Glinus oppositifolius is an endemic herbaceous plant found in tropical Asian countries and is native in Vietnam. It is used in traditional folk medicine because of its flavor and antiseptic and ...laxative effects. In the current research, the effects of Tox-off, Biovip, and the purified compounds isolated from G. oppositifolius in the previous study were evaluated on the activation of adenosine 5′-monophosphate-activated protein kinase (AMPK)-activated protein kinase (AMPK) and acetyl-coenzyme A carboxylase (ACC) in C2C12 myoblasts. In addition, the most potent active compounds, traphanoside-GO1 (TRA-GO1) and TRA-GO5 have validated the reduction of fatty acid synthase (FAS) and sterol regulatory element binding protein (SREBP)-1c in HepG2 cells. We found that Tox-off and Biovip significantly increased the phosphorylation of AMPK and ACC in C2C12 myoblasts. Furthermore, TRA-GO1 and TRA-GO5 significantly increased the AMPK activation and phosphorylation of its downstream substrate ACC in a concentration-dependent way compared to the dimethyl sulfoxide (DMSO) control. Besides, the protein level of FAS and SREBP-1c decreased by TRA-GO1 and TRA-GO5 in a concentration-dependent manner. Taken together, our results showed that the increased AMPK and ACC phosphorylation by active components of G. oppositifolius may activate the AMPK signaling pathways, which are useful for the anti-obesity and its related metabolic disorders.
Many medicinal plants have been shown to possess biological effects, including immuno-modulatory activities on human and other mammals. However, studies about the potential mechanisms of plant ...extracts on the humoral and tissular immunities in fish have received less attention. This study aimed to screen the immunestimulating properties of 20 ethanol plant extracts on striped catfish Pangasianodon hypophthalmus leukocytes. The peripheral blood mononuclear cells (PBMCs) and head kidney leukocytes (HKLs) of striped catfish (50 ± 5 g per fish) were stimulated at 10 and 100 μg of each plant extract per mL of cell culture medium. Several humoral immune parameters (lysozyme, complement and total immunoglobulin) were examined at 24-h post stimulation (hps). Furthermore, the responses of four cytokine genes, namely il1β, ifrγ 2a and b, and mhc class II were assessed by quantitative real-time PCR at 6, 12, 24, and 48 hps. The results showed that lysozyme, complement as well as total immunoglobulin levels in both PBMCs and HKLs were regulated by some of the plant extracts tested in a concentration-dependent manner; some plant extracts induced the highest immune responses at the low dose (10 μg mL−1) while others were more efficient at high dose (100 μg mL−1). Among the extracts, five extracts including garlic Allium sativum L. (As), neem Azadirachta indica A. Juss (Ai), asthma-plant Euphorbia hirta L. (Eh), bhumi amla Phyllanthus amarus Schum. et Thonn (Pa), and ginger Zingiber officinale Rosc (Zo) induced significant changes in the expression of pro-inflammatory cytokine (il1β), antiviral cytokines (ifrγ 2a and b) and adaptive immune cytokine (mhc class II) in striped catfish cells. Pa always modulated the strongest expression of the four cytokines in PBMCs and HKLs over the whole experimental period (p < 0.05), whereas Zo did not stimulate the mhc class II expression in striped catfish leukocytes throughout experimental periods. These in vitro results demonstrated that some plant extracts could differently modulate great potential immune response in fish, supporting their applications in further in vivo experiments.
•Plant extracts modulated humoral immune parameters in striped catfish leukocytes by in vitro test.•Different plant extracts regulated differently potential immune response in striped catfish.•Ethanol plant extracts stimulated striped catfish immune system by affecting PBMCs and HKLs.•il1β, ifrγ 2a and b, and mhc class II genes were regulated in leukocytes during in vitro extract-stimulation.
This study aimed to identify major phytochemical constituents, as well as compare the immunomodulatory effects of Psidium guajava L. and Phyllanthus amarus Schun and Thonn crude ethanol extracts and ...their fractions on striped catfish (Pangasianodon hypophthalmus) head kidney leukocytes (HKLs). Moreover, pure constituents were also investigated for their effects on those cells: hypophyllanthin, identified as a major constituent of P. amarus crude extracts and its hexane fraction; corosolic acid, ursolic acid, and oleanolic acid, identified in P. guajava crude extract, ethyl acetate and dichloromethane fractions; with other terpenic derivatives, as well as guajaverin and avicularin, identified with other flavonoids by LC-UV-MS in the crude P. guajava extract and its ethyl acetate fraction. Cell viability, respiratory burst assay (RBA), nitric oxide synthase (NOS) and lysozyme activity in HKLs were analyzed after 24 h stimulation with each extract (10, 20 and 40 μg/mL) or pure compound (7.5, 15 and 30 μM). Our results show that the hexane fraction of both plant extracts inhibited the viability of HKLs, while several other fractions enhanced the cell viability. All P. guajava fractions at all or some concentration considerably enhanced the RBA production in HKLs. Similarly, NOS production was also significantly increased by some or all concentrations of P. guajava dichloromethane and ethyl acetate fractions. However, the NOS production was dose-dependently inhibited in HKLs treated with Pa ethyl acetate and both plants aqueous fractions at 10 or 10 and 40 μg/mL respectively. The lysozyme activity in cells treated with P. guajava crude extracts and all its organic solvent fractions were stronger than those in P. amarus treatments. Pure compounds including corosolic acid, guajaverin, ursolic acid, hypophyllanthin inhibited the HKLs viability according to concentration and type of compound. All pure compounds except avicularin significantly stimulated, at certain or all concentrations, the RBA production and/or the lysozyme activity in HKLs. The NOS production was significantly reduced in HKLs treated with oleanolic acid (30 μM) and hypophyllanthin (7.5 μM) while its level was increased by hypophyllanthin at 30 μM. These results highlighted that the crude ethanol extracts of P. guajava and P. amarus, their fractions and some of their pure components at certain concentrations can potentially act as immunomodulators, and could be considered as valuable candidates in fishery sciences.
•P. amarus and P. guajava ethanol extracts and their fractions modulate the HKLs viability, RBA, NOS and lysozyme activities.•Hypophyllanthin was a major component in P. amarus crude extracts before and after removing tannins, and its hexane fraction.•The major components of the crude ethanol leaf extract of P. guajava were mainly flavonoids and triterpenic derivatives.•Pure compounds identified in P. amarus and P. guajava extracts potentially modulate the striped catfish HKLs immune response.
The aim of this study is first to identify the major phenolic compound of a crude ethanol extract of Psidium guajava leaves collected in Vietnam and to develop validated methods for quantification of ...phenolic and triterpenic components by HPLC-PDA-HRMS. The major phenolic compound was determined as quercetin-3-O-sulfate which is isolated and quantified for the first time in P. guajava. Validated HPLC-DAD quantification methods were developed to quantify the major triterpenic and phenolic derivatives of this extract and found to be accurate in the concentration range of 2–50 μg/mL for phenolic, and 5–100 μg/mL for triterpenic compounds. Four crude ethanol extracts of guava leaves collected at different periods of the year were analyzed using the developed methods and were found to be richer in triterpenic than phenolic derivatives. We also observed that the weather or rainfall influenced the richness in bioactive compounds in guava leaves.
•Quercetin-3-O-sulfate was isolated from Psidium guajava for the first time.•A new validated method to quantify both triterpenic aromatic esters and acids in P. guajava leaves.•Ethanol extract of guava leaves collected in September is the richest in bioactive metabolites in our research.•Ethanol crude extracts contain more triterpenic derivatives than phenolic compounds.
In this article, the influence of the medium refractive index on optical properties of gold nanorods (GNRs) and their surface enhanced Raman spectroscopy application were studied. In particular, GNRs ...have been applied in biomedical sensors to detect diseases by monitoring the changes in the environment. In this study, the changes in optical properties of GNRs were investigated according to the medium refractive index changes in the cationic surfactant cetyltrimethylammonium bromide (CTAB) during synthesis processes as well as GNR dispersion in different medium refractive indices. For instance, in the solutions with different concentrations of CTAB, GNRs were coated by biomolecules such as PEG, bovine serum albumin (BSA), and glutathione (GSH), which have different refractive indices. The fundamental reason for the change in optical properties of GNRs is also elucidated. GNRs have been used to enhance surface Raman scattering to detect indigo molecules. The results showed that due to the surface plasmon resonance effect, the GNRs could strongly enhance the scattering signal of indigo dyes, with the lowest detectable concentration of up to 10−8 M and with an enhancement coefficient of over 2000 times.
A method for seeded growth of particles with uniform, smooth spherical shape, and narrow size distributions is presented. By using formaldehyde (HCHO) as a reductant and without any stabilizer in an ...aqueous solution, gold nanoparticles with sizes up to 220 nm were prepared at room temperature. The gold nanoparticles (diameter in the range of 1–3 nm) for the first seeds are synthesized by the reduction of tetrachloroauric acid trihydrate (HAuCl
4
) with tetrakis (hydroxymethyl) phosphonium chloride THPC (P(CH
2
OH)
4
Cl). These seeds are dispersed in the gold plating solution at pH 9.0 in the presence of HCHO. Through multi-step seeding growth, their sizes are precisely controlled just by adjusting the ratio of gold precursor to seeds. The obtained gold nanospheres are characterized by using transmission electron microscopy, a Zetasizer Nano, and UV–VIS absorption spectroscopy. This approach has excellent reproducibility and can significantly improve the monodispersity of nanospheres.
Graphic abstract
This study aimed to examine: (1) how the Internet has changed consumers food-buying behavior and identify its associated factors; (2) consumers' concern about food safety information of online food ...products. A cross-sectional study was performed from October to December 2015 in Hanoi-a Vietnamese epicenter of food service. One thousand seven hundred and thirty six (1736) customers were randomly chosen from food establishments of 176 communes. Data were collected through face-to-face interviews using structured questionnaires. The majority of participants reported using the Internet to search for food products (81.3%). The most crucial factors influencing food purchases through the Internet were convenience (69.1%) and price (59.3%). Only one-third of participants selected products based on accurate evidence about food safety certification or food origin. The majority of participants were concerned about the expiration date (51.6%), while brand (9.8%) and food licensing information (11.3%) were often neglected. People who were:(1) female, (2) highly influenced by online relationships, and (3) having difficulty in doing usual activities were more likely to look for online food products. These findings produce practical advice to consumers when purchasing their desired food products on the Internet, to online food retailers and to the Government of Vietnam to implement appropriate legislation regarding trading online food products.
This study aimed to screen the in vitro antioxidant and antimicrobial activities of ethanolic extracts from 20 plants and three herbal commercial products empirically used for aquaculture improvement ...in Vietnam. The results of 2,2-diphenyl-1-pycrylhydrazyl (DPPH) radical scavenging assays showed that Phyllanthus amarus extract was the strongest antioxidant, followed by four extracts in the subsequent order: Piper betle > Psidium guajava > Euphorbia hirta > Mimosa pudica. These five plant extracts were very active in a DPPH radical scavenging assay with concentrations needed to scavenge half of the DPPH (IC
50
) below 30 µg/mL. Seven plant extracts showed an IC
50
ranging from 31.9 to 59.7 µg/mL, while eleven extracts showed an IC
50
above 70 µg/mL. A positive association was found between phenolic content (expressed as gallic acid equivalents) and antioxidant activity of the plant extracts. Concerning in vitro antimicrobial activities, P. amarus extract showed the highest activity against two different strains of Aeromonas hydrophila as demonstrated by its low minimal inhibitory concentration (MIC) of 156 and 625 µg/mL, respectively; whereas, P. betle displayed a moderate activity against Edwardsiella ictaluri with a MIC value of 625 µg/mL. Tannins were observed as significant factors contributing to antioxidant and antimicrobial properties of the plant extracts tested.
Silver meso-particles (SMPs) were successfully synthesized by a simple chemical method in the presence of L-ascorbic acid reducing agent and silver ions precursor in AgNO 3. Silver meso-structures of ...different topographies have been synthesized by varying the concentration of the reactants such as the L-AA concentration or the Ag+ ions concentration as well as by varying the temperature reaction. The structural morphology and optical properties of SMPs were thoroughly investigated by employing different characterization methods such as ultraviolet–visible spectroscopy (UV–Vis), X-ray spectroscopy and transmission electron microscopy (TEM). The results showed that the smaller the concentration of Ag+ ions and the greater the concentration of reducing agent L-AA, the more hierarchical SMPs. This investigation is explained by the mechanism of formation and development of SMPs in the solution. The surface-enhanced Raman scattering (SERS) effects of the synthesized SMPSs are also estimated by using the detection of the Rhodamine B (RB) pigments. The investigation confirmed that the highly branched silver meso-structures exhibit a higher efficiency in enhancing surface Raman scattering in comparison with the less branched ones. The enhancement factor EF scattering at the featured peaks for 10−6 M RB on the SMPs substrate are calculated around 104. Our work might give a good reference for the fabrication of SMPs, which are suitable to be applied in sensing.
•Silver meso-particles (SMPs) were successfully synthesized by a simple chemicalmethod using L-ascorbic acid as reducing agent.•Numerous branches of SMPs were created at low temperatures with the low concentration of the Ag+ ions and the high concentration of L-AA. The silver mesostructures had the most branching at 40 °C.•Fabricated SMPs enhanced greatly the effect of surface Raman scattering, in which the coral-like SMPs with more branches exhibited a better detection ability of RB dye molecules.
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