Latest ArticlesTumor 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.
Eighteen dihydroartemisinin-fluoroquinolone molecules conjugated with L-homoserine were designed and synthesized using fragmented drug splicing approaches. The in vitro activities of the synthesized conjugates against Mycobacterium tuberculosis (MTB) and the lipid-lowering target PCSK9 were evaluated. The bioassay test results showed that most of the synthesized molecules had anti-tuberculosis (anti-TB) activity. Five compounds showed greater than 80% inhibitory activity against MTB in the replication state and three compounds exhibited more than 50% inhibitory activity against H37Rv in the non-replication state. A structure-activity relationship analysis demonstrated that TM2 series compounds (Boc protection) have better anti-TB activity than TM1 series compounds (Cbz protection). There were 13 compounds with strong inhibitory activity toward PCSK9 (>73%) and TM1-3 compounds reached 92%. The determination of physical parameters showed that all the molecules are largely nontoxic. The structure-toxicity relationship analysis showed that the safety of TM2 is higher than that of TM1 in all parameters, perhaps related to the protecting group of the amino acid in the target molecule, and provides new ideas for the design and structural modification of subsequent molecules. This study sets a precedent for L-homoserine as a linking structural unit in multi-target drug molecules.
Ferroptosis is a cell death path for the abnormal accumulation of iron dependent reactive oxygen species, which leads to the dysregulation of redox homeostasis. As a new type of cancer treatments, ferroptosis has attracted extensive attention of researchers. With the development of nanoscience, various functional nanomaterials can produce H2O2, exhaust glutathione, and gather Fenton reaction catalysts in tumor site. Therefore, these nanomaterials can play a stronger role in tumor inhibition in coordination with the ferroptosis-inducing agents. Firstly, this paper introduced the mechanism of ferroptosis and the feasibility of ferroptosis-inducing strategy in cancer therapy. Secondly, we summarized the construction strategies of the ferroptosis-inducing nanomedicines for cancer therapy, including accelerating intracellular Fenton reaction, inhibiting the activity of glutathione peroxidase 4, and increasing the exogenous delivery of lipid peroxides. In addition, we also discussed the combination therapy based on ferroptosis, including the combination of ferroptosis with traditional therapy strategies (combined with apoptosis-inducing drugs, immunotherapy and gene therapy) and external energy (including ultrasound therapy and photodynamic therapy). Finally, the expectations and challenges of ferroptosis-inducing nanomedicines for cancer therapy in the future were discussed.
Glucagon-like peptide-1 (GLP-1) could increase the level of cyclic adenosine monophosphate (cAMP) in cells to stimulate insulin secretion in β cells of pancreas. So GLP-1 analogues, such as liraglutide, have become new anti-hyperglycemia drugs for type 2 diabetes. In this study, a set of in vitro activity detection method suitable for GLP-1 analogues was established using GLP-1R-GFP (green fluorescent protein, GFP)-HEK293A cells which stably expressing GLP-1 receptor (GLP-1R). After optimizing the detection parameters such as assay sensitivity, cell density, and the incubation condition, the cAMP content level of GLP-1R-GFP-HEK293A cells stimulated by four GLP-1 analogues, such as liraglutide, were detected by homogeneous time-resolved fluorescence (HTRF). The values of concentration for 50% of maximal effect (EC50) of GLP-1 analogues were calculated by cAMP dose-response curve to evaluate the in vitro activity of those drugs. In addition, enzyme-linked immunosorbent assay and quantitative polymerase chain reaction were applied to determine the content of host cell protein and host residual DNA, respectively. This study provides a stable, reliable, and sensitive in vitro activity analysis and host impurity detection method for high-throughput screening of GLP-1 analogues.
The 2-oxoglutarate-dependent dioxygenase (2-ODD) gene is regarded as the key enzyme gene involved with aryl naphthalene lignan-podophyllotoxin synthesis. To study the expression pattern and function of the Sc2-ODD gene, a full-length cDNA of the gene was cloned. Bioinformatic analysis, the expression pattern, and prokaryotic expression and purification were implemented. The open reading frame of Sc2-ODD gene was 1 077 bp and encoded 358 amino acids with a molecular weight of 40.16 kD. The Sc2-ODD protein contained the conserved 2OG-FeII-oxy sequence of the 2-ODD protein. The results of phylogenetic analysis revealed that Sc2-ODD is most closely related to Corchorus olitorius 2-ODD. qRT-PCR results showed that Sc2-ODD expression displayed obvious up-regulation at the fruit-swelling stage, then down-regulation in the fruit-coloring period. The Sc2-ODD gene was cloned into the bacterial expression vector pGS21T, the recombinant Sc2-ODD protein was expressed in Escherichia coli Rosetta (DE3) cells and the fusion protein was obtained and purified by GST fusion protein purification technology. This study will lay a foundation for further research on the function and expressional regulation of the Sc2-ODD gene in the aryl naphthalene lignans biosynthesis pathway, and also provides a scientific basis for improving the lignan content and the medicinal quality of Schisandra chinensis using plant genetic engineering.
The chemical structures of new components of Epimedium were deduced and verified by combining the secondary metabolism of Epimedium flavonoids with high resolution mass spectrometry. Based on the literature of Epimedium chemistry, the biosynthesis pathway of Yinyanghuo was constructed, and the possible metabolites were deduced. This metabolite information was entered into the PeakView software program and the ions meeting the quality error of less than 5 ppm with correct isotope distribution and containing secondary fragments were taken as the target compounds. Through the use of the software Formula Finder, Mass Calculators, online database (ChemSpider, Metlin, HMDB, etc.) and the fragmentation law of secondary fragments, the chemical structures of 22 metabolites were determined. One new component and eight new compounds were identified in 54 batches of Epimedium samples from 15 varieties by high resolution mass spectrometry. This study avoids the long time and tedious steps of phytochemical separation, saves experimental costs, and provides a new method for the analysis and identification of secondary metabolites with pharmacodynamic activity.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen that caused the global COVID-19 outbreak. The 3C-like protease (3CLpro) of SARS-CoV-2 plays a key role in virus replication and has become an ideal target for antiviral drug design. In this paper, we report the validation and use of bioluminescence resonance energy transfer (BRET) technology to establish a cell-based assay for screening for SARS-CoV-2 virus 3CL protease inhibitors. The results show that the method is able to monitor the cleavage efficiency of 3CL protease with good reproducibility (Z' factor is 0.59), and is consistent with antiviral activity analysis in cell culture. This work demonstrates that this method can be applied to the screening and evaluation of 3CL protease inhibitors, providing a powerful tool for the development of new drugs.
Drug metabolites in the systemic circulation can be closely related to the safety or efficacy of drugs, so it is necessary to evaluate the pharmacokinetics of both the parent drug and its major metabolites in plasma. Bisthianostat, a novel histone deacetylase (HDAC) inhibitor, is currently under development. An LC-MS/MS method was developed and validated for the simultaneous determination of bisthianostat and its hydrolyzed N-hydroxyamide metabolite M351 in human plasma to evaluate their pharmacokinetic characteristics in humans. After extraction from the plasma by acetonitrile-induced protein precipitation, the analytes and endogenous substances were separated on a Waters BEH C18 column (2.1 mm×50 mm, 1.7 μm). The mobile phase consisted of acetonitrile and 5 mmol·L-1 ammonium acetate (containing 0.2% formic acid, v/v) for gradient elution. Positive electrospray ionization was performed using multiple reaction monitoring (MRM) with transitions of m/z 367.1→235.0 for bisthianostat, m/z 352.1→207.0 for M351, m/z 371.1→235.0 for d4-bisthianostat, and m/z 357.1→208.0 for d5-M351. The method was linear over a concentration range of 2.00-2000 ng·mL-1 for bisthianostat and 4.00-4 000 ng·mL-1 for M351. The results of quality control samples showed that the intra-and inter-day precision were no more than 6.2% for bisthianostat and 6.8% for M351. The accuracy ranged from -1.1% to 4.3% for bisthianostat and -0.5% to 4.9% for M351. The pharmacokinetic results show that after a single oral administration of 100 mg bisthianostat, the time to peak (tmax) of M351 in the plasma of three patients with tumors was significantly longer than that of the parent drug (tmax was 4.00 h and 0.67 h, respectively), and the Cmax and plasma exposure of M351 were about 1.7 times and 11 times higher, respectively, than that of the parent drug. This clinical trial was approved by the society of ethics and conducted in Renji Hospital, Shanghai Jiaotong University School of Medicine.
The pharmacodynamic material basis and mechanisms of Ju-Hong Tan-Ke liquid (JHTKL) for its anti-tussive, anti-asthmatic and expectorant effects were investigated by using network pharmacology. We collected, screened, and predicted potential targets and signaling pathways for 24 compounds in the 8 herbs of JHTKL and grouped them according to their efficacy. Combined with the evidence analysis in the literature database, we explored molecular mechanisms of the components of this formula in different diseases and analyzed their compatibility laws. To verify the network analysis results, we used software to perform molecular docking of a part of the pivotal targets with their corresponding compounds. The results show that the main active ingredients in JHTKL may be naringin, L-ephedrine, glaucogenin C, amygdalin, deoxyschizandrin, neotuberostemonine, pachymic acid and glycyrrhizic acid. Moreover, efficacy groups of JHTKL may play a role by acting on pivotal gene targets such as the muscarinic acetylcholine receptor M1, acetylcholinesterase, beta-2 adrenergic receptor, prostaglandin G/H synthase 2, tumor necrosis factor, epidermal growth factor receptor and biological pathways such as the neuroactive ligand-receptor interaction, cholinergic synapses, calcium signaling pathway, NF-kappa B signaling pathway, MAPK signaling pathway, and PI3K-Akt signaling pathway. In this study, we have confirmed the pharmacodynamic material basis and mechanisms of JHTKL by using network pharmacology, laying a foundation for improving the quality standards of JHTKL and providing a reference basis for its potential expansion in clinical applications.
Chalcone synthase (CHS) is the rate-limiting enzyme involved in the biosynthetic pathway of flavonoids in Glycyrrhiza uralensis. It plays an important role in the regulation and control of flavonoids biosynthesis. In this study, X-ray irradiated G. uralensis samples with high or low content of flavonoids were studied. The CHS gene polymorphism in these samples were analyzed, the specific haplotypes were identified, and CHS function was parsed. 109 CHS cDNA sequences with a length of 1 170 bp were cloned, 220 variable sites (116 missense mutation sites) were found and 85 haplotypes were identified, which encoded 65 amino acid sequences with 96 variable sites. aa-20 and aa-45 were the most common amino acid sequences in samples with high flavonoid content, while aa-11 was the most sequence in samples with low flavonoid content. Molecular docking results showed that the mutation sites at 383 in aa-20 and 229 in aa-45 were related to substrate binding, while the mutation sites at 383 and 229 in aa-11 were not involved. Therefore, we speculate that the two mutation sites have significant influence on the function of CHS. We analyzed a large number of CHS cDNA sequences and identified the important functional sites, which will provide a basis for further functional studies. This paper will provide ideas for further research of the molecular regulation of the flavonoid biosynthetic pathway in G. uralensis.