Latest ArticlesPlant-derived extracellular vesicles (EVs) are membranous vesicles secreted by plants, which include lipid bilayer as the basic framework and encapsulate various proteins, nucleic acid and other active substances. They play an important role in plant growth and development, tissue repair and self-defense. In recent years, extracellular vesicle-like nanoparticles (EVNs) are prepared from plant samples referring to the separation method of EVs and show unique functions. In this review, the above structures are collectively called plant-derived vesicles (PDVs). The biogenesis, separation and characterization methods, in vivo and in vitro properties of PDVs have been reviewed. The biomedical applications of PDVs as natural therapeutic agents and functional drug carriers are described, and finally some opinions on the existing problems and future prospect in this field are put forward.
To improve the fluidity and compactibility properties of raw powders of traditional Chinese medicine by particle modification technology, Lonicera Japonica Flos was used as a model drug, fluidized bed bottom spray technology was used, and Plasdone S-630 was used as a modifier to prepare modified particles. The powder properties, tablet compactibility parameters, disintegration time and dissolution were measured. The surface morphology of the powder particles before and after modification and compressed tablets were characterized by combining with scanning electron microscopy technology. The results showed that the particle size of Lonicera Japonica powder has been increased after particle modification, the fluidity, compressibility and compactibility of the powder have been improved to some extent, the disintegration time has also been reduced, and the dissolution in vitro is not affected. Therefore, this study can provide reference and ideas for the common problem that raw powder of traditional Chinese medicine that cannot meet the needs of preparation production due to poor powder properties such as fluidity and compressibility.
At present, the research of Moutan cortex carbonisata (MCC) mainly focuses on the changes of chemical composition before and after charcoal production, and there is a lack of material basic research directly related to the efficacy at home and abroad. In this study, Moutan cortex, as a precursor, and was calcined to MCC at high temperature. The Moutan cortex carbonisata nano-components (MCC-NCs) were extracted and separated from MCC to explore its cooling-blood and hemostatic effects. In the experiment, the MCC was calcined at a high temperature in a muffle furnace (350℃, 1 h), and then MCC-NCs were extracted for MCC, and characterized by transmission electron microscopy and UV-vis absorption spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. In addition, the study evaluated the bloodcooling and hemostatic effects of MCC-NCs. The results showed that MCC-NCs have a size distribution of 0.80-2.8 nm, a lattice spacing of 0.26 nm. MCC-NCs are mainly composed of C, O and N elements and have abundant surface functional groups such as OH, C=O, C-N and C=C. The fluorescence yield of MCC-NCs was 7.18%. The experiments complied with the Animal Ethics Committee of Beijing University of Chinese Medicine. The result indicated that pretreatment MCC-NCs can significantly (P < 0.05) reduce the high, medium, and low viscosity of whole blood and plasma viscosity, and reduce hematocrit, red blood cell distribution width, hemoglobin and red blood cell level. In addition, MCC-NCs significantly reduced the levels of activated partial thromboplastin time, thrombin time and fibrinogen (P < 0.05). The pathological examination results showed that MCC-NCs can significantly reduce lung tissue damage, reduce bleeding and inflammatory cell infiltration. At the same time, it can also significantly reduce the symptoms of gastric mucosal bleeding. In conclusion, the results indicated that MCC-NCs has significantly the effect of blood cooling and hemostasis, and its hemostatic effect is mainly related to the activation of endogenous coagulation pathway or fibrinogen system, which provided a novel strategy for exploring the material basis of traditional Chinese medicine for hemostasis.
Artificial intelligence technology is being widely applied in drug screening. This paper introduces the characteristics of artificial intelligence, and summarizes the application and progress of artificial intelligence technology especially deep learning in drug screening, from ligand-based and receptor structure-based aspects. This paper also introduces how to apply artificial intelligence to drug design from these two aspects. Finally, we discuss the main limitations, challenges, and prospects of artificial intelligence technology in the field of drug screening.
Gastric pH is an important factor that affects drug absorption, as gastric pH may lead to lower bioavailability, especially for weak-base drugs. Acid-reducing agents (ARAs) such as antacids, histamine-2 receptor antagonists, and proton pump inhibitors, are susceptible to drug-drug interactions (DDIs), potentially resulting in the loss of efficacy. Physiologically based pharmacokinetic (PBPK) modeling is an important tool for the evaluation of oral drug-drug interactions and the most commonly used models include the advanced comparative absorption and transport (ACAT) model and the advanced dissolution, absorption and metabolism (ADAM) model. These models can be used for adjustment of the dosage regimen and the screening of candidate drugs in drug development by simulating the change of gastric pH to predict the change in drug absorption. This review summarizes the theoretical basis, the most common PBPK models used to predict drug absorption, and the effects of different kinds of ARAs drugs on gastric pH. Some successful applications of PBPK modeling in predicting the effects of gastric pH on drug absorption are also presented.
The active ingredients in traditional Chinese medicine have been reported to possess significant pharmacological activity and played an important role in clinical treatments. However, lots of the active ingredients in traditional Chinese medicine suffer from disadvantages such as low solubility, high melting point and low stability that results in low bioavailability and limit its clinical application. Crystal structure plays an important role in improving physicochemical properties and efficacy of the active ingredients in traditional Chinese medicine. This review concludes the research advances of several crystal forms used in the active ingredients in traditional Chinese medicine in terms of polymorph, cocrystal, amorphous/coamorphous and nanocrystal. And the effects of crystal forms on the physicochemical properties and efficacy of the active ingredients in traditional Chinese medicine were reviewed. This research may be useful for the formulation preparation and development of the active ingredients in traditional Chinese medicine.
Desorption electrospray ionization mass spectrometry (DESI-MS) is a newly emerging in-situ ionization mass spectrometry analysis technology. The ionization process occurs in an open ambient environment at atmospheric pressure, and has the characteristics of simple sample pretreatment, quick and sensitive analysis, and is widely used in biomedicine, pharmaceutical analysis, food safety, environmental monitoring, and material characterization. Natural medicines, such as Chinese herbal medicines, contain a variety of chemical components. Extraction, separation, identification, and in vitro and in vivo efficacy evaluation of natural medicines, especially research on active ingredients with significant efficacy, have received long-term attention. The development of DESI-MS technology provides many new opportunities for direct and rapid analysis of active ingredients in natural medicines. This article briefly introduces the principles, characteristics, influencing factors, and technical progress of DESI-MS technology, and systematically summarizes progress in the research and application of this technology to natural medicines such as Chinese herbal medicines and other plant samples with pharmacological activity. The future application prospects in this field are further presented.
Traditional Chinese medicine (TCM) preparations have made tremendous progresses in modernization, whereas there exist relatively few researches pertaining to preparation structures. As demonstrated by the theory and practice of structure pharmaceutics, the structure properties of dosage forms have significant influences on the quality and efficacy of drugs, which might offer reference for the research and development of TCM dosage forms. With the application of synchrotron radiation X-ray micro-computed tomography (SR-μCT) and other novel technologies in recent years, researches in structure pharmaceutics have made huge advancement, which provide reference and methodology basis for the study of TCM preparations. The article generalized and summarized the recent progresses and methods in the structure researches of pharmaceutics and TCM preparations, and further explored the significance of the researches of structure of TCM preparations. It is expected to provide the basis for the dosage form design, production process improvement, and quality evaluation of TCM and promote the modernization of TCM preparations.
Six compounds were isolated from the crude extract of the liquid culture of Alternaria sp. W-1 by silica gel column chromatography, Sephadex LH-20 gel column chromatography, and HPLC. They were identified as 6-iso-tricycloalternarene 6a (1), tricycloalternarene 6a (2), tricycloalternarene B (3), uracil (4), 5-methyluracil (5), and lumichrome (6) through HR-MS, NMR and literature comparison. 6-iso-Tricycloalternarene 6a (1) is a new compound which has never been reported in the literature. In cytotoxicity assay, compounds 1-3 showed weak inhibition activity to human hepatoma cell line SMMC-7721 and human gastric cell line SGC-7901.
We previously reported that active Astragalus polysaccharides APS-Ⅱ generate strong immune activity. Here we establish the optimal method for APS-II acid degradation. After preliminary structural studies and separation and preparation of the degradation products, the oligosaccharide active center with the strongest immune activity was identified by in vitro immune cell culture experiments. The optimum acid degradation conditions for APS-II were determined by a single factor experiment and an orthogonal experiment. Astragalus oligosaccharides prepared under the optimal conditions were subjected to structural analysis by hydrophilic interaction chromatography-electrospray ionization source-high resolution time-of-flight mass spectrometry. The products were separated and oligosaccharide fragments with different degrees of polymerization were isolated by preparative purification chromatography. Finally, fragments of the immunologically active centers were identified by in vitro immune cell cultures from multiple perspectives. The results show that the optimal acid hydrolysis conditions for APS-Ⅱ are hydrolysis temperature 80℃, trifluoroacetic acid concentration 1.0 mol·L-1, hydrolysis time 1 h. The degradation conditions have good repeatability. The degradation product is a six-carbon aldehyde glycan structure with the main chain 1→4 connected. The immune activity screening experiment for six oligosaccharide fragments showed that larger molecular weight oligosaccharides have stronger immune-promoting effects. It is speculated that the immunologically active center of Astragalus oligosaccharide is located in the sugar chain of DP9-DP19. The animal welfare and the experimental process in this study follow the requirements of the Animal Ethics Committee of Shanxi University. This result suggests a foundation for the structural characterization and structure-activity relationship research of Astragalus oligosaccharides, and may promote the development of Astragalus oligosaccharide drugs.