS method, rat liver microsomes in vitro and CCl4 intoxicated rats in vivo. Four known effective lignans, schisandrin, schisantherin A, deoxyschizandrin and gamma-schisandrin, were detected as the standard references in SC alcoholic extract with high concentration. SC alcoholic extract and four lignans when incubated with rat liver microsomes produced several metabolites in NAPDH-dependent manner. Chemical fingerprint of some components with bioactivities were also identified in PK and PD fingerprints in normal and ALI rats that explained the material foundation of SC alcoholic extract for multiple pharmacological effects. Schisandrin, schisantherin A, deoxyschizandrin and gamma-schisandrin could be considered as the "PK marker" of SC alcoholic extract or its relevant preparations, while two metabolites of the four lignans, 7, 8-dihydroxy-schizandrin and another one (M(W) 432), could be recognized as drug-metabolism (DM) Marker. This work provides experimental data for the further studies of metabolism or material foundation of SC components.

Development of a UFLC-MS/MS method for simultaneous determination of six lignans of Schisandra chinensis (Turcz.) Baill. in rat plasma and its application to a comparative pharmacokinetic study in normal and insomnic rats.

Schisandra chinensis (Turcz.) Baill., a traditional Chinese medicine, has been used for treating insomnia for centuries. This paper was designed to study on the plasma pharmacokinetic for its absorption process, and to compare the pharmacokinetics of its active ingredients in normal and insomnic rats orally administrated with the prescription. Therefore, an efficient, sensitive and selective ultra fast liquid chromatography/tandem mass spectrometry (UFLC-MS/MS) method for the simultaneous determination of six sedative and hypnotic lignans (schisandrin, schisandrol B, schisantherin A, deoxyshisandrin, γ-schisandrin and gomisin N) of Schisandra chinensis (Turcz.) Baill. in rat plasma has been developed and validated. The analysis was performed on a Shim-pack XR-ODS column (75mm×3.0mm, 2.2µm) using gradient elution with the mobile phase consisting of acetonitrile and 0.1% formic acid waterat a flow rate of 0.4ml/min. The detection of the analytes was performed on 4000Q UFLC-MS/MS system with turbo ion spray source in the positive ion and multiple reaction-monitoring mode. The method was validated in plasma samples, which showed good linearity over a wide concentration range (r(2)>0.99), and obtained lower limits of quantification were 10, 1.2, 1.2, 1.2, 1.0 and 1.2ngmL(-1) for the analytes. The intra- and inter-day assay variability was less than 15% for all analytes. The mean extraction recoveries of analytes and IS from rats plasma were all more than 85.0%. The validated method has been successfully applied to comparing pharmacokinetic profiles of analytes in rat plasma. The results indicated that significant difference in pharmacokinetic parameters of the analytes was observed between two groups, while absorptions of these analytes in insomnic group were all significantly higher than those in normal group.