BrABF3 promotes flowering through the direct activation of CONSTANS transcription in pak choi.

Drought stress triggers the accumulation of the phytohormone abscisic acid (ABA), which in turn activates the expression of the floral integrator gene CONSTANS (CO), accelerating flowering. However, the molecular mechanism of ABA-induced CO activation remains elusive. Here, we conducted a yeast one-hybrid assay using the CO promoter from Brassica campestris (syn. Brassica rapa) ssp. chinensis (pak choi) to screen the ABA-induced pak choi library and identified the transcription activator ABF3 (BrABF3). BrABF3, the expression of which was induced by ABA in pak choi, directly bound to the CO promoter from both pak choi and Arabidopsis. The BrABF3 promoter is specifically active in the Arabidopsis leaf vascular tissue, where CO is mainly expressed. Impaired BrABF3 expression in pak choi decreased BrCO expression levels and delayed flowering, whereas ectopic expression of BrABF3 in Arabidopsis increased CO expression and induced earlier flowering under the long-day conditions. Electrophoretic mobility shift assay analysis showed that BrABF3 was enriched at the canonical ABA-responsive element-ABRE binding factor (ABRE-ABF) binding motifs of the BrCO promoter. The direct binding of BrABF3 to the ABRE elements of CO was further confirmed by chromatin immunoprecipitation quantitative PCR. In addition, the induction of BrCO transcription by BrABF3 could be repressed by BrCDF1 in the morning. Thus, our results suggest that ABA could accelerate the floral transition by directly activating BrCO transcription through BrABF3 in pak choi.

Cold acclimation can specifically inhibit chlorophyll biosynthesis in young leaves of Pakchoi.

BACKGROUND: Leaf color is an important trait in breeding of leafy vegetables. Y-05, a pakchoi (Brassica rapa ssp. chinensis) cultivar, displays yellow inner (YIN) and green outer leaves (GOU) after cold acclimation. However, the mechanism of this special phenotype remains elusive. RESULTS: We assumed that the yellow leaf phenotype of Y-05 maybe caused by low chlorophyll content. Pigments measurements and transmission electron microscopy (TEM) analysis showed that the yellow phenotype is closely related with decreased chlorophyll content and undeveloped thylakoids in chloroplast. Transcriptomes and metabolomes sequencing were next performed on YIN and GOU. The transcriptomes data showed that 4887 differentially expressed genes (DEGs) between the YIN and GOU leaves were mostly enriched in the chloroplast- and chlorophyll-related categories, indicating that the chlorophyll biosynthesis is mainly affected during cold acclimation. Together with metabolomes data, the inhibition of chlorophyll biosynthesis is contributed by blocked 5-aminolevulinic acid (ALA) synthesis in yellow inner leaves, which is further verified by complementary and inhibitory experiments of ALA. Furthermore, we found that the blocked ALA is closely associated with increased BrFLU expression, which is indirectly altered by cold acclimation. In BrFLU-silenced pakchoi Y-05, cold-acclimated leaves still showed green phenotype and higher chlorophyll content compared with control, meaning silencing of BrFLU can rescue the leaf yellowing induced by cold acclimation. CONCLUSIONS: Our findings suggested that cold acclimation can indirectly promote the expression of BrFLU in inner leaves of Y-05 to block ALA synthesis, resulting in decreased chlorophyll content and leaf yellowing. This study revealed the underlying mechanisms of leaves color change in cold-acclimated Y-05.

Dendrobium officinale Attenuates Myocardial Fibrosis via Inhibiting EMT Signaling Pathway in HFD/STZ-Induced Diabetic Mice.

Cardiac fibrosis is a major contributor for diabetic cardiomyopathy and Dendrobium officinale possessed therapeutic effects on hyperglycemia and diabetic cardiomyopathy. To further investigate the possible mechanisms of the Dendrobium officinale on diabetic myocardial fibrosis in mice. Water-soluble extracts of Dendrobium officinale (DOE) from dry stem was analyzed by HPLC and phenol-sulfuric acid method. Diabetic mice were induced by intraperitoneal injection of streptozotocin (STZ) (30 mg/kg) for 4 consecutive days after intragastric administration of a high-fat diet (HFD) for 2 weeks. The groups were as follows: control group, model group, DOE low, medium, high dose group (75, 150, 300 mg/kg) and Metformin positive group (125 mg/kg). The results showed that DOE dose-dependently lower serum insulin, total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and grew the high-density lipoprotein cholesterol (HDL-C) after 12 weeks of daily administration with DOE. Hematoxylin-eosin staining and Sirius red staining showed obvious amelioration of cardiac injury and fibrosis. In addition, the result of immunoblot indicated that DOE increased the expression of peroxisome proliferator activated receptor-α (PPAR-α), phosphorylation of insulin receptor substrate 1 (p-IRS1) and E-cadherin and repressed the expression of transforming growth factor ß1 (TGF-ß1), phosphorylation of c-Jun N-terminal kinase (p-JNK), Twist, Snail1 and Vimentin. The present findings suggested that DOE ameliorated HFD/STZ-induced diabetic cardiomyopathy (DCM). The possible mechanism mainly associated with DOE accelerating lipid transport, inhibiting insulin resistant and suppressing fibrosis induced by epithelial mesenchymal transition (EMT).

Preparation of tilmicosin-resin complex microsphere and its Pharmacokinetics study in rat.

The objective of this study is to mask the extremely bitter taste of tilmicosin, and the tilmicosin-resin complex (DRC) microsphere were prepared by entrapping tilmicosin into resins (Tulsion® 339 and Eudragit® RS/ RL 100) for further pharmacokinetics study in rat. The DRC was characterized by FTIR and X-ray diffraction, and the microsphere containing DRC and Eudragit® RS/RL 100 were characterized by scanning electron microscopy (SEM). The rats were orally administrated with tilmicosin phosphate (10 mg/kg) and the microsphere containing the same dose of tilmicosin, respectively. These microspheres do not taste bitter and the kinetics study suggests that the drug released from microsphere meet the first order kinetics (r = 0.9911). The experimental results showed that T½ and Tmax of microsphere were much longer than tilmicosin phosphate, which indicates that the oral microsphere can be a promising long-active formulation for taste masking of tilmicosin.

Potential Biomarkers in Diagnosis of Human Gastric Cancer.

The high incidence of gastric cancer (GC) and its consequent mortality rate severely threaten human's health. It is not frequently diagnosed until a relatively advanced stage. Surgery is the only potentially curative treatment. Thus, early screening and diagnosis are critical for patients with GC. The tumor marker assays used currently for detecting GC are simple and rapid, but the usage is limited by its low sensitivity and specificity. Here, we provide a brief description of some new potential markers and new biotechnological methods for the diagnosis of GC, hoping to find out more effective approaches for early detection of GC.

Absorption properties and effects of caffeic acid phenethyl ester and its p-nitro-derivative on P-glycoprotein in Caco-2 cells and rats.

CONTEXT: Caffeic acid phenethyl ester (CAPE), isolated from honeybee propolis, has pharmacological applications. A synthesized CAPE derivative, p-nitro-caffeic acid phenethyl ester (CAPE-NO2), showed similar activities with CAPE. The pharmacological activities of CAPE and CAPE-NO2 are related to their absorption properties. OBJECTIVE: To understand the pharmacokinetic profiles of CAPE and CAPE-NO2 in rats and investigate the absorption mechanisms and effects on P-glycoprotein in Caco-2 cells. MATERIALS AND METHODS: The pharmacokinetic profiles of CAPE and CAPE-NO2 were obtained after oral administration (10 mg/kg) to rats. Transport studies of CAPE and CAPE-NO2 (5, 10, 20 µM) were performed in Caco-2 cell model. P-gp activities were assayed by rhodamine 123 cellular retention. Expression of P-gp was determined after the cells were administrated with CAPE and CAPE-NO2 (5, 20 µM) for 48 and 72 h. RESULTS: The AUC(0-t) of CAPE-NO2 (3239.9 ± 352 ng × h/mL) was two-time greater than CAPE (1659.6 ± 152 ng × h/mL) in rats. The Papp values of CAPE and CAPE-NO2 were (4.86 ± 0.90) × 10-6 cm/s and (12.34 ± 1.6) × 10-6 cm/s, respectively. The accumulation of rhodamine 123 was increased by 1.3- to 1.9-fold and 1.4- to 2.3-fold in CAPE and CAPE-NO2 groups after 1 h administration, respectively. However, CAPE and CAPE-NO2 increased the P-gp levels by 2.1- and 1.7-fold, respectively. CONCLUSION: The absorption of CAPE-NO2 can be enhanced in rats and Caco-2 cells compared with CAPE. The two compounds are potential inhibitors of P-gp. The increased P-gp levels generated by CAPE and CAPE-NO2 played a role as a defense mechanism by limiting intracellular xenobiotic levels.

A CAPE analogue as novel antiplatelet agent efficiently inhibits collagen-induced platelet aggregation.

OBJECTIVE: Platelet activation plays a pivotal role in the pathogenesis of thrombosis, which can lead to fatal diseases such as myocardial or cerebral infarction, and atherosclerosis. The present study focused on investigating the effect of CAPE-NO2 against collagen-induced platelet aggregation. METHODS: Caffeic acid phenethyl ester (CAPE) is an active component in propolis. CAPE-NO2 is a nitro derivative of CAPE. Its effects on rat platelet aggregation induced by collagen were tested in vitro and the potential mechanisms underlying the activities were investigated. RESULTS: CAPE-NO2 significantly inhibited collagen-induced platelet aggregation in a concentration-dependent manner. It also reduced TXB2 formation and COX-1 activity in collagen-activated platelets. Moreover, CAPE-NO2 caused an increase in NO production and cGMP levels and attenuated 5-HT release in the collagen-activated platelets. CONCLUSION: These findings suggest that the inhibitory mechanism of CAPE-NO2 on collagen-induced platelet aggregation might be associated with the down-regulation of TXB2, COX-1 and 5-HT and the elevation of NO and cGMP production. These indicators are closely related to platelet function. So CAPE-NO2 may be a promising candidate for the extension of the current spectrum of antiplatelet drugs.

Are cities under bright lights more innovative? Evidence from China.

The prosperity of the nighttime economy is an important criterion for measuring urban development. Based on regression analysis of data from 330 prefecture-level cities in China, this study explores the potential link between urban lighting and urban innovation capacity. The results show that the relationship between nighttime light intensity and urban innovation capacity follows an inverted U-shaped curve. Moreover, urban nighttime light stability moderates the above relationship. In addition, the heterogeneity analysis indicates that low population density, weak economic foundation, and high administrative grade weaken the relationship between lighting intensity and urban innovation capacity. Finally, the mechanism analysis suggested that the inverted U-shaped relationship between urban lighting and innovation capacity may be caused by the encroachment of the service industry and the loss of urban attractiveness. By exploring the proxy effect of nighttime lighting on urban innovation, this study reveals the imbalance between extrinsic image and the intrinsic capacity of cities, which not only extends the research on urban construction and development but also provides guidance for local governments concerning how to achieve all-round coordination of cities.

Physical Adversarial Attack Meets Computer Vision: A Decade Survey.

Despite the impressive achievements of Deep Neural Networks (DNNs) in computer vision, their vulnerability to adversarial attacks remains a critical concern. Extensive research has demonstrated that incorporating sophisticated perturbations into input images can lead to a catastrophic degradation in DNNs' performance. This perplexing phenomenon not only exists in the digital space but also in the physical world. Consequently, it becomes imperative to evaluate the security of DNNs-based systems to ensure their safe deployment in real-world scenarios, particularly in security-sensitive applications. To facilitate a profound understanding of this topic, this paper presents a comprehensive overview of physical adversarial attacks. Firstly, we distill four general steps for launching physical adversarial attacks. Building upon this foundation, we uncover the pervasive role of artifacts carrying adversarial perturbations in the physical world. These artifacts influence each step. To denote them, we introduce a new term: adversarial medium. Then, we take the first step to systematically evaluate the performance of physical adversarial attacks, taking the adversarial medium as a first attempt. Our proposed evaluation metric, hiPAA, comprises six perspectives: Effectiveness, Stealthiness, Robustness, Practicability, Aesthetics, and Economics. We also provide comparative results across task categories, together with insightful observations and suggestions for future research directions.

Effect of diallyl trisulfide derivatives on the induction of apoptosis in human prostate cancer PC-3 cells.

The effects of five derivatives of diallyl trisulfide (DATS) were investigated on apoptosis in prostate cancer PC-3 cells, including dibutenyl trisulfide (DBTS), bis(2-methylallyl) trisulfide (2-M-DATS), dipentenyl trisulfide (DPTS), bis(3-methylbut-2-enyl) trisulfide (3-M-DBTS), and dihexenyl trisulfide (DHTS). Our present study demonstrated that DATS derivatives can suppress proliferation of PC-3 cells in a dose- and time-dependent manner, and that a change in the DATS structure could have an impact on its biological activity in the following order: 2-M-DATS > DBTS ≈ DPTS ≈ DATS > 3-M-DBTS ≈ DHTS. Typical apoptotic nuclei were shown by Hoechst 33342 staining with 80 µM concentrations of DATS derivatives for 24 h. And flow cytometric analysis and DNA fragmentation assay also demonstrated that DATS derivatives induced apoptosis in PC-3 cells. Meanwhile, experimental results showed that DBTS, 2-M-DATS, and DPTS cause G2-M phase cell cycle arrest. Furthermore, a series of apoptosis-associated features were observed, which include a notable decrease in the expression of procaspases-3, up-regulation of pro-apoptotic proteins Bax expression, and down-regulation of anti-apoptotic proteins Bcl-2 expression in PC-3 cells. All of the evidences above indicate that DATS derivatives suppressed proliferation of PC-3 cells which was associated with the induction of apoptosis regulated by Bax/Bcl-2.

Synthesis of 2H-benzo[b][1,4]oxazin-3(4H)-one derivatives as platelet aggregation inhibitors.

Novel 2H-benzo[b][1,4]oxazin-3(4H)-ones have been synthesized by condensation, reduction, O-alkylation and Smiles rearrangement using 3-bromo-4-hydroxy benzaldehyde, anilines, and chloroacetyl chloride as starting materials. All the synthesized compounds have been characterized by (1)H NMR, (13)C NMR, and HRMS, and tested for the inhibitory ability on platelet aggregation. The results have shown that the ADP (adenosine 5'-diphosphate)-induced platelet aggregation was inhibited by 7a-g with the IC(50) value at 10.14-18.83 µmol/L. Compound 7a exhibited the most potent inhibitory effect (IC(50)=10.14 µmol/L) among all the compounds, but less potent than the control drug ticlopidine (3.18 µmol/L) and aspirin (6.07 µmol/L). The preliminary structure-activity relationship (SAR) was initially investigated in the study.

[Synthesis of baicalin-copper and baicalin-aluminium complex and its bioactivity].

OBJECTIVE: To study synthesis of baicalin-copper and baicalin-aluminium complex and its antimicrobial, anti-tumor activity and anti-tumor effect against macrophages. METHOD: Baicalin was reacted with metallic salt under a weak base condition to produce baicalin-copper and baicalin-aluminium complex. Baicalin and its synthesized complex were detected for antimicrobial activity against Staphylococcus aureus, Hay bacillus, Escherichia coli, Salmonella and Candida albicans by twofold broth dilution technique. Their anti-tumor activity against A549 and IC50 of HepG2 cells and anti-tumor effect against macrophages were detected by the MTT. And their phagocytic effect on macrophages was determined by the neutral red assay. RESULT: The yields of baicalin-copper and baicalin-aluminium complex were 73.93% and 91.08%, respectively. The minimum inhibitory concentration (MIC) value against Staphylococcus aureus, Hay bacillus, Escherichia coli, Salmonella and Candida albicans was 0.0004, 0.0009, 0.0004, 0.0009, 0.000 4 mol x L(-1) for baicalin-copper complex and 0.0011, 0.0011, 0.0011, 0.0011, 0.0005 mol x L(-1) for baicalin-aluminium complex. The IC50 values against A549 and HepG2 cells were 89.6, 22.6 micromol x L(-1) for baicalin-copper complex, and 138.8, 97.2 micromol x L(-1) for baicalin-aluminium complex. The inhibitory ratio of macrophage on A549 cell was 43.52%, 80.89%, 52.66%, respectively, after the macrophages were stimulated by baicalin, baicalin-copper and baicalin-aluminium complex at a concentration of 160 micromol x L(-1). CONCLUSION: The acute toxicity test in mice showed that the complex was nontoxic to mice. Baicalin-copper complex showed the highest antimicrobial, anti-tumor activity, and the strongest effect on the anti-tumor activity of macrophage, while baicalin showed the lowest activities compared with baicalin-copper and baicalin-aluminium complex.

[Advance of studies on bioactivity of flavonoid-metal complexes].

The flavonoid-metal complexes showed obviously stronger bioactivities such as antibiosis, antivirus, anti-inflammatory, anti-tumor and anti-free-radical, possibly because of the stronger binding force caused by the change in complex structure and accessibility to target spots, or the synergy effect between flavonoids and metallic ions. This essay summarizes studies on bioactivity and mechanism of flavonoid-metal complexes, in order to provide reference for in-depth study and development on effective constituents contained in flavonoid traditional Chinese medicines.

Regulatory interaction of BcWRKY33A and BcHSFA4A promotes salt tolerance in non-heading Chinese cabbage [Brassica campestris (syn. Brassica rapa) ssp. chinensis].

Salinity is a universal environmental stress that causes yield reduction in plants. WRKY33, which has been extensively studied in plant defense against necrotrophic pathogens, has recently been found to be important in salt-responsive pathways. However, the underlying molecular mechanisms controlling the involvement of WRKY33 in salt tolerance have not been fully characterized. Here, we explored the function of BcWRKY33A in non-heading Chinese cabbage (NHCC). Under salt stress, BcWRKY33A expression is significantly induced in roots. As a nuclear protein, BcWRKY33A has strong transcriptional activation activity. Overexpression of BcWRKY33A confers salt tolerance in Arabidopsis, whereas silencing of BcWRKY33A causes salt sensitivity in NHCC. Furthermore, BcHSFA4A, a protein that interacts with BcWRKY33A, could directly bind to the HSE motif within the promoters of BcZAT12 and BcHSP17.6A, which are involved in the plant response to salt stress. Finally, we found that BcWRKY33A could enhance the transcriptional activity of BcHSFA4A and affect its downstream genes (e.g. BcZAT12 and BcHSP17.6A), and co-overexpression of BcWRKY33A and BcHSFA4A could promote the expression of salt-related genes, suggesting that the regulatory interaction between BcWRKY33A and BcHSFA4A improves salt tolerance in plants. Overall, our results provide insight into the molecular framework of the BcWRKY33A-BcHSFA4A signaling pathway, which also aids in our understanding of the molecular mechanism of salt tolerance in plants.

Protection of CAPE-pNO2 Against Chronic Myocardial Ischemia by the TGF-Β1/Galectin-3 Pathway In Vivo and In Vitro.

Although it is known that caffeic acid phenethyl ester (CAPE) and its derivatives could ameliorate acute myocardial injury, their effects on chronic myocardial ischemia (CMI) were not reported. This study aimed to investigate the potential effect of caffeic acid p-nitro phenethyl ester (CAPE-pNO2, a derivative of CAPE) on CMI and underlying mechanisms. SD rats were subjected to high-fat-cholesterol-diet (HFCD) and vitamin D3, and the H9c2 cells were treated with LPS to establish CMI model, followed by the respective treatment with saline, CAPE, or CAPE-pNO2. In vivo, CAPE-pNO2 could reduce serum lipid levels and improve impaired cardiac function and morphological changes. Data of related assays indicated that CAPE-pNO2 downregulated the expression of transforming growth factor-ß1 (TGF-ß1) and galectin-3 (Gal-3). Besides, CAPE-pNO2 decreased collagen deposition, the number of apoptotic cardiomyocytes, and some related downstream proteins of Gal-3 in the CMI rats. Interestingly, the effects of CAPE-pNO2 on TGF-ß1, Gal-3, and other proteins expressed in the lung were consistent with that in the heart. In vitro, CAPE-pNO2 could attenuate the fibrosis, apoptosis, and inflammation by activating TGF-ß1/Gal-3 pathway in LPS-induced H9c2 cell. However, CAPE-pNO2-mediated cardioprotection can be eliminated when treated with modified citrus pectin (MCP, an inhibitor of Gal-3). And in comparison, CAPE-pNO2 presented stronger effects than CAPE. This study indicates that CAPE-pNO2 may ameliorate CMI by suppressing fibrosis, inflammation, and apoptosis via the TGF-ß1/Gal-3 pathway in vivo and in vitro.

Determination of corosolic acid, a natural potential anti-diabetes compound, in rat plasma by high-performance liquid chromatography-mass spectrometry and its application to pharmacokinetic and bioavailability studies.

A simple, robust, and sensitive high-performance liquid chromatography/mass spectrometric method was developed for the determination of corosolic acid, a potential anti-diabetes substance, in rat plasma using glycyrrhetinic acid as the internal standard (IS). This method involved a liquid-liquid extraction with acetic ether and a subsequent analysis performed on an LC-MS system which contained an electrospray ionization interface. Chromatographic separation was performed using an ODS column, and the mobile phase was composed of methanol and 5 mmol/L ammonium acetate (88 : 12, v/v). Good linearity was observed over the concentration range of 20-10 ,000 ng/mL with a correlation coefficient (r² ≥ 0.995. The method was proved to be accurate and reliable and was applied to a pharmacokinetic study in the rat following intragastric and intravenous administration of corosolic acid.

Janus Kinase Signaling: Oncogenic Criminal of Lymphoid Cancers.

The Janus kinase (JAK) family are known to respond to extracellular cytokine stimuli and to phosphorylate and activate signal transducers and activators of transcription (STAT), thereby modulating gene expression profiles. Recent studies have highlighted JAK abnormality in inducing over-activation of the JAK/STAT pathway, and that the cytoplasmic JAK tyrosine kinases may also have a nuclear role. A couple of anti-JAK therapeutics have been developed, which effectively harness lymphoid cancer cells. Here we discuss mutations and fusions leading to JAK deregulations, how upstream nodes drive JAK expression, how classical JAK/STAT pathways are represented in lymphoid malignancies and the noncanonical and nuclear role of JAKs. We also summarize JAK inhibition therapeutics applied alone or synergized with other drugs in treating lymphoid malignancies.

CAPE-pNO2 ameliorates diabetic brain injury through modulating Alzheimer's disease key proteins, oxidation, inflammation and autophagy via a Nrf2-dependent pathway.

AIMS: CAPE-pNO2, an active derivative of caffeic acid phenethyl ester, has been verified to exert protection of diabetic cardiomyopathy and diabetic nephropathy. The present study aims to explore the brain protection effects and potential mechanisms of CAPE-pNO2 on streptozotocin-induced diabetic brain injury in vivo and in vitro. MAIN METHODS: Biochemical indexes including triglyceride, total cholesterol, superoxide dismutase and malondialdehyde contents were detected. The histopathological structure of hippocampus and cerebral cortex were determined. Immunofluorescence and immunoblot methods were used to assess expression of oxidative stress, inflammation and autophagy pathway-related proteins of diabetic brain in vivo. Alzheimer's disease (AD)-associated key proteins were also checked in vivo. DCFH-DA assay, immunofluorescence and immunoblot methods were applied to verify the master role of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in vitro. KEY FINDINGS: First, CAPE-pNO2 could rescue the diabetic brain atrophy and diminish CA1 and CA3 cells of hippocampus and cerebral cortex. Second, CAPE-pNO2 could decrease Aß and p-tau (S396) expression through anti-oxidation, anti-inflammation and autophagy induction in vivo. Last, CAPE-pNO2 could down-regulate p-tau (S396) expression through Nrf2-related anti-oxidation mechanisms in vitro. SIGNIFICANCE: CAPE-pNO2 may exert brain protection via Nrf2-dependent way in diabetes. Additionally, Nrf2 was capable of regulating p-tau (S396) expression that is critical to AD.

[Study on pharmacokinetics of matrine by intramuscular administration in rat].

OBJECTIVE: To study the pharmacokinetics of matrine (MT) intramuscular administration in rat. METHOD: Plasma concentration of matrine was determined by HPLC under the following conditions: column (Shim-pack VP-ODS, 4. 6 mm x 150 mm, 5 m); eluent (acetonitrile-0.02 mol ammonium acetate buffer-triethylamine 30: 70: 0.04); flow rate was 1 mL x min(-1) and ultraviolet detection wavelength was set at 220 nm; column temperature 40 degrees C; aliquot injected 20 microL. All data of concentration-time of matrine were treated with pharmacokinetics program DAS 2. 1. 1. RESULT: A simple, sensitive and reliable method for determining matrine in rat plasma by HPLC was established. The plasma concentration time profiles of MT fitted in with two-compartment models well, and the main pharmacokinetic parameters found for MT after i. m. infusion were as follows: C(max) = 21.113 9 mg x L(-1), t(max) = 0.75 h, t1/2alpha 1.34 h, t1/2beta = 3.509 h, AUC(0-t) = 90.984 mg x h(-1) x L(-1), AUC(0-infinity) = 100.346 mg x h(-1) x L(-1). CONCLUSION: Compare with oral administration, the matrine is absorbed well and distributes fast with intramuscular administration; the absolute bioavailability of matrine is higher. According to this, the pharmacological action is also stronger and duration is longer.

[Effect of ceftiofur hydrochloride on pharmacokinetics of matrine in rats].

OBJECTIVE: To investigate the effect of ceftiofur hydrochloride on the pharmacokinetics of matrine in rats. METHOD: The rats were divided into two groups: one group was administrated with matrine only (control group) and the other was administrated with matrine in combination with ceftiofur hydrochloride. HPLC-UV method was used for determining the plasma concentration of matrine in both groups. The pharmacokinetic parameters were calculated from the plasma concentration-time data using the DAS 2. 1. 1 software program. RESULT: The main pharmacokinetic parameters for the control group were C(max) = 21.113 9 mg x L(-1), T(max) = 0.75 h, t1/2alpha = 1.34 h, t1/2beta = 3.509 h, AUC(0-t) = 90.984 mg x h(-1) x L(-1) and AUC(0-inifinity) = 100.346 mg x h(-1) x L(-1), and the data for the combination group were C(max) = 11.707 mg x L(-1), T(max) = 0.917 h, t1/2alpha = 1.598 h, t1/2beta = 3.247 h, AUC(0-t) = 53.28 mg x h(-1) x L(-1) and AUC(0-inifinity) = 60.035 mg x h(-1) x L(-1). CONCLUSION: The plasma concentration of matrine and bioavailability in combination group were significantly lower than those of the control group. In combination group, matrine had a higher clearance and volume of distribution in the central compartments, as well as a lower volume of distribution in the peripheral compartments.