Latest ArticlesL-Proline-m-bis (2-chloroethyl) amino-L-phenylalanyl-L-norvaline ethyl ester hydrochloride (MF13) is a new anticancer tripeptide. Our previous study in vitro and in vivo showed that MF13 had anti-proliferative activities in a panel of human hepatocellular carcinoma (HCC) cell lines from different origin. In the present study, we focused on the inhibition effect on HCC of MF13 combined with other anti-cancer drugs. The results of combination chemotherapy in vitro indicated that the combination of MF13 with mitomycin C (MMC) at appropriate concentrations led to a synergistic effect; however, the combination of MF13 with vincristine (VCR) showed no synergistic effect. In the Bel-7402 tumor bearing nude mice, the antitumor effect of the groups of 2 mg·kg-1 MF13 + 2 mg·kg-1 MMC or 2 mg·kg-1 MF13 + 50 mg·kg-1 cyclophosphamide (CTX) exhibited synergistic anticancer efficacies while the group of 2 mg·kg-1 MF13 + 0.3 mg·kg-1 VCR did not have the same effect. Based on our data, we believe that MF13 can be considered as a potential agent against human hepatocellular carcinoma no matter how treated, alone or combined with other drugs.
Cryptococcal meningitis, caused by fungus Cryptococcus neoformans, is responsible for over a million infections and 600 000 deaths annually. Largely due to the limited treatment options and the intrinsic drawbacks coupled with drug resistance to current therapies, it is urgent to discover novel antifungal agents against cryptococcosis. An ideal antifungal drug should at least satisfy the following criteria: fungicidal, fungus-specific, permeable for the host barriers such as cell membranes of phagocytes and the blood-CNS barrier. Both discovery of candidates with novel mode of action and repurposing existing molecules with potent anti-cryptococcal activity are effective ways in discovery of new anti-cryptococcal agents. Here, we summarized recent advances in the study of anti-fungal activities, mechanisms of action, and clinical developments of new anti-cryptococcal drugs.
Acting as the key step of various cell signaling pathways, protein-protein interaction (PPIs) plays a significant role in the regulation of biological functions. Many of the proteins involved are potential drug targets, therefore manipulation of PPI would greatly a great interest in physiology and pharmacology. Most PPIs could not be directly targeted by small molecule drugs due to their flat and shallow interaction surfaces. Selective regulator may be obtained by extraction and chemical synthesis helical peptide that forms folding substructure scaffold in PPI. However, most peptides when separated from its protein progenitor are not able to maintain its biological active helical structure, but tend to form random coil conformation, which is vulnerable to enzyme and suffer low potency and drugability. By modification through all-hydrocarbon bridged cyclic peptide designating 'stapled peptide', it turned out to be the most effective and directive methodology to solve the drawbacks. Stapled peptide not only can boost its potency, but also its biostability and cell permeability. These significant advantages make peptide stapling an important way of modification, which may definitely generate more and more peptide drug candidates targeting PPIs in the foreseen future. In this paper, chemistry and bioactivity of the stapled peptides reported up-to-date are systematically reviewed and discussed.
Strategies and techniques are extremely important to improve the evaluation efficiency and fully guarantee the consistency of dosage forms. For preparations with a structural feature as solid dosage forms and particulate dispersion systems, the structures of dosage forms are the outcome of the specific formulation and production process, which determine the drug delivery behaviors as well as the pharmacokinetics of the dosage forms. Conventional techniques failed to quantitatively determine the structures of dosage forms. Synchrotron radiation micro-computed tomography is a new generation of structural quantitative characterization technology in revealing the internal structure of dosage forms with unprecedented capability for quantitative characterization of the static and dynamic structures of dosage forms, enabling to reversely analyze the production process and identify the structure differences between the generics and brand products. Based on synchrotron radiation micro-computed tomography methodology researches and applications in static structures (powders, particulate systems, tablets, films, membranes, etc.), dynamic structures (hydration) and de-formulation of production process, we have classified the structures of dosage forms into four levels from macro-scope to molecular level as dosage forms, granular intermediates for formulation, dynamic structure and molecular structures, and proposed dosage form structure based new strategy for consistency evaluation. Along with conventional dissolution/ release behavior similarity, the internal structure consistency ensures high consistency between the brand product and the generics.
Thirty-three compounds were designed and synthesized directly from three-component, one-pot condensation of 1-(4-methylphenyl) ethanone and aromatic amines with some aromatic aldehydes. The chemical structures of the Mannich bases were confirmed by 1H NMR, IR and MS. The screening results of bioactivity indicated that all of these title compounds possessed the inhibitory activity at the concentration of 1×10-4 mol·L-1. Among them, the compound TM33 displayed the strongest bioactivity with the inhibition percentage of 60.3% against P338 cancer cell line at the concentration of 1×10-8 mol·L-1, and the value of the half maximal inhibitory concentration (IC50) was as low as 0.45 nmol·L-1. This study suggests a new type of potential anti-leukemia molecules.
The aim of the present study was to explore a sensitive, stable and reliable method for evaluating the phagocytosis, in which RAW264.7 macrophages engulfed GFP-Escherichia coli was tested by high-content screening technology. The study was conducted to optimize the method in evaluation of traditional Chinese medicine in the promotion of macrophage function. By testing macrophages at different ratio of bacteria to cells (multiplicity of infection, MOI), and at different incubation time, we optimized a high content screening method and the experimental parameters to determine the impact of bacteria in macrophages (fluorescence intensity index = be swallowed bacteria/macrophages). The method was used to determine whether Dendrobium moniliforme (DM) have effects on macrophage phagocytosis. The results show that the index has a positive relationship with MOI values, and the highest index was observed at incubation time of 1.5 h. The optimized conditions was 1×104 cells/well with a MOI of 50:1 (bacteria:cells) with incubation of 1.5 h. Under this condition, the relative standard deviation (RSD) was less than 10% in the precision test. Using the method to detect DM regulating macrophage phagocytosis experiment results showed that in 0.31-2.50 g·L-1 concentration range, DM has a dose-response effect in promoting phagocytosis. We successfully established the method for evaluation of macrophage phagocytosis, and proved the activity of DM in promotion of macrophage phagocytosis.
Rhizoma Dioscoreae Bulbiferae is a traditional Chinese medicine with hepatotoxicity, but the metabolic profile of fatty acids has not been identified in the rats with liver injury. In this project, a gas chromatography-mass spectrometry method was applied to simultaneous quantification of 16 non-esterified fatty acids (NEFA) and esterified fatty acids (EFA) in the serum of control, ethanol extraction of Rhizoma Dioscoreae Bulbiferae (ethanol extraction, ET) and diosbulbin B (DB)-treated rats. Meanwhile, the change of fatty acid metabolic profile of liver injured rats was analyzed by principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). The results of NEFA concentration indicated that the serum concen-trations of palmitic acid (C16:0), stearic acid (C18:0), palmitoleic acid (C16:1n7), oleic acid (C18:1n9), vaccenic acid (C18:1n7), linoleic acid (C18:2n6), linolenic acid (C18:3n3), eicosatrienoic acid (C20:3n6), arachidonic acid (C20:4n6) and docosahexaenoic acid (C22:6n3) in DB-treated rats decreased significantly, while that of C18:2n6 and C20:3n6 obviously increased and that of C20:4n6 and C22:6n3 noticeably dropped in ET-treated rats when compared with control. Furthermore, the results of EFA concentration illus-trated that the serum concentrations of C16:0, C18:0, C20:4n6, C22:6n3 and eicosapentaenoic acid (C20:5n3) in two toxic groups were remarkably decreased when compared with control. The fatty acid meta-bolic profiles of the two toxic groups exhibited significant difference from the normal levels, and the degree of deviation of ET group was higher than that of DB group. More importantly, the results of PLS-DA showed that C20:4n6 and C22:6n3 were important indicators of the hepatotoxicity induced by ET and DB, and the serum concentrations of the two fatty acids had good correlation with the levels of alanine aminotransferase, aspartate aminotransferase and total bilirubin using Pearson's correlation analysis and canonical correlation analysis (CCA). Therefore, C20:4n6 and C22:6n3 were identified as potential biomarkers of ET and DB-induced liver injury. The project can provide a foundation for furture investigation of molecular mechanism of hepato-toxicity caused by Rhizoma Dioscoreae Bulbiferae.
The study was aimed to establish a liquid chromatography-tandem mass spectrometric method for the determination of the duloxetine concentration in rat plasma, and compare the pharmacokinetics in normal and diabetes mellitus rat models. Diazepam was used as an internal standard. The separation was achieved on a Waters Xterra® RP18 column (100 mm × 4.6 mm, 3.5 μm) with a mobile phase consisting of methanol-0.3% formic acid containing 5 mmol·L-1 ammonium acetate (75:25) at the flow rate of 0.6 mL·min-1. Electrospray ionization source was applied and operated in the positive multiple reaction monitoring mode. A good linearity of duloxetine was obtained in the concentration range of 10-5 000 ng·mL-1. The rat models of diabetes mellitus were established by intraperitoneal injection of streptozotocin. The same dose of duloxetine (40 mg·kg-1) was given by intragastric administration to the normal and diabetic rats. Blood samples were collected from the orbital venous plexus to determinate duloxetine concentration in the plasma. The pharmacokinetic parameters were calculated by DAS software. Statistical analysis was performed by SPSS software. The major pharma-cokinetic parameters of diabetes group were as follows: Cmax was 1 185 ± 190.0 ng·mL-1; AUC0-∞ was 8 398 ± 1 835 ng·mL-1·h; tmax was 1.6 ± 0.4 h; t1/2z was 3.6 ± 0.9 h. The major pharmacokinetic parameters of normal group were as follows: Cmax was 368.1 ± 40.7 ng·mL-1; AUC0-∞ was 4145 ± 640.1 ng·mL-1·h; tmax was 1.6 ± 0.3 h; t1/2z was 4.1 ± 0.8 h. The results of pharmacokinetic experiments suggest that the exposure amount of duloxetine in diabetic rats is twice higher than that in normal rats.
This study was aimed to build a new photo-sensitive co-delivery liposomes which combine photodynamic therapy with chemotherapy to reverse drug resistance of breast cancer. Photodynamic photosen-sitizer chlorin e6 trimethyl ester (Ce6tM) and chemotherapeutic drug doxorubicin hydrochloride (DOX) were loaded into the liposomes (liposomes loaded with Ce6tM and DOX, CDL) by thin-film hydration extrusion and ammonium sulfate active loading methods. CDL was characterized with cryo-transmission electron microscopy (Cryo-TEM), dynamic light scattering particle size, zeta potentials and photo-sensitive DOX release behaviors in vitro. CDL cytotoxicity, singlet oxygen production, DOX accumulation, intracellular ATP level and cell cycle analysis in MCF7/ADR cells were evaluated. Finally, the tissue distribution of DOX and antitumor effects of CDL in BALB/c-nu nude mice bearing MCF7/ADR tumor were investigated. The results showed that the particle size of obtained CDL was 90.7 ± 1.1 nm and distributed uniformly. CDL possessed outstanding properties of photo-sensitive drug release profile. The accumulated release of DOX reached (96.52 ± 0.11)% in 2 min under 671 nm laser irradiation (2 W·cm-2). Interestingly, DOX in CDL could maintain rapid release after 671 nm laser irradiation with low power and short time (15 s, 0.25 W·cm-2). This phenomenon was caused by oxidation of unsaturated phospholipids in CDL under 671 nm laser irradiation and had nothing to do with the slightly elevated temperature. Photo-sensitive drug release behavior contributed to increased DOX accumulation in MCF7/ADR cells. The half inhibition concentration (IC50) of DOX in CDL laser group in MCF7/ADR cells was decreased by 601.9-fold compared with no laser group, which could be related to increased accumulation of DOX, decreased ATP levels and cell cycle arrest in MCF7/ADR cells. With the help of CDL, DOX accumulation in tumor was increased and in cardiac toxicity was reduced in vivo. CDL laser group showed a good anti-tumor effect. The tumor inhibition rate was (94.7 ± 6.2)%. These results suggest that CDL has a promising potential in reversing drug resistance of breast cancer.
Serotonin (5-hydroxytryptamine, 5-HT) is an endogenous molecule playing key roles in life activity. In the treatment of metabolic diseases such as obesity, the traditional paradigm of appetite suppression by serotonin in the central nervous system has some limitations. In recent years, great progress has been made in the study of the regulation of energy metabolism by peripheral serotonin system. Recent studies revealed that peripheral serotonin plays an important role in regulation of adipogenesis and energy expenditure in adipose tissues, insulin secretion in pancreatic β-cell and glycogen synthesis in liver, etc. This review summarizes the recent advances in the function of serotonin in the peripheral organs of energy metabolism. We propose that peripheral serotonin system may serve as an attractive new therapeutic target for the treatment of metabolic diseases in the near future.