Latest ArticlesXanthine oxidase (XO) is a key enzyme in the synthesis of uric acid. Therefore, XO inhibitors play an important role in the antihyperuricemic therapy. Based on the template structures of febuxostat and topiroxostat, 18 amide derivatives were designed and synthesized. Among them, six showed apparent inhibitory activity against XO under the concentration of 10 μmol·L-1. Molecular docking revealed the possible interaction mode of this compound class, which may provide a clue for further molecular design.
Two flavanone glucosides were isolated from the 80% ethanol extract of Glycyrrhiza uralensis using various chromatographic techniques, including macroporous adsorbent resin, RP-C18, Sephadex LH-20, MCI and preparative HPLC. On the basis of chemical properties and spectra data, these compounds were identified as (2S)-liquiritigenin-4´-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranoside (1), (2R)-liquiritigenin-4´-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranoside (2), respectively. Compounds 1 and 2 are new compounds, and their aglycones are enantiomers.
This study was designed to establish an ultra-liquid chromatography-mass spectrometry method for the reliable identification the multiple chemical components in Huangqi Jianzhong Tang (HQJZ). The ultra-high performance liquid chromatography coupled with hybrid quadrupole-orbitrap mass spectrometry method was applied to identify the chemical constituents in the HQJZ rapidly. A total of 71 compounds including two major categories of saponins and flavonoids were identified or tentatively deduced on the basis of their retention behaviors, fragments of multistage mass spectrometry or by comparing with reference substances and literatures. Among them, 20 compounds were from Astragali Radix, 14 were from Paeoniae Radix Alba, 37 were from Glycyrrhizae Radix et Rhizoma Praeparata cum Melle, 3 were from Rhizoma Zingiberis Recens, 2 were from Cinnamomi Ramulus and Jujubae Fructus, respectively. The LC-MS method was used to qualitatively analyze the chemical constituents of HQJZ, which provides a scientific basis for the quality control of HQJZ.
Although multiple studies have shown that matrine can inhibit the proliferation of hepatoma cells, its mechanism of action has not been systematically investigated. In this study, the effects of matrine on the proliferation and migration of human hepatoma SMMC-7721 cells were investigated. Based on this result, anti-hepatoma target-functionally related protein interaction network of matrine was constructed, and topological analysis and clustering analysis were performed to predict the crucial targets of matrine for the anti-hepatoma effects. Pathway enrichment analysis was performed on the validated targets to predict the crucial pathways of matrine. Parts of the crucial proteins were examined by Western blot. Cellular experiments showed that matrine at concentrations of 1, 2 and 4 mg·mL-1 significantly inhibited the proliferation of SMMC-7721 cells, and matrine at concentrations of 0.5, 1 and 2 mg·mL-1 significantly inhibited the migration of SMMC-7721 cells. The results of network pharmacology suggest that matrine exerts its anti-hepatoma effects through acting on the key validated targets of heparanase (HPSE), caspase 3 (CASP3), Myc proto-oncogene protein (MYC), matrix metalloproteinases 2 (MMP2) and predicted targets of carbonic anhydrase 1 (CA1), lithostathine 1 alpha precursor (REG1A), carboxylesterases 1 (CES1) and acetaldehyde dehydrogenase 2 (ALDH2), and invasion and migration associated pathways. Western blot results suggest that matrine can down-regulate the expression of MMP2 and up-regulate the expression of CASP3. In this paper, we applied network pharmacology to explain the targets and pathways of matrine against hepatoma. The results provide a scientific basis for elucidation of the mechanisms of matrine against hepatoma.
This study was designed to establish a multiplex allele-specific polymerase chain reaction method for simultaneous identification of Dendrobium huoshanense, D. officinale and D. devonianum, which may resolve identification problems of caulis dendrobii. Internal transcribed spacer sequences and trnL-trnF sequences of the Dendrobium species were aligned by BioEdit software, then specific SNPs of the three species were analyzed for designing allele-specific primers and the multiplex allele-specific PCR reaction system was established. The different origin of Dendrobium huoshanense, D. officinale and D. devonianum was amplified and identified by the sizes of respective band. The results showed that 584 bp, 397 bp and 211 bp bands could be amplified by D. devonianum, Dendrobium officinale and Dendrobium huoshanense respectively, when the annealing temperature was 61 ℃ and the number of cycles was 35. The limit of detection (LOD) of D. devonianum and D. huoshanense were both 1.2 ng, while D. officinale was low than 0.24 ng. The detection limit of adulterates in D. devonianum, D. devonianum and D. huoshanense mixture sample was 1%, 1% and 5% respectively. This result suggests that the method of multiplex allele-specific PCR is useful to identify D. huoshanense, D. officinale and D. devonianum is accurate and specific.
This study was designed to establish a high performance liquid chromatography (diode array detector, DAD)-tandem mass chromatography (HPLC-DAD-MS/MS) method for the simultaneously screening 12 kinds of cough-relieving chemical drugs illegally added in anti-cough and antiasthmatic traditional Chinese medicines. This method involved liquid chromatography-tandem mass spectrometry. The separation was conducted by Kromasil100-5C18 (250 mm × 4.6 mm, 5 μm) and the mobile phase was consisted of 0.3% ammonium formate (pH 2.97) and methanol. After separated by HPLC, the suspected components were analyzed by MS/MS and DAD and ultra scan was used to identify these illegally added drugs. A fast and sensitive HPLC-DAD-MS/MS method for the simultaneously screening for illegal chemical compositions was established. The LOD of these substances were below 50 ng. The method was sufficiently selective and sensitive to detect illegal chemical compositions in anti-cough and antiasthmatic traditional Chinese medicines.
Flexible liposomes are an excellent drug delivery nanocarrier, however, the leakage of drugs from liposomes has become common technical obstacle in the industry and also hindered its further application seriously. It is very urgent and necessary to avoid or reduce the leakage of drugs from liposomes. In this work, five kinds of essential oils such as Folium Artemisiae Argyi oil (FA), Folium Eucalypti oil (FE), Arabian Jasmine oil (AJ), Syzygium Aromaticum oil (SA) and Fructus Forsythiae oil (FF) were encapsulated in the lipid bilayer of palmatine chloride (PC) loaded flexible nano-liposomes (PFL), then the optimal essential oil and its dosage level were determined by the external leakage curve of PC. The female Japanese white rabbits were used to evaluate the vaginal irritancy potential of liposomes samples. The pharmaceutical properties such as encapsulation efficiency, particle size, zeta potential, deformability and structure of liposomes samples were evaluated. In order to investigate the permeability of liposomes samples to deliver PC across skin and mucous membrane in vitro, the side-by-side diffusion cells were used. The results showed that the leakage of hydrosoluble PC from PFL was reduced at different degrees by the essential oils in the lipid bilayer of PFL, however, the reduction in leakage degree was obviously higher for FA than thoses of FE, AJ, SA and FF (P < 0.05), and the highest reduction in leakage degree was obtained when the FA and lipid mass ratio was 1:6. The encapsulation efficiency, particle size, zeta potential and deformability of PFL were not significantly changed after FA was encapsulated in the lipid bilayer of the PFL (P > 0.05), so did the lamellar structure of PFL. In addition, the transdermal and transmucosal permeability of PC were also enhanced obviously by encapsulating FA in the lipid bilayer of PFL, and there was no vaginal/vulvar irritation observed in the rabbits. In summary, the drug leakage was reduced by encapsulating suitable essential oil (such as FA) in the lipid bilayer of flexible liposomes, and the vaginal mucosa permeability were improved for the drug. These results provide a novel technique in the improvement of flexible nano-liposomes for drug delivery.
The purpose of this study was to develop a screening method to determine the activity and selectivity of SGLT2 inhibitor. Human SGLT1/SGLT2 cDNA was inserted into the pMSCVpuro mammalian expression vector and the plasmid was transfected into HEK293 cells. Stably transfected clones were selected in puromycin containing medium. To evaluate the expression of human SGLT1 and SGLT2 in stable transfected cells, RT-PCR, Western blot and immunofluorescence analysis were performed. 1-[N-(7-Nitrobenz-2-oxa-1, 3-diazol-4-yl)amino]-1-deoxy-D-glucose (1-NBDG) was used as a substrate in the uptake assay to evaluate the Na+ dependent glucose transport activities of SGLT1/2. The inhibitory activity and selectivity of dapagliflozin/phloridzin were also determined, respectively. The hypoglycemic efficacy of dapagliflozin was evaluated in mice with normal blood glucose and mice with alloxan-induced T1DM. The result showed that SGLT1 was overexpressed in pMSCVpuro-SGLT1 transfected HEK293 cells. SGLT2 protein was overexpressed in pMSCVpuro-SGLT2 transfected HEK293 cells and located in both cytoplasm and membrane. The Na+ dependent 1-NBDG uptake was significantly increased in pMSCVpuro-SGLT1/SGLT2 transfected cells compared to that in pMSCVpuro-null transfected cells. The selectivity of dapagliflozin, whose half maximal inhibitory concentration (IC50) for SGLT2 (2.24×10-10 mol·L-1) was far lower than that for SGLT1 (6.20×10-7 mol·L-1), was better than that of phloridzin. The oral glucose tolerance was elevated after a single dose of dapagliflozin in normal mice. In T1DM mice, compared with model group, no-fasting glucose level was decreased at 1 h after administration and maintained at a lower level for 24 h in a dose-dependent manner. A 20-day administration with dapagliflozin dose-dependently improved the hyperglycemia status. Taken together, a system to evaluate the activity and selectivity of SGLT2 inhibitors was established using 1-NBDG in vitro and the hypoglycemic efficacy in vivo in this study. The advantages of this system include non-radioactivity, high efficiency, and good stability which may provide a technique platform for development of novel SGLT2 inhibitors.
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.
Scorpion toxin BmK AngM1 has been reported to have a strong analgesic effect. However, its anti-inflammatory activity was unknown. In this study, the recombinant BmK AngM1 (rBmK AngM1) was expressed in Escherichia coli BL21 trxB (DE3). The purified rBmK AngM1 was obtained efficiently through the IMPACTTM-TWIN system. The anti-inflammatory activity of the recombinant protein was investigated. In order to improve the anti-inflammatory activity of rBmK AngM1, the potential active sites (Y5, Y42, R58) were substituted with different amino acids. The results showed that rBmK AngM1 and its mutants all have significant anti-inflammatory activity. The activities were significantly increased in the single mutant R58N and mutants Y5F/R58N, Y42F/R58N over the wild type protein. The data suggest that position 58 in BmK AngM1 plays a functional role in the anti-inflammatory activity. This study lays a foundation for the protein engineering design of BmK AngM1 to improve its pharmacological activity.