Latest ArticlesK-values of 56 batches of 7 types of povidone were measured by microfluidic rheometry and with a Ubbelohde capillary viscometer. The K-values of the two methods were tested by SPSS software and the results showed that there was no significant difference between the two methods (P > 0.05). Taking K-values measured with the Ubbelohde capillary viscometer (Ku) as the abscissa and K-values measured by microfluidic rheometry (Km) as the ordinate a linear equation was calculated:Km=0.893 9Ku + 4.617 6, R2=0.986 2, with good linearity, indicating that the microfluidic rheometer method can replace the Ubbelohde capillary viscometer in determining K-values of povidone. The microfluidic rheometer method has the benefits of less sample consumption, faster determination, and is more accurate, and it can be used with high-throughput automatic acquisition, which provides a more convenient method for the determination of K-values of different types of povidone. The weight-average molecular weights (Mw) of each type of povidone were measured by gel permeation chromatography-multi angle laser light scattering (GPC-MALLS), and the relationship between Mw and Km was lgMw=-0.000 4 Km2 + 0.072 7 Km + 2.791, R2 =0.990 1. The fitting relationship was good, and Mw could be calculated by Km by the equation.
Epithelial cell adhesion molecule (EpCAM) is a popular target for cancer therapy. In this research, 3 nanobodies with high specificity and endocytosis activity against EpCAM were developed, which provides a basis for the study of immunotoxin based on EpCAM. In our preliminary experiments, we have immunized a camel with EpCAM-Fc antigen and constructed a high-quality phage display library. Seventeen nanobodies with different complementarity determining region (CDR) 3 sequences have been screened after 3 rounds of biopanning by phage display technology. The animal procedures were approved by the Institutional Animal Care and Use Committee (IACUC) of Fudan University School of Pharmacy. After purification, 7 nanobodies showed high cell binding activity by fluorescent activated cell sorting (FACS) identification. Furthermore, 3 nanobodies presented high endocytosis activity based on FACS and laser confocal microscopy, which also showed high affinity to EpCAM measured by ForteBio. According to this study, we aimed to provide a novel alternative approach to the EpCAM-targeted therapy and to provide guidance for the study of nanobody based immunotoxins for other targets.
Tumor immune therapy has been remarkably successful in recent years and several kinds of PD-1/PD-L1 (programmed death-1/programmed death-ligand 1) antibody drugs have been approved by the FDA for treatment of advanced malignant neoplasms. However, as biomacromolecules these antibody drugs have certain drawbacks such as high cost, injection-only administration and immunogenicity; thus, we turned to small molecules that have lower immune risks and better modifiability. Considering the structural diversity of natural products, we chose to investigate the active components in Panax ginseng, a famous and highly valued traditional Chinese medicine. Nine compounds were separated and identified in this research using a HPLC-coupled MS system, and 3 PD-1 binding compounds were identified using the SPR method. The PD-1/PD-L1 inhibitory ability of ginsenoside Rg1, as a representative ginsenoside, was verified by cytopharmacological methods. This research provides a new method for the identification of immune blockade inhibitors in natural products.
Dendrobium officinale Kimura et Migo (D. officinale) has been used as a valuable traditional Chinese medicine for more than 2 000 years in China. Modern research has confirmed a wide range of pharmacological activities, such as regulating blood sugar, improving gastrointestinal inflammation, and regulating immunity. Polysaccharides are the main active ingredients of D.officinale. With the intensive studies of the pharmacological activities of D.officinale, evidence for the pharmacological effects and potential mechanisms of D.officinale polysaccharides has increased dramatically. In this review, we summarized the latest progress in the pharmacological and mechanical studies of D.officinale polysaccharides, and based on the pharmacological efficacy and oral absorption and utilization characteristics of D.officinale polysaccharides, it is proposed that regulating the gut microbiota may be one of the key mechanisms for D.officinale to exert its beneficial effects. Research on the mechanism of D.officinale polysaccharides puts forward new research directions and prospects.
The technology of lipid-drug conjugates is developed on the basis of prodrug principle, which overcomes some drawbacks of drugs via increasing the lipophilicity of hydrophilic or poorly soluble drugs to promote the absorption of drugs and enhance the curative effect. This article sums up the research progress of lipid-drug conjugates from the chemical synthesis methods of conjugates, the types of conjugates, the influence on biological activity of drugs, the application in nanoparticles for drug delivery and the mechanism of absorption and degradation.
A high performance liquid chromatography charged aerosol detector (HPLC-CAD) method was established for the simultaneous determination of five saponins (notoginsenoside R1, ginsenoside Rg1, ginsenoside Re, ginsenoside Rb1, Ginsenoside Rd) in Yaobitong capsule, providing a method for quality control. The sample was extracted with methanol and chromatographic separation was performed on a Waters Xbridge Phenol column (150 mm×4.6 mm, 3.5 μm) using acetonitrile-water as the mobile phase with gradient elution at a flow rate of 1.0 mL·min-1. The column temperature was 30℃ and the injection volume was 10 μL. The nebulizer temperature of CAD was 35℃ and the air pressure was 60.2 psi, the filtration was 3.6 s, and the collection frequency was 5 Hz. Notoginsenoside R1, ginsenoside Rg1, ginsenoside Re, ginsenoside Rb1 and ginsenoside Rd showed a good linear relationship in the range of 16.96-203.5 μg·mL-1 (R2=0.999 3), 54.46-653.5 μg·mL-1 (R2=0.999 3), 10.96-131.5 μg·mL-1 (R2=0.999 6), 51.50-618.0 μg·mL-1 (R2=0.999 0), 15.94-191.3 μg·mL-1 (R2=0.999 4), respectively. The average recoveries were 98.96%, 100.8%, 94.76%, 100.1%, 103.1%, and RSDs were 0.87%, 1.46%, 1.85%, 2.06%, 0.96% (n=6), respectively. The proposed method is accurate, simple and reliable, and can be used for the determination of five saponins in Yaobitong capsule.
We utilized a multi-step derivatization gas chromatography-mass spectrometry method for the determination of common amino acid enantiomers, combined with deuterated hydrochloric acid hydrolysis, to identify nine trace D-amino acids in thymalfasin. We optimized the conditions for multi-step derivatization, the volume of reagent for redissolving samples, and the conditions for chromatography and mass spectrometry with isopropanol and trifluoroacetic anhydride as derivatization reagents, and validated the procedure, including sensitivity, linear range, precision, accuracy and recovery. Sixteen pairs of D/L-amino acids and glycine derivatives were separated within 29 min, with the limit of quantification as low as 0.09-2.79 μmol·L-1. Nine amino acid derivatives of thymalfasin showed a good linear relationship within the concentration range examined (r2>0.992 3). The precision results showed that RSD values were less than 10.90%. Accuracy test results of a reference substance ranged from 76.69% to 128.18%. Average recoveries of spiked samples ranged from 70.41% to 125.39%. For the nine D-amino acids assayed, D-Asp and D-Glu content in six batches of thymalfasin were highest, ranging 0.41%-0.49% and 0.25%-0.33%, respectively, with others less than 0.25%. The method is sensitive, efficient and reliable, available for seventeen common amino acids and their enantiomers, and works well with simultaneous determination of nine trace D-amino acids in thymalfasin, providing a reference for the comprehensive control of racemic peptide impurities in this synthetic polypeptide drug.
Liver fibrosis is a critical pathological structural basis of a variety of chronic liver diseases such as alcoholic liver disease, viral hepatitis and nodular cirrhosis, while liver regeneration is the key mechanism for protecting liver against multiple injuries, promoting inflammation resolution and reversing liver fibrosis. When fibrosis occurs after liver injuries, the alternation of liver regeneration status in fibrosis usually plays an essential role in the outcome of diverse liver diseases. In this review, the differences between "homeostatic regeneration", "normal regeneration" and "aberrant regeneration" were identified in terms of the occurrence conditions, the basic state of the liver, the effects on liver repair, the types of cells involved and the pathogenesis. Emphatically, we not only summarize the differences of mechanisms between "aberrant regeneration" and "normal regeneration" in the pathogenesis of liver fibrosis, but also elucidate the features of "aberrant regeneration" in various liver fibrosis models, as well as the therapeutic strategies for the treatment of liver fibrosis based on "aberrant regeneration", expecting to provide evidence and clues for considering the risks and proposing possible solutions in clinical treatment of liver fibrosis.
To screen active components of Desmodium styracifolium in protecting calcium oxalate monohydrate (COM) -induced human proximaltubular epithelial cell (HK-2) damage model, and furtherly explore its mechanism of action, total flavonoids of Desmodium styracifolium (TFDS) and eight flavonoids (schaftoside, isoschaftoside, vicenin-2, isovitexin, isoorientin, apigenin, luteolin and genistein) were tested by COM-induced HK-2 damage model. MTT assay was used to detect the effects of different components on the cell viability of COM-induced HK-2 damage model. The lactate dehydrogenase (LDH) release in the cell supernatant and the activity level of superoxide dismutase (SOD) and reactive oxygen species (ROS) of cell were detected by the kit. Western blot was used to detect the expression levels of NLRP3, caspase-1, HMGB1 in HK-2 of different groups. Compared with the model group, the cell activity was significantly increased after 24 h co-culture with TFDS and four flavonoids (isoorientin, apigenin, genistein and luteolin). These active components can reduce the LDH leakage and ROS in cell supernatant and increase the activity of SOD, with regulating the expression of NLRP3, caspase-1, HMGB1. TFDS, apigenin, isoorientin, luteolin and genistein can protect COM-induced HK-2 cell damage, including enhancing cell viability, protecting cell membrane integrity and enhancing oxidative stress, and regulate the expression of proteins related to NLRP3 inflammasome.
The aim of this research is to investigate the effects of resveratrol on the inflammatory factors, oxidative stress indexes and the related genes of nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in RAW264.7 macrophages induced by monosodium urate (MSU) and to provide a theoretical basis for the treatment of acute gouty arthritis (AGA). Different concentrations of resveratrol were used to treat RAW264.7 cells for 5 hours, then MSU was added to stimulate them for 24 hours. The proliferation of RAW264.7 cells were detected by CCK-8 method. The level of tumor necrosis factor α secreted by cells were detected by ELISA method. The content of reaction oxygen species (ROS) in cells were detected by 2', 7'-dichlorodi-hydrofluorescein diacetate (DCFH-DA) probe method. The contents of superoxide dismutase (SOD) and malonaldehyde (MDA) in cells were detected by the kits. The expression of Nrf2, Kelch like ECH related protein 1 (Keap1), NAD(P)H quinone oxidoreductase 1 (NQO1), HO-1 mRNA were detected by real time PCR method. The results showed that resveratrol could inhibit the proliferation of RAW264.7 cells, significantly inhibit the TNF-α level of RAW264.7 cells induced by MSU, significantly inhibit the expression of ROS and MDA, and increase the expression of SOD in RAW264.7 cells induced by MSU. Resveratrol could reduce the expression of Keap1 mRNA in RAW264.7 cells induced by MSU, and increase the expression of Nrf2, NQO1, HO-1 mRNA. It is suggested that resveratrol can inhibit the inflammatory response of RAW264.7 macrophages induced by MSU, and improve the antioxidant capacity of macrophages by regulating Nrf2/HO-1 signal pathway.