Quantitative analysis and pharmacokinetic comparison of multiple bioactive components in rat plasma after oral administration of Qi-Shen-Ke-Li formula and its single-herb extracts using ultra-high-performance liquid chromatography-tandem mass spectrometry.

Qi-Shen-Ke-Li (QSKL), a traditional Chinese formula prepared from six herbs, has long been used for the treatment of coronary heart disease and chronic heart failure. However, the herbal combination mechanism and underlying material basis of this multi-herbal formula are not clear. In this study, an ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to simultaneously determine multiple bioactive compounds in QSKL was established and validated. Using the developed method, 18 bioactive components in rat plasma after oral administration of QSKL formula and its single herb extracts were quantified. Based on these results, pharmacokinetic (PK) parameters (T1/2 , Tmax , Cmax , AUC0-48h , and AUC0-∞ ) of the 18 bioactive components were analyzed and compared using PKSlover 2.0 PK software. The experimental data suggested that significant changes in PK profiles were observed between the QSKL formula and its single-herb extracts. The herbal combination in QSKL significantly influences the system exposure and the PK behaviors of the 18 bioactive components, indicating multicomponent interactions among the herbs. This study provides insight into the herbal combination mechanism and underlying material basis of the QSKL formula.

Comparison of pulmonary availability and anti-inflammatory effect of dehydroandrographolide succinate via intratracheal and intravenous administration.

Dehydroandrographolide succinate (DAS) injection, which was approved in China for the treatment of viral pneumonia and upper respiratory tract infections, is often off-label used for nebulization therapy to avoid the adverse drug reactions associated with the injection. However, the aerodynamic properties and pulmonary fate of nebulized DAS was largely uninvestigated. In this study, the main objectives were to evaluate the in vitro aerodynamic deposition profiles of nebulizer generated aerosols and comparatively investigate the local drug availability and anti-inflammatory efficacy of DAS between intratracheal and intravenous dosing. The in vitro evaluation of aerodynamic characteristics and droplet size distribution showed more than 50% aerosol particles with size being <5 µm, allowing the aerosols to reach the lower respiratory tract. Following intratracheal administration, the drug underwent pulmonary absorption into the bloodstream, rendering an absolute bioavailability of 47.3%. Compared to the intravenous delivery, the intratracheal administration dramatically increased the drug availability in the lung tissue in rats by more than 80-fold, leading to an improved and prolonged local anti-inflammatory efficacy in a lipopolysaccharide induced lung injury model in mice. The present results demonstrated that inhalation delivery of DAS is a convenient and effective alternative to intravenous injections.

Development and application of a rapid and sensitive LC-MS/MS method for simultaneous quantification of six diterpene lactones in rats after oral administration of Rhizoma Dioscoreae Bulbiferae extract.

Diterpene lactones have been considered as the main therapeutic and hepatotoxic constituents of Rhizoma Dioscoreae Bulbiferae in recent years. In this work, a simple, rapid and accurate LC-MS/MS method was established and validated to determine six diterpene lactones in rat plasma simultaneously, including Diosbulbin B (DIOB), Diosbulbin C (DIOC), Diosbulbin D (DIOD), Diosbulbin G (DIOG), Diosbulbin J (DIOJ) and Diosbulbin L (DIOL), after oral administration of Rhizoma Dioscoreae Bulbiferae extract. The six diterpene lactones, with the inclusion of two pairs of isomer (DIOB & D, DIOC & L), and Buspirone (internal standard, IS) were successfully separated using an XDB-C18 column with the gradient elution, consisting of water with 0.1% (v/v) FA and methanol with 0.1% (v/v) FA, under a flow rate of 0.50 mL/min in 5.8 min. Precursor-product ion transitions were optimized to be m/z 362.1 → 317.1, 363.1 → 207.1, 345.0 → 299.2, 364.3 → 347.0, 396.3 → 379.3, 363.2 → 345.1 and 386.3 → 122.2 for DIOB, DIOC, DIOD, DIOG, DIOJ, DIOL and buspirone at positive ion mode with an electrospray ionization source (ESI), respectively. The linearity ranges of this present method were 0.50 to 500 µg/L for DIOB, 20.0 to 20,000 µg/L for DIOC and 2.00 to 2000 µg/L for DIOD, DIOG, DIOJ and DIOL, respectively. And the LLOQs were as low as 0.20 µg/L for DIOB, 20.0 µg/L for DIOC and 2.00 µg/L for DIOB, D, G, J and L. The accuracy of each analyte was within the range of 95.8% to 101.0% and the precision was <11.3%. No matrix effect and carry over was observed, and the recovery of the six analytes ranged from 87.3% to 109% with the RSD <11.4% within the concentrations range. The validated method was further applied to the pharmacokinetics investigation of DIOB, DIOC, DIOD, DIOG, DIOJ and DIOL successfully after oral administration of Rhizoma Dioscoreae Bulbiferae extract at 1.53 g/kg in rats.

Bioavailability of the diterpenoid 14-deoxy-11,12-didehydroandrographolide in rats and up-regulation of hepatic drug-metabolizing enzyme and drug transporter expression.

BACKGROUND: 14-Deoxy-11,12-didehydroandrographolide (deAND) is the second most abundant diterpenoid in Andrographis paniculata (Burm. f.) Nees, a traditional medicine used in Asia. To date, the biological activity of deAND has not been clearly investigated. PURPOSE: In this study, we intended to examine the modulatory effect of deAND on hepatic drug metabolism as well as its bioavailability. STUDY DESIGN: deAND prepared from A. paniculata was orally given to Sprague-Dawley rats and changes in plasma deNAD were determined by HPLC-MS. Modulation of deAND on drug-metabolizing enzyme and drug transporter expression as well as the possible mechanism involved was examined in primary rat hepatocytes. RESULTS: After a single oral administration of 50 mg/kg deAND to rats, the maximum plasma concentration (Cmax), time to reach the Cmax, area under the curve (AUC0-24h), mean retention time, and half-life (t1/2) of deAND were 2.65 ± 0.68 µg/ml, 0.29 ± 0.15 h, 6.30 ± 1.66 µg/ml•h, 5.55 ± 2.52 h, and 3.56 ± 1.05 h, respectively. The oral bioavailability was 3.42%. In primary rat hepatocytes treated with up to 10 µM deAND, a dose-dependent increase was noted in the expression of cytochrome P450 (CYP) 1A1/2, CYP2C6, and CYP3A1/2; UDP-glucuronosyltransferase (UGT) 1A1, NAD(P)H:quinone oxidoreductase (NQO1), π form of GSH S-transferase (GSTP), multidrug resistance-associated protein 2, p-glycoprotein, and organic anion transporter protein 2B1. Immunoblotting assay and EMSA revealed that deAND increases the nuclear translocation and DNA binding activity of aryl hydrocarbon receptor (AhR), pregnane X receptor (PXR), and nuclear factor erythroid-derived 2-related factor 2 (Nrf2). Knockdown of AhR and Nrf2 expression abolished deAND induction of CYP isozymes and UGT1A1, NQO1, and GSTP expression, respectively. CONCLUSION: These results indicate that deAND quickly passes through enterocytes in rats and effectively up-regulates hepatic drug-metabolizing enzyme and drug transporter expression in an AhR-, PXR-, and Nrf2-dependent manner.

Multiple modulatory activities of Andrographis paniculata on immune responses and xenograft growth in esophageal cancer preclinical models.

BACKGROUND: Esophageal cancer (EC) is a malignant gastrointestinal cancer with high morbidity worldwide and is the fourth leading cause of cancer-related deaths in China. Even though surgery and/or chemotherapy/chemoradiation might achieve good therapeutic response, recurrence rate is high due to cancer metastasis. Hence, the use of alternative adjuvant treatments, such as herbal medicines, for metastatic EC remains a great desire of the patients. Our previous studies have demonstrated the anti-metastatic efficacy of hot water extract of Andrographis paniculata (APW) in human esophageal cancer cells and tumor-bearing nude mice. PURPOSE: In the present study, the immunomodulatory activities of APW were further evaluated in human peripheral blood mononuclear cells (PBMCs) and in a carcinogen-induced esophageal tumorigenesis model using immune-competent C57BL/6 mice. Besides, the inhibitory effects of APW on esophageal cancer cell line-based xenografts and patient-derived xenografts (PDX) were examined so as to illustrate the potential multi-targeted efficacies of APW in esophageal cancer in pre-clinical models. RESULTS: In vitro results showed that APW could stimulate proliferation of PBMCs, as well as TNF-α and IFN-γproductions. In mice with 4-nitroquinoline 1-oxide-induced tumorigenesis, 21-day oral treatment with APW (1600 mg/kg) decreased the level of dysplasia in esophagus and significantly modulated the population of regulatory T cells. The cytokines productions by spleen lymphocytes of APW-treated mice were shifted towards normal resting state (i.e. unchallenged with carcinogen). Furthermore, APW treatment suppressed the growth of cell line-based xenografts by significantly increasing apoptosis in tumors, without causing severe body weight loss as chemotherapeutics did. Most importantly, the inhibitory effects of APW treatment on esophageal patient-derived xenografts growth were demonstrated for the first time. Besides, several diterpenes were detected in the plasma after oral administration of APW in mice, suggesting that multi-components of APW were bioavailable and might have contributed towards the varied pharmacological activities demonstrated in our studies. CONCLUSION: APW was shown to possess anti-tumor, anti-metastatic and immunomodulatory activities in esophageal cancer cell-based and animal models, including immunocompromised mice model and clinically relevant PDX model. Our findings illustrated the potential multi-targeted efficacies of APW in esophageal cancer management.

Determination of kaurenoic acid in rat plasma using UPLC-MS/MS and its application to a pharmacokinetic study.

Kaurenoic acid (KA), a kaurane diterpene found in several medicinal plants, is an active ingredient with potential anti-inflammatory, anticonvulsant, antibacterial and antitumor activities. In this work, an ultra-performance liquid chromatography-tandem mass spectrometry method (UPLC-MS/MS) was firstly developed and validated to quantify kaurenoic acid in rat plasma. Rhein was chosen as the internal standard (IS) and the plasma was processed with one-step acetonitrile protein precipitation; the chromatographic separation was achieved on a HSS T3 (2.1 × 50 mm, 1.8 µm) column with the mobile phase consisting of acetonitrile and water containing 0.1% formic acid via gradient elution. An electrospray ionization source was applied and operated in the negative ion and multiple reaction monitoring (MRM) modes. Kaurenoic acid and IS were quantified using the transitions of m/z 301.2→301.2 (pseudo MRM) and m/z 283.2 → 238.9, respectively. The calibration curves were linear over the range of 5∼ 100 ng/mL (R2 = 0.990). The lower limit of quantification (LLOQ) was 5 ng/mL. The intra- and inter- day precision (RSD) ranged from 3.0% to 11.4%. The matrix effect and extraction recovery were within acceptable limits. The validated method was successfully applied to the pharmacokinetic study of kaurenoic acid in rats after oral administration at three dosages.

Relationships between the Toxicities of Radix Aconiti Lateralis Preparata (Fuzi) and the Toxicokinetics of Its Main Diester-Diterpenoid Alkaloids.

The processed lateral root of Aconitum carmichaelii Deb (Aconiti Radix lateralis praeparata or Fuzi) is a potent traditional herbal medicine extensively used in treatment of cardiovascular diseases, rheumatism arthritis, and bronchitis in many Asian countries. Although Fuzi has promising therapeutic effects, its toxicities are frequently observed. Three main C19-diester-diterpenoid alkaloids (DDAs) are believed to be the principal toxins of the herb. Although toxicokinetic profiles of the toxic DDAs have already been examined in several studies, they have seldom been correlated with the toxicities of Fuzi. The current article aimed to investigate the relationship between the up-to-date toxicokinetic data of the toxic DDAs and the existing evidence of the toxic effects of Fuzi. Relationships between the cardiac toxicity and the plasma and heart concentration of DDAs in mice and rats were established. Based on our findings, clinical monitoring of the plasma concentrations of DDAs of Fuzi is recommended to prevent potential cardiac toxicities. Additionally, caution with respect to potential hepatic and renal toxicity induced by Fuzi should be exercised. In addition, further analyses focusing on the preclinical tissue distribution profile of DDAs and on the long-term toxicokinetic-toxicity correlation of DDAs are warranted for a better understanding of the toxic mechanisms and safer use of Fuzi.

Investigation of potential toxic components based on the identification of Genkwa Flos chemical constituents and their metabolites by high-performance liquid chromatography coupled with a Q Exactive high-resolution benchtop quadrupole Orbitrap mass spectrometer.

Genkwa Flos, a famous traditional Chinese medicine has been reported to have significant hepatotoxicity. A high-throughput and reliable method was established to explore potential toxic components by high-performance liquid chromatography coupled with a Q Exactive high-performance benchtop quadrupole-Orbitrap mass spectrometer. A total of 68 compounds including 22 chemical components and 46 metabolites were tentatively identified based on the accurately measured mass value, retention time, and fragmentation pattern. Besides, the metabolic pathways of main components in Genkwa Flos were also illustrated. The results indicated that hydroxylation, demethylation, methylation, glucuronidation, sulfation, cysteine conjugation, and glutathione conjugation participated in the metabolic reactions of Genkwa Flos. Moreover, 12 Genkwa Flos chemical components and 26 metabolites were detected in cell lysate, which were considered as the bound components to HL-7702 cells. In view of cell affinity theory, these compounds were preliminarily deduced to be potential toxic ingredients for the hepatotoxicity induced by Genkwa Flos. The results demonstrated that the developed method was a very feasible and efficient approach for the components identification even in the complex matrix. In conclusion, this study will provide a deep insight into the toxic substances of Genkwa Flos and lay a chemical basis for in-depth toxic studies on Genkwa Flos hepatotoxicity.

Simultaneous determination of phenolic acids and diterpenoids and their comparative pharmacokinetic study in normal and acute blood stasis rats by UFLC-MS/MS after oral administration of Guan-Xin-Shu-Tong capsules.

Guan-Xin-Shu-Tong capsules are one of the well-known and first-line Chinese traditional herbal formula for treating coronary heart disease. A validated and sensitive method via ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) was established to simultaneously determinate five phenolic acids and four diterpenoids in rats in order to investigate their pharmacokinetic profiles firstly. Analytes were extracted by ethyl acetate and determined via multiple reaction monitoring mode in both positive and negative ion modes. The values for limit of quantification were in range of 0.025-1.250ng/ml. Inter- and intra-day precisions were no more than 10.9% with accuracy of -11.0%-10.6%, meanwhile the stable and suitable extraction recoveries were also obtained. And finally such excellent method was used to compare the pharmacokinetics of nine compounds in normal and acute blood stasis rats after oral administration of Guan-Xin-Shu-Tong capsules.

A Combination of Coffee Compounds Shows Insulin-Sensitizing and Hepatoprotective Effects in a Rat Model of Diet-Induced Metabolic Syndrome.

Since coffee may help to prevent the development of metabolic syndrome (MetS), we aimed to evaluate the short- and long-term effects of a coffee-based supplement on different features of diet-induced MetS. In this study, 24 Sprague Dawley rats were divided into control or nutraceuticals groups to receive a high-fat/high-fructose diet with or without a mixture of caffeic acid (30 mg/day), trigonelline (20 mg/day), and cafestol (1 mg/day) for 12 weeks. An additional 11 rats were assigned to an acute crossover study. In the chronic experiment, nutraceuticals did not alter body weight or glycemic control, but improved fed hyperinsulinemia (mean difference = 30.80 mU/L, p = 0.044) and homeostatic model assessment-insulin resistance (HOMA-IR) (mean difference = 15.29, p = 0.033), and plasma adiponectin levels (mean difference = -0.99 µg/mL, p = 0.048). The impact of nutraceuticals on post-prandial glycemia tended to be more pronounced after acute administration than at the end of the chronic study. Circulating (mean difference = 4.75 U/L, p = 0.014) and intrahepatocellular alanine transaminase activity was assessed by hyperpolarized-13C nuclear magnetic resonance NMR spectroscopy and found to be reduced by coffee nutraceuticals at endpoint. There was also a tendency towards lower liver triglyceride content and histological steatosis score in the intervention group. In conclusion, a mixture of coffee nutraceuticals improved insulin sensitivity and exhibited hepatoprotective effects in a rat model of MetS. Higher dosages with or without caffeine deserve to be studied in the future.

Relationship between blood toxin level and clinical features in patients with grayanotoxin poisoning - six clinical cases.

BACKGROUND: The purpose of this study was to investigate grayanotoxin (GTX) levels in the blood of patients with GTX intoxication and in the consumed Rhododendron liqueur, and to determine whether there was an association between blood GTX level and the patient's clinical status. METHODS: In September 2015, six patients were concurrently presented to the emergency department with various toxicity symptoms, which occurred after the consumption of Rhododendron liqueur at the same toxin concentration. Liquid chromatography-tandem mass spectrometry analysis was conducted on blood samples obtained from six cases of GTX intoxication treated in our emergency department. RESULTS: At the initial evaluation in the emergency department, the mean arterial pressure of the patients ranged from 36.7 to 76.7 mm Hg. The concentrations of GTX-I and GTX-III in Rhododendron liqueur were 1.436 and 16.907 ng/mL, respectively. The initial blood GTX-III and GTX-I levels ranged from 2.9 to 58.0 ng/mL and the lower limit of quantification (LLOQ) to 8.33 ng/mL, respectively. After 20 h, the mean arterial pressure ranged from 76.7 to 93.3 mm Hg, while the blood GTX-III and GTX-I levels ranged from the LLOQ to 17.8 and 2.52 ng/mL, respectively. DISCUSSION: We estimated that the minimum blood GTX-III and GTX-I levels that caused hypotension were between 17.83 and 27.3 ng/mL, and 2.52 and 4.55 ng/mL, respectively.

Determination and Pharmacokinetic Study of Three Diterpenes in Rat Plasma by UHPLC-ESI-MS/MS after Oral Administration of Rosmarinus officinalis L. Extract.

Rosmarinus officinalis L. is commonly used as a spice and flavoring agent. Diterpenes are the main active compounds of R. officinalis. An Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-ESI-MS/MS) method was developed for the determination of carnosol, rosmanol, and carnosic acid isolated from R. officinalis in rat plasma, and applied to a pharmacokinetic study after oral administration of R. officinalis extract. Sample preparation involved a liquid-liquid extraction of the analytes with ethyl acetate. Butylparaben was employed as an internal standard (I.S.). Chromatographic separation was carried out on a C18 column (ACQUITY UPLC® HSS T3, 1.8 µm, 2.1 mm × 100 mm) with a gradient system consisting of the mobile phase solution A (0.1% formic acid in water) and solution B (acetonitrile) at the flow rate of 0.3 mL/min. The quantification was obtained using multiple reaction monitoring (MRM) mode with electrospray ionization (ESI). The UHPLC-MS/MS assay was validated for linearity, accuracy, precision, extraction recovery, matrix effect and stability. This study described a simple, sensitive and validated UHPLC-MS/MS method for the simultaneous determination of three diterpene compounds in rat plasma after oral administration of R. officinalis extract, and investigated on their pharmacokinetic studies as well.

A Simple and Sensitive LC-MS/MS Method for Determination of Four Major Active Diterpenoids from Andrographis paniculata in Human Plasma and Its Application to a Pilot Study.

Andrographis paniculata contains four major active diterpenoids, including andrographolide (1), 14-deoxy-11, 12-didehydroandrographolide (2), neoandrographolide (3), and 14-deoxyandrographolide (4), which exhibit differences in types and/or degrees of their pharmacological activity. Previous pharmacokinetic studies in humans reported only the parameters of compound 1 and its analytical method in human plasma. The purpose of this study was to develop a simple, sensitive, and selective liquid chromatography tandem-mass spectrometry technique for the simultaneous determination of all four major active diterpenoids in the A. paniculata product in human plasma. These four diterpenoids in plasma samples were extracted by a simple protein precipitation method with methanol and separated on a Kinetex C18 column using a gradient system with a mobile phase of acetonitrile and water. The liquid chromatography tandem-mass spectrometry was performed in the negative mode, and the multiple reaction monitoring mode was used for the quantitation. The method showed a good linearity over a wide concentration range of 2.50-500 ng/mL for 1 and over the range of 1.00-500 ng/mL for the other diterpenoids with a correlation coefficient R(2) > 0.995. The lower limit of quantification of 1 was found to be 2.50 ng/mL, while those of the other diterpenoids were 1.00 ng/mL. The intraday and interday accuracy (relative error) ranged from 0.03 % to 10.03 %, and the intraday and interday precisions (relative standard deviation) were in the range of 2.05-9.67 %. The extraction recovery (86.54-111.56 %) with a relative standard deviation of 2.78-8.61 % and the matrix effect (85.15-112.36 %) were within the acceptance criteria. Moreover, these four major active diterpenoids were stable in plasma samples at the studied storage conditions with a relative error ≤-9.79 % and a relative standard deviation ≤ 9.26 %. Hence, this present method was successfully validated and used in the pilot study to determine the pharmacokinetic parameters of all four major active diterpenoids in human plasma after multiple oral doses of the A. paniculata product were administered to a healthy, Thai female volunteer.

Development and validation of an LC-MS/MS method for the determination of bullatine A in rat plasma: application to a pharmacokinetic study.

Bullatine A is a diterpenoid alkaloid of Xue-Shang-Yi-Zhi-Hao (Aconitum brachypodum), which is widely used in traditional Chinese medicine for the treatment of rheumatism and pain. The plasma levels of bullatine A were measured by a rapid and sensitive LC-MS/MS method. Samples were prepared using acetonitrile precipitation and the separation of bullatine A was achieved on a Capcell Pak MG-C18 column by isocratic elution using acetonitrile (phase A) and 0.1% formic acid (phase B, pH 4.0; A:B, 30:70, v/v) as the mobile phase at a flow rate of 0.5 mL/min. Detection was performed on a triple-quadrupole tandem mass spectrometer by multiple-reaction monitoring of the transitions at m/z 344.2 → 105.2 for bullatine A and m/z 256.2 → 167.1 for the internal standard. The linearity was found to be within the concentration range of 1.32-440 ng/mL with a lower limit of quantification of 1.32 ng/mL. Only 1.3 min was needed for an each analytical run. This method was successfully applied in the determination of the active component bullatine A in rat plasma after intramuscular administration of A. brachypodum injection.

Identification of chemical constituents and rat metabolites of Kangxianling granule by HPLC-Q-TOF-MS/MS.

A high-performance liquid chromatography coupled with quadrupole time-of-flight mass tandem mass spectrometry method was established to characterize the chemical constituents of Kangxianling granule (KXL), a traditional Chinese medicine formula, and the metabolic profile in rat urine and plasma after oral administration of KXL. A total of 27 compounds in KXL extract and 13 prototype compounds with 12 metabolites in rat urine and plasma were identified. Among the 27 detected compounds, 15 were identified by comparing the retention time and MS data with that of reference compounds and the other 12 compounds were tentatively assigned based on the MS data and reference literature. The main prototype components absorbed in rat were amygdalin, salvianolic acid B, tanshinones and anthraquinones. Hydroxylation, glucuronidation and sulfation were the principal metabolic pathways in rat. The results revealed that the 25 compounds identified in rat urine and plasma were the potential active ingredients of KXL, which provides helpful chemical information for further study of the pharmacology mechanism of KXL.

Simultaneous determination of andrographolide, dehydroandrographolide and neoandrographolide in dog plasma by LC-MS/MS and its application to a dog pharmacokinetic study of Andrographis paniculata tablet.

In this study, a sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously determinate andrographolide (AP), dehydroandrographolide (DP), and neoandrographolide (NP) in plasma of beagle dogs after oral administration of Andrographis paniculata tablet (A. paniculata). The analytes and bilobalide (internal standard) were separated on an Agilent ZORBAX XDB-C18 column (50mm×2.1mm, 3.5µm) by using gradient elution consisting of methanol and water at a flow rate of 0.50mL/min in 7min. Multiple reaction monitoring (MRM) mode was performed to quantify data under monitoring precursor-product ion transitions of m/z 348.8→286.9, 330.9→107.9, 479.1→160.8 and 325.0→163.0 for AP, DP, NP and internal standard (IS) at negative ion mode, respectively. This method was developed at linearity ranging from 0.50 to 250ng/mL for AP, 1.00 to 500ng/mL for DP and 0.20 to 100ng/mL for NP. The accuracy of each analyte ranged between 94.8% and 107.1% and the precision was within 14.6%. No significant matrix effect was observed. AP, DP and NP were stable during sample storage, preparation and analytic procedures. Furthermore, this method was successfully applied in the investigation of the pharmacokinetic profile of AP, DP and NP in beagle dogs after oral administration of A. paniculata tablet (49.5mg for AP, 7.0mg for DP, 22.0mg for NP). Biological half-life (t1/2) was 2.08±0.99, 3.13±1.19 and 1.07±0.38h for AP, DP and NP, respectively. The areas under curves (AUC0-t) of AP, DP and NP was 494.50±150.64, 26.01±8.72 and 78.78±18.29ngh/mL, respectively.

Matrix effect and optimization of LC-MSn determination of trachylobane-360 in mice blood.

Xylopia langsdorffiana A. St.-Hil. & Tul. (Annonaceae) is popularly known as "pimenteira-da-terra". Various constituents have been isolated from this species, including diterpenes, such as 8(17), 12E, 14-labdatrien-18-oic acid, ent-atisan-7α, 16α-diol (xylodiol), ent-7α-hydroxytrachyloban-18-oic acid (trachylobane-318) and ent-7α-acetoxytrachyloban-18-oic acid, a crystalline solid with a molecular weight of 360 and molecular formula of C22H32O4 (trachylobane-360). When administered intraperitoneally to mice, trachylobane-360 (T-360) significantly inhibits growth of the solid tumor sarcoma 180 transplanted in mice, without causing alterations in biochemical, hematological and histopathological parameters that are frequently associated with the clinical use of antineoplastic. Furthermore, this diterpene blocks voltage-dependent calcium channels (Cav), showing spasmolytic activity. The present study shows that variables such as extraction solvent (methanol, acetonitrile and chloroform), centrifugation force (1000, 7000 and 14,000×g), and centrifugation time (5, 15 and 25min), are important in the liquid-liquid extraction of T-360 from male Swiss mice blood in HPLC-MSn studies. The study confirms matrix influence on recovery and detection of T-360. The recovery for T-360 was 37.02% using chloroform as better extractor solvent, while centrifuged at 14,000×g for 15min demonstrated the importance of the parameters chosen for the extraction/recovery process of analyte. The effect of mice blood matrix for T-360 was -51.23%. This method was optimized by repeating the extraction procedure and acidification of samples. These conditions were essential in increasing recovery (49.47%) by decreasing the matrix effect (-37.60%). The efficiency of the process, after optimization with two extractions and acidification, increased by 14.19% when compared to the initial method, from 18.05% to 32.24%. According to Marchi et al. (2010), the matrix effect does not necessarily need to be reduced or eliminated, but it does need to be identified and quantified. Therefore, these findings are essential for the subsequent evaluation of the pharmacokinetic parameters of this promising natural product.

Development and validation of a UHPLC-qTOF-MS method for quantification of fuziline in rat plasma and its application in a pharmacokinetic study.

A specific and sensitive UHPLC-qTOF-MS method was developed and validated for quantification of fuziline in rat plasma after oral administration of three dosages. The analyte was separated on an Acquity UPLC BEH C18 column with a total running time of 3 min using a mobile phase of 0.1% formic acid aqueous solution and methanol (80:20, v/v) at a flow-rate of 0.25 mL/min. The calibration curves for fuziline showed good linearity in the concentrations ranging from 1 to 200 ng/mL with correlation coefficients >0.997. The precision, accuracy, recovery and stability were deemed acceptable. The method was applied to a pharmacokinetics study of fuziline in rats. The mean half-life was 5.93, 6.13 and 5.12 h for 1, 2 and 4 mg/kg oral administration of fuziline, respectively. The peak concentration and area under the concentration-time curve increased linearly with the doses. The sum of these results indicated that, in the range of the doses examined, the pharmacokinetics of fuziline in rat was based on first-order kinetics.

LC-ESI-MS/MS analysis and pharmacokinetics of jolkinolide B, a potential antitumor active component isolated from Euphorbia fischeriana, in rat plasma.

A simple, specific and reproducible liquid chromatography-electrospray ionization mass spectrometry was developed and validated for the determination of jolkinolide B, a potential antitumor active component isolated from Euphorbia fischeriana, in rat plasma. Chromatographic separation was achieved on a Venusil MP-C18 column using an isocratic elution. Jolkinolide B and osthole (internal standard) were monitored by positive electrospray ionization in the selected reaction monitoring mode. Good linearity (r(2) > 0.996) was achieved by a weighted (1/x(2) ) linear least-squares regression over a concentration range of 6.50-2600 ng/mL. The accuracy and precision of the assay were satisfactory and the method proved to be applicable to pharmacokinetics following a single intravenous bolus injection of jolkinolide B to rats.

[Studies on absorption kinetics characteristics of diterpenoid alkaloids in rats after oral administration of Sini Tang powder].

The purpose of this study was to investigate the absorption kinetics of aconitine, mesaconitine and hypaconitine in rats after oral administration of Sini Tang powder. With cannulate portal and jugular veins cannulated (double-cannulate), conscious moving rats were orally administered Sini Tang. Then samples of portal and systemic blood were collected at the designated periods of time and analyzed for aconitine, mesaconitine and hypaconitine by HPLC. Apparent absorption coefficient of aconitine, mesaconitine and hypaconitine was caculated respectively. The results indicated that the apparent absorption coefficient of aconitine, mesaconitine and hypaconitine come from Sini Tang were 0. 336, 0. 090, 0. 176, respectively, which had some differences among them. It was also suggested that double-cannulated rat was useful for estimating the absorption kinetics of aconitine, mesaconitine and hypaconitine after orally administered Sini Tang by determining the AUC values for drugs in portal and systemic blood samples. The three alkaloids could all be detected in blood, but the absorption differences were existed among the three alkaloids.