Improvement of solubility of epimedium flavonoid secondary glycoside components by traditional Chinese medicine polysaccharides and its mechanism / 中国中药杂志

The poor solubility of insoluble components of traditional Chinese medicine(TCM) is an important factor restricting the development of its preparations. Natural polysaccharides of TCM can be used as functional components to increase the solubility of insoluble components. Epimedium flavonoid secondary glycoside components(EFSGC) have been shown to have positive effects on the prevention and treatment of osteoporosis, but they exhibit poor solubility. Therefore, the strategy of solubilizing EFSGC with TCM polysaccharides was adopted, and its effect on the permeability and stability of EFSGC was evaluated in this study. Based on the equilibrium solubility experiment of EFSGC, it was found that Panax notoginseng crude polysaccharide(PNCP) had the best solubilization effect on EFSGC among the ten kinds of TCM polysaccharides, which increased the solubility of EFSGC from 0.8 mg·mL~(-1) to 13.3 mg·mL~(-1). It should be noted that after the solubilization of EFSGC by preparation technology, the effects on permeability and stability should be considered. Therefore, this study also investigated these two properties. The results showed that PNCP increased the effective transmittance of EFSGC from 50.5% to 71.1%, which could increase the permeability of EFSGC significantly. At the same time, it could improve the stability of EFSGC in the simulated gastric juice environment. In order to explain the solubilization mechanism of PNCP on EGSGC, critical micelle concentration, particle size, potential, differential scanning calorimetry, and infrared spectroscopy were analyzed. It was preliminarily inferred that the mechanism was as follows: PNCP and EFSGC could self-assemble into aggregates for solubilization by intermolecular hydrogen bonding interaction in water. In summary, PNCP can not only improve the solubility of EFSGC but also improve its permeability and stability. This study lays the foundation for the application of TCM polysaccharides as a functional component to solubilize insoluble components.

Spatial heterogeneity and physical structure basis of antibacterial activity of Ma-Xing-Shi-Gan Decoction / 药学学报

Ma-Xing-Shi-Gan Decoction is a classic prescription. However, the interaction among multiple components of the decoction and the change of phase state are not clear. Moreover, the relationship between the physical phase state aggregated by multiple components and the efficacy still needs to be studied. In this study, we monitored the particle size changes of Ma-Xing-Shi-Gan Decoction in real time. Then we isolated different phase states by centrifugation, analyzed their composition distribution and tested their antibacterial activity. We added chemical interference agents to investigate the interaction of multi-component physical phase states accompanied by the observation of particle size change and morphology. We also studied the correlation between antibacterial activity and physical structure of phase states. The results showed during boiling process the degree of hybridization of particles was decreased and the particle size distribution was narrowed and stabilized at 170 nm. The distribution of organic and inorganic components was heterogeneous among different phase states. S-13500, supernatant isolated by 13 500 ×g centrifugation, constituted by ephedrine, amygdalin, glycyrrhizic acid and inorganic components Ca, K, Mg, etc., had the strongest antibacterial activity. The molecular interaction force in the active physical phase state was mainly hydrophobic and hydrogen bond. The destruction of the interaction force will lead to the change of phase structure and the decrease of antibacterial activity in vitro and in vivo. This study confirms that, in the boiling process of the Ma-Xing-Shi-Gan Decoction, the chemical components interweave and interact to form new physical phase states, leading to heterogeneous distribution of components. The antimicrobial activity of the active phase depends on both chemical composition and physical structure, which provides a direct evidence for the physical basis of the efficacy of traditional Chinese medicine.

Research Progress on Changes and Interaction Mechanisms of Aging Articular Cartilage and Subchondral Bone / 医用生物力学

Aging is a major risk factor for diseases such as osteoarthritis (OA) and osteoporosis. However, they are not necessarily the results of aging, and the relationship between changes in bone and cartilage associated with aging and disease progression is still unclear. Studies have shown that the development and progression of OA is not a simple cartilage wear process, while its occurrence involves complex biological, chemical and mechanical changes in the tissues of the entire joint, especially the interaction of mechanics and biochemistry between cartilage and subchondral bone. Aging contributes to the occurrence and development of OA, but it is not the cause of OA. Changes associated with aging provide a foundation for OA to start, making joints more susceptible to other factors such as abnormal biomechanics and biochemistry, thereby promoting the development of OA. Therefore, understanding the basic mechanisms by which aging affects joint tissue may provide new targets for slowing or preventing the development of OA. In this paper, the related research progresses are reviewed from three aspects, i.e. age-related changes in cartilage and subchondral bone, mechanical conduction and angiogenesis.

Metabonomics study of interaction mechanism between Dendrobium officinale and Colletotrichum gloeosporioides based on GC-MS / 中草药

Objective To investigate the metabolites related to the course of anthracnosis of Dendrobium officinale and its possible mechanism based on the technique of metabonomics, so as to provide theoretical support for the creation or breeding of disease resistant varieties of D. officinale. Methods The normal and infected by Colletotrichum gloeosporioides leaves of D. officinale were collected respectively, and to find out the differential metabolites through the sample pretreatment, GC-MS analysis, and bioinformatics analysis. Then the differential metabolites and analysis of metabolic pathways involved in the course of disease were carried on the preliminary discussion. Results The multidimensional statistical models of each analysis group were successfully established. The dispersion points of VIP > 1.0 were selected as the potential differential materials, combined with P < 0.05 in the analysis of single dimensional Statistics (test) as the standard to verify. A total of 84 differential metabolites screened from 305 identified metabolites were considered to be pathogenesis related metabolites. A total of 34 differential metabolites were found out to be involved in the metabolic pathways through the pathway enrichment analysis, and the obtained ZC-GB metabolic pathways were of significance. Conclusion Based on GC-MS technology, the metabolomics analysis of D. officinale samples (normal/infected) was carried out and the metabolites related to the course of anthracnosis of D. officinale were found out. It could lay the foundation for studying the disease of D. officinale and cultivating resistant varieties on molecular level.

Research progress in interaction mechanism of enveloped glycoproteins of human parainfluenza virus type 3 / 中华实验和临床病毒学杂志

Human parainfluenza viruses (hPIVs), a series of single-stranded RNA viruses of Paramyxoviridae, are the main pathogen of respiratory tract infection. hPIV3 is the main cause of lower respiratory tract infection leading to bronchiolitis and pneumonias in young children under the age of six months, and it is the second major pathogen only next to respiratory syncytial virus (RSV). In this paper, we mainly discuss two kinds of virulence-related surface glycoprotein of hPIV3: hemagglutinin-neuraminidase (HN) protein and fusion protein (F) by briefly introducing the protein structure and physiological functions of HN and F. According to the latest research progress, we focus on the models which have been postulated to explain how F and HN work in concert to bring about membrane fusion.

Interacción warfarina y acetaminofén Evaluación para establecer su relevancia clínica / Warfarin and acetaminophen interaction Assessment to establish its clinical relevance

Objetivo: realizar una revisión estructurada de la interacción warfarina y acetaminofén, buscando establecer su relevancia clínica y profundizar en el mecanismo de dicha interacción. Método: revisión estructurada en PubMed/Medline, de artículos en inglés y español, buscando los términos warfarin AND (acetaminophen OR paracetamol) en el título o resumen. La búsqueda se complementó con las referencias de artículos valorados como importantes. Los trabajos se agruparon en: relacionados con el aumento de sangrado por la interacción warfarina-acetaminofén, o relacionados con el mecanismo de la interacción. Resultados: se identificaron 45 artículos, de los cuales se incluyeron 15 en la revisión: 11 relacionados con el aumento del riesgo de sangrado por la interacción y cuatro con el mecanismo de la interacción. La gravedad del efecto (aumento de la probabilidad de sangrado) se consideró moderada; mientras que la probabilidad de aparición fue valorada como definida. Además, se identificó una relación entre la dosis de acetaminofén y el riesgo de sangrado. Por su parte, el N-acetil-para-benzoquinona-imina (metabolito del acetaminofén) inhibe enzimas del ciclo de la vitamina K y tiene un efecto sinérgico con el efecto anticoagulante de la warfarina. Conclusiones: la relevancia clínica de la interacción warfarina - acetaminofén es de riesgo alto, debido a que la gravedad del efecto (aumento del riesgo de sangrado) es moderada y su probabilidad de presentación es definida. Por tanto, estos dos medicamentos pueden ser utilizados conjuntamente, pero se debe realizar una estricta monitorización. El metabolito N-acetil-para-benzoquinona-imina es el responsable del aumento del efecto anticoagulante de la warfarina. (Acta Med Colomb 2013; 38: 22-27).

Objective: to make a structured review of the interaction between warfarin and acetaminophen, seeking to establish its clinical relevance and deepen in the mechanism of this interaction. Method: structured review of PubMed/Medline of articles in English and Spanish, looking warfarin and acetaminophen or paracetamol in the title or abstract. The search was complemented with references of articles rated as important. The papers were grouped in: related to increased bleeding due to warfarin-acetaminophen interaction, or related to the mechanism of the interaction. Results: we identified 45 articles, of which 15 were included in the review: 11 related to increased risk of bleeding due to the interaction and 4 with the mechanism of the interaction. The severity of the effect (increased likelihood of bleeding) was considered moderate, whereas the probability of appearance was rated as definite. In addition, we identified a relationship between the dose of acetaminophen and the risk of bleeding. In turn, the N-acetyl-para-benzoquinone-imine (metabolite of acetaminophen) inhibits enzymes of the vitamin K cycle and has a synergistic effect with the anticoagulant effect of warfarin. Conclusions: the clinical relevance of the interaction warfarin-acetaminophen is of high risk due to the fact that the severity of the effect (increased risk of bleeding) is moderate and the probability of its presentation is definite. Therefore, these two drugs can be used together, but a strict monitoring should be conducted. The metabolite N-acetyl-para-benzoquinone-imine is responsible for the increase in the anticoagulant effect of warfarin. (Acta Med Colomb 2013; 38: 22-27).

Potent in vitro interference of fleroxacin in DNA-binding, unwinding and ATPase activities of Bloom helicase / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the effect of fleroxacin (FLRX) on biological properties of Bloom (BLM) helicase catalytic core (BLM642-1290 helicase) in vitro and the molecular mechanism of interaction between the two molecules.</p><p><b>METHODS</b>DNA-binding and unwinding activities of BLM642-1290 helicase were assayed by fluorescence polarization and gel retardation assay under conditions that the helicase was subjected to different concentrations of FLRX. Effect of FLRX on helicase ATPase activity was analyzed by phosphorus-free assay based on a colorimetric estimation of ATP hydrolysis-produced inorganic phosphate. Molecular mechanism of interaction between the two molecules was assayed by ultraviolet and fluorescence spectra.</p><p><b>RESULTS</b>The DNA unwinding and ATPase activities of BLM642-1290 helicase were inhibited whereas the DNA-binding activity was promoted in vitro. A BLM-FLRX complex was formed through one binding site, electrostatic and hydrophobic interaction force. Moreover, the intrinsic fluorescence of the helicase was quenched by FLRX as a result of non-radioactive energy transfer. The biological activity of helicase was affected by FLRX, which may be through an allosteric mechanism and stabilization of enzyme conformation in low helicase activity state, disruption of the coupling of ATP hydrolysis to unwinding, and blocking helicase translocation on DNA strands.</p><p><b>CONCLUSION</b>FLRX may affect the biological activities and conformation of BLM642-1290 helicase, and DNA helicase may be used as a promising drug target for some diseases.</p>

Cloud Point Extraction of Bisphenol A from Water Utilizing Cationic Surfactant Aliquat 336 / 分析化学

Cloud point extraction(CPE) utilizing a cationic surfactant, tricaprylmethylammonium chloride(Aliquat 336), was carried out to separate and concentrate bisphenol A(BPA) from aqueous media. Cloud point phase separation of Aliquat 336 at room temperature(about 25 ℃) was induced by the addition of Na_2SO_4. The parameters affecting extraction efficiency, such as concentrations of Aliquat-336 and Na_2SO_4, pH, and equilibration time were evaluated. The results showed that the extraction efficiency was practically constant in the studied range of Aliquat 336, co-solvent(methanol), pH and dissolved organic matters. At the operational CPE conditions, distribution constant, K_D, of the distribution of BPA between the surfactant-rich and aqueous phases of the CPE system was estimated to be 10~4. Coupled to liquid chromatography with UV detection, the CPE method offered a detection limit of 0.34 μg/L in distilled water and recovery of BPA ranged from 90% to 108.6% with a sample volume of 50 mL in three matrices studied. The high extraction efficiency might be due to combination of ion-pair, hydrophobic effects and cation-π interaction, based on the micelles' size distribution and zeta potential analysis.