Latest ArticlesFifteen compounds were isolated from the 95% ethanol extract of the whole plant of Elephantopus tomentosus L. by silica gel column chromatography, Sephadex LH-20 column chromatography, MCI column chromatography and semi-preparative HPLC methods. Their structures were identified on the basis of physicochemical properties, and spectral data (UV, IR, NMR, MS and CD) analysis as tomenlephanlide A (1), molephantinin (2), molephantin (3), 8-O-methacryloylelephanpane (4), apigenin (5), tricin (6), 2-phenyl acetamide (7), 3, 4-dihydroxybenzoic acid methyl ester (8), caffeic acid methyl ester (9), caffeic acid ethyl ester (10), (+)-(4S)-(2E)-4-hydroxy-2-nonenoic acid (11), E-4-hydroxyhex-2-enoic acid (12), 1H-indole-3-carboxylic acid (13), 1H-indole-3-carbaldehyde (14) and isohematinic acid (15). Among them, compound 1 is a new germacrene-type sesquiterpenoid, 5-15 were obtained from E. tomentosus L. for the first time. It was the first time the absolute configuration of compound 2 was reported. Compound 1 showed weak cytotoxicity against gastric cancer cells (SGC-7901).
The aim is to study the tissue distribution characteristics of eight effective components in normal rats after oral administration of Ziziphi Spinosae Semen (ZSS) aqueous extract. An ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) analysis method was developed and validated for the determination of four flavonoids and four saponins in rat tissue using puerarin and ginsenoside Re as the internal standard (IS), respectively. Tissue samples including the heart, liver, spleen, lung, kidney, muscle, brain, small intestine, and serum, were collected from each rat at 0.5 h, 1.0 h, and 2.0 h after oral administration of ZSS aqueous extract (15 g·kg-1). All calibration curves exhibited good linearity (r > 0.994 6) over a wide concentration range for all components. The intra-day and inter-day precisions (RSD) at four different levels were both less than 19.77%, and the accuracies (RE) ranged from -19.68% to 19.46%; The extraction recoveries of the eight components ranged from 86.70% to 114.29%, and the matrix effects were from 82.14% to 114.57%. The validated method was successfully applied to the tissue distribution study of the eight components. The levels of swertisin, spinosin, 6‴-feruloylspinosin, and kaempferol-3-O-rutinoside in the small intestine were highest, then followed by the kidney, heart, and liver. Meanwhile, the levels of jujuboside A (JuA), jujuboside B (JuB), and jujuboside A1 (JuA1) in the small intestine were highest, then followed by the lung, spleen, and kidney. The concentrations of betulinic acid in the small intestine were higher than heart, lung, kidney, and liver. The flavonoids and saponins of ZSS with extremely low content could pass through the blood-brain barrier. The research results will provide an experimental basis for explaining the mechanism of nourishing the heart and tranquilizing the mind of ZSS. The animal experimental operations involved in this study followed the regulations of the Animal Ethics Committee of Shanxi University of Chinese Medicine and passed the animal experimental ethical review (No. 2021DW172).
Pro-inflammatory macrophages play key regulatory role in the occurrence and development of rheumatoid arthritis (RA). In this study, we constructed a celastrol (Cel)-loaded polyamide-amine dendrimer (PAMAM) drug delivery system, which could target folate receptor and mitochondria. It could target inflammatory macrophages and realize chemo-photothermal synergistic therapy. Using PAMAM as the nano-carrier, folate receptor-targeting group folic acid (FA) and mitochondria-targeting group IR808 (also known as the photothermal agent) were conjugated with PAMAM through amide reaction, and then complexed with anti-inflammatory drug Cel to prepare the FA-PAMAM-IR808/Cel nanocomplex. In vitro characterization results showed that the drug loading efficiency of the nanocomplex was 50.90%, particle size was between 130 and 160 nm, average potential was between 1.0 and 3.5 mV, the drug release showed pH sensitivity, temperature reached to 42.5 ℃ after near-infrared (NIR) light irradiation for 10 min. In vitro cellular uptake experiments showed that the nanocomplex had obvious folate receptor-targeting and mitochondria-targeting ability. Following irradiation with NIR light, the cytotoxicity and cellular apoptosis enhanced. The secretion of pro-inflammatory factors tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6 and nitric oxide (NO) decreased in a concentration-dependent manner. This study provided insights for the development of novel anti-RA nanomedicines.
From the process of human immunodeficiency virus-1 (HIV-1) invading cells, the combination of gp120 and CD4 is the first step for HIV-1 to invade cells. Interfering with this process can prevent HIV from recognizing target cells and inhibit virus replication. Therefore, HIV-1 gp120 is an important part of the HIV-1 life cycle. Fostesavir, a phosphatate prodrug derived from the gp120 inhibitor BMS-626529 modified by the prodrug strategy, was approved for the treatment of adult patients with multidrug resistant HIV-1 infection by the US FDA and the European Medicines Agency in 2020 and 2021, respectively. In this review, we focus on the research progress of small molecule inhibitors targeting the interaction of gp120-CD4 from the perspective of medicinal chemistry, in order to provide reference for the subsequent research of gp120 inhibitors.
Superoxide dismutase (SOD) is a key enzyme that scavenge superoxide anion free radical (O2·-) in vivo, and plays an important role in plant growth and development and stress. In this study, according to the genome and transcriptome data of Salvia miltiorrhizae, 9 SOD genes were identified and the expression patterns of SOD family genes were further analyzed, including 5 Cu/Zn-SOD, 2 Fe-SOD and 2 Mn-SOD. On the basis of proteomic analysis, combined with transcriptome data, one full-length cDNA of Mn-SOD gene, namely SmMSD2 was cloned from Salvia miltiorrhizae. The results of amino acid sequence alignment and phylogenetic analysis showed that SmMSD2 protein belongs to the manganese superoxide dismutase (Mn-SOD) subfamily, and SmMSD2 protein shares high sequence identity with the Mn-SOD proteins of various plants that all contain a C-terminal conserved metal-binding domain "DVWEHAYY". The prokaryotic expression vector pMAL-c2X-SmMSD2 was constructed and transformed into E. coli BL21 expressing strain, and the target recombinant protein was successfully induced and its enzymatic properties were analyzed. Spatiotemporal expression analysis showed that SmMSD2 gene was expressed in all tissues, indicating that SmMSD2 gene was constitutively expressed at a stable level. Real-time quantitative PCR indicated that drought (15% PEG6000), abscisic acid (ABA) and indole-3-acetic acid (IAA) could induce the expression of SmMSD2 gene, suggesting that SmMSD2 may be involved in the response of Salvia miltiorrhizae to abiotic stress such as drought, as well as the signaling pathways of phytohormone ABA and IAA. These results lay the foundation for further elucidating the involvement of superoxide dismutase in the stress response and accumulation of active components of Salvia miltiorrhiza.
Along with the progress of pharmaceutical science in the past century, the theme of pharmacology has gone through pseudo agent scheme, to ligand-receptor model, and then to the theory of targeted therapy today. Due to the success of drug R&D, current drug research keeps its focus mainly on drugs with single target and precise treatment, in which the molecular mechanism is relatively clear but the therapeutic efficacy is often limited. Thus, there is a big space for exploration in the field of pharmacology. In the past 30 years, several novel chemical drugs, originated from traditional Chinese medicine, have been identified and then used in clinic, provoking a strong interest to explore new theory for pharmacology, of which the term of "Biao Ben Jian Zhi" (treating diseases by directing symptoms and root causes) has demonstrated a promising nature. We consider this concept useful for future drug discovery, drug design and clinical therapy. In this review, example drugs such as berberine, metformin and azvudine, are discussed, and "drug Cloud" (dCloud) model is introduced to elaborate the mechanism of treating diseases by directing symptoms and root causes of diseases.
Carnosic acid (CA) is the main phenolic diterpenoid active ingredient in plants such as rosemary and sage, and has antiviral, antioxidant, anti-inflammatory effects and so on, however, its antiviral activity against influenza virus infections was not reported. In this study, antiviral activities against influenza A virus infections of three main bioactive ingredients from rosemary, including rosmarinic acid, CA and ursolic acid, were evaluated using virus titer titration assay, and CA showed remarkable inhibition on influenza H5N1 replication in A549 cells. The antiviral activity of CA was further confirmed and its mechanism of action was investigated using the indirect immunofluorescence assay (IFA), Western blot and real-time fluorescence quantification polymerase chain reaction (qRT-PCR). The results showed that the 50% effective concentration (EC50) of CA against influenza H5N1 in A549 cells and MDCK cells were 4.30 and 3.64 μmol·L-1, respectively. Meanwhile, CA also showed inhibition on influenza virus 2009panH1N1 (EC50: 10.1 μmol·L-1) and H3N2 (EC50: 12.8 μmol·L-1) replications in A549 cells. Mechanistic studies showed that antiviral activity of CA is related to its induction of heme oxygenase-1 (HO-1) in A549 cells and suppression on production of reactive oxygen in H5N1-infected cells.
The metabolism study of radiolabeled drugs plays an important role in the development of new drugs. It provides information on drug absorption, metabolism, tissue distribution and excretion, and plays an irreplaceable role in the metabolite safety evaluation and mass balance of new drugs. The new guidance draft on clinical trials of radiolabeled drugs recently released by the US FDA puts forward higher standards and has been widely concerned by the industry. In recent years, in the research and development of new drugs in China, 14C labeled drugs have been used to carry out clinical metabolism studies, which has overcome key technical bottlenecks and accumulated experience. This paper summarizes the above research progress, analyzes the existing problems, and preliminarily looks forward to the future technological development and application.
Asialoglycoprotein receptor (ASGPR) is highly expressed on the surface of parenchymal liver cells. It can specifically recognize and bind to desialylated glycoproteins which contain terminal galactose or N-acetylgalactosamine residues, and endocytosed by clathrin-mediated endocytosis, transported and then degraded in lysosome. Based on this character, ASGPR mediated liver-targeted drug delivery is likely to increase drug distribution, reduce potential side effects and lower dose. This article reviewed the expression, structure, ligand binding and endocytosis of ASGPR, and summarized the design and optimization of ASGPR ligands and the release strategies. Finally, we put forward some expects about the clinical drug development for ASGPR.
Developmental changes in children can affect drug disposition and clinical effects. A physiologically-based pharmacokinetic (PBPK) model is a mathematical model that can be used to predict blood drug concentrations in children and gain insight into age-dependent physiological differences in drug disposition impact. Pediatric PBPK (P-PBPK) models have attracted attention over the past decade. With the concerted efforts of academia, pharmaceutical companies, and regulatory agencies, there are more and more examples of pediatric clinical studies using PBPK models. Nevertheless, the number of P-PBPK models and their predictive performance still lag behind adult models. By referring to the literature, we study the process of children adapting to adult absorption, distribution, metabolism, and excretion (ADME) parameters and analyze the general principles of P-PBPK model establishment. In addition, we summarize the functions and application examples of commonly used P-PBPK modeling software to provide a basis for the rational application of modeling software.