Cytotoxic and Anti-Plasmodial Activities of Stephania dielsiana Y.C. Wu Extracts and the Isolated Compounds.

Natural products remain a viable source of novel therapeutics, and as detection and extraction techniques improve, we can identify more molecules from a broader set of plant tissues. The aim of this study was an investigation of the cytotoxic and anti-plasmodial activities of the methanol extract from Stephania dielsiana Y.C. Wu leaves and its isolated compounds. Our study led to the isolation of seven alkaloids, among which oxostephanine (1) is the most active against several cancer cell lines including HeLa, MDA-MB231, MDA-MB-468, MCF-7, and non-cancer cell lines, such as 184B5 and MCF10A, with IC50 values ranging from 1.66 to 4.35 µM. Morever, oxostephanine (1) is on average two-fold more active against cancer cells than stephanine (3), having a similar chemical structure. Cells treated with oxostephanine (1) are arrested at G2/M cell cycle, followed by the formation of aneuploidy and apoptotic cell death. The G2/M arrest appears to be due, at least in part, to the inactivation of Aurora kinases, which is implicated in the onset and progression of many forms of human cancer. An in-silico molecular modeling study suggests that oxostephanine (1) binds to the ATP binding pocket of Aurora kinases to inactivate their activities. Unlike oxostephanine (1), thailandine (2) is highly effective against only the triple-negative MDA-MB-468 breast cancer cells. However, it showed excellent selectivity against the cancer cell line when compared to its effects on non-cancer cells. Furthermore, thailandine (2) showed excellent anti-plasmodial activity against both chloroquine-susceptible 3D7 and chloroquine-resistant W2 Plasmodium falciparum strains. The structure-activity relationship of isolated compound was also discussed in this study. The results of this study support the traditional use of Stephania dielsiana Y.C. Wu and the lead molecules identified can be further optimized for the development of highly effective and safe anti-cancer and anti-plasmodial drugs.

Temperature inversion and air pollution relationship, and its effects on human health in Hanoi City, Vietnam.

This study aimed to investigate the effects of temperature inversions on the concentration of some pollutants in the atmosphere in Hanoi City, Vietnam, during the period from 2011 to 2015. This work also aimed to evaluate relationships between the thermal inversion and health effects that are associated with air pollution. During this period, the temperature inversions were most frequently presenting from November to March in Hanoi City. Air quality data was gathered from air quality monitoring stations located in the study area. The data showed that levels of NO2, SO2, PM10 and PM2.5 increased when the inversions strengthened. Cases of two types of diseases (acute respiratory diseases and cardiovascular diseases), which are linked to atmospheric air pollution, were considered on number of patients under 15 and above 60 years old at National Geriatric Hospital and National Otorhinolaryngology Hospital. There was significant increase in the daily average number of hospital visits with increasing surface-based inversions. The statistical analysis showed that the temperature inversions correlated with concentration of air pollutants and the number of patients in 5 years.

A Novel Peptide Aptamer to Detect Plasmodium falciparum Lactate Dehydrogenase.

Alternative antibody (aptamer)-based biosensors are attracting increasing attention owing to advantages such as simplicity and low cost, which are beneficial for point-of-care diagnosis, particularly where resources are limited. In this study based on in silico modeling predictions made with Autodock Vina, the binding affinity of an optimized novel peptide (Pf_P1: KITTTDEEVEGIFD) was altered compared to that of the original epitope peptide (P1: KITDEEVEGIFDC). The binding energy of Pf_P1 implies that it has stronger interactions with Plasmodium falciparum lactate dehydrogenase (LDH) than with human LDH. Fluorescence-linked immunosorbent assay (FLISA) demonstrated significant interactions (P < 0.05) between the Pf_P1 peptide and P. falciparum LDH at 35.7 nmol. A peptide- and antibody-linked sandwich FLISA was able to detect at least 100 infected red blood cells (RBC)/µL significantly (P < 0.001). The clinical diagnostic performance of peptide- and antibody-linked sandwich FLISA was evaluated using blood samples from patients infected by P. falciparum with parasitemia values of 151 to 128,636. All positive samples exhibited higher fluorescence than normal samples did. In conclusion, in silico modeling was used to efficiently design a Plasmodium LDH epitope-derived peptide aptamer to function as an alternative to antibodies in immunoassays.

Development of a smartphone-based rapid dual fluorescent diagnostic system for the simultaneous detection of influenza A and H5 subtype in avian influenza A-infected patients.

Accurate and rapid diagnosis of highly pathogenic avian influenza A H5N1 is of critical importance for the effective clinical management of patients. Here, we developed a rapid and simultaneous detection toolkit for influenza A H5 subtype viruses in human samples based on a bioconjugate of quantum dots (QDs) assembly and a smartphone-based rapid dual fluorescent diagnostic system (SRDFDS). Methods: Two types of QDs were assembled on a latex bead to enhance the detection sensitivity and specificity of influenza A infection (QD580) and H5 subtype (QD650). The dual signals of influenza A and H5 subtype of H5N1-infected patients were detected simultaneously and quantified separately by SRDFDS equipped with two emission filters. Results: Our results showed a high sensitivity of 92.86% (13/14) and 78.57% (11/14), and a specificity of 100% (38/38, P < 0.0001) and 97.37% (37/38) for influenza A and H5 subtype detection, respectively. Conclusion: Therefore, our multiplex QD bioconjugates and SRDFDS-based influenza virus detection toolkit potentially provide accurate and meaningful diagnosis information with improved detection accuracies and sensitivities for H5N1 patients.

Improvement of a rapid diagnostic application of monoclonal antibodies against avian influenza H7 subtype virus using Europium nanoparticles.

The development of a sensitive and rapid diagnostic test is needed for early detection of avian influenza (AI) H7 subtype. In this study, novel monoclonal antibodies (mAbs) against influenza A H7N9 recombinant hemagglutinin (rHA)1 were developed and applied to a Europium nanoparticle-based rapid fluorescent immunochromatographic strip test (FICT) to improve the sensitivity of the rapid diagnostic system. Two antibodies (2F4 and 6D7) exhibited H7 subtype specificity in a dot-FICT assay by optimization of the conjugate and the pH of the lysis buffer. The subtype specificity was confirmed by an immunofluorescence assay and Western blot analysis. The limit of detection of the FICT employing novel mAbs 31 ng/mL for H7N9 rHA1 and 40 hemagglutination units/mL for H7 subtype virus. Sensitivity was improved 25-fold using Europium as confirmed by comparison of colloidal gold-based rapid diagnostic kit using the 2F4 and 6D7 mAbs.

Stephanine from Stephania venosa (Blume) Spreng Showed Effective Antiplasmodial and Anticancer Activities, the Latter by Inducing Apoptosis through the Reverse of Mitotic Exit.

Extracts from the tubers of Stephania venosa (Blum) Spreng growing in Vietnam significantly inhibited cell proliferation against a number of cancer cells including HeLa, MDA-MB231 and MCF-7 cells. A bioassay-guided fractionation led to the isolation of four aporphine and one tetrahydroprotoberberine alkaloids: dehydrocrebanine 1, tetrahydropalmatine 2, stephanine 3, crebanine 4 and O-methylbulbocapnine 5. The characterization of these compounds was based on MS, NMR and published data. A study by structure-bioactivity relationship on these isolates showed that stephanine is the most active compound. Cell biological studies showed that stephanine induces the reverse of mitotic exit, eventually leading to cell death by apoptosis. This data suggests that stephanine has a unique mode of cell-killing activity against cancer cells, which is seldom observed with known synthetic compounds. In addition to its anticancer property, our data from an in vitro study showed that S. venosa also possesses effective antiplasmodial activity and stephanine was also the most interesting compound but is the most cytotoxic with the lowest selectivity index. Copyright © 2017 Her Majesty the Queen in Right of Canada Phytotherapy Research StartCopTextCopyright © 2017 John Wiley & Sons, Ltd.

Rapid Detection of Avian Influenza Virus by Fluorescent Diagnostic Assay using an Epitope-Derived Peptide.

Currently, the point of care testing (POCT) is not fully developed for subtype-specific avian influenza virus detection. In this study, an H5N1 hemaglutinin 1 (HA1) epitope (P0: KPNDAINF) and three modified peptides (P1: KPNTAINF, P2: KPNGAINF, P3: KPNDAINDAINF) were evaluated as POCT elements for rapid detection of avian influenza virus. Based on modeling predictions by Autodock Vina, binding affinity varied depending on alteration of one amino acid in these peptides. The binding energy of P2 indicated its potential for a strong interaction with HA. Fluorescence-linked immunosorbent assay experimentally demonstrated the interaction between these peptides and virus. The four peptides interacted with HA1 of H5N3 with different binding affinities with P2 showing the strongest binding affinity. When P0 and P2 peptides were used in rapid fluorescent immunochromatographic test (FICT) as detection elements, the inter-assay coefficients of variation (CV) indicated that P2-linked FICT was more acceptable than the P0-linked FICT in the presence of human specimens. Antibody pair-linked FICT was influenced by clinical samples more than the P2-linked FICT assay, which showed a 4-fold improvement in the detection limit of H5N3 and maintained H5 subtype-specificity. Compared to the rapid diagnostic test (RDT) which is not specific for influenza subtypes, P2-linked FICT could increase virus detection. In conclusion, results of this study suggest that HA epitope-derived peptides can be used as alternatives to antibodies for a rapid fluorescent diagnostic assay to detect avian influenza virus.

Rapid detection of avian influenza A virus by immunochromatographic test using a novel fluorescent dye.

Sensitive and rapid diagnostic systems for avian influenza (AI) virus are required to screen large numbers of samples during a disease outbreak and to prevent the spread of infection. In this study, we employed a novel fluorescent dye for the rapid and sensitive recognition of AI virus. The styrylpyridine phosphor derivative was synthesized by adding allyl bromide as a stable linker and covalently immobilizing it on latex beads with antibodies generating the unique Red dye 53-based fluorescent probe. The performance of the innovative rapid fluorescent immnunochromatographic test (FICT) employing Red dye 53 in detecting the AI virus (A/H5N3) was 4-fold and 16-fold higher than that of Europium-based FICT and the rapid diagnostic test (RDT), respectively. In clinical studies, the presence of human nasopharyngeal specimens did not alter the performance of Red dye 53-linked FICT for the detection of H7N1 virus. Furthermore, in influenza A virus-infected human nasopharyngeal specimens, the sensitivity of the Red dye 53-based assay and RDT was 88.89% (8/9) and 55.56% (5/9) relative to rRT-PCR, respectively. The photostability of Red dye 53 was higher than that of fluorescein isothiocyanate (FITC), showing a stronger fluorescent signal persisting up to 8min under UV. The Red dye 53 could therefore be a potential probe for rapid fluorescent diagnostic systems that can recognize AI virus in clinical specimens.

Chemical Constituents of Chirita drakei.

Chirita drakei Burtt (now accepted as Primzina drakei (B.L.Burtt) Mich.M61ler & A.Weber) is growing on limestone mountain slopes of Ha Long Bay islands in Vietnam. The chemical investigation of the aerial parts of C. drakei led to the isolation and structural elucidation of two new compounds named chiridrakoside A (1) and chiridrakoside B (2) besides twelve known compounds comprising five phenylethanoid glycosides (3-7), two lignans (8, 9), a phenyl propanoid (10), an anthraquinone (11), a furan derivative (12) and two triterpenes (13, 14). All described compounds, except 4, 5 and 11, were obtained for the first time from the genera Chirita or Primulina. The cytotoxic activity of the isolated compounds was evaluated against the four human cancer cell lines KB (mouth epidermal carcinoma), HepG2 (hepatocellular carcinoma), Lu (lung carcinoma) and MCF7 (breast carcinoma). Epoxyconiferyl alcohol (10) exhibited cytotoxic activity against the tested cell lines (IC50 from 46 to 128 µM).

20-Hydroxyecdysone from Dacrycarpus imbricatus bark inhibits the proliferation of acute myeloid leukemia cells

Objective To investigate the anti-proliferative effects of 20-hydroxyecdysone isolated from the bark of Dacrycarpus imbricatus (Blume) de Laub. Methods Column chromatography was used for isolation of compounds from plant material. The structure of the isolated compound was identified by mass spectrometry and nuclear magnetic resonance techniques, including HSQC, HMBC, NOE-difference experiments. The isolated compound was tested for its anti-proliferative activity in acute myeloid leukemia (AML) and OCI-AML cells. Results Compound 1 was isolated from the ethyl acetate fraction of Dacrycarpus imbricatus barks by column chromatography. Its chemical structure was identified as 20-hydroxyecdysone (20HE), a cholestane-type ecdysteroid, by a combination of mass spectrometry and nuclear magnetic resonance spectrometric analyses. Our goal was to test the anti-proliferative activity of 20HE using the OCI-AML cell line. 20HE significantly decreased OCI cell number at a concentration of 1 mg/mL, whereas lower concentrations were ineffective. Moreover, this decrease was due to partial blockage of the G

20-Hydroxyecdysone from Dacrycarpus imbricatus bark inhibits the proliferation of acute myeloid leukemia cells

OBJECTIVE@#To investigate the anti-proliferative effects of 20-hydroxyecdysone isolated from the bark of Dacrycarpus imbricatus (Blume) de Laub.@*METHODS@#Column chromatography was used for isolation of compounds from plant material. The structure of the isolated compound was identified by mass spectrometry and nuclear magnetic resonance techniques, including HSQC, HMBC, NOE-difference experiments. The isolated compound was tested for its anti-proliferative activity in acute myeloid leukemia (AML) and OCI-AML cells.@*RESULTS@#Compound 1 was isolated from the ethyl acetate fraction of Dacrycarpus imbricatus barks by column chromatography. Its chemical structure was identified as 20-hydroxyecdysone (20HE), a cholestane-type ecdysteroid, by a combination of mass spectrometry and nuclear magnetic resonance spectrometric analyses. Our goal was to test the anti-proliferative activity of 20HE using the OCI-AML cell line. 20HE significantly decreased OCI cell number at a concentration of 1 mg/mL, whereas lower concentrations were ineffective. Moreover, this decrease was due to partial blockage of the G/S phase of the cell cycle, with a reduction of cells in the GM phase, not due to increased apoptosis.@*CONCLUSIONS@#This indicates that 20HE significantly decreases the number of cells in the G/S phase of the cell cycle in human AML cells. This is the first time that the anti-proliferative activity of 20HE against a human tumor cell line has been reported.

Procarcinogens - Determination and Evaluation by Yeast-Based Biosensor Transformed with Plasmids Incorporating RAD54 Reporter Construct and Cytochrome P450 Genes.

In Vietnam, a great number of toxic substances, including carcinogens and procarcinogens, from industrial and agricultural activities, food production, and healthcare services are daily released into the environment. In the present study, we report the development of novel yeast-based biosensor systems to determine both genotoxic carcinogens and procarcinogens by cotransformation with two plasmids. One plasmid is carrying human CPR and CYP (CYP3A4, CYP2B6, or CYP2D6) genes, while the other contains the RAD54-GFP reporter construct. The three resulting coexpression systems bearing both CPR-CYP and RAD54-GFP expression cassettes were designated as CYP3A4/CYP2B6/CYP2D6 + RAD54 systems, respectively and used to detect and evaluate the genotoxic potential of carcinogens and procarcinogens by selective activation and induction of both CPR-CYP and RAD54-GFP expression cassettes in response to DNA damage. Procarcinogens were shown to be predominantly, moderately or not bioactivated by one of the CYP enzymes and thus selectively detected by the specific coexpression system. Aflatoxin B1 and benzo(a)pyrene were predominantly detected by the CYP3A4 + RAD54 system, while N-nitrosodimethylamine only moderately activated the CYP2B6 + RAD54 reporter system and none of them was identified by the CYP2D6 + RAD54 system. In contrast, the genotoxic carcinogen, methyl methanesulfonate, was detected by all systems. Our yeast-reporter system can be performed in 384-well microplates to provide efficient genotoxicity testing to identify various carcinogenic compounds and reduce chemical consumption to about 53% as compared with existing 96-well genotoxicity bioassays. In association with a liquid handling robot, this platform enables rapid, cost-effective, and high-throughput screening of numerous analytes in a fully automated and continuous manner without the need for user interaction.

In vivo anticancer activity of maesopsin 4-O-β-glucoside isolated from leaves of Artocarpus tonkinensis A. Chev. Ex Gagnep

Objective: To investigate the antitumor effect of maesopsin 4-O-β-glucoside (TAT2) isolated from the leaves of Artocarpus tonkinensis (A. tonkinensis) A. Chev. ex Gagnep. Methods: The antitumor activity of TAT2 was evaluated in Lewis lung carcinoma (LLC) tumor-bearing mice. BALB/c mice had tumors induced by implantation with 2 × 10

In vivo anticancer activity of maesopsin 4-O-β-glucoside isolated from leaves of Artocarpus tonkinensis A. Chev. Ex Gagnep

OBJECTIVE@#To investigate the antitumor effect of maesopsin 4-O-β-glucoside (TAT2) isolated from the leaves of Artocarpus tonkinensis (A. tonkinensis) A. Chev. ex Gagnep.@*METHODS@#The antitumor activity of TAT2 was evaluated in Lewis lung carcinoma (LLC) tumor-bearing mice. BALB/c mice had tumors induced by implantation with 2 × 10(6) LLC cells into the subcutaneous right posterior flank. Tumor-bearing mice were treated orally with a range of doses of TAT2 and a standard drug, doxorubicin. Animals were observed for tumor growth and mortality rate. Blood was collected to determine hematological and biochemical parameters.@*RESULTS@#TAT2 was isolated from an ethanolic extract of A. tonkinensis leaves. Its structure was determined by MS and NMR spectroscopy, and identified as TAT2. The compound did not show acute toxicity at the highest dose tested (2000 mg/kg body weight). TAT2 exhibited antitumor activity by decreasing tumor growth, increasing the survival rate, and ameliorating some hematological and biochemical parameters at doses of 100 and 200 mg/kg body weight (P < 0.05).@*CONCLUSIONS@#These results indicate that TAT2 possesses clear antitumor activity. Due to its bioavailability and low toxicity, and the fact that it could be isolated in a large scale from A. tonkinensis leaves, the compound shows promise as a potential anticancer drug.