[Structural Chinese medicine: new research field on pharmacodynamic substance basis of traditional Chinese medicine].

The research on the pharmacodynamic substance basis of traditional Chinese medicine(TCM) is a key scientific issue for the inheritance and development of TCM. At present, a large number of remarkable achievements have been made in the field of chemical components in Chinese medicine, however, another important aspect, namely the physical structure and mode of action of the multi-component assembly of TCM, has not been clearly understood and deeply studied. From the bottleneck of restricting material ba-sic research, we objectively analyzed the common cause of the existing problems. Based on the new discoveries and advances of active substances from TCM emerging in recent years, we extracted and summarized the concept of structural Chinese medicine, elaborated the basic ideas, main features and research modes, hoping to provide theoretical and practical references for the study on the pharmacodynamic substance basis and other research fields of TCM.

The heterologous expression of CmBBX22 delays leaf senescence and improves drought tolerance in Arabidopsis.

KEY MESSAGE: CmBBX22, a transcription factor of chrysanthemum, was verified to confer drought tolerance in Arabidopsis thaliana. The BBX proteins are known to operate as regulators of plant growth and development, but as yet their contribution to the abiotic stress response has not been well defined. Here, the chrysanthemum BBX family member CmBBX22, an ortholog of AtBBX22, was found to be transcribed throughout the plant, although at varying intensity, and was induced by imposing moisture deficiency via exposure to polyethylene glycol. The heterologous, constitutive expression of this gene in Arabidopsis thaliana compromised germination and seedling growth, but enhanced the plants' ability to tolerate drought stress. In transgenic plants challenged with abscisic acid, leaf senescence was delayed and the senescence-associated genes and chlorophyll catabolic genes SAG29, NYE1, NYE2 and NYC1 were down-regulated. We speculated that CmBBX22 may serves as a regulator in mediating drought stress tolerance and delaying leaf senescence.

[Recent development of natural and reconstituted lipoprotein based nano drug delivery vehicles].

Lipoproteins are biological lipids carriers. The natural and reconstituted lipoprotein based drug delivery systems have been extensively developed in recent years. This article reviews the development of natural and reconstituted low-density lipoprotein and high-density lipoprotein based vehicles in the antitumor area.

Safety and efficacy of pulse-induced contour cardiac output monitoring in elderly patients with coronary artery disease and severe heart failure at coronary care units.

Background: The optimal treatment for elderly patients with severe heart failure depends on the accurate assessment of their hemodynamic status. Due to its less invasive nature, the safety and efficacy of invasive pulse-induced contour cardiac output (PiCCO)-based hemodynamic monitoring remains uncertain. Methods: This was a prospective observational study. Between January 2016 and July 2020, 190 elderly patients with severe heart failure were consecutively enrolled. The PiCCO group (89 patients) and non-invasive hemodynamic monitoring group (101 patients) were observed. Hospital stays results were evaluated. Results: No significant difference in clinical data (P > 0.05) or the incidence of 1-month mortality (16.0 vs. 35.0%, P = 0.141) were observed between groups. The coronary care unit (CCU) stay was shorter in the PiCCO group than in the non-invasive group (40.0 vs. 43.0%, P = 0.049). Indicators such as low Extravascular Lung Water Index (EVLWI), high Body Mass Index (BMI), low Pulmonary Artery Pressure (PAP), and high Left Ventricular Ejection Time (LVET), were associated with favorable clinical results. Conclusion: Early invasive PiCCO monitoring is safe in critically ill elderly patients with severe heart failure. The hospital stay was reduced using PiCCO monitoring. These encouraging PiCCO results favor its use in elderly patients with severe heart failure at CCUs.

Pt1 enhanced C-H activation synergistic with Ptn catalysis for glycerol cascade oxidation to glyceric acid.

The selective oxidation of glycerol to glyceric acid, an important value-added reaction from polyols, is a typical cascade catalytic process. It is still of great challenge to simultaneously achieve high glycerol activity and glyceric acid selectivity, suffering from either deep oxidation and C-C cleavage or poor oxidation efficiency from glyceraldehyde to glyceric acid. Herein, this work, inspired by nature, proposes a cascade synergistic catalysis strategy by atomic and low-coordinated cluster Pt on well-defined Cu-CuZrOx, which involves enhanced C-H activation on atomic Pt1 and O-H activation on cluster Ptn in the oxidation of glycerol to glyceraldehyde, and cluster Ptn for C=O activation followed by O-H insertion and atomic Pt1 for C-H activation in the tandem oxidation of glyceraldehyde to glyceric acid. The enhanced C-H activation in the cascade process by atomic Pt1 is revealed to be essential for the high glycerol activity (90.0±0.1%) and the glyceric acid selectivity (80.2±0.2%).

[Water in oil microemulsions containing NaCl for transdermal delivery of fluorouracil].

This study is to prepare the W/O microemulsion containing NaCl and fluorouracil (5-Fu) as a model drug to investigate the transdermal characteristics and skin irritation of the microemulsion in vitro. Isopropylmyristate (IPM) acting as oil phase, Aerosol-OT (AOT) as surfactant, Tween 85 as cosurfactant, NaCl solution was added dropwise to the oil phase to prepare W/O microemulsion at room temperature using magnetic stirring, and then 5-Fu powder was added. According to the area of microemulsion based on the pseudo-tertiary phase diagrams, the optimum formulation was screened initially. And the permeation flux of fluorouracil across excised mice skin was determined in vitro using Franz diffusion cells to study the influence of the amount of water and the drug loading capacity and optimize the formulation further. Refer to 5-Fu cream, the irritation of microemulsion on the rat skin was studied. The optimum formulation was composed of 0.7% (w/v) 5-Fu, 50% NaCl solution (0.05 mol x L(-1)), 20% mix-surfactant (AOT/Tween 85, K(m) = 2) and 29.3% oil (IPM). The cumulative amount of fluorouracil permeated in 12 h was (2 013.4 +/- 41.6) microg x cm(-2), 20.23 folds and 10.38 folds more than 0.7% fluorouracil aqueous solution and 2.5% (w/w) fluorouracil cream, respectively. Microemulsion exhibited some irritation, but could be reversed after drug withdrawal. The addition of NaCl significantly increased the content of water and the drug loading in microemulsion systems. The NaCl/AOT-Tween 85/IPM microemulsion system promoted the permeation of fluorouracil greatly, which may be a promising vehicle for the transdermal delivery of fluorouracil and other hydrophilic drug.

Solidified mPEG-PDLLA micelles as a novel oral delivery system of indomethacin.

In this study, indomethacin (IND) loaded solidified-polymeric micelles (IND-SPM) were prepared. Their in vitro characteristics were investigated. Methoxy-poly(ethylene glycol) poly(D, L-lactide) copolymer (mPEG-PDLLA) was used as IND carrier. The preparation of IND-SPM was conducted by solution-absorption method and evaporation by rotary evaporator. Polyplasdone XL-10 was used as adsorbent. The solution-absorption method was conducted by the following procedure; IND and mPEG-PDLLA were dissolved in acetone, followed by addition of polyplasdone XL-10 and stirred to obtain a suspension. The powder of IND-SPM was simply obtained after the organic solvent was completely evaporated. More than 90% (w/w) of IND (20 mg) in the powder was dissolved in 250 mL PBS within 30 min. DSC, 1H NMR and SEM results proved that IND was encapsulated within mPEG-PDLLA. The solubility of IND in the system increased 4.6 times with the highest amount of copolymer. The solidified particles were found to be suitable for the formulation of tablets or capsules.

[Microemulsion-based gel of fluorouracil for transdermal delivery].

This study is to prepare the microemulsion-based gel based on the W/O microemulsion and fluorouracil (5-Fu) as a model drug to study the transdermal characterization and observe its skin irritation of the microemulsion-based gel in vitro. IPM acted as oil phase, AOT as surfactant, Tween 85 as cosurfactant, water was added dropwise to the oil phase to prepare W/O microemulsion at room temperature using magnetic stirring, then 5-Fu powder was added. The gelatin was used as substrate to prepare 5-Fu microemulsion-based gel. The permeation flux of 5-Fu from 5-Fu microemulsion-based gel across excised mice skin was determined in vitro using Franz diffusion cell to study the influence of the amount of gelatin and the drug loading capacity. Refer to 5-Fu cream, the irritation of microemulsion and microemulsion-based gel on the rat skin was studied. Based on the water/AOT/Tween 85/IPM microemulsion, only the gelatin can form the microemulsion-based gel. At 25 degrees C, 32 degrees C and 40 degrees C, the amount of gelatin required for the formation of microemulsion-based gel were 7%, 14% and more than 17%, respectively. The 12 h transdermal cumulated permeation amount of 5-Fu from microemulsion-based gel containing 14% gelatin and 0.5% drug loading were (876.5 +/- 29.1) microg x cm(-2), 12.3 folds and 4.5 folds more than 0.5% 5-Fu aqueous solution and 2.5% (w/w) 5-Fu cream, respectively. Microemulsion-based gel exhibited some irritation, but could be subsided after drug withdrawal. Microemulsion-based gel may be a promising vehicle for transdermal delivery of 5-Fu and other hydrophilic drug.

A combination of receptor mediated transcytosis and photothermal effect promotes BBB permeability and the treatment of meningitis using itraconazole.

Fungal infections of the central nervous system (CNS) may lead to life-threatening meningitis. Itraconazole (ITZ) is an effective antifungal agent that can be used to treat various fungal infections; however, its poor solubility along with poor permeability of the blood-brain barrier (BBB) prevents it from treating meningitis. Receptor mediated transcytosis (RMT) shows modest efficacy in BBB crossing, while affinity and saturability of interactions between ligands and receptors account for the limited efficacy of RMT in crossing the BBB. Mild hyperthermia could temporarily disrupt the BBB to increase its permeability. Therefore, we speculated that the combination of mild hyperthermia with RMT could potentially increase BBB permeability of ITZ leading to improved efficacy in fungal meningitis. Here, we have constructed for the first time, apolipoprotein E (Apo E) mimicked peptide COG1410 modified polydopamine (PDA)-coated bovine serum albumin nanoparticles (ApoE-PDA@ITZ-NPs). Different levels of COG1410-modified NPs were prepared and characterized. ApoE-PDA@ITZ-NPs have a superior photothermal effect under 808 nm light irradiation and exhibited favorable plasma stability and photothermal stability. Moreover, the cellular uptake of nanoparticles increased with an increase in COG1410. H-ApoE-PDA@ITZ-NPs increased cellular uptake and in vitro BBB permeability by 4.2-fold and 4.8-fold, respectively, compared to the ITZ-NPs. Live imaging implied that H-ApoE-PDA@ITZ-NPs could significantly increase the distribution of ITZ in the brain under 808 nm light irradiation. Histopathological analysis of periodic acid-Schiff-stained brain sections of the H-ApoE-PDA@ITZ-NP treated C. albicans meningitis model indicated that H-ApoE-PDA@ITZ-NPs showed superior antifungal activity after 808 nm light irradiation. Hence, we report ApoE-PDA@ITZ-NPs in tandem with 808 nm irradiation as a novel strategy of RMT combination with a photothermal effect in enhancing BBB permeability to facilitate drug accumulation in the brain region and enhance the therapeutic efficacy of ITZ in meningitis.

[The effect of polyamidoamine (PAMAM) dendrimers on the solubility and pharmacokinetics of breviscapine].

To study the solubilization of breviscapine with polyamidoamine (PAMAM) dendrimers and probe the solubilizing mechanism and investigate the influence of PAMAM dendrimers on the pharmacokinetics of breviscapine, the solubilization of breviscapine by PAMAM dendrimers of generations G1, G1.5, G2 and G2.5 with different concentrations were determined and compared in different pH conditions. Twelve rats randomized into 2 groups were separately orally administered breviscapine and breviscapine combining with PAMAM. Drug in plasma was extracted and determined with HPLC. In pH condition lower than 7.0, the solubilization of breviscapine by PAMAM dendrimers enhanced as the generation and concentration of PAMAM dendrimers as well as the pH increased. Its solubilizing mechanism involves an electrostatic interaction between the carboxyl group of breviscapine and the primary amines and tertiary amines of PAMAM dendrimers. The pharmacokinetics parameters Cmax and AUC0-8 h of breviscapine were (119.65 +/- 9.36) ng x mL(-1) and (370.09 +/- 63.08) ng x h x mL(-1). For breviscapine combined with PAMAM dendrimers, the Cmax and AUC0-8 h were (518.17 +/- 17.07) ng x mL(-1) and (1,219.47 +/- 201.87) ng x h x mL(-1), respectively. There were significant differences of AUC0-8 h between breviscapine and breviscapine combined with PAMAM dendrimers (P < 0.01). PAMAM dendrimers can greatly increase the solubility of breviscapine in water and can improve the oral bioavailability of breviscapine significantly.

[Water in oil microemulsions for transdermal delivery of fluorouracil].

An Aersol-OT (AOT) included microemulsion containing fluorouracil was prepared by using appropriate proportion of oil, co-surfactant and water for increasing the drug transdermal delivery ability. According to the area of microemulsion basing on the pseudo-tertiary phase diagrams, the optimum formulation was screened initially. And the permeation flux of fluorouracil across excised mice skin was determined in vitro using Franz diffusion cell to optimize the formulation further. The effect of the kind of co-surfactant, the content of water, the content of mixed surfactant, the mass ratio of surfactant/cosurfactant (Km) and the drug load on skin permeation of fluorouracil were evaluated. The optimum formulation was composed of 0.5% (w/v) fluorouracil, 30% water, 20% mix-surfactant (AOT/Tween 85, Km = 2) and 49.5% oil (IPM). The cumulative amount permeated of fluorouracil in 12 hour was 1 355.5 microg x cm(-2), 19.1 folds and 7 folds more than 0.5% fluorouracil aqueous solution and 2.5% (w/w) fluorouracil cream, respectively. The permeation of this microemulsion accorded with first-order model. The water/AOT/Tween 85/IPM microemulsion system promoted the permeation of fluorouracil greatly, which may be a promising vehicle for the transdermal delivery of fluorouracil and other hydrophilic drug.

[The enhancing effect of borneol on the absorption of tetramethylpyrazine].

To explore the mechanism of the absorption enhancement of borneol, the effect of borneol on the intestinal absorption and the pharmacokinetics of tetramethylpyrazine phosphate after oral administration were investigated. In situ intestinal recirculation was performed to study the effect of various concentrations of borneol on the absorption of tetramethylpyrazine phosphate at duodenum, jejunum, ileum and colon. After oral administration of tetramethylpyrazine phosphate, the mixture of tetramethylpyrazine phosphate and borneol and the mixture of tetramethylpyrazine phosphate and verapamil in rats, the concentrations of tetramethylpyrazine phosphate in plasma were determined by RP-HPLC at predesigned time. The pharmacokinetic parameters were compared based on the results of the three animal experiments, and analyzed with software program 3p97. The result showed that tetramethylpyrazine phosphate could be absorbed at all of the four intestinal segments with increasing absorption amount per unit as follows: colon > duodenum > jejunum > ileum, but without saturation, which demonstrated that tetramethylpyrazine phosphate was absorbed via simple diffusion. Borneol could enhance the intestinal absorption of tetramethylpyrazine phosphate, however, not in proportion. There was no obvious difference between the test group and the control group when 10 microg x mL(-1) borneol was added (P > 0.05), while when the concentration comes to 25 microg x mL(-1) and 50 microg x mL(-1), significant differences were observed (P < 0.05). Borneol and verapamil did enhance the bioavailability of tetramethylpyrazine phosphate after oral administration in rats. The enhancing effect of borneol showed only when the concentration came to a certain level but with no specific sites existed in the intestine. One of the mechanisms of borneol on the enhancing effect on absorption of tetramethylpyrazine phosphate might be the inhibition of the metabolism of CYP 3A and exocytosis of P-gp.

The heterologous expression in Arabidopsis thaliana of a chrysanthemum gene encoding the BBX family transcription factor CmBBX13 delays flowering.

Members of the B Box (BBX) family of proteins are known to be important for directing the growth and development of the Arabidopsis thaliana plant. Here, an analysis of a newly isolated chrysanthemum gene encoding a BBX family member implied that it was a likely ortholog of AtBBX13. The gene (designated CmBBX13) was most actively transcribed in the leaves and stem apex. CmBBX13 transcription was arrhythmic under either continuous darkness or continuous light, so the observed diurnal variation in its transcription appeared not to respond to the circadian clock. The outcome of transiently expressing CmBBX13 in onion epidermal cells suggested that the CmBBX13 protein localized to the nucleus. Both a yeast- and a protoplast-based assay showed that the protein has transactivational activity. When CmBBX13 was constitutively expressed in A. thaliana, flowering was delayed under both short and long day conditions. The presence of the transgene also down-regulated a number of genes known to promote flowering, including APETALA1 (AP1), SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1), FLOWERING LOCUS T (FT) and FD, while simultaneously up-regulating the floral inhibitor-encoding genes FLOWERING LOCUS C (FLC) and TARGET OF EAT 2 (TOE2). The data suggested that CmBBX13 regulates flowering time independently of the photoperiod pathway.

Distribution of nobiletin chitosan-based microemulsions in brain following i.v. injection in mice.

The purpose of this study was to characterize the in vitro properties of a number of chitosan-based microemulsions containing nobiletin and determine its distribution in mice brain following i.v. administration. The phase behavior and properties of chitosan-based microemulsions were investigated in a pseudo-ternary system composed of polyoxyethylene 35 castor oil/benzyl alcohol/medium-chain triglyceride/tea oil/water with the chitosan. The droplet sizes were found to be smaller than 25 nm by photo correlation spectrometer. The nobiletin-loaded hyaluronic acid chitosan-based microemulsion (HAC-ME) carried negative charge and nobiletin-loaded hydrochlorate chitosan-based microemulsion (HCC-ME) carried positive charge. The concentrations of nobiletin in tissues were determined by HPLC after i.v. administration of HAC-ME, nobiletin-loaded microemulsion (ME), HCC-ME and nobiletin solution. Based on AUC(0-t), MRT and C(max), HAC-ME delivered more nobiletin to the brain compared to nobiletin solution, ME and HCC-ME. The long-circulation effect might contribute to the higher AUC(0-t) for HAC-ME in brain. On the other hand, the AUC(0-t) in plasma and brain after i.v. administration of HCC-ME were not significantly increased relative to ME. These results indicate that HAC-ME may be presented as potential candidates for delivering more drugs into the brain.

[Research of oral prodrugs: opportunities and challenges].

Prodrug is an effective way to improve the oral absorption of the drugs which belong to Biopharmaceuticals Classification System (BCS) class III and IV. This review addresses the progress of the oral prodrugs in recent years, mainly including classical prodrug design and targeted prodrug design. Classical prodrug design is focused on modification of oil-water partition coefficient or decrease the metabolism of parent drugs. Targeted prodrug design is actively concerned with the physiological characteristics of the gastrointestinal tract to target tissues, enzymes and influx transporters. Intestinal influx transporter, the peptide transporter-targeted prodrug design is a growing field of the research of oral prodrugs recently. Challenges of prodrug strategy, design and investigation in vivo are also discussed.

[Free amino groups on the surface of chitosan nanoparticles and its characteristics].

The relationship of free amino groups on the surface and the characteristics of chitosan nanoparticles (CS-NPs) prepared by ionic gelation method was investigated. Free amino groups on the surface of CS-NPs were determined by colloidal titration, and the effects of the amount of free amino groups and its ionizable level on the particle size, zeta potential, appearance, drug entrapment efficiency and drug release profile in vitro of CS-NPs were investigated. The result showed that the surface free amino groups reduced, the average size, zeta potential, stability of nanoparticles, and the drug release rate and degree all decreased while the drug entrapment efficiency was not affected with the increase of tripolyphosphate (TPP) concentration. With the increase of pH, the free amino groups could be deprotonated and the ionizable level was stepped down, correspondingly the particle size and zeta potential of CS-NPs decreased. Additionally, the drug release rate and degree were elevated in acid medium while descended in neutral or base medium. The amount and ionizable level of free amino groups on the surface are affected by the gelation degree and pH, which further affected the volume phase transitions (swelling/shrinking processes) of CS-NPs. The properties of CS-NPs have correlation with the surface free amino groups.

[Characteristics of nobiletin-loaded nanoemulsion and its in vivo distribution in mice].

The purpose of this study was to prepare the nobiletin-loaded nanoemulsions (NOB-NE) and study its in vivo distribution in mice. The characteristics and stability of the unloaded and drug-loaded nanoemulsions were investigated. The size, apparent viscosity and pH value of NOB-NE were respectively (15.5 +/- 2.9) nm, (3.10 +/- 0.33) mPa x s and 6.56 +/- 0.05, which were all higher than those of unloaded nanoemulsions. The zeta potential of unloaded and drug-loaded nanoemulsions carried negative charge. The NOB-NE after diluted by 5% glucose solution was stable in 8 h, and there was no significant difference in the size, content and diluted stability of its preconcentrate in long-term storage. The concentration of nobiletin in plasma and tissues was determined by HPLC after intravenous administration of NOB-NE. Based on AUC(0-t), MRT and C(max), the nanoemulsions delivered more nobiletin into the brain and kidney compared to those of nobiletin solution. The brain and kidney targeting efficiency was improved. In addition, the results fitting using SAAM II software show that the higher drug concentration of the NOB-NE in the brain might be owed to the quicker transport rate from the blood to the brain, and that in the kidney relate to the probable accumulation effect. These results indicate that the in vivo distribution of NOB-NE with consistent quality in mice could be changed and its brain and kidney targeting absorption capability was enhanced comparing with nobiletin solution.

[The entrapped efficiency of BSA liposome].

BSA liposomes were prepared with approximately 100 nm mean particle size under rather gentle experiment conditions, and two-colorimetric coomassie brilliant blue protein was employed to measure the free drug in the entrapped efficiency (EE%) determination of BSA liposomes. Gel filtration was used to measure the EE%, and several Sephadex gels were examined by the separation of liposomes and free drug. To determine the free drug, three methods were compared on two-colorimetric UV spectrophotography, Bradford and two-colorimetric coomassie brilliant blue, separately. Two-colorimetric coomassie brilliant blue process increased the accuracy and improved the sensitivity of the assay about 20-fold comparing with the Bradford method. Two-colorimetric coomassie brilliant blue assay appeared to be more sensitive and showed broader dynamic range to measure the free BSA in the EE% determination of BSA liposome.

[Distribution behavior of lipophilic drugs in the oil-in-water microemulsions].

Distribution behavior of lipophilic drugs in the oil-in-water (O/W) microemulsions was studied. Fluorescence spectra analysis was performed to investigate the effect of the compositions of microemulsions on the fluorescence spectra of armillarisin and ofloxacin which were used as the model drugs. The fluorescence spectra of the model drugs in the microemulsions with various amount of the compositions were compared. The results showed that the armillarisin were both localized in the interfacial film of microemulsion systems with both phenylmethanol and PEG 400 as the co-surfactants, separately. Ofloxacin was localized in the interfacial film of microemulsion systems with Gradamol GTCC as the oil phase, but in the oil pool of microemulsion systems with oleic acid/olive oil (OA/OO) (1:1) as the oil phase. Besides, it was found that the drug would have the tendency to locate in the microenvironment where the composition with the largest solubility to model drug is located, and its actual localized position would be dependent on the amount of this composition. The results indicate that the localized region of lipophilic drug in the O/W microemulsion systems is related with the solubility of the model drug in various compositions.

[Microstructure of novel solid lipid nanoparticle loaded triptolide].

Novel solid lipid nanoparticle (SLN) system is prepared with Compritol ATO 888 and tricaprylic glyceride. DSC, XRD, SAXS and NMR are employed to study the novel carrier property and microstructure. When the peak melting point decreased from 70.8 degrees C to 61.4 degrees C, the enthalpy sharply decreased. It could be concluded that the regular crystal lattices in the novel carriers are broken out for the oil joined in them. Melting behavior is occurred at -17.7 degrees C while novel SLN is composed of oil and solid lipid mixture from the DSC measurement. Most alpha phase and least beta' phase are in the nano carrier system whether drug loading or not from the XRD investigation. There is only 0.1 nm change of long space among the novel SLN made of mixture and the lipid matrix and traditional SLN; therefore, it is impossible of the oil molecular insert into the solid glyceride structure. Since the different melting behavior (DSC measurements) and molecular move state (NMR investigations), two lipid matrix are still in two state of liquid and solid lipid in the novel SLN carrier. Presume the microstructure of the novel SLN prepared by our experiment would be that liquid oil has formed superfine nano accommodation encapsulated with solid lipid, but the whole particle is still in nano size range.