Most peptides have high binding affinity and good selectivity for endogenous receptors and are good lead compounds to develop into drugs. Many approved drugs are derived from the structural optimization of peptide molecules, such as the antihypertensive drug captopril and the anti-hepatitis C drug telaprevir. At present, the main problems in the development of peptide drugs include poor stability, short half-life, and high plasma clearance rate; lack of oral availability and poor patient compliance, a complex production process, and high production cost. Therefore, rational modification of peptides can not only reduce the production cost, but also improve the druggability of the peptides. Here we review structural modification strategies for peptides from the perspective of improving their physicochemical properties. These modification strategies are divided into two parts:one is modification of the peptide backbone, including unnatural amino acid modification, pseudopeptide strategy, inverse-peptide strategy, cyclization strategy, and terminal structure modification. Another is modification of the side chains of peptides, including fatty acid conjugation, polyethylene glycol conjugation, protein fusion strategy, and cholesterol conjugation.

Neuropathic pain (NP), as a kind of chronic pain syndrome, seriously endangers the quality of life of patients, and the pathogenesis is complex, clinical treatment is limited, and it is easy to relapse. More and more reports have found that Wnt signaling pathway is closely related to the occurrence and development of neuropathic pain. Therefore, further study of the Wnt signaling pathway may provide useful ideas for exploring the pathogenesis of NP and discovering effective treatment methods. This article reviews the role and mechanism of Wnt signaling pathway in neuropathic pain.

The property of medicine is the "identity card" of traditional Chinese medicine (TCM), and the key to crack the theory of property of TCM. Based on molecular thermodynamics, the effects of interaction between TCM and organs in vitro were studied from the perspective of micro-energy release and absorption in order to construct a new idea of characterizing meridian theory. Scutellaria baicalensis, for example, application of isothermal titration calorimetry (ITC) were used to determine the energy changes during the interaction of Scutellaria baicalensis and its main active ingredient baicalin with brain, heart, lung, spleen and kidney in vitro, comparison including the association constant (K_a) and disassociation constant (K_d), combined with thermodynamic parameters, such as stoichiometry ratio (n), enthalpy change (ΔH), entropy change (ΔS), Gibbs free energy (ΔG), it is found that the interaction intensity between Scutellaria baicalensis and lung is significantly stronger than that of other organs, which is consistent with the theory of the return of Scutellaria baicalensis in ancient books. In addition, baicalin, the main active ingredient, showed the same action pattern as Scutellaria baicalensis. The thermodynamic parameters analysis showed that the action was a weak bond-induced spontaneous chemical binding reaction driven by both entropy and enthalpy. The results of specific curl measurement further proved the interaction between baicalin and lung, and were consistent with the results of ITC titration, indicating that ITC could be used to characterize the meridian tropism of TCM. Therefore, based on ITC, it is scientific and feasible to characterize the meridian of TCM by the energy change of the interaction between the decoction of TCM and its active components and the in vitro tissues respectively. This experiment provides a new idea for the discussion of meridian of TCM.

To explore the affect and mechanisms of rapamycin on mesangial cell proliferation and cell cycle, rat mesangial cells (HBZY-1) were cultured and divided into the six groups:normal; normal with platelet derived growth factor (PDGF) 20 ng·mL^-1; PDGF + rapamycin 1, 10, 100, 1 000 nmol·L^-1. The cell proliferation was measured by MTT in 24 and 48 h; flow cytometry was used to detect the cell cycle phase. Western blot was performed to determine cyclin D1, cyclin E, cyclin-dependent kinase 2 (CDK2), cyclin-dependent kinase 4 (CDK4), p27, p70S6K/p-p70S6K protein expression. The p27 mRNA was detect by Real-time PCR. The results showed that rapamycin significantly suppressed PDGF induced glomerular mesangial cells (MCs) proliferation in a dose and time-dependent manner, but with the dose increased (1 to 1 000 nmol·L^-1), the time dependence gradually weakened. Rapamycin inhibited mesangial cell proliferation and arrested the cell cycle in the G0/G1 phase. PDGF at 20 ng·mL^-1 significantly increased the expression of cyclin D1, cyclin E and CDK2, CDK4 (P < 0.05), but rapamycin did not affect the expression of cyclin D1, cyclin E and CDK2, CDK4. Rapamycin can significantly inhibited p70S6K phosphorylation, up-regulated the expression of p27 protein and mRNA. Collectively, rapamycin has the effect of inhibiting the glomerular mesangial cells proliferation of mesangial cells by regulating the transcription of p27 mRNA, increasing its protein expression through the mTORC1/p70S6K pathway, resulting in decreased activity of cyclin-CDK, and blocking cell cycle in G0/G1 phase.

Oral transmucosal drug delivery can be defined as the administration of drug through the oral mucosa to achieve systemic effects. It has the advantages of high bioavailability and rapid drug response. In this review, we introduce the physiology of oral mucosa, and analyze the factors affecting the pharmacokinetic properties of oral transmucosal drug delivery in detail, such as physiological barriers, different administration sites, physicochemical properties of drugs, dosage forms, and formulation strategies. In addition, we describe the methods to evaluate the pharmacokinetic properties of this delivery systems, including in vitro permeability studies, buccal absorption studies, in vivo pharmacokinetic studies and physiologically based pharmacokinetics (PBPK) modeling, which provide methods and reference for the development of oral transmucosal drug delivery systems.

To determine the relationship between the effect of wuzhi capsules on the blood concentration of tacrolimus as compared to diltiazem and with regard to cytochrome P450 (CYP)3A5 gene polymorphisms, 170 patients who underwent renal transplantation from November 2014 to March 2018 and used tacrolimus combined with diltiazem 30 mg bid were selected in this study retrospectively. Patients were divided into an observation group (105 patients) and a control group (65 patients) according to whether they used wuzhi capsules after the operation. The polymorphisms of CYP3A5*3 were determined and the effect of wuzhi capsules on the blood concentration of tacrolimus, as compared with that of diltiazem was determined in patients with different CYP3A5*3 genotypes. This study complies with relevant ethical norms. The results show that compared with diltiazem, an increase of tacrolimus C₀/D was significantly correlated with the patient's CYP3A5*3 genotype in both the self-control and the control group. CYP3A5 expressers in the observation group were able to increase the tacrolimus C₀/D by about 76.8% by replacing the wuzhi capsules with diltiazem, but this effect was not observed in CYP3A5 non-expressers. In CYP3A5 expressers wuzhi capsules had a greater ability relative to diltiazem to increase the blood concentration of tacrolimus.

Uranium[U(Ⅵ)] in the blood is known to form stable complexes with apotransferrin (apo-Tf), which plays an important role in mediating the cytotoxicity induced by U(Ⅵ) transported to cells. The present study aimed to establish an new in vitro screening model of U(Ⅵ) decorporation agents through exploring the capability of chelating agents competing with U(Ⅵ) binding to apo-transferrin based on enzyme-linked immunosorbent assay (ELISA). The optimal concentrations of apo-Tf coated antigen, Tf antibody, secondary antibody and U(Ⅵ) treatment were achieved and the stability and reproducibility of this method were validated by methodology study. Using this model, the ability of four chelating agents to mobilize the U(Ⅵ) binding to apo-Tf was evaluated, and the rank of competitiveness was catechol-3, 6-bis(methyleiminodiacetic acid) (CBMIDA) ≈ Tiron > apo-Tf > DTPA-CaNa₃ ≈ DTPA-ZnNa₃. The efficacy of these chelating agents in removal of U(Ⅵ) was tested by animal experiments. The results showed that immediate administration of CBMIDA or Tiron after injection of U(Ⅵ) in mice significantly promoted urinary U(Ⅵ) excretion and reduced U(Ⅵ) accumulation in kidneys and femurs, while DTPA-CaNa₃ and DTPA-ZnNa₃ have no obvious effects as compared to U(Ⅵ)-exposed mice alone, which was consistent with the results of competitive ELISA method. The animal experiments conform to the rules of the Animal Research Ethics Committee of School of Pharmacy of Fudan University. These results show that the new proposed method is rapid, simple and convenient with good reproducibility and has the potential to be used for in vitro screening of U(Ⅵ) decorporation agents.

Eight triterpenes were isolated from the methanol extract of Galbanum by various chromatographic methods including silica gel, ODS opening column, recrystallization and semi-preparative HPLC. Their structures were determined by spectroscopic methods and physicochemical properties as 3β, 19α, 21α-trihydroxyl-12-en-28-oic acid (1), sumaresinolic acid (2), 3β, 19α-dihydroxyl-12-en-28-oic acid (3), oleanolic acid (4), 3β, 6β, 19α-trihydroxyl-12-en-28-oic acid (5), 19α-hydroxy oleanonic acid (6), 6α-hydroxy oleanonic acid (7), and (11R, 12R)-3α, 6α-dihydroxy-epoxyolean-28α, 13α-olide (8). Among them, compound 1 is a new compound, while compounds 2-8 were newly isolated from the Apiaceae family. The ability of compounds 1-8 to inhibit cholinesterase was determined with an improved Ellman method. Compound 1 showed strong inhibitory activity against butyrylcholinesterase. The molecular docking results indicated that Trp82, His438, Phe329 and Ala328 played an important role in the binding of compound 1 to butyrylcholinesterase.

The objective of this research was to clone 1-deoxy-D-xylulose 5-phosphate reductoisomerase gene (MoDXR) and its promoter sequence from Morinda officinalis and carry out bioinformatic analysis, cis-acting elements analysis, and prokaryotic expression. On the basis of the MoDXR gene sequence obtained from the M. officinalis transcriptome and with NCBI-ORFfinder analysis, a pair of specific primers were designed, and used for RT-PCR amplification. The promoter region sequence at the 5' end of MoDXR gene was isolated by the genome walking technique. Localization of MoDXR was carried out by subcellular analysis. The prokaryotic expression plasmid pET-28a-MoDXR was constructed and transfected into Escherichia coli BL21(DE3) chemically-competent cells; the recombiant plasmid expressed fusion protein after the induction by IPTG. The full-length cDNA of MoDXR was 2 015 bp, and open reading frame (ORF) size was 1 425 bp, and it encoded 474 amino acid residues and had a molecular mass of 51.27 kD. Sequence comparison with BlastP to the NCBI database revealed that MoDXR had high sequence similarity with many other DXRs, such as Coffea arabica DXR (CaDXR) and Rauvolfia verticillata DXR (RvDXR). A phylogenetic tree revealed that MoDXR had its closest relationship with DXR from Coffea arabica and Gardenia jasminoides. The subcellular localization revealed that MoDXR protein was located on the chloroplast. Plantcare analysis indicated that the promoter region sequence of MoDXR was 1 493 bp, covering multiple light, stress, and hormone-responsive cis-regulatory elements; protein electrophoresis showed that the expressed protein was the anticipated size. This research lays the foundation for further purification and structural and functional characterization of the MoDXR protein.

Xiaoshuan Tongluo formula is effective in treating mental retardation and speech astringency caused by cerebral thrombosis, but its mechanism remains unclear. In this investigation, by collecting the chemical constituents from Xiaoshuan Tongluo formula and the targets related to stroke, we obtained 1 251 constituents from the formula and 10 drug targets related with stroke. We established 18 prediction models of compound-target interaction for 10 stroke-related targets, using molecular docking method and machine learning methods includes Naive Bayesian and recursive partitioning based on the input of molecular fingerprints and molecular descriptors. Using these models, we predicted the active chemical constituents from Xiaoshuan Tongluo formula and their drug targets, 153 potential active constituents were discovered, 22 among them could interact with at least two drug targets related with stroke. On this basis, the chemical constituent-target network was constructed using network construction software, and then the important metabolic pathways of the targets were identified by using Gene-Ontology (GO) enrichment analysis, such as blood coagulation, positive regulation of angiogenesis, positive regulation of ion transport and so on. On this basis, a target-pathway network was constructed. In conclusion, using machine learning, molecular docking, virtual screening, data mining and network construction, this study explored and partially revealed the active chemical constituents and chemical constituent-target-pathway network action mechanism of Xiaoshuan Tongluo formula against stroke, which will provide important information for its further study.