The Uptake and Distribution Evidence of Nano- and Microplastics in vivo after a Single High Dose of Oral Exposure / 生物医学与环境科学（英文）

OBJECTIVE@#Tissue uptake and distribution of nano-/microplastics was studied at a single high dose by gavage in vivo.@*METHODS@#Fluorescent microspheres (100 nm, 3 μm, and 10 μm) were given once at a dose of 200 mg/(kg∙body weight). The fluorescence intensity (FI) in observed organs was measured using the IVIS Spectrum at 0.5, 1, 2, and 4 h after administration. Histopathology was performed to corroborate these findings.@*RESULTS@#In the 100 nm group, the FI of the stomach and small intestine were highest at 0.5 h, and the FI of the large intestine, excrement, lung, kidney, liver, and skeletal muscles were highest at 4 h compared with the control group ( P < 0.05). In the 3 μm group, the FI only increased in the lung at 2 h ( P < 0.05). In the 10 μm group, the FI increased in the large intestine and excrement at 2 h, and in the kidney at 4 h ( P < 0.05). The presence of nano-/microplastics in tissues was further verified by histopathology. The peak time of nanoplastic absorption in blood was confirmed.@*CONCLUSION@#Nanoplastics translocated rapidly to observed organs/tissues through blood circulation; however, only small amounts of MPs could penetrate the organs.

Effect of Compatibility of Wujiwan on Pharmacokinetics and Tissue Distribution of Representative Components / 中国实验方剂学杂志

ObjectiveTo study the plasma pharmacokinetics and tissue distribution of five representative components in Wujiwan， and to illustrate the difference of metabolism and tissue distribution before and after compatibility. MethodHealthy male SD rats were divided into four groups， including Wujiwan group（A group， 62.96 g·L-1）， Coptidis Rhizoma group（B group， 38.4 g·L-1）， processed Euodiae Fructus group（C group， 5.88 g·L-1） and fried Paeoniae Radix Alba group（D group， 18.68 g·L-1）， with 65 rats in each group， and were administered the drugs according to the clinical dose of decoction pieces converted into the dose of the extracts. Then plasma， liver， small intestine and brain were taken at pharmacokinetic set time in each group after administration. Ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry was developed for the quantitative analysis of five representative components［berberine（Ber）， palmatine（Pal）， evodiamine（Evo）， rutecarpine（Rut） and paeoniflorin（Pae）］ in Wujiwan， their concentrations in plasma， liver， small intestine and brain were detected at different time， plasma samples were processed by protein precipitation， and tissue samples were pretreated by protein precipitation plus liquid-liquid extraction. Non-atrioventricular model was used to calculate the pharmacokinetic parameters of each component， and the parameters of each group were compared. ResultPharmacokinetic results of A group showed that area under the curve（AUC0-t） of the five representative components were ranked as follows：Ber and Pal were small intestine>liver>blood， Evo and Rut were liver>small intestine>plasma， Pae was small intestine>plasma， which was not detected in the liver， no other components were detected in brain except for Ber. In comparison with plasma and other tissues， peak concentration（Cmax） of Ber， Pal， Evo， and Rut were the highest and time to peak（tmax） were the lowest in the liver of A group. In plasma， the AUC0-t and Cmax of Evo and Rut were increased in A group compared with C group， tmax of Pea was elevated and its Cmax was decreased in A group compared with D group. In the liver， compared with B-D groups， Cmax values of 5 representative components except Pae were elevated， AUC0-t of Pae was decreased and AUC0-t of Evo and Rut were increased in the A group. In the small intestine， half-life（t1/2） of each representative components in A group was elevated and tmax was decreased， and Cmax of each representative ingredient except Pal was decreased， AUC0-t values of Ber and Pal were increased， whereas the AUC0-t values of Evo and Rut were decreased. ConclusionThe small intestine， as the effector organ， is the most distributed， followed by the liver. The pharmacokinetic parameters of the representative components in Wujiwan are changed before and after compatibility， which is more favorable to the exertion of its pharmacodynamic effects.

Analysis of Chemical Components and Tissue Distribution of Lujiao Formula Based on UPLC-Q-Orbitrap-MS / 中国实验方剂学杂志

ObjectiveTo qualitatively analyze the chemical constituents and their tissue distribution in Lujiao formula based on ultra performance liquid chromatography-quadrupole-electrostatic field orbitrap high resolution mass spectrometry（UPLC-Q-Orbitrap-MS）. MethodThe separation was performed on an ACQUITY UPLC® BEH C18 column（2.1 mm×100 mm， 1.7 μm） with the mobile phase of 0.1% formic acid aqueous solution（A）-methanol（B） in a gradient elution（0-2 min， 4%B； 2-6 min 4%-12%B； 6-38 min， 12%-70%B； 38-38.5 min， 70%B； 38.5-39 min， 70%-95%B； 39-43 min， 95%B； 43-43.1 min， 95%-4%B； 43.1-45 min， 4%B）， the flow rate was 0.3 mL·min-1 with the column temperature of 40 ℃ and the injection volume of 5 µL. The data were acquired by an electrospray ionization（ESI） in the full scanning mode of positive and negative ions， the scanning rang was set at m/z 100-1 500， the collision energies were 10， 20， 40 eV. Retention time， precise relative molecular mass and secondary mass spectrometry fragment ions were used to identify the compounds in Lujiao formula and analyze their tissue distribution， combing with self-established database and comparing with standard substances and published literature data. ResultA total of 260 compounds， including 156 flavonoids， 43 terpenoids， 18 coumarins， 13 organic acids， 7 phenylethanoids， 7 alkaloids and 16 others， were identified or hypothesized from Lujiao formula， 68 of which were identified by comparison with standard substances. And the results of tissue distribution showed that 100， 143， 129 and 126 prototype components were detected in blood， heart， liver and kidney， respectively. ConclusionThe chemical composition of Lujiao formula and their tissue distribution were systematic analyzed， which can provide reference for the quality control， clinical application， pharmacokinetics and pharmacodynamic material basis of Lujiao formula and its medicinal materials.

Recent advances in mass spectrometry imaging and its application in drug research / 中国药科大学学报

@#Mass spectrometry imaging (MSI), a label-free molecular imaging technique, has been applied widely in the spatial localization of small molecule metabolites, lipids, peptides, and proteins, with its unique advantage of high spatial resolving power compared to traditional liquid chromatography-mass spectrometry (LC-MS).With the nonstop advancement of its achievable sensitivity and spatial resolution, MSI technique has been providing novel perspectives into the preclinical studies of drugs, such as in vivo localization of drugs and their metabolites, visualization of drug metabolism, and drug delivery tracking.This review introduces the basics of MSI techniques, including basic principles, key features, technical advantages, and limitations, with particular highlight of the recent applications of MSI in drug efficacy and safety evaluation, drug distribution research, drug delivery research, and analysis of Chinese medicine from recent publications, aiming to promote the utilization and further expansion of MSI in the research and development of drugs.

Tissue distribution of Qingfei Paidu Decoction based on HPLC-MS/MS / 中国中药杂志

The tissue distribution of Qingfei Paidu Decoction was studied by HPLC-MS/MS in vivo. Hypersil GOLD C_(18) column(2.1 mm×50 mm, 1.9 μm) was used for gradient elution with acetonitrile as the mobile phase A and 0.1% formic acid solution as the mobile phase B. High-resolution liquid chromatography-mass spectrometry in both positive and negative ion scanning mode and multiple response monitoring(MRM) mode was employed to analyze the behaviors of the active components of Qingfei Paidu Decoction in diffe-rent tissues. The results showed that 19, 9, 17, 14, 22, 19, 24, and 2 compounds were detected in plasma, heart, liver, spleen, lung, kidney, large intestine, and brain, respectively. The compounds belonged to 8 groups, covering 14 herbs in the prescription. After administration with Qingfei Paidu Decoction, the compounds were rapidly distributed in various tissues, especially in the lung, liver, large intestine, and kidney. The majority of the compounds displayed secondary distribution. This study comprehensively analyzed the distribution rules of the main active components in Qingfei Paidu Decoction and provided a basis for the clinical application.

Pharmacokinetics and tissue distribution of four alkaloids in Ermiao Pills and Sanmiao Pills in normal and arthritic model rats / 中国中药杂志

This work aimed to investigate the differences of pharmacokinetics and tissue distribution of four alkaloids in Ermiao Pills and Sanmiao Pills in normal and arthritic model rats. The rat model of arthritis was established by injecting Freund's complete adjuvant, and ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) in the positive ion multiple reaction monitoring(MRM) mode was used for the determination of four alkaloids in plasma and tissues of normal and arthritic rats after administration of Ermiao Pills and Sanmiao Pills, respectively. The differences in pharmacokinetics and tissue distribution of the four active components were compared, and the effect of Achyranthis Bidentatae Radix on the major components of Sanmiao Pills was explored. This study established an UPLC-MS/MS for simultaneous determination of four alkaloids, and the specificity, linearity, accuracy, precision, and stability of this method all met the requirements. Pharmacokinetics study found that as compared with normal rats, the AUC and C_(max) of phellodendrine, magnoflorine, berberine and palmatine in model rats were significantly decreased after administration of Ermiao Pills, the clearance rate CL/F was significantly increased, and the distribution and tissue/plasma concentration ratio of the four alkaloids in the liver, kidney, and joint were significantly reduced. Achyranthis Bidentatae Radix increased the AUC of phellodendrine, berberine, and palmatine, reduced the clearance rate, and significantly increased the distribution of the four alkaloids in the liver, kidney, and joints in arthritic rats. However, it had no significant effect on the pharmacokinetics and tissue distribution of the four alkaloids in normal rats. These results suggest that Achyranthis Bidentatae Radix may play a guiding role in meridian through increasing the tissue distribution of effective components in Sanmiao Pills under arthritis states.

Chemical Components Distribution and Transcriptome Analysis of Different Tissues from Codonopsis pilosula / 中国实验方剂学杂志

ObjectiveThe transcriptome characteristics of different tissues of Codonopsis pilosula were analyzed to illustrate the genetic basis of the accumulation of active ingredients in the root of C. pilosula， and to provide theoretical basis for its high-quality production and cultivation. MethodDifferent tissues of C. pilosula at flowering stage were selected as experimental materials， and the contents of tangshenoside Ⅰ， lobetyolin and atractylenolide Ⅲ were detected by high performance liquid chromatography（HPLC）. RNA-Seq was used to perform transcriptome sequencing of different tissues， and the differentially expressed genes were screened and analyzed by Gene Ontology（GO） and Kyoto Gene and Encyclopedia of Genes and Genomes（KEGG） enrichment analysis， in order to explore the characteristics of active compound distribution and the transcriptional profiles. ResultThe contents of polysaccharides and tangshenoside Ⅰ in the root of C. pilosula were significantly higher than those in other tissues. The transcriptional profiles of the root were significantly different from those of stem， leaf and flower. Cluster analysis， GO and KEGG enrichment analysis of differential gene expression showed that the differential expression genes were mainly enriched in flavonoid and phenylpropanoid biosynthesis， sucrose-starch metabolism， plant hormone signal transduction， plant-pathogen interaction， mitogen-activated protein kinase（MAPK） cascade signal transduction， Adenosine triphosphate（ATP）-binding cassette（ABC） transporter and other pathways. The expression of genes related to biosynthesis of phenylpropanoid compounds were significantly up-regulated in the roots and flowers， and ABC transporter proteins were mostly highly expressed in the flowers. The expression of key enzyme genes for polysaccharide synthesis， such as sucrose：sucrose 1-fructosyltransferase（1-SST） and fructan 1-exohydrolase（1-Feh）， were significantly up-regulated in the roots， and a large number of stress-responsive genes closely related to the accumulation of secondary metabolites were significantly up-regulated in the roots. ConclusionThe active compound content and transcriptional profiles in C. pilosula roots were significantly different from those in stem， leaf， flower and other tissues， showing tissue specificity. Meanwhile， the genes related to stress response and biosynthesis of active compound， such as fructan and phenylpropanoid compounds， were up-regulated in roots of C. pilosula.

Study on the tissue distribution of eight effective components of Ziziphi Spinosae Semen aqueous extract by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry / 药学学报

The aim is to study the tissue distribution characteristics of eight effective components in normal rats after oral administration of Ziziphi Spinosae Semen (ZSS) aqueous extract. An ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) analysis method was developed and validated for the determination of four flavonoids and four saponins in rat tissue using puerarin and ginsenoside Re as the internal standard (IS), respectively. Tissue samples including the heart, liver, spleen, lung, kidney, muscle, brain, small intestine, and serum, were collected from each rat at 0.5 h, 1.0 h, and 2.0 h after oral administration of ZSS aqueous extract (15 g·kg-1). All calibration curves exhibited good linearity (r > 0.994 6) over a wide concentration range for all components. The intra-day and inter-day precisions (RSD) at four different levels were both less than 19.77%, and the accuracies (RE) ranged from -19.68% to 19.46%; The extraction recoveries of the eight components ranged from 86.70% to 114.29%, and the matrix effects were from 82.14% to 114.57%. The validated method was successfully applied to the tissue distribution study of the eight components. The levels of swertisin, spinosin, 6‴-feruloylspinosin, and kaempferol-3-O-rutinoside in the small intestine were highest, then followed by the kidney, heart, and liver. Meanwhile, the levels of jujuboside A (JuA), jujuboside B (JuB), and jujuboside A1 (JuA1) in the small intestine were highest, then followed by the lung, spleen, and kidney. The concentrations of betulinic acid in the small intestine were higher than heart, lung, kidney, and liver. The flavonoids and saponins of ZSS with extremely low content could pass through the blood-brain barrier. The research results will provide an experimental basis for explaining the mechanism of nourishing the heart and tranquilizing the mind of ZSS. The animal experimental operations involved in this study followed the regulations of the Animal Ethics Committee of Shanxi University of Chinese Medicine and passed the animal experimental ethical review (No. 2021DW172).

Study on tissue distribution of curcumin solid lipid nanoparticles in rats / 中国药房

OBJECTIVE To study the tissue distribution characteristics of curcumin solid lipid nanoparticles （Cur-SLN） in rats. METHODS Cur-SLN was prepared with microemulsion. SD rats were randomly divided into Cur raw material group and Cur- SLN group， with 45 rats in each group. The rats of two groups were injected with the corresponding drugs （by Cur， 25 mg/kg） by single intravenous injection. The heart， lung， kidney and liver tisse were separated at 0.25， 0.5， 1， 2， 4， 6， 8， 12 and 24 h after administration. The contents of Cur in different tissues were determined by high-performance liquid chromatography method. Their tissue distribution was analyzed. RESULTS The linear range of detected mass concentration of Cur in heart， lung， kidney and liver tissues were 0.064 75-129.50， 0.064 75-64.75， 0.064 75-129.50， 0.064 75-129.50 μg/mL， respectively （all r＞0.99）. The lower limits of quantitation were all 0.064 75 μg/mL， and the limit of detection were all 0.012 95 μg/mL. The intra-day and inter-day precision， accuracy and extraction recovery were in line with the requirements of quantitative analysis. Compared with Cur raw material group， the contents of Cur in heart， kidney， lung （at each time point of 0.25-24 h） and liver tissue （at each time point of 0.25-1 h， 12-24 h） of samples were significantly increased in the Cur-SLN group （P＜0.05 or P＜0.01）， while the contents of Cur in liver tissue （at each time point of 2-8 h） were significantly decreased （P＜0.01）. CONCLUSIONS After Cur was prepared into solid lipid nanoparticles， its distribution in heart， kidney and lung tissues is increased.

Mercury species analysis and tissue distribution in rats after continuous administration of Cinnabaris / 中国中药杂志

Cinnabaris is a traditional Chinese medicine(TCM) commonly used for sedation and tranquilization in clinics, and its safety has always been a concern. This study intends to investigate the species and tissue distribution of mercury in rats after continuous administration of Cinnabaris. In the experiment, 30 rats were randomly divided into the control group(equivalent to 0.5% carboxy-methyl cellulose sodium), low-dose Cinnabaris group(0.2 g·kg~(-1)), high-dose Cinnabaris group(2 g·kg~(-1)), pseudogerm-free control group(equivalent to 0.5% sodium carboxymethyl cellulose), and pseudogerm-free Cinnabaris group(2 g·kg~(-1)). They were orally administered for 30 consecutive days. Ultrasound-assisted acid extraction method combined with high performance liquid chromatography and inductively coupled plasma-mass spectrometry(HPLC-ICP-MS) was adopted to determine inorganic mercury [Hg(Ⅱ)], methylmercury(MeHg), and ethylmercury(EtHg) in different tissue, plasma, urine, and feces of rats. The optimal detection conditions and extraction methods were optimized, and the linearity(R~2>0.999 3), precision(RSD<7.0%), and accuracy(spike recoveries ranged from 73.05% to 109.5%) of all the mercury species were satisfied, meeting the requirements of analysis. The results of mercury species detection showed that Hg(Ⅱ) was detected in all the tissue of the five experimental groups, and the main accumulating organs were the intestinal tract, stomach, and kidney. MeHg existed at a low concentration in most tissue, and EtHg was not detected in all groups. In addition, pathological examination results showed that hepatocyte vacuolar degeneration, loose cytoplasm, light staining, and mononuclear cell infiltration were observed in the high-dose Cinnabaris group, low-dose Cinnabaris group, and pseudogerm-free Cinnabaris group, with slightly milder lesions in the low-dose Cinnabaris group. Hydrous degeneration of renal tubular epithelium could be seen in the high-dose Cinnabaris group and pseudogerm-free Cinnabaris group, but there was no significant difference between the other groups and the control group. No abnormal changes were found in the brain tissue of rats in each group. This paper studied the different mercury species and tissue distribution in normal and pseudogerm-free rats after continuous administration of Cinnabaris for 30 days and clarified its effects on the tissue structure of the liver, kidney, and brain, which provided supporting evidence for the safety evaluation of Cinnabaris.

Comparison of distribution of eight components from Liangxue Tuizi Mixture between normal and Henoch-Schonlein purpura rats / 中国中药杂志

This study used UPLC-TQ-MS technology to replicate a Henoch-Schonlein purpura(HSP) model in rats by administering warm drugs by gavage and injecting ovalbumin with Freund's complete adjuvant emulsion. The distribution differences and characteristics of eight major components(ferulic acid, caffeic acid, neochlorogenic acid, cryptochlorogenic acid, benzoyl oxypaeoniflorin, tracheloside, loganin, and paeoniflorin) in rat liver, lung, heart, spleen, and kidney tissues were determined after oral administration of the Liangxue Tuizi Mixture at a dose of 42 g·kg~(-1) in both normal physiological and HSP states at 0.5, 1, 2, 6, and 12 hours. The results showed that the distribution patterns of the eight components of Liangxue Tuizi Mixture in the tissues of normal and HSP model rats were different. The main component, paeoniflorin, in Moutan Cortex and Paeoniae Radix Alba had higher content in all tissues. The eight components were predominantly distributed in the liver, lung, and kidney tissues, followed by spleen and heart tissues.

Pharmacokinetics, pharmacodynamics, and tissue distribution of oral co-loaded puerarin/daidzein mixed micelles in rats / 中国中药杂志

This study investigated the drug delivery performance of oral co-loaded puerarin(PUE) and daidzein(DAZ) mixed micelles(PUE/DAZ-FS/PMMs) from the perspectives of pharmacokinetics, pharmacodynamics, and tissue distribution. The changes in PUE plasma concentration in rats were evaluated based on PUE suspension, single drug-loaded micelles(PUE-FS/PMMs), and co-loaded micelles(PUE/DAZ-FS/PMMs). Spontaneously hypertensive rats(SHR) were used to monitor systolic blood pressure, diastolic blood pressure, and mean arterial pressure for 10 weeks after administration by tail volume manometry. The content of PUE in the heart, liver, spleen, lung, kidney, brain, and testes was determined using LC-MS/MS. The results showed that compared with PUE suspension and PUE-FS/PMMs, PUE/DAZ-FS/PMMs significantly increased C_(max) in rats(P<0.01) and had a relative bioavailability of 122%. The C_(max), AUC_(0-t), AUC_(0-∞), t_(1/2), and MRT of PUE/DAZ-FS/PMMs were 1.77, 1.22, 1.22, 1.17, and 1.13 times higher than those of PUE suspension, and 1.76, 1.16, 1.08, 0.84, and 0.78 times higher than those of PUE-FS/PMMs, respectively. Compared with the model control group, PUE/DAZ-FS/PMMs significantly reduced systolic blood pressure, diastolic blood pressure, and mean arterial pressure in SHR rats(P<0.05). The antihypertensive effect of PUE/DAZ-FS/PMMs was greater than that of PUE suspension, and even greater than that of PUE-FS/PMMs at high doses. Additionally, the distribution of PMMs in various tissues showed dose dependency. The distribution of PMMs in the kidney and liver, which are metabolically related tissues, was lower than that in the suspension group, while the distribution in the brain was higher than that in the conventional dose group. In conclusion, PUE/DAZ-FS/PMMs not only improved the bioavailability of PUE and synergistically enhanced its therapeutic effect but also prolonged the elimination of the drug to some extent. Furthermore, the micelles facilitated drug penetration through the blood-brain barrier. This study provides a foundation for the development of co-loaded mixed micelles containing homologous components.

Comparison on blood-prostate barrier permeability of tanshinone extract and corresponding major monomers / 中国中药杂志

In this study, the transmittance of tanshinone Ⅱ_A(Tan Ⅱ_A) and cryptotanshinone(CTS) through the blood-prostate barrier and their distributions in the prostate tissue were compared between tanshinone extract(Tan E) treatment group and the corresponding monomer composition group under the equivalent dose conversion in vitro and in vivo. First, the human prostate epithelial cell line RWPE-1 was cultured in vitro for 21 days for the establishment of a blood-prostate barrier model, and the transmission of Tan Ⅱ_A and CTS through the barrier model was investigated after administration of Tan E and corresponding single active components. Second, SD rats were administrated with 700 mg·kg~(-1) Tan E, 29 mg·kg~(-1) CTS, and 50 mg·kg~(-1) Tan Ⅱ_A by gavage, and plasma and prostate tissue samples were collected at the time points of 2, 4, 8, 12, and 24 h. The Tan Ⅱ_A and CTS concentrations in the samples were determined. The results showed that in the cell model, the cumulative transmission amounts of CTS and Tan Ⅱ_A in the extract at each time point were higher than those of the corresponding single active components(P<0.01). In rats, after the administration of Tan E, the concentrations of Tan Ⅱ_A and CTS in rat plasma and prostate were higher than those of the corresponding single active components. This study demonstrated that the coexisting components in Tan E promoted the penetration of its main pharmacological components Tan Ⅱ_A and CTS through the blood-prostate barrier. The findings provide a theoretical and experimental basis for the application of Tan E in the clinical treatment of prostate-related diseases.

Comparative stomach tissue distribution profiles of four major bio-active components of Radix Astragali in normal and gastric ulcer mice

Numerous studies have demonstrated that Radix Astragali can inhibit gastric ulcers in mice. Anhydrous ethanol (0.01 mL/g) administered to mice by intragastric infusion can induce gastric ulcer injury. This study was performed to compare the stomach tissue distribution profiles of four major bioactive constituents of Radix Astragali(calycosin-7-O-ß-d-glucoside, calycosin, ononin and formononetin) after oral administration of extract of Radix Astragali (ERA)in normal and gastric ulcer mice. The abundance of Radix Astragali constituents was determined using an ultra-pressure liquid chromatograph with a photodiode array detector (UPLC-PDA), after which histograms were drawn. In comparison with normal mice, the contents of calycosin- 7-O-ß-d-glucoside, calycosin, ononin and formononetin in the stomach tissue samples of gastric ulcer mice showed significant differences at the selected time points (P < 0.05).The abundance of each of the four tested constituents in the normal groups was higher than that of the gastric ulcer groups. This study provides an empirical foundation for future studies focused on developing clinical applications of Radix Astragali

Absolute bioavailability,dose proportionality,and tissue distribution of rotundic acid in rats based on validated LC-QqQ-MS/MS method / 药物分析学报

Rotundic acid(RA),an ursane-type pentacyclic triterpene acid isolated from the dried barks of Ilex rotunda Thunb.(Aquifoliaceae),possesses diverse bioactivities.To further study its pharmacokinetics,a simple and sensitive liquid chromatography with triple quadrupole mass spectrometry(LC-QqQ-MS/MS)method was developed and validated to quantify RA concentration in rat plasma and tissue using etofesalamide as an internal standard(IS).Plasma and tissue samples were subjected to one-step protein precipitation.Chromatographic separation was achieved on a ZORBAX Eclipse XDB-C18 col-umn(4.6 mm×50 mm,5 μm)under gradient conditions with eluents of methanol:acetonitrile(1∶1,V/V)and 5mM ammonium formate:methanol(9∶1,V/V)at 0.5mL/min.Multiple reaction monitoring transitions were performed at m/z 487.30 → 437.30 for RA and m/z 256.10 → 227.10 for IS in the negative mode.The developed LC-QqQ-MS/MS method exhibited good linearity(2-500 ng/mL)and was fully validated in accordance with U.S.Food and Drug Administration bioanalytical guidelines.Dose proportionality and bioavailability in rats were determined by comparing pharmacokinetic data after single oral(10,20,and 40 mg/kg)and intravenous(10 mg/kg)administration of RA.Tissue distribution was studied following oral administration at 20 mg/kg.The results showed that the absolute bioavailability of RA after administration at different doses ranged from 16.1％to 19.4％.RA showed good dose proportionality over a dose range of 10-40 mg/kg.RA was rapidly absorbed in a dose-dependent manner and highly distributed in the liver.In conclusion,this study is the first to systematically elucidate the absorption and distribution characteristics of RA in rats,which can provide additional information for further development and evaluation of RA in drug metabolism and pharmacokinetic studies.

Effects of different administration methods on the pharmacokinetics and tissue distribution of ribavirin in rats / 中国临床药理学与治疗学

AIM: To establish a HPLC-QqQ-MS with multiple reaction monitoring (MRM) method for pharmacokinetics and tissue distribution study of ribavirin by oral and respiratory administration. METHODS: The experiment established a high-sensitivity LC-MS analytical method for the detection of ribavirin, and the linearity, specificity, recovery, accuracy, and precision were investigated. The established methods were used to investigate the pharmacokinetics and tissue distribution of the oral and respiratory administration methods. RESULTS: The concentration of drugs in the blood through respiratory tract administration is higher, and the drug absorption is faster. Respiratory tract administration C

Application of Matrix-assisted Laser Desorption Ionization Mass Spectrometry in Analysis of Traditional Chinese Medicine：A Comprehensive Review / 中国实验方剂学杂志

Traditional Chinese medicine （TCM）， which owns abundant chemical components and complex action pathways， has been widely recognized in the prevention and treatment of diseases. Some analysis methods have been emerged in order to ensure the quality of TCM and to develop new TCM drugs. Matrix-assisted laser desorption ionization mass spectrometry （MALDI-MS） is a soft ionization mass spectrometric technique with the advantages of high throughput， high sensitivity， low cost and so on. It provides technical support for the molecular level study on TCM. At present， this technique has been used in the field of composition analysis and metabonomics research of TCM， and plays an important role in the identification of Chinese herbal medicines， real-time molecular screening and the construction of metabolic network pathway of active ingredients. Among them， the selection of appropriate matrix and sample preparation technology is the key to ensure the detection effect of MALDI-MS. With the development and optimization of new matrix， the continuous improvement of sample preparation technology and the combination of MALDI-MS with various analytical methods will greatly improve the detection effect. Based on this， this paper discusses the application of MALDI-MS in TCM， including high-throughput detection of active ingredients in TCM， monitoring of the original medicines and their metabolites in vivo， and in situ visualization and characterization of tissue distribution information of active ingredients in TCM. It also discusses the application prospect and existing problems of MALDI-MS in TCM， so as to provide technical support for the identification of active ingredients in TCM， drug utilization and metabolism.

Effect of Acute Liver Injury on Pharmacokinetics and Tissue Distribution of Baicalin Magnesium in Rats / 中国实验方剂学杂志

ObjectiveTo establish a high performance liquid chromatography （HPLC） for simultaneous determination of baicalin magnesium and baicalein in rat plasma and tissues， and to investigate the effect of acute liver injury on pharmacokinetics and tissue distribution of baicalin magnesium in rats. MethodAcute liver injury rat model was induced by carbon tetrachloride （CCl4）. Normal rats and acute liver injury model rats were given an equal dose （287.31 mg·kg-1） of baicalin magnesium aqueous solution by intragastric administration， the orbital blood was collected at different time points， and HPLC was used to simultaneously determine the concentrations of baicalin magnesium and baicalein in rat plasma at each time point， the concentration-time curves were drawn， the pharmacokinetic parameters were calculated with DAS 3.0， and SPSS 23.0 was used for statistical analysis. After oral administration of baicalin magnesium aqueous solution， HPLC was used to simultaneously determine the contents of baicalin magnesium and baicalein in rat liver， lung， kidney， stomach， brain and small intestine at different time points， the mobile phase was 0.1% phosphoric acid aqueous solution-methanol， and the detection wavelength was 278 nm. ResultIn the acute liver injury model group， the peak concentration （Cmax） of baicalin magnesium was 0.58 times that of the normal group， the area under concentration-time curve （AUC0-t） was 0.5 times that of the normal group （P<0.05）， the apparent volume of distribution （Vd） was 2.3 times that of the normal group （P<0.05）， and baicalein is almost undetectable in plasma. The content of baicalin magnesium in liver， stomach and brain of the acute liver injury model group was higher than that of the normal group at each time point， while the content of baicalin magnesium in the samples of lung at 8 h， kidney at 8 h and 12 h， and small intestine at 0.333 h was lower than that of the normal group. The content of baicalein in lung， stomach and small intestine of the model group was higher than that of the normal group at each time point， while the content of baicalein in the tissue samples of liver at 6， 8 h and kidney at 0.333， 4， 6 h was lower than that in the normal group， and baicalein could hardly be detected in the brain. ConclusionAfter intragastric administration of the same dose of baicalin magnesium aqueous solution， acute liver injury induced by CCl4 can affect the pharmacokinetics and tissue distribution characteristics of baicalin magnesium in rats， and there is biotransformation of baicalin magnesium and baicalein in liver， lung， kidney， stomach and small intestine.

Biological fate and interaction with cytochromes P450 of the nanocarrier material, d-α-tocopheryl polyethylene glycol 1000 succinate

d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS, also known as vitamin E-TPGS) is a biodegradable amphiphilic polymer prepared by esterification of vitamin E with polyethylene glycol (PEG) 1000. It is approved by the US Food and Drug Administration (FDA) and has found wide application in nanocarrier drug delivery systems (NDDS). Fully characterizing the in vivo fate and pharmacokinetic behavior of TPGS is important to promote the further development of TPGS-based NDDS. However, to date, a bioassay for the simultaneous quantitation of TPGS and its metabolite, PEG1000, has not been reported. In the present study, we developed such an innovative bioassay and used it to investigate the pharmacokinetics, tissue distribution and excretion of TPGS and PEG1000 in rat after oral and intravenous dosing. In addition, we evaluated the interaction of TPGS with cytochromes P450 (CYP450s) in human liver microsomes. The results show that TPGS is poorly absorbed after oral administration with very low bioavailability and that, after intravenous administration, TPGS and PEG1000 are mainly distributed to the spleen, liver, lung and kidney before both being slowly eliminated in urine and feces as PEG1000. In vitro studies show the inhibition of human CYP450 enzymes by TPGS is limited to a weak inhibition of CYP3A4. Overall, our results provide a clear picture of the in vivo fate of TPGS which will be useful in evaluating the safety of TPGS-based NDDS in clinical use and in promoting their further development.

Spatial distribution characteristics of metabolities in rhizome of Paris polyphylla var. yunnanensis: based on MALDI-MSI / 中国中药杂志

In this study, a method was established for in-situ visualization of metabolite distribution in the rhizome of Paris polyphylla var. yunnanensis. To be specific, through matrix-assisted laser desorption/ionization-mass spectrometry imaging(MALDI-MSI), the spatial locations of steroidal saponins, amino acids, organic acids, phytosterols, phytoecdysones, nucleosides, and esters in rhizome of the medicinal plant were directly analyzed, and six unknown compounds with differential distribution in rhizome tissues were identified. The specific procedure is as follows: preparation of rhizome tissue section, matrix screening and optimization, and MALDI-MSI analysis. The results showed that the steroidal saponins were mainly distributed in the central, amino acids in epidermis and cortex, low-molecular-weight organic acids in central epidermis, phytosterols in the epidermis and lateral cortex, the phytoecdysones in epidermis and cortex, nucleosides(uneven distribution) in epidermis and cortex, growth hormones around the epidermis and cortex, particularly outside the cortex, and esters in cortex with unobvious difference among different tissues. In this study, the spatial distribution of meta-bolites in the rhizome of P. polyphylla var. yunnanensis was characterized for the first time. The result can serve as a reference for identifying and extracting endogenous metabolites of P. polyphylla var. yunnanensis, exploring the synthesis and metabolism mechanisms of the metabolites, and evaluating the quality of medicinal materials.