scholarly journals Inhibition of glycoprotein oligosaccharide processing in vitro and in influenza-virus-infected cells by α-d-mannopyranosylmethyl-p-nitrophenyltriazene

1988 ◽  
Vol 255 (3) ◽  
pp. 991-998 ◽  
Author(s):  
W McDowell ◽  
A Tlusty ◽  
R Rott ◽  
J N BeMiller ◽  
J A Bohn ◽  
...  

The effects of alpha-D-mannopyranosylmethyl-p-nitrophenyltriazene (MMNT) on mannosidases involved in asparagine-linked oligosaccharide processing were investigated. MMNT was found to inhibit the activity of rat liver Golgi alpha-mannosidase I in a concentration-dependent manner (50% inhibition with 0.18 mM-MMNT), whereas rat liver endoplasmic-reticulum alpha-mannosidase appeared to be resistant (less than 5% inhibition at 1 mM-MMNT). Jack-bean alpha-mannosidase was also sensitive to inhibition by MMNT (50% inhibition with 0.32 mM-MMNT). Treatment of influenza-virus-infected chick-embryo cells with 1 mM-MMNT led to a decrease in the formation of complex-type asparagine-linked oligosaccharides and an accumulation of high-mannose-type oligosaccharides with the composition Man8(GlcNAc)2 and Man7(GlcNAc)2 on the viral glycoproteins. The biological activities of influenza-virus haemagglutinin and neuraminidase synthesized in the presence of 1 mM-MMNT remained unchanged, but the virus was less infectious than the control.

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hend M. Tag ◽  
Amna A. Saddiq ◽  
Monagi Alkinani ◽  
Nashwa Hagagy

AbstractHaloferax sp strain NRS1 (MT967913) was isolated from a solar saltern on the southern coast of the Red Sea, Jeddah, Saudi Arabia. The present study was designed for estimate the potential capacity of the Haloferax sp strain NRS1 to synthesize (silver nanoparticles) AgNPs. Biological activities such as thrombolysis and cytotoxicity of biosynthesized AgNPs were evaluated. The characterization of silver nanoparticles biosynthesized by Haloferax sp (Hfx-AgNPs) was analyzed using UV–vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The dark brown color of the Hfx-AgNPs colloidal showed maximum absorbance at 458 nm. TEM image analysis revealed that the shape of the Hfx-AgNPs was spherical and a size range was 5.77- 73.14 nm. The XRD spectra showed a crystallographic plane of silver nanoparticles, with a crystalline size of 29.28 nm. The prominent FTIR peaks obtained at 3281, 1644 and 1250 cm− 1 identified the Functional groups involved in the reduction of silver ion reduction to AgNPs. Zeta potential results revealed a negative surface charge and stability of Hfx-AgNPs. Colloidal solution of Hfx-AgNPs with concentrations ranging from 3.125 to 100 μg/mL was used to determine its hemolytic activity. Less than 12.5 μg/mL of tested agent showed no hemolysis with high significant decrease compared with positive control, which confirms that Hfx-AgNPs are considered non-hemolytic (non-toxic) agents according to the ISO/TR 7405-1984(f) protocol. Thrombolysis activity of Hfx-AgNPs was observed in a concentration-dependent manner. Further, Hfx-AgNPs may be considered a promising lead compound for the pharmacological industry.


Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1039
Author(s):  
Li-Ping Sun ◽  
Feng-Feng Shi ◽  
Wen-Wen Zhang ◽  
Zhi-Hao Zhang ◽  
Kai Wang

Safflower honey is a unique type of monofloral honey collected from the nectar of Carthamus tinctorius L. in the Apis mellifera colonies of northwestern China. Scant information is available regarding its chemical composition and biological activities. Here, for the first time, we investigated this honey’s chemical composition and evaluated its in vitro antioxidant and anti-inflammatory activities. Basic physicochemical parameters of the safflower honey samples in comparison to established quality standards suggested that safflower honeys presented a good level of quality. The in vitro antioxidant tests showed that extract from Carthamus tinctorius L. honey (ECH) effectively scavenged DPPH and ABTS+ free radicals. In lipopolysaccharides (LPS) activated murine macrophages inflammatory model, ECH treatment to the cells inhibited the release of nitric oxide and down-regulated the expressions of inflammatory-relating genes (iNOS, IL-1β, TNF-α and MCP-1). The expressions of the antioxidant genes TXNRD, HO-1, and NQO-1, were significantly boosted in a concentration-dependent manner. ECH decreased the phosphorylation of IκBα and inhibited the nuclear entry of the NF-κB-p65 protein, in LPS-stimulated Raw 264.7 cells, accompany with the increased expressions of Nrf-2 and HO-1, suggesting that ECH achieved the anti-inflammatory effects by inhibiting NF-κB signal transduction and boosting the antioxidant system via activating Nrf-2/HO-1 signaling. These results, taken together, indicated that safflower honey has great potential into developing as a high-quality agriproduct.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jassem G. Mahdi ◽  
Eamon J. Mahdi ◽  
Amal Al-Hazzaa ◽  
Chris J. Pepper

There has been a growing interest in the beneficial effects of simple phenolic acids and their ability to exhibit various biological activities. The aim of this study was to assess in vitro biological activities of 2-, 3-, and 4-hydroxybenzoate lithium (HBLi) complexes on HT-1080 human fibrosarcoma cells by methods of using a metabolic activity assay, immunochemical and morphological techniques. Results showed that HBLi complexes exert their cytotoxic activities in a concentration- and chemical structure-dependent manner in the following order: 4-HBLi > 3-HBLi > 2-HBLi. Flow cytometry displayed evidence of apoptosis induced by 3-HBLi (21.8%) and 4-HBLi (33.2%). These results were verified by SEM, which revealed the formation of apoptotic bodies. In addition, these 3-HBLi and 4-HBLi caused an increase in HT-1080 cell cycle arrest in G0/G1 phase when compared to the controls (25% and 30.6%, resp.) when cells were treated with 6 mM for 24 hours. Immunochemical studies related to the molecular mechanism of apoptosis indicated that HBLi complexes downregulated the expression of Bcl-2 and upregulated Bax, p53, and caspases-3 in a concentration-dependent manner. HBLi complexes lowered Bcl-2/Bax ratios and induced the expression of p53 and caspase-3. These results suggest that HBLi complexes may exert their apoptotic effects through mitochondrial-mediated, caspase-dependent, apoptotic mechanisms.


2021 ◽  
Author(s):  
Masaru Nakayasu ◽  
Kohei Ohno ◽  
Kyoko Takamatsu ◽  
Yuichi Aoki ◽  
Shinichi Yamazaki ◽  
...  

Abstract Saponins are the group of plant specialized metabolites which are widely distributed in angiosperm plants and have various biological activities. The present study focused on α-tomatine, a major saponin present in tissues of tomato (Solanum lycopersicum) plants. α-Tomatine is responsible for defense against plant pathogens and herbivores, but its biological function in the rhizosphere remains unknown. Secretion of tomatine was higher at the early growth than the green-fruit stage in hydroponically grown plants, and the concentration of tomatine in the rhizosphere of field-grown plants was higher than that of the bulk soil at all growth stages. The effects of tomatine and its aglycone tomatidine on the bacterial communities in the soil were evaluated in vitro, revealing that both compounds influenced the microbiome in a concentration-dependent manner. Numerous bacterial families were influenced in tomatine/tomatidine-treated soil as well as in the tomato rhizosphere. Sphingomonadaceae species, which are commonly observed and enriched in tomato rhizospheres in the fields, were also enriched in tomatine- and tomatidine-treated soils. Moreover, a jasmonate-responsive ETHYLENE RESPONSE FACTOR 4 mutant associated with low tomatine production caused the root-associated bacterial communities to change with a reduced abundance of Sphingomonadaceae. Taken together, our results highlight the role of tomatine in shaping the bacterial communities of the rhizosphere and suggest additional functions of tomatine in belowground biological communication.


Author(s):  
Vijayta Gupta ◽  
Vinay Kant ◽  
Meena Sharma

The promising results of metal oxides nanoparticles in different areas including the biological system lead us to investigate the antioxidant and antimicrobial actions of chemically synthesized cobalt oxide (Co3O4) nanoparticles. The different concentrations of synthesized Co3O4 nanoparticles were prepared and evaluated for different parameters at different time intervals i.e.  on day 1, 30 and 60 after preparations.  Co3O4 nanoparticles synthesized in this study were of 52.2 nm average size with a polydispersity index of 0.465. We observed that Co3O4 nanoparticles scavenge different in vitro free radicals (DPPH, ABTS, superoxide anion and hydrogen peroxide radicals) in concentration dependent manner. The percentage of inhibitions of free radicals by Co3O4 nanoparticles was markedly more on day 1 as compared to day 30 and 60. The IC50 values of Co3O4 nanoparticles for these free radicals were also on day 1 as compared to day 30 and 60. The Co3O4 nanoparticles showed the antibacterial actions against both the bacterial strains i.e. S. aureus and E. coli. The MIC and MBC values revealed that action of Co3O4 nanoparticles was more against E. coli than S. aureus. The MIC and MBC values were lower on day 1 as compared to day 30 and 60 with respective to specific bacteria. In conclusions, the Co3O4 nanoparticles synthesized in this study showed potent antioxidant and antibacterial properties due to which it may serve as promising candidate for the combat the biological problems humans, animals and plants associated with reactive oxygen species and bacteria.


Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1249 ◽  
Author(s):  
Mahboob Adekilekun Jimoh ◽  
Oladayo Amed Idris ◽  
Muhali Olaide Jimoh

This study aimed at assessing the biological activities of Mucuna pruriens seeds using cytotoxicity, phytochemical, antiparasitic screening, and antioxidant assays. Mature fruits of M. pruriens were harvested from Fort Hare University’s Research Farm located in Alice, South Africa. The collected seeds were pulverized in a standard process and taken to the laboratory for crude extraction and further treatments. Cytotoxic, antimalarial, and trypanocidal effects of crude extracts obtained from ethanol and water were tested, while the total phenolic, proanthocyanidin, and flavonoid contents of the aqueous extracts as well as their pharmacological activities were determined in vitro using 2,2-diphenyl-1-picrylhydrazyl ethanol (DPPH), ferric reducing antioxidant power (FRAP), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. Although the extracts showed mild antiparasitic (antiplasmodial and trypanocidal) effects, results from the cytotoxic experiment revealed that M. pruriens is not toxic to human cervix adenocarcinoma (HeLa) cells when tested using 50 µg/mL of extracts. It was observed that the seeds were remarkably rich in phenol (3730.1 ± 15.52 mg gallic acid equivalent (GAE)/g) compared to flavonoids (63.03 ± 1.95 mg quercetin equivalent (QE)/g) and proanthocyanidin (18.92 ± 1.09 mg catechin equivalent (CE)/g). Also, the antioxidant activities of the extracts were comparable to those of the standard antioxidant drugs (rutin and gallic acid) used, in a concentration-dependent manner. There was a direct relationship between phenolic acid content and antioxidant effects. It is therefore suggested that M. pruriens seeds be incorporated into human diets as a supplement to promote healthy living. Pharmaceutical industries with a particular interest in natural phenolic acids should consider using seeds of M. pruriens as pharmaceutical precursors.


Biomolecules ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 211 ◽  
Author(s):  
Thi My Hanh Pham ◽  
Dai-Hung Ngo ◽  
Dai-Nghiep Ngo ◽  
Thanh Sang Vo

Wild bitter melon (Momordica charantia L. var. Abbreviata Ser.) is a wild edible variety of M. charantia, often used in folk medicine. In this study, the biological activities of its extract and fractions were investigated in vitro. It was found that ethyl acetate (EA) fraction exhibited high 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging activity with a half maximal inhibitory concentration (IC50) value of 0.43 ± 0.04 mg/mL, while the chloroform (CF), EA, and n-butanol (Bu) fractions had strong 2,2-azinobis-3-ethyl benzothiazoline-6-sulfonic acid (ABTS)+ scavenging ability with IC50 values of 0.36 ± 0.04 mg/mL, 0.35 ± 0.02 mg/mL, and 0.35 ± 0.05 mg/mL, respectively. Moreover, the EA and Bu fractions exhibited the highest protective effect against H2O2-induced DNA damage in a concentration-dependent manner. Furthermore, the EA fraction was effective in the inhibition of enzyme α-amylase activity with an IC50 value of 0.27 ± 0.029 mg/mL. Finally, it was observed that the production of nitric oxide (NO), a pro-inflammatory mediator, was significantly reduced from LPS-stimulated murine macrophage RAW 264.7 cells by the ethanol extract (ET) and the EA fraction. Therefore, wild bitter melon could be considered as a promising biomaterial for the development of pharmaceutical products.


2003 ◽  
Vol 14 (2) ◽  
pp. 75-80 ◽  
Author(s):  
Julia Serkedjieva ◽  
Maria Velcheva

The pavine alkaloid (-)-thalimonine (Thl), isolated from the Mongolian plant Thalictrum simplex inhibited markedly the reproduction of influenza virus A/Germany/27, str. Weybridge (H7N7) and A/Germany/34, str. Rostock (H7N1) in cell cultures of chicken embryo fibroblasts. In a number of assays at a non-toxic concentration range of 0.1–6.4 μM the alkaloid inhibited viral reproduction in a selective and specific way (selectivity index=640, 106.6, respectively). Expression of viral glycoproteins haemagglutinin (HA), neuraminidase (NA) and nucleoprotein (NP) on the surface of infected cells, virus-induced cytopathic effect, infectious virus yields, HA production and virus-specific protein synthesis were all reduced. The inhibition was dose-related and depended on virus inoculum. The time of addition experiments indicated that viral reproduction was markedly inhibited when Thl was added at 4–5 h of infection. No inactivating effect on extracellular virus was found.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4302
Author(s):  
Xiao-Long Sun ◽  
Mei-Lin Zhu ◽  
Yi-Qun Dai ◽  
Hong-Mei Li ◽  
Bo-Han Li ◽  
...  

Magnolol (MAG), a biphenolic neolignan, has various biological activities including antitumor effects. In this study, 15 MAG derivatives were semi-synthesized and evaluated for their in vitro anticancer activities. From these derivatives, compound 6a exhibited the best cytotoxic activity against four human cancer cell lines, with IC50 values ranging from 20.43 to 28.27 μM. Wound-healing and transwell assays showed that compound 6a significantly inhibited the migration and invasion of MDA-MB-231 cells. In addition, Western blotting experiments, performed using various concentrations of 6a, demonstrated that it downregulates the expression of HIF-1α, MMP-2, and MMP-9 in a concentration-dependent manner. Overall, these results suggest that substituting a benzyl group having F atoms substituted at the C2 position on MAG is a viable strategy for the structural optimization of MAG derivatives as anticancer agents.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 97
Author(s):  
Stefania Lamponi ◽  
Maria Camilla Baratto ◽  
Elisabetta Miraldi ◽  
Giulia Baini ◽  
Marco Biagi

This study aimed to characterize the chemical profile of an ethanolic extract of Tuscan Rosmarinus officinalis (Roex) and to determine its in vitro bioactivity. The content of phenolic and flavonoid compounds, hydroxycinnamic acids and triterpenoids was determined, and high-performance liquid chromatography-diode array detection (HPLC-DAD) analysis revealed that rosmarinic acid and other hydroxycinnamic derivatives were the main constituents of the extract. Roex demonstrated to have both antioxidant activity and the capability to scavenge hydrogen peroxide in a concentration dependent manner. Moreover, NIH3T3 mouse fibroblasts and human breast adenocarcinoma cells MDA-MB-231 viability was influenced by the extract with an IC50 of 2.4 × 10−1 mg/mL and 4.8 × 10−1 mg/mL, respectively. The addition of Roex to the culture medium of both the above cell lines, resulted also in the reduction of cell death after H2O2 pre-treatment. The Ames test demonstrated that Roex was not genotoxic towards both TA98 and TA100 strains, with and without S9 metabolic activation. The extract, by inactivating thrombin, showed to also have an anti-coagulating effect at low concentration values. All these biological activities exerted by Roex are tightly correlated to its phytochemical profile, rich in bioactive compounds.


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