In this study, we established a novel bioassay to determine the activity of polyethylene glycolated recombinant human growth hormone (PEG-rhGH) using Nb2-11 cells. We performed experimental condition optimization and methodological verification, and then detected the relative potency of PEG-rhGH products using this method. We demonstrated that the bioactivity of PEG-rhGH in promoting Nb2-11 cell proliferation displays a dose-response relationship, which conformed to the four-parameter model. Using PEG-rhGH reference as a control, we analyzed the relative potency of six batches of PEG-rhGH products, as well as linearity, regression and parallelism of the obtained curves. The relative potency of six batches of PEG-rhGH products was 95% to 105%. These results implied that the new bioassay established may be employed in quality control of PEG-rhGH products.

Celastrol, extracted from Tripterygium wilfordii, is a natural pentacyclic triterpene compound, which has an anti-pulmonary fibrosis effect. However, its effect, binding targets and regulatory mechanism in pulmonary fibroblasts remain unclear. In this study, we found that celastrol could prevent fibroblast-myofibroblast transformation (FMT) by significantly inhibiting transforming growth factor β1 (TGFβ1)-induced α-smooth muscle actin and type Ⅰ collagen expression. Previous studies suggested that heat shock protein 60 (HSP60) may be the target of celastrol. This study confirmed the direct interaction between celastrol and HSP60 through cellular thermal shift assay and surface plasmon resonance experiment, and demonstrated that the K_D value of celastrol binding to HSP60 was 8.59 μmol·L^-1. Further studies showed that knockdown of HSP60 promoted TGFβ1-induced FMT, especially in the medium and low dose TGFβ1 treatment group, and that the anti-FMT effect of celastrol was significantly weakened after HSP60 knockdown. These results indicated that HSP60 was involved in maintaining the resting state of fibroblasts, and the anti-FMT effect of celastrol was dependent on HSP60. Furthermore, the autophagy promotion and antioxidant effects of celastrol were also weakened after HSP60 knockdown. In conclusion, celastrol inhibits FMT by targeting HSP60, thus exerting anti-pulmonary fibrosis function.

The composition of intestinal microflora is closely related to the occurrence and development of colorectal cancer (CRC). Among them, Fusobacterium nucleatum (Fn) has been proved directly related to the recurrence, metastasis and chemotherapy resistance of CRC. Therefore, it is of great significance for the prevention and treatment of colorectal cancer by the exploration potential anti-Fn drug targets and discovery small molecule drugs. However, no selective anti-Fn small molecule inhibitors have been reported so far as well as their anti-Fn thereby "anti-Fn further anticancer" mechanisms are unclear. Herein, this article reviews the potential therapeutic targets and small molecule ligands of Fn in order to provide a reference for the development of anti-Fn and anti-CRC small molecule drugs.

Sphingosine kinase (SphK), sphingosine-1-phosphate (S1P) and S1P receptor (S1PR) are involved in the tumor biological processes such as tumor cell proliferation and migration, and play an important role in the development of cancer. In recent years, researchers have increasingly focused on the interaction between cancer cells and the tumor microenvironment. The tumor microenvironment is genetically stable and can be induced to an antitumor phenotype, which has significant therapeutic advantages. Studies have shown that SphK/S1P/S1PR can regulate multiple aspects of the tumor microenvironment. This review summarizes the effects of SphK and S1P/S1PR signaling on the tumor microenvironment from four perspectives: tumor immune microenvironment, cancer associated fibroblasts, tumor angiogenesis and tumor hypoxic microenvironment, and also outlines potential drug research related to these signal molecules, aiming to elucidate the role of SphK/S1P/S1PR in tumor occurrence and development and provide new ideas for the research of anti-tumor drugs.

Exosome is a self-secreted phospholipid bilayer nanovesicles, and has shown great potential in drug delivery field due to the important advantages of low immunogenicity and homologous targeting. Phototherapy, mainly includes photodynamic therapy (PDT) and photothermal therapy (PTT), utilize light to activate photoactive drug for tumor cell killing. The advanced therapeutic strategy shows low toxic side-effect and non-invasion precise advantages, and thus has made great progress in tumor treatment over the past few years. Therefore, using exosomes as a drug delivery system to deliver phototherapeutic agents can improve therapeutic performances with a reduced side-effect, and further enhance their application potential for clinical tumor therapy. This review focus on the rising cross-subjects field involving exosomes and phototherapy, and mainly introduce the research progress and relative case of exosomes-based delivery system for cancer phototherapy. Additionally, the advantages and challenges of exosome-based phototherapy are also discussed and proposed.

The purity of 4,4′-dimethoxy-5,6,5′,6′-bis (methylenedioxy)-2′-morpholine methylenebiphenyl-2-methyl formate methanesulfonate (IMH), a new drug for fatty liver treatment, was determined through differential scanning calorimetry (DSC). Analysis of two-factor non repeatability method was performed in the investigation the effects of two factors (heating rate and sample weight) on purity determination. The DSC experimental parameters were optimized as follows: heating rate was 10 ℃·min^-1, temperature range was 150-300 ℃, sample weight was 2.0-4.1 mg, and N₂ flow rate was 80 mL·min^-1. The linear correlation coefficient (r) of this DSC method was 0.999 8. The RSD value (n = 6) of precision was 0.03%. The standard value and uncertainty of the purity results of the multiple batches of IMH drugs were (99.74 ± 0.29)%, (99.91 ± 0.28)%, (99.90 ± 0.28)%, and (99.81 ± 0.28)% with inclusion factor (K) of 2 and confidence probability (P) of 0.95. The results were basically consistent with the results of the mass balance method. The DSC mehod is a simple, rapid and accurate method, and provides a new reference method for determining the purity of IMH drugs, improves the accuracy and reliability of purity determination.

Protein-protein interaction (PPI) plays an important role in the regulation of life. Most of the PPI interfaces are large and discontinuous, and it is difficult for small molecules to specifically bind to them. Peptides are critical in PPI surface interactions due to their higher affinity and specificity. However, peptides have some defects such as easy hydrolysis by protease and poor membrane permeability. Due to good biocompatibility and chemical diversity, cyclic peptides play an important role in drug discovery. Therefore, the development of efficient cyclic peptide construction methods has become a frontier issue in peptide drug research. In recent years, a series of new progresses have been made in the synthesis strategy and the application of cyclic peptides, providing powerful technical tools for the research and development of cyclic peptide drugs. In this review, the synthesis strategies of cyclic peptides and their application will be reviewed from four aspects: synthesis strategies, property improvement, biological activity and prospect.

The last essential enzyme in the biosynthetic pathway of trilobatin, phloretin-4'-O glycosyltransferase (P4'-OGT), catalyzes the conversion of trilobatin to phloretin in vitro. However, only a few P4'-OGTs have been found in plants. This study used Malus domestica phloretin-4'-O glycosyltransferase (MdPh-4'-OGT) as a query to identify and clone two UDP-glucuronosyltransferase (UGT) genes, designated UGT74L2 and UGT74L3, from the transcriptome of Andrographis paniculata. According to a phylogenetic tree analysis, UGT74L2 and UGT74L3 belonged to the UGT74 family, which has been linked to several activities in other species. The in vitro enzymatic reaction demonstrated that UGT74L2 could particularly catalyze the formation of trilobatin from phloretin, but UGT74L3 had no effects. By using Ni-NTA affinity chromatography to extract the soluble UGT74L2 recombinant protein, the enzymatic kinetics of the activity was investigated using phloretin as the substrate. The results showed that the optimal temperature and pH for UGT74L2 enzymatic reaction were 40 ℃ and 8.0 (Tris-HCl system), respectively. Three metal ions (Ca²⁺, Mn²⁺ and Co²⁺) showed inhibitory effect on the activity of UGT74L2, while Mg²⁺ could improve the activity of UGT74L2. Other tested metal ions have no significant effect on UGT74L2. The results of enzymatic kinetic parameters that the K_m value was 29.84 μmol·L^-1, the k_cat was 0.02 s^-1, and the k_cat·K_m^-1 was 572.6 mol^-1·s^-1. By homology modeling, molecular docking and mutation experiments, we found that multiple amino acids residues around the substrate binding pocket play quite an important role during catalytic process, In summary, we identified a novel P4'-OGT gene from medicinal plant Andrographis paniculata and provided a new efficient catalyst to synthesize trilobatin. Meanwhile, this study provides a reference for mining new efficient glycosylation modules from plants.

The cis-emodin-emodin dianthrone (compound 1) and trans-emodin-emodin dianthrone (compound 2) were extracted from Polygonum multiflorum Thunb. The protective effect and mechanism of compound 1 and compound 2 (emodin-emodin dianthrones) on acute liver injury induced by concanavalin A (ConA) in ICR mice was first investigated. The results indicated that emodin-emodin dianthrones at 1 mg·kg^-1 significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) level (P < 0.05). Emodin-emodin dianthrones also improved liver histopathological damage in liver-injured mice. The level of Bcl-2-associated X protein (Bax) mRNA in liver was significantly reduced by 1 mg·kg^-1 of emodin-emodin dianthrones, while the level of B-cell lymphoma-2 (Bcl-2) mRNA expression was significantly increased (P < 0.05). The protective activity of compounds 1 and 2 against hepatocyte injury was further evaluated by hydrogen peroxide (H₂O₂)-induced hepatocyte injury. Compounds 1 and 2 significantly inhibited H₂O₂-induced hepatocyte injury and reduced the levels of ALT, AST, alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) in cell culture. Compounds 1 and 2 also significantly improved the cell survival rate and decreased H₂O₂-induced oxidative stress in hepatocytes. Compound 1 (0.5 µmol·L^-1) significantly increased the enzymatic activity of superoxide dismutase (SOD) in hepatocytes (P < 0.01), and 0.5 µmol·L^-1 of compound 2 significantly decreased the intracellular reactive oxygen species (ROS), increased SOD enzyme activity, and glutathione (GSH) content (P < 0.01). Compounds 1 and 2 at 0.5 µmol·L^-1 also inhibited hepatocyte apoptosis by increasing the protein expression ratio of Bcl-2/Bax (P < 0.05) and decreasing the protein expression ratio of cleaved caspase-3 and pro caspase-3 (P < 0.05). This study indicates that the emodin-emodin dianthrones from Polygonum multiflorum Thunb. have liver-protective activity. Compounds 1 and 2 exerted hepatoprotective effects by inhibiting apoptosis and oxidative stress. The study provides an important material basis for the hepatoprotective effect of commonly used amounts of Polygonum multiflorum Thunb.

In this study, we explored the mechanism of Huganning tablet (HGNP) in the treatment of nonalcoholic fatty liver disease (NAFLD) based on network pharmacology and computer-aided drug design. Firstly, the potential ingredients and targets of HGNP were identified from TCMSP database, Swiss Target Prediction database, Chinese pharmacopoeia (2015) and literatures, and then the targets of HGNP intersected with NAFLD disease targets that obtained in GeneCards database to acquired potential targets. The bioconductor bioinformatics package of R software was used for gene ontology (GO) enrichment and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis. The network of "potential ingredient-key target-pathway" was formed in Cytoscape software to study the interactions between potential ingredients of HGNP, key targets, pathways and NAFLD. Based on the results of network pharmacology, the molecular docking analysis of the key targets and potential active ingredients in HGNP tablets with top degree in the network was conducted using Discovery Studio 2020 software, followed by molecular dynamics simulations, binding free energy calculation, drug-likeness properties analysis and ADMET (absorption, distribution, metabolism, excretion and toxicity) properties prediction. In vitro, HepG2 cells were used to establish steatosis model, and the effects of five key compounds on hepatocyte steatosis were analyzed by oil red O staining and triglyceride (TG) content determination. The results showed that 141 ingredients and 151 potential targets were obtained. A total of 2 526 items and 151 pathways were identified by GO and KEGG enrichment analysis. The molecular docking suggested that five components, isorhamnetin, salvianolic acid B, emodin, resveratrol and rhein, exhibited strong binding ability with key targets [retinoic acid receptor RXR-alpha (RXRA), tumor necrosis factor (TNF), glycogen synthase kinase-3 beta (GSK3B), serine/threonine-protein kinase 1 (AKT1)]. It was further verified that isorhamnetin and salvianolic acid B bind to key targets with good structural stability and binding affinity based on molecular dynamics simulations and binding free energy calculations. The drug-likeness properties, pharmacokinetic properties and toxicity of five key compounds were more comprehensively analyzed through drug-likeness properties analysis and ADMET properties prediction. In vitro, all five compounds, isorhamnetin, salvianolic acid B, emodin, resveratrol, and rhein, improved hepatocyte steatosis of HepG2 cells, confirming the reliability of the present study. In conclusion, based on network pharmacology, computer-aided drug design and in vitro validation, this study investigated the mechanism of HGNP for the treatment of NAFLD at multiple levels and provided a basis for its clinical application.