Safety, tolerability, pharmacokinetics, and food effect of baicalein tablets in healthy Chinese subjects: A single-center, randomized, double-blind, placebo-controlled, single-dose phase I study.

ETHNOPHARMACOLOGICAL RELEVANCE: Scutellaria baicalensis (Huang-Qin in Chinese) is a dry root of the perennial herb Scutellaria baicalensis Georgi, which has been used extensively in current prescriptions. Scutellaria baicalensis is an herb high in flavonoids, and baicalein is the one flavonoid found in the highest amount in Scutellaria baicalensis. AIM OF THE STUDY: Influenza virus could cause mild respiratory tract illness to severe pneumonia and even death. Baicalein has been proved to be one of the effective components against the influenza virus. However, there have been few reports on human trials of baicalein. The purpose of this study was to evaluate the safety of baicalein in vivo and analyze its pharmacokinetic characteristics. MATERIALS AND METHODS: Three randomized studies were conducted to evaluate the pharmacokinetics (PK), safety, tolerability, and food effects of baicalein tablets. In the 7-month single-dose safety study, 60 subjects were enrolled and randomized to receive 100-800 mg baicalein tablets or placebo. In the single-dose PK study, 40 subjects were enrolled and randomized to receive 200 mg, 400 mg, 600 mg, 800 mg baicalein tablets. In the study of food effect on PK of baicalein, an additional 10 subjects were enrolled in the 400 mg group, this part of the trial lasted for 7 months. Blood and urine samples for PK analysis were collected at a pre-specified time. PK properties in both fasted and fed states were evaluated, as well as safety and tolerability. RESULTS: Among the 80 subjects who were evaluable for the single-dose safety and tolerability, 56 adverse events (AEs) were observed in 32/80 subjects, of which 49 events were from 28/68 subjects in baicalein group and 7 events were from 4/12 subjects in placebo group. All AEs were mild and resolved without any medical intervention. The most common AEs were elevated high-sensitivity C-reactive protein (hs-CRP) level and high triglycerides. After a single administration of baicalein tablets (200 mg, 400 mg, 600 mg, or 800 mg), Cmax were 280.44, 628.80, 845.20, 489.55 ng/mL; AUC0-∞ were 2035.57, 2939.31, 4494.88, and 3754.43 h*ng/mL, respectively. And t1/2z ranged from 7.80 to 14.91 h. The exposure of baicalein and its metabolites increased in a less than dose-proportional manner. CONCLUSION: Baicalein tablets within the studied dose range were safe and well-tolerated in healthy Chinese subjects with no serious or severe adverse effects. Further investigation will be needed to assess the safety and efficacy in the target patients.

Screening the Q-markers of TCMs from RA rat plasma using UHPLC-QTOF/MS technique for the comprehensive evaluation of Wu-Wei-Wen-Tong Capsule.

The appropriate selection of quality marker (Q-marker) for performing the comprehensive quality evaluation of traditional Chinese medicines (TCMs) has much more significance. Wu-Wei-Wen-Tong Capsule (WWWTC), a TCMs prescription, is mainly utilized to treat rheumatoid arthritis (RA) in China. However, the comprehensive quality control for WWWTC has not been achieved because of lacking system analysis for the Q-marker. In this study, a dual wavelength, 203 and 270 nm, was selected based on the feature of 15 Q-markers, and a reliable UHPLC-UV fingerprinting approach was established, achieving the comprehensive quality evaluation of WWWTC. First, we identified 91 prototypes in rat plasma after administering a set amount of WWWTC by using UHPLC-QTOF/MS technique and selected them as the candidate Q-markers. Next, based on the "five principles" of Q-marker selection, 15 absorbed components among them including coumarin, cinnamic acid, cinnamaldehyde, cinnamic alcohol, and 2-methoxycinnamaldehyde derived from Monarch medicine of Cmnamomi Mmulus; epimedin C, icariin, baohuoside I, and anhydroicaritin derived from Monarch medicine Epimedii Folium; germacrone, the sesquiterpene compound in Minister medicine Rhizoma Wenyujin Concisum; pachymic acid, the tetracyclic triterpenoid acids in Assistant medicine Poria; baicalin, baicalein, wogonin, and wogonoside in Guide medicine Scutellariae Radix, respectively, were seriously chosen as the Q-markers, indicating preferable pharmacological effect on RA, characterization of transitivity and traceability as well as measurable components in WWWTC. The effective and meaningful strategy displayed a unique perspective for the exploration of Q-markers in the quality evaluation and further ensured efficacy and safety of the TCMs.

A stepwise integrated multi-system to screen quality markers of Chinese classic prescription Qingzao Jiufei decoction on the treatment of acute lung injury by combining 'network pharmacology-metabolomics-PK/PD modeling'.

BACKGROUND: Previously, we have investigated the therapeutic mechanism of Qingzao Jiufei Decoction (QZJFD), a Chinese classic prescription, on acute lung injury (ALI), however, which remained to be further clarified together with the underlying efficacy related compounds for quality markers (Q-markers). HYPOTHESIS/PURPOSE: To explore Q-markers of QZJFD on ALI by integrating a stepwise multi-system with 'network pharmacology-metabolomics- pharmacokinetic (PK)/ pharmacodynamic (PD) modeling'. METHODS: First, based on in vitro and in vivo component analysis, a network pharmacology strategy was developed to identify active components and potential action mechanism of QZJFD on ALI. Next, studies of poly-pharmacology and non-targeted metabolomics were used to elaborate efficacy and verify network pharmacology results. Then, a comparative PK study on active components in network pharmacology was developed to profile their dynamic laws in vivo under ALI, suggesting Q-marker candidates. Next, quantified analytes with marked PK variations after modeling were fitted with characteristic endogenous metabolites along drug concentration-efficacy-time curve in a PK-PD modeling to verify and select primary effective compounds. Finally, Q-markers were further chosen based on representativeness among analytes through validity analysis of PK quantitation of primary effective compounds. RESULTS: In virtue of 121 and 33 compounds identified in vitro and in vivo, respectively, 33 absorbed prototype compounds were selected to construct a ternary network of '20 components-47 targets-113 pathways' related to anti-ALI of QZJFD. Predicted mechanism (leukocytes infiltration, cytokines, endogenous metabolism) were successively verified by poly-pharmacology and metabolomics. Next, 18 measurable components were retained from 20 analytes by PK comparison under ALI. Then, 15 primary effective compounds from 18 PK markers were further selected by PK-PD analysis. Finally, 9 representative Q-markers from 15 primary effective compounds attributed to principal (chlorogenic acid), ministerial (methylophiopogonanone A, methylophiopogonanone B), adjuvant (sesamin, ursolic acid, amygdalin), conductant drugs (liquiritin apioside, liquiritigenin and isoliquiritin) in QZJFD, were recognized by substitutability and relevance of plasmatic concentration at various time points. CONCLUSION: 9 Q-markers for QZJFD on ALI were identified by a stepwise integration strategy, moreover, which was a powerful tool for screening Q-makers involved with the therapeutic action of traditional Chinese medicine (TCM) prescription and promoting the process of TCM modernization and scientification.

Quantification of 10 bioactive components of Yazhangsan in rat plasma by LC-MS/MS and its application.

Yazhangsan (YZS) is a common prescription for the treatment of cough and asthma caused by wind-cold. The purpose of this study was to investigate the pharmacokinetic profiles of 10 bioactive components in YZS. A simple, sensitive and reliable high-performance liquid chromatography coupled with a triple-quadruple mass spectrometry method (LC-MS/MS) was developed and fully validated in this study for the measurement of these 10 bioactive compounds in rat plasma. One-step protein precipitation method using methanol was applied to the treatment of rat plasma samples. Chromatographic separation was conducted on a C18 column by gradient elution, and water (containing 0.1% formic acid) and acetonitrile were chosen as the mobile phase. The analytes were quantified by using a mass spectrometer in multiple reaction monitoring scanning mode, and electrospray ionization was performed in positive and negative ion modes. The established method met the requirements for the quantification of these 10 bioactive compounds in biological samples, and it was successfully applied to the pharmacokinetic study of 10 components in rats after the intragastrical administration of YZS. This study will lay a foundation for the investigation of the mechanism of action of YZS and provide useful data for the rational use of YZS in clinical.

Metabolic profiling of mice plasma, bile, urine and feces after oral administration of two licorice flavonones.

ETHNOPHARMACOLOGICAL RELEVANCE: Licorice is an ancient food and medicinal plant. Liquiritigenin and liquiritin, two kinds of major flavonoes in licorice, are effective substances used as antioxidant, anti-inflammatory and tumor-suppressive food, cosmetics or medicines. However, their in vivo metabolites have not been fully explored. AIM OF STUDY: To clarify the metabolism of liquiritigenin and liquiritin in mice. MATERIALS AND METHODS: In this study, we developed a liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry approach to determine the metabolites in mice plasma, bile, urine and feces after oral administration of liquiritigenin or liquiritin. The structures of those metabolites were tentatively identified according to their fragment pathways, accurate masses, characteristic product ions, metabolism laws or reference standard matching. RESULTS: A total of 26 and 24 metabolites of liquiritigenin or liquiritin were respectively identified. The products related with apigenin, luteolin or quercetin were the major metabolites of liquiritigenin or liquiritin in mice. Seven main metabolic pathways including (de)hydrogenation, (de)hydroxylation, (de)glycosylation, (de)methoxylation, acetylation, glucuronidation and sulfation were summarized to tentatively explain their biotransformation. CONCLUSION: This study not only can provide the evidence for in vivo metabolites and pharmacokinetic mechanism of liquiritigenin and liquiritin, but also may lay the foundation for further development and utilization of liquiritigenin, liquiritin and then licorice.

Correlation study between the pharmacokinetics of seven main active ingredients of Mahuang decoction and its pharmacodynamics in asthmatic rats.

The aim of this study was to investigate the pharmacokinetics and pharmacodynamics of seven main active components of Mahuang decoction (MHD) and its time-concentration-effect relationship. The asthmatic rat model was established by the method of ovalbumin (OVA) sensttization. The plasma concentrations of ephedrine, pseudoephedrine, methylephedrine, amygdalin, liquiritin, cinnamic acid, glycyrrhizic acid in asthmatic model rat were investigated by a selective and rapid HPLC/MS-MS method. Simultaneously, the asthma-involved cytokines including leukotrienes B4 (LTB4), thromboxane B2 (TXB2), 6-Keto-Prostaglandin F1α (6-K-PGF1α) and histamine (HIS) levels in rat plasma were determined by using ELISA. A mathematics method was applied to assess the trend of percentage rate of change among different time intervals of the seven components. The sigmoid E max function was used to establish the PK-PD modeling of MHD. The results indicated that MHD could control or ameliorate asthma. There was a hysteresis between the peaked drug concentration and maximum therapeutic effect of MHD. The PK-PD curves of MHD showed clockwise or counter-clockwise hysteresis loop. In addition, amygdalin might exert a more significant influence on regulating cytokines levels in asthmatic rats among the seven components of MHD.

Comparative pharmacokinetics and metabolites study of seven major bioactive components of Shaoyao-Gancao decoction in normal and polycystic ovary syndrome rats by ultra high pressure liquid chromatography with tandem mass spectrometry.

A simple and sensitive liquid chromatography with tandem mass spectrometry method was developed for simultaneous quantification of paeoniflorin, albiflorin, oxypaeoniflorin, liquiritin, liquiritigenin, glycyrrhetinic acid, and glycyrrhizin in rat plasma after oral administration of Shaoyao-Gancao decoction, which is traditionally used in the treatment of polycystic ovary syndrome. The plasma samples were pretreated with methanol as precipitant. The method exhibited good linearity (correlation coefficient (R2 ) > 0.99) with lower quantification limits of 0.595-4.69 ng/mL for all analytes. Intra- and interbatch precision, accuracy, recovery, and stability of the method were all within accepted criteria. The results showed that the pharmacokinetic behaviors of the seven compounds were altered in the pathological status of polycystic ovary syndrome. Furthermore, a total of 36 metabolites were structurally identified based on their accurate masses and fragment ions. The major metabolic pathway involves phase I metabolic reactions (such as hydroxylation), phase II metabolic reactions (such as sulfation and glucuronidation conjugation) as well as the combined multiple-step metabolism. This study is the first report on the pharmacokinetic and metabolic information of Shaoyao-Gancao decoction in both normal and model rats, which would provide scientific evidences for the bioactive chemical basis of herbal medicines and also promote the clinical application of Shaoyao-Gancao decoction for treating polycystic ovary syndrome.

Simultaneous Determination and Pharmacokinetic Characterization of Glycyrrhizin, Isoliquiritigenin, Liquiritigenin, and Liquiritin in Rat Plasma Following Oral Administration of Glycyrrhizae Radix Extract.

Glycyrrhizae Radix is widely used as herbal medicine and is effective against inflammation, various cancers, and digestive disorders. We aimed to develop a sensitive and simultaneous analytical method for detecting glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin, the four marker components of Glycyrrhizae Radix extract (GRE), in rat plasma using liquid chromatography-tandem mass spectrometry and to apply this analytical method to pharmacokinetic studies. Retention times for glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin were 7.8 min, 4.1 min, 3.1 min, and 2.0 min, respectively, suggesting that the four analytes were well separated without any interfering peaks around the peak elution time. The lower limit of quantitation was 2 ng/mL for glycyrrhizin and 0.2 ng/mL for isoliquiritigenin, liquiritigenin, and liquiritin; the inter- and intra-day accuracy, precision, and stability were less than 15%. Plasma concentrations of glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin were quantified for 24 h after a single oral administration of 1 g/kg GRE to four rats. Among the four components, plasma concentration of glycyrrhizin was the highest and exhibited a long half-life (23.1 ± 15.5 h). Interestingly, plasma concentrations of isoliquiritigenin and liquiritigenin were restored to the initial concentration at 4-10 h after the GRE administration, as evidenced by liquiritin biotransformation into isoliquiritigenin and liquiritigenin, catalyzed by fecal lysate and gut wall enzymes. In conclusion, our analytical method developed for detecting glycyrrhizin, isoliquiritigenin, liquiritigenin, and liquiritin could be successfully applied to investigate their pharmacokinetic properties in rats and would be useful for conducting further studies on the efficacy, toxicity, and biopharmaceutics of GREs and their marker components.

Pharmacokinetic study of the prokinetic ABCs liquiritigenin, naringenin and hesperitin following the oral administration of Si-Ni-San decoction to functional dyspepsia patients.

1. The pharmacokinetics (PKs) analysis of compounds absorbed after the oral administration of Si-Ni-San (SNS) decoction to functional dyspepsia (FD) patients was designed to detect whether the effects were similar to prokinetics administered to healthy rats, without ethical limitation. 2. First, the absorbed compounds, liquiritigenin (L), naringenin (N) and hesperitin (H) in the plasma were identified by UPLC-MS/MS following the oral administration of SNS decoction to subjects with FD. Next, the natural ratio of LNH in the SNS decoction was determined by UPLC. Third, gastric emptying and intestinal transit after the oral administration of LNH, in combination or alone, was compared with those observed after SNS administration in healthy rats. Additionally, the clinical PKs of LNH was studied. 3. The prokinetic efficacy of LNH administered at their natural ratios (7.5:5:1) increased dose-dependently and was better than the observed efficacy when administered alone in rats. Analysis of the clinical PK parameters, calculated using a one-compartment model, showed that the Cmax parameters of LNH in 3, 4 and 4 h were 639.17, 410.00 and 181.67 µg/L, respectively. 4. The clinical herbal PK analysis of the absorbed LNH preclinical prokinetic compounds, in their natural ratio from SNS, highlights the impact of an herbal translational pharmacology study.

Simultaneous Quantification of Five Flavanone Glycosides in Rat Plasma by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry: Application to a Comparative Pharmacokinetic Study of Aurantii Fructus Immaturus and Aurantii Fructus Extracts.

Background: Aurantii Fructus Immaturus (AFI) and Aurantii Fructus (AF) are two traditional citrus herbs with health-promoting and nutritive properties. Objective: This paper presents the first attempt to simultaneously investigate the absorption of five major flavanone glycosides, namely narirutin, naringin, hesperidin, neohesperidin, and poncirin, in rat plasma following a single oral administration of AFI and AF extracts to rats. Methods: The plasma concentrations were determined by liquid-liquid extraction followed by a rapid and sensitive ultra-performance LC-tandem mass spectrometry method. Pharmacokinetic parameters were analyzed by noncompartmental modeling using DAS software. Results: The developed method was validated and successfully applied to the pharmacokinetic study of these five flavanone glycosides. Conclusions: The comparison of the pharmacokinetic parameters of flavanone glycosides showed that the absorption of AF extract was lower, while the elimination was relatively rapid, compared with those of AFI extract. Highlights: This study may be useful for further utilization of these two citrus herbs.

Simultaneous quantification of fifteen compounds in rat plasma by LC-MS/MS and its application to a pharmacokinetic study of Chaihu-Guizhi decoction.

A simple, sensitive and selective high-performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method was developed and validated for simultaneous determination and pharmacokinetic study of 15 active compounds (Saikosaponin A, Baicalin, Wogonin, Glycyrrhizic acid, Glycyrrhetinic acid, Albiflorin, Paeoniflorin, Liquiritin, Isoliquiritin, Liquiritigenin, Isoliquiritigenin, Cinnamic acid, Gallic acid, Wogonoside and Oroxylin A) in rat plasma. After a feasible protein precipitation using methanol for sample preparation, chromatographic separation was carried out with a Halo® C18 column (2.1 × 100 mm, 2.7 µm) at 35 °C, water containing 0.1% formic acid and acetonitrile were used as the mobile phase with a flow rate of 0.3 mL/min. Multiple reaction monitoring (MRM) with positive and negative ion switching mode was performed for the quantification of the standards and internal standard in plasma. All the calibration curves showed good linear regression within the linear range (r2 > 0.9923). In particular, the results of the method validation including specificity, linearity, accuracy, precision, extraction recovery, matrix effect, and stability of compounds in bio-samples were all within the current acceptance criteria. The established method was successfully applied to the pharmacokinetic study of 15 compounds in rats after oral administration of CGD and laid the foundation for studying the active components and mechanism of CGD in vivo.

Phosphorus doped graphitic carbon nitride nanosheets as fluorescence probe for the detection of baicalein.

Phosphorus doped graphitic carbon nitride (P-g-C3N4) nanosheets were synthesized by calcination. P-g-C3N4 nanosheets were characterized by XRD, XPS, TEM, fluorescence, ultraviolet-visible absorption and Fourier transform infrared spectroscopy. The fluorescence of the P-g-C3N4 nanosheets was gradually quenched with the increase in the concentration of baicalein at room temperature. The proposed probe was used for the determination of baicalein in the concentration 2.0-30µM with a detection limit of 53nM. The quenching mechanism was discussed. The P-g-C3N4 nanosheets have been successfully applied for effective and selective detection of baicalein in human urine samples and blood samples.

Quantification and pharmacokinetics of alpinetin in rat plasma by UHPLC-MS/MS using protein precipitation coupled with dilution approach to eliminate matrix effects.

Alpinetin, a bioactive flavonoid, has attracted great attention due to its diverse therapeutic effects, namely anti-oxidant, anti-tumor and anti-inflammatory effects with low systemic toxicity. Various determination methods have been developed in quality control and plant chemistry areas. However, quantification and pharmacokinetics of alpinetin in biological matrix have not been studied. In the present research, a sensitive, efficient and reliable ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of alpinetin in rat plasma was developed and validated. Plasma samples were processed with protein precipitation (PP) followed by a 5-fold acetonitrile/water (50:50, v/v) dilution to significantly decrease matrix effect which exited in one step PP method. Determination of alpinetin was conducted using positive electrospray ionization tandem mass spectrometry in multiple reaction monitoring mode. Results demonstrated that the method was precise (3.3%-12.3%), accurate (-5.8% to 10.8%) and linear in the range of 1-1000 ng/mL. The new developed method was subsequently applied to a pharmacokinetic research of alpinetin following oral and intravenous dosing to healthy Sprague-Dawley rats. Alpinetin was demonstrated rapid absorption after oral administration with an absolute bioavailability of ∼15.1% and extensive distribution after dosing.

Pharmacokinetic Assessments of Liquiritin, Protocatechuic Aldehyde and Rosmarinic Acid in Rat Plasma by UPLC-MS-MS After Administration of ZibuPiyin Recipe.

The three analytes of the Traditional Chinese Medicine ZibuPiyin Recipe (ZBPYR), namely, liquiritin, protocatechuic aldehyde and rosmarinic acid, may synergistically play an important role in regulating memory and learning. However, the pharmacokinetic behaviors of these compounds after their co-administration remain unclear. To this end, a selective and sensitive ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated in rat plasma for the study of these three major bioactive ingredients in ZBPYR. The analytes in the plasma samples were separated on a Shiseido Capcell core C18 column using bendrofluazide as an internal standard, with a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid. Electrospray ionization in the negative-ion mode and multiple reaction monitoring were used to identify and quantify the three analytes. All of the calibration curves showed good linearity (r > 0.992) over the concentration range, with a lower limit of quantification of 5 ng/mL. The precision of the analytical method was evaluated by intra- and inter-day assays, and the percentage of relative standard deviation (SD) was within 15%. Satisfactory extraction efficiency (between 83.4 and 99.4%) and matrix effects (76.4-107.4) were obtained by liquid-liquid extraction. The pharmacokinetic results showed that the three bioactive ingredients were rapidly absorbed and had a short terminal half-life in rats after oral administration of ZibuPiyin recipe. This UPLC-MS-MS study method used in this study may be useful for assessing the pharmacokinetic characteristics of various compounds, which would be helpful in determining their clinical potential.

The Influence of Compatibility of Rhubarb and Radix Scutellariae on the Pharmacokinetics of Anthraquinones and Flavonoids in Rat Plasma.

BACKGROUND AND OBJECTIVES: Rhubarb-Radix scutellariae is a classic herb pair, which is commonly used to clear away heat and toxin in clinic. The aim of this study was to investigate the influence of compatibility of Rhubarb and Radix scutellariae on the pharmacokinetic behaviors of anthraquinones and flavonoids in rat plasma. METHODS: Eighteen rats were randomly divided into three groups, and were orally administered Rhubarb and/or Radix scutellariae extracts. A sensitive and rapid UPLC-MS/MS method was developed and validated to determine the concentrations of baicalin, baicalein, wogonside, wogonin, rhein, and emodin in rat plasma. The concentrations of phase II conjugates of flavonoid aglycones and anthraquinone aglycones were also determined after hydrolyzing the plasma with sulfatase. RESULTS: Compared with administration of Radix scutellariae alone, co-administration of Rhubarb significantly decreased the first maximum plasma concentration (C max1) of baicalin, wogonside, and the phase II conjugates of baicalein, wogonin to 46.40, 61.27, 41.49, and 20.50%, respectively. The area under the plasma concentration-time curve from time zero to infinity (AUC0-∞) was significantly decreased from 82.60 ± 20.22 to 51.91 ± 7.46 µM·h for rhein and 276.83 ± 98.02 to 175.42 ± 86.82 µM·h for the phase II conjugates of wogonin after compatibility. The time to reach the first maximum plasma concentration (T max1) of anthraquinones was shortened and the second peak of anthraquinones disappeared after compatibility. CONCLUSIONS: Compatibility of Rhubarb and Radix scutellariae can significantly affect the pharmacokinetic behaviors of characteristic constituents of the two herbs. The cause of these pharmacokinetic differences was further discussed combined with the in vivo ADME (absorption, disposition, metabolism, and excretion) processes of anthraquinones and flavonoids.

Evaluation of estrogenic potency of a standardized hops extract on mammary gland biology and on MNU-induced mammary tumor growth in rats.

Supplements with estrogenic activities are intensively investigated as potential alternatives for the treatment of menopausal symptoms. These investigations include studies on their safety regarding potential breast cancer risks. Therefore, the aim of this study was to assess whether or not a standardized hops (Humulus lupulus) extract, containing 0.42% of the estrogenic flavanone, 8-prenylnaringenin, would stimulate growth of methyl-nitrosourea (MNU) induced mammary cancer in ovariectomized (OVX) Sprague-Dawley (SD) rats or would impact on the proliferative activity within the normal mammary gland of Wistar rats. To induce tumorigenesis SD-rats received an intraperitoneal injection of 50mg/kg body weight of MNU on postnatal days PND 50 and 52. 28days later animals were OVX or were SHAM operated (positive control) and randomly allocated and maintained for 140days on either a phytoestrogen-free placebo diet (SHAM and negative control) or on the hops fortified diet. For the investigations in the normal mammary gland young adult Wistar rats were bilaterally OVX and randomly allocated to a control group fed to a phytoestrogen-free diet, or to a diet supplemented either with E2-benzoate or the hops extract. As a major result, the tumor incidence was 15% (3 tumors totally) in OVX controls, whereas it was 85% (39 tumors totally) in SHAM operated positive controls. No tumors were detectable in the hops group. In addition, no estrogenic activity of the hops extract was detectable in uterus and liver of these animals. In investigations on the normal mammary gland, no impact of hops extract on the expression of estrogen dependent proliferation markers or of progesterone receptor became apparent. In conclusion, the lack of growth stimulation of MNU-induced breast cancer in OVX SD-rats and the lack of stimulation proliferative events in the normal mammary gland of OVX Wistar rats by standardized hops extracts provides an important piece of evidence regarding the safety of these extracts in the management of menopausal symptoms.

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.

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.

Simultaneous determination of the bioactive components in rat plasma by UPLC-MS/MS and application in pharmacokinetic studies after oral administration of radix Scutellariae extract.

A highly sensitive and rapid ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed and validated for simultaneous quantification of the four main bioactive compounds, i.e. baicalin, baicalein, wogonoside and wogonin, in rat plasma after oral administration of Radix Scutellariae extract. Clarithromycin was used as an internal standard (IS). Plasma samples were processed by protein precipitation with methanol. The separation was performed on an Acquity BEH C18 column (100 × 2.1 mm, 1.7 µm) at a flow rate of 0.4 mL/min, using 0.1% formic acid-acetonitrile as mobile phase. The MS/MS ion transit ions monitored were 447.5 → 270.1 for baicalin, 270.1 → 168.1 for baicalein, 461.2 → 284.0 for wogonoside, 284.2 → 168.1 for wogonin and 748.5 → 158.1 for IS. Method validation was performed according to US Food and Drug Administration guidelines and the results met the acceptance criteria. The lower limit of quantification (LLOQ) achieved was 1.13 ng/mL for baicalin, 1.23 ng/mL for baicalein, 0.82 ng/mL for wogonoside and 0.36 ng/mL for wogonin. The calibration curves obtained were linear (r > 0.99) over the concentration range ~ 1-1000 ng/mL. The intra- and inter-day precision was <15% and the accuracy was within ±14.7%. After validation, this method was successfully applied to a pharmacokinetic study of Radix Scutellariae extract.

Development and validation of a sensitive and fast UPLC-MS/MS method for simultaneous determination of seven bioactive compounds in rat plasma after oral administration of Guizhi-gancao decoction.

Rapid, sensitive, selective and accurate UPLC-MS/MS method was developed and fully validated for simultaneous determination of cinnamaldehyde, cinnamic acid, 2-methoxy cinnamic acid, glycyrrhizic acid, glycyrrhetinic acid, liquiritigenin and isoliquiritin in rat plasma after oral administration of Guizhi-gancao decoction. Plasma samples were processed with a simple protein precipitation technique using acetonitrile, followed by chromatographic separation using a Thermo Hypersil GOLD C18 column. A 11.0min linear gradient elution was used at a flow rate of 0.2mL/min with a mobile phase of 0.1% acetic acid containing 0.2mM ammonium acetate in water and acetonitrile. The analytes and internal standard, schisandrin, were detected using both positive and negative ion electrospray ionization in multiple reaction monitoring mode. The developed method was validated for intra-day and inter-day accuracy and precision whose values fell in the acceptable limits. Matrix effect was found to be minimal. Recovery efficiency of all the analytes was found to be >60%. Stability results showed that the analytes were stable at all the conditions. This validated method was successfully used to study the pharmacokinetics of multiple compounds in rat plasma after oral administration of Guizhi-gancao decoction.