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.
The mesoporous silica nanoparticles (MSN) in different pore size and sirolimus (SRL) loaded self-microemulsifying drug delivery system (SMEDDS) were prepared. The results in morphology were collected by scanning electron microscope, transmission electron microscope, small-angle X-ray diffraction, and N2 adsorption-desorption. The results showed that the prepared MSN has ordered nanochannels with a pore size of 6.3, 8.1, 10.8 nm, respectively. The particle size of SRL-SMEDDS were measured by particle sizing system, which was 20.6±1.3 nm. The stirring method was developed to prepare SRL-SMEDDS-MSN. It was found that the optimal ratio of SRL-SMEDDS to MSN was 2:1, while the drug loading rate was near 0.83%, and the flow properties of SRL-SMEDDS-MSN were of good condition. The differential scanning calorimetry results proving a molecular or amorphous dispersed state of SRL in MSN while the suspension experiment has shown great reconstitution properties of SRL-SMEDDS-MSN. There is no significant influence on maximum drug release rate of different pore size of SRL-SMEDDS-MSN in 250 mL water within 2 h, while the results of the first 40 min have an obvious difference. Above all, MSN might provide a new strategy for the solidification of SMEDDS.
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.
The study was aimed to investigate the correlation between the immunocompetence and the fingerprints of supernatant extracts from Radix Astragali by multi-index integrated evaluation, and reveal the material basis of Radix Astragali improving the immunological function. After oral administration 10 batch of supernatant extracts from Radix Astragali on immunosuppressed mice, phagocytic index, delayed type hypersensitivity (DTH) degree, organs index and the level of cytokines IFN-γ, IL-4 (ELISAs) were measured, and each common peak from HPLC-DAD/HPLC-ELSD fingerprints were correlated with the above data. A number of components in supernatant extracts of Radix Astragali display a substantial correlation with the immunocompetence. Supernatant extracts of Radix Astragali can significantly enhance immunological function on mice, which is related to various components in Radix Astragali.
To develop a taste-masking oral preparation of azithromycin for pediatrics, the reversed lipid nano-micelle techniques were used to mask the bitterness of azithromycin. Dry emulsion (DE) for taste-masking was prepared by solidifying the reversed-micelle oil solution containing azithromycin. Colloidal silicon dioxide was used as absorbent and solid carrier. Solidification was confirmed through dying test and observed by scanning electron microscope (SEM). The DE formulation was characterized by X-ray powder diffraction and SEM in order to investigate the crystal state of drug. Reconstitution emulsion droplet size and morphology were also determined using Nano ZS90 Zetasizer and transmission electron microscopy (TEM). The taste testing was performed in two different ways, namely, human taste panel test and the measurement of the amount of drug released in simulated oral cavity condition. The intestinal mucosal irritation test of DE formulation was also investigated in rats in comparison with commercial product (Zithromax). The optimal taste-masking formulation of azithromycin can be re-dispersed immediately with mean diameter of 530.1 nm after agitation in water. The results of taste testing showed that the bitterness of azithromycin was successfully masked by DE formulation similar with Zithromax at the same dose, moreover reduced intestinal irritation compared to Zithromax. These results indicate that the DE formulation for taste-masking of azithromycin is promising and valuable in the future development of azithromycin for pediatrics.
Compound Yizhihao, consists of Radix isatidis, Folium isatidis, Artemisia rupestris, has a significant therapeutic effect on the treatment of influenza and fever. However, the mechanism of its action is still unclear. In this investigation, we collected the key target molecule of influenza disease and the chemical constituents of Compound Yizhihao, and developed Naïve Bayesian classification models based on the input molecular fingerprints and molecule descriptors. The built models were further applied to construct classifiers for predicting the effective constituents. We used the professional network-building software to build the constituent-target network and target-pathway network, which revealed the network pharmacology of the effective constituents in Compound Yizhihao. It will contribute to the further research of mechanism of Compound Yizhihao.
Lepidium apetalum was used as an experimental material in this study. By analyzing the tran-scriptome data of L. apetalum and application of the specific primers, cDNA of cinnamate-4-hydroxylase (C4H) gene was isolated from L. apetalum and named as LaC4H (GenBank accession No. KX064050). Meanwhile, the bioinformatic analysis, prokaryotic expression, purification, tissue-specific expression analysis and expres-sion analysis after methyl jasmonate (MeJA) treatment were carried out. The results indicated that: ① The open reading frame (ORF) of LaC4H was 1 518 bp, which encoded a protein of 505 amino acid residues, with a predicted molecular mass of 57.73 kD. ② Bioinformatic analysis showed that LaC4H protein contained the conserved sequences of cytochrome P450 (CYP450) and 5 substrate recognition sites (SRSs) of CYP73A1, therefore LaC4H protein was a member of CYP450 superfamily. The phylogenetic analysis indicated that LaC4H protein showed the highest homology with C4H protein from cruciferous plants (such as AtC4H from Arabidopsis thaliana). ③ Through the construction of the prokaryotic expression vector pET-32a-LaC4H, the recombinant LaC4H protein was successfully expressed in E. coli BL21 (DE3) cells and the recombinant LaC4H protein was purified by Ni2+ affinity chromatography. ④ Real-time PCR analysis indicated that LaC4H was expressed in a high transcript level in stems, lower levels in leaves and flowers, the lowest level in roots. After MeJA treatment, the expression level of LaC4H in leaves was increased significantly to reach the highest level at 48 h. Furthermore, the expression levels of LaC4H were positively correlated with the flavonoids contents in leaves. The results of this study provide the fundamental information on LaC4H gene in the flavonoids biosyn-thesis pathway of L. apetalum.
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.
To develop a cell-penetrating peptide with high membrane penetrating ability and effective antitumor activity, we designed and synthesized an analogue of penetratin, [Cys-CPT2, 9] penetratin, by substitution of Gln2 and Asn9 with Cys-CPT. We investigated the transmembrane activity and antitumor activity of [Cys-CPT2, 9] penetratin. The fluorescence intensity of [Cys-CPT2, 9] penetratin in HeLa cells was observed by laser confocal microscopy and flow cytometry, and the cell uptake mechanism of [Cys-CPT2, 9] penetratin was evaluated by using different endocytic inhibitors, finally the anti-tumor activity of [Cys-CPT2, 9] penetratin was tested by MTT assay. The results showed that the membrane activity of [Cys-CPT2, 9] penetratin was significantly enhanced in laser confocal microscopy and flow cytometry assay, and the intracellular fluorescence intensity was 5 times higher than penetratin. The cell uptake mechanism study of [Cys-CPT2, 9] penetratin indicated that it mainly entered the cell through the clathrin and endocytosis. Moreover, [Cys-CPT2, 9] penetratin exhibited anti-tumor activity against HeLa cells, and its inhibitory effect on cancer cells was stronger than CPT. [Cys-CPT2, 9] penetratin is a new cell-penetrating peptide with high translocation ability, and has anti-tumor activity against HeLa cells.
With the development of polymeric materials and nanotechnology, the potential application of nanoscaled drug delivery system (NDDS) is gradually manifested in the field of pharmaceutics. Especially, NDDS has the obvious advantages in the delivery of gene or drug. Comparing to the delivery system of single-drug, co-delivery system of gene and drug can significantly improve the therapeutic effects by enhancing transfection efficiency of gene and reversing multidrug resistance, etc. The co-delivery systems of gene and drug, which had the triggered release characteristics in the inner and outer of tumor, could be constructed by introducing the environment-responsive (pH-responsive, redox-responsive and light-responsive, etc) groups into the co-delivery system. The antitumor activity was further improved. In the present paper, the environment-responsive delivery systems in the application of co-delivery gene and drug in recent years were reviewed, and their remarkable properties in the antitumor activity were analyzed and summarized.