scholarly journals Inhibition of Zika Virus by Marine Algae

2017 ◽  
Author(s):  
Claudio Cirne-Santos ◽  
Caroline De Souza Barros ◽  
Caio Cesar Richter Nogueira ◽  
Renata Mendonça Campos ◽  
Valéria Teixeira ◽  
...  
Keyword(s):  
Zika Virus ◽  
Marine Algae ◽  
Kappaphycus Alvarezii ◽  
Strong Association ◽  
Public Health Problem ◽  
Brazilian Coast ◽  
Dependent Manner ◽  
Sulphated Polysaccharides ◽  
Low Concentrations ◽  
Dose Dependent

For many years marine algae has been subject of numerous researches and as a source of natural products with antiviral activity, such as terpenes, alkaloids and sulphated polysaccharides. However, the anti-Zika virus (ZIKV) potential of algae has not been studied. In this study we evaluated extracts seven species of the three major classes of seaweeds (Phaeophyceae, Chlorophyceae and Rhodophyceae) against ZIKV. All seaweeds tested are native of the Brazilian coast, except for Kappaphycus alvarezii that can be cultivated. ZIKV a mosquito-borne flavivirus, has become a public health problem. In recent years there has been an increase in the number of cases and a strong association between ZIKV outbreak and the spread of cases of Guillain-Barré Syndrome and microcephaly. All seaweed extracts tested in this work inhibits ZIKV replication in a dose-dependent manner. Caulerpa racemosa, Kappaphycus alvarezii and Osmundaria obtusiloba extracts were able to inhibit viral replication at low concentrations with EC50 values ranging from 1.38 to 1.98 µg/mL. We observed that O. obtusiloba presented a significant virucidal effect. Our results suggest that extracts of C. racemosa, K. alvarezii and O. obtusiloba presented very promising results, being excellent candidates for further studies, demonstrating that marine algae are an interesting source for the development of novel anti-ZIKV agents.

Effects of ethanol on gastric epithelial cell phospholipid dynamics and cellular function

1987 ◽  
Vol 252 (2) ◽  
pp. G237-G243
Author(s):  
R. E. Bailey ◽  
R. A. Levine ◽  
J. Nandi ◽  
E. H. Schwartzel ◽  
D. H. Beach ◽  
...  
Keyword(s):  
Membrane Structure ◽  
Lipid Membrane ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Dependent Manner ◽  
Chloride Uptake ◽  
Peak Intensity ◽  
Low Concentrations ◽  
Resonance Band ◽  
Dose Dependent

The lipid profile of isolated gastric superficial epithelial cells (SEC) was evaluated by proton nuclear magnetic resonance spectroscopy (1H-NMR). The most conspicuous resonance band in SEC spectra was due to the protons of +N(CH3)3 groups of phosphatidylcholine and, to a lesser degree, other phospholipid derivatives, on the basis of their chemical shift and addition of purified phospholipids. NMR of cell lysates and phospholipid extracts of SEC in deutero-chloroform provided further spectral resolution of these components. Phospholipase or ethanol treatments of SEC produced membrane disorganization reflected as increased peak intensity of the phospholipid signals. In addition, ethanol, in a dose-dependent manner, attenuated paranitrophenyl phosphatase activity, which correlated with inhibition of total and ouabain-sensitive 86Rubidium chloride uptake by SEC. This study suggests that NMR used in conjunction with other biochemical techniques can monitor SEC membrane structure-function relationships. NMR is a potentially powerful noninvasive probe to show changes in lipid membrane organization induced by low concentrations of ethanol (1%) and may indicate an early sign of "cytotoxicity" in intact SEC.

Mode of Action of the Hypertrehalosaemic Peptides from the American Cockroach

1985 ◽  
Vol 40 (9-10) ◽  
pp. 670-676 ◽  
Author(s):  
Gerd Gäde
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Mode Of Action ◽  
Glycogen Phosphorylase ◽  
Fat Body ◽  
American Cockroach ◽  
Dependent Manner ◽  
Low Concentrations ◽  
First Time ◽  
Dose Dependent

Abstract Although crude extracts of cockroach (Periplaneta amencana) corpora cardiaca have been shown previously to affect the activity of adenylate cyclase and phosphorylase, we demonstrate in the present study for the first time that low concentrations (0.5 to 5 pmol) of the synthetic myoactive peptides. M I and M II, also affect these systems; these myoactive peptides are identical to the hypertrehalosaemic hormones I and II, and cause an increase in the concentration of the second messenger cyclic AMP in the fat body.In addition, both octapeptides activate fat body glycogen phosphorylase and promote breakdown of fat body glycogen. Both peptides increase the levels to haemolymph carbohydrate in a dose-dependent manner.

scholarly journals Biphasic Dose–Response Induced by PCB150 and PCB180 in HeLa Cells and Potential Molecular Mechanisms

Dose-Response ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 155932582091004
Author(s):  
Ainy Zehra ◽  
Muhammad Zaffar Hashmi ◽  
Abdul Majid Khan ◽  
Tariq Malik ◽  
Zaigham Abbas
Keyword(s):  
Hela Cells ◽  
Molecular Mechanisms ◽  
Dependent Manner ◽  
Genotoxic Effects ◽  
Species Formation ◽  
Low Concentrations ◽  
Extracellular Signal ◽  
High Concentrations ◽  
High Doses ◽  
Dose Dependent

The polychlorinated biphenyls (PCBs) are persistent and their dose-dependent toxicities studies are not well-established. In this study, cytotoxic and genotoxic effects of PCB150 and PCB180 in HeLa cells were studied. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that the cell proliferation was stimulated at low doses (10−3 and 10−2 µg/mL for 12, 24, 48, and 72 hours) and inhibited at high doses (10 and 15 µg/mL for 24, 48, and 72 hours) for both PCBs. Increase in reactive oxygen species formation was observed in the HeLa cells in a time- and dose-dependent manner. Malondialdehyde and superoxide dismutase showed increased levels at high concentrations of PCBs over the time. Glutathione peroxidase expression was downregulated after PCBs exposure, suggested that both PCB congeners may attributable to cytotoxicity. Comet assay elicited a significant increase in genotoxicity at high concentrations of PCBs as compared to low concentrations indicating genotoxic effects. PCB150 and PCB180 showed decrease in the activity of extracellular signal–regulated kinase 1/2 and c-Jun N-terminal kinase at high concentrations after 12 and 48 hours. These findings may contribute to understanding the mechanism of PCBs-induced toxicity, thereby improving the risk assessment of toxic compounds in humans.

scholarly journals Purification and some properties of the 45 kDa diphenylene iodonium-binding flavoprotein of neutrophil NADPH oxidase

1990 ◽  
Vol 265 (1) ◽  
pp. 95-100 ◽  
Author(s):  
C M Yea ◽  
A R Cross ◽  
O T G Jones
Keyword(s):  
Polyclonal Antibodies ◽  
Specific Inhibitor ◽  
Small Subunit ◽  
Dependent Manner ◽  
Superoxide Generation ◽  
Diaphorase Activity ◽  
Low Concentrations ◽  
Diphenylene Iodonium ◽  
Neutrophil Superoxide ◽  
Dose Dependent

The 45 kDa diphenylene iodonium-binding flavoprotein of the human neutrophil superoxide-generating oxidase has been purified by affinity chromatography. The polypeptide was eluted from Blue Memsep or 2′,5′-ADP-agarose columns with either NADP or low concentrations of the specific inhibitor diphenylene iodonium. The purified protein was shown to bind FAD at a ratio of 1.09 mol of FAD/mol of protein. The reconstituted flavoprotein had a fluorescence spectrum similar, but not identical, to that of free FAD. It had an isoelectric point of approx. 4.0. The reconstituted flavoprotein displayed no diaphorase activity towards a range of artificial electron acceptors. Polyclonal antibodies raised against the pure protein inhibited superoxide generation by solubilized oxidase in a dose-dependent manner, and inhibited superoxide generation when incubated with either cytosol or membrane fractions in a reconstituted system. These antibodies precipitated the 45 kDa polypeptide together with a haem-containing 23 kDa protein thought to be the small subunit of cytochrome b-245. Antibodies raised against cytochrome P-450 reductase also precipitated these two polypeptides. These results are consistent with the 45 kDa polypeptide being the flavoprotein of the neutrophil superoxide-generating oxidase.

scholarly journals Association ofFTOPolymorphisms with Early Age of Obesity in Obese Italian Subjects

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Federica Sentinelli ◽  
Michela Incani ◽  
Federica Coccia ◽  
Danila Capoccia ◽  
Valentina Maria Cambuli ◽  
...  
Keyword(s):  
Age Of Onset ◽  
Association Studies ◽  
Strong Association ◽  
Italian Population ◽  
Dependent Manner ◽  
Major Health Problem ◽  
Risk Alleles ◽  
Obese Subjects ◽  
Dose Dependent

Obesity is recognized as a major health problem worldwide. Genetic factors play a major role in obesity, and genomewide association studies have provided evidence that several common variants within the fat mass- and obesity-associated (FTO) gene are significantly associated with obesity. Very limited data is available onFTOin the Italian population. Aims of our study are to investigate: (1) the association ofFTOgene SNPs rs9939609 and rs9930506 with body mass index (BMI) and obesity-related parameters in a large cohort (n=752) of Italian obese subjects; (2) the association between the twoFTOSNPs and age of onset of obesity. Our results demonstrate a strong association betweenFTOSNPs rs9939609 (P<0.043) and rs9930506 (P<0.029) with BMI in the Italian population.FTOrs9930506 was significantly associated with higher BMI in a G allele dose-dependent manner (BMI+1.4 kg/m2per G allele). We also observed that the association with BMI of the twoFTOvariants varied with age, with the carriers of the risk alleles developing an increase in body weight earlier in life. In conclusion, our study further demonstrates a role of the genetic variability inFTOon BMI in a large Italian population.

Biofilm Formation and Virulence of Shigella flexneri is Modulated by pH of Gastrointestinal Tract

2021 ◽  
Author(s):  
I-Ling Chiang ◽  
Yi Wang ◽  
Satoru Fujii ◽  
Brian D. Muegge ◽  
Qiuhe Lu ◽  
...  
Keyword(s):  
Small Intestine ◽  
Epithelial Cells ◽  
Type Iii Secretion ◽  
Shigella Flexneri ◽  
Public Health Problem ◽  
Dependent Manner ◽  
Specific Amino Acid ◽  
Cellular Invasion ◽  
Ph Conditions ◽  
Dose Dependent

Shigella infection remains a public health problem in much of the world. Classic models of Shigella pathogenesis suggest that microfold epithelial cells in the small intestine are the preferred initial site of invasion. However, recent evidence supports an alternative model whereby Shigella primarily infects a much wider range of epithelial cells that reside primarily in the colon. Here, we investigated whether the luminal pH difference between the small intestine and colon could provide evidence in support of either model of Shigella flexneri pathogenesis. As virulence factors culminating in cellular invasion are linked to biofilms in S. flexneri , we examined the effect of pH on S. flexneri ’s ability to form and maintain adherent biofilms when induced by deoxycholate. We showed that a basic pH (as expected in the small intestine) inhibited formation and dispersed pre-assembled mature biofilms while an acidic pH (similar to the colonic environment) did not permit either of these effects. To further elucidate this phenomenon at the molecular level, we probed the transcriptomes of biofilms and S. flexneri grown in different pH conditions. We identified specific amino acid metabolic pathways (cysteine and arginine) that were enriched in the bacteria that formed the biofilms, but decreased when pH increased. We then utilized a type III secretion system reporter strain to show that increasing pH reduced deoxycholate-induced virulence of S. flexneri in a dose dependent manner. Taken together, these experiments support a model whereby Shigella infection is favored in the colon because of the local pH differences in these organs.

scholarly journals Assessment of Potential Anticancer Activity of Brown Seaweed Compounds Using Zebrafish Phenotypic Assay

2019 ◽  
Vol 14 (6) ◽  
pp. 1934578X1985790
Author(s):  
Nur ‘Afina Rusdi ◽  
Chin Siang Kue ◽  
Ke-Xin Yu ◽  
Beng Fye Lau ◽  
Lip Yong Chung ◽  
...  
Keyword(s):  
Brown Seaweed ◽  
Dependent Manner ◽  
Anticancer Compounds ◽  
Lead Compounds ◽  
Anticancer Effects ◽  
Morphogenetic Protein ◽  
Low Concentrations ◽  
Screening Platform ◽  
Zebrafish Embryogenesis ◽  
Dose Dependent

Despite the extensive work on anticancer drug discovery, the number of potent lead compounds that enter the preclinical and clinical trials thus far is still low due to the poor selectivity and understanding in pharmacodynamics. In view of the homology between zebrafish embryogenesis and carcinogenesis in human, zebrafish embryos can be used in the screening platform to elucidate the molecular targets of potential anticancer compounds. In the present study, the possible targets modulating the potential anticancer effects of selected brown seaweed-derived compounds (ie alginate, fucoidan, phloroglucinol, fucosterol, and fucoxanthin) were examined. Teratogenic effects induced by the compounds were observed after 72 hours post-fertilization. Fucoidan, phloroglucinol, and fucosterol were observed to significantly reduce the pigmentation of the zebrafish in a dose-dependent manner at low concentrations (fucoidan, <60 µg/mL; phloroglucinol, <10 µg/mL; fucosterol, <3 µg/mL). On the other hand, embryos treated with fucoxanthin at 200 µg/mL and 300 µg/mL exhibited either phenotypes of curved trunk or bent tail. Further validation work using dual antiplatelet therapy (DAPT) and dorsomorphin as positive controls suggest that fucoxanthin might target the Notch and bone morphogenetic protein (BMP) pathways, respectively. Findings from this exploratory study henceforth have demonstrated the utility of zebrafish embryo to accelerate the discovery of potential compounds for targeted anticancer therapy.

scholarly journals Steroid hormones modulate galectin-1 in the trophoblast HTR-8/SVneocell line

2008 ◽  
Vol 60 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Zanka Bojic-Trbojevic ◽  
Milica Bozic ◽  
Ljiljana Vicovac
Keyword(s):  
Steroid Hormones ◽  
Cell Invasion ◽  
Regulatory Role ◽  
Dependent Manner ◽  
Data Support ◽  
Low Concentrations ◽  
Dose Dependent

The effects of steroids on galectin-1 (gal-1) were studied in HTR-8/SVneo cells by immunocytochemistry, cell-based ELISA, the MTT proliferation test and the Matrigel TM invasion test. Dexamethasone (DEX), progesterone (PRG), and mifepristone (RU486) were used. Gal-1 was modulated in a steroid- and dose-dependent manner by DEX, which mildly but significantly stimulated production at low concentrations (0.1-10 nM), and inhibited it at 100 nM, while the effects of PRG and RU486 were opposite. HTR-8/SVneo cell invasion of Matrigel was significantly decreased in the presence of DEX and lactose. The obtained data support the proposed regulatory role of steroids in trophoblast gal-1 production.

scholarly journals The effect of low concentrations of ethanol on gastric adenocarcinoma cell lines

2014 ◽  
Vol 66 (1) ◽  
pp. 317-321 ◽  
Author(s):  
Lingjiao Wu ◽  
Shaohua Chen ◽  
Yu Zhang ◽  
Hongming Pan
Keyword(s):  
Alcohol Dehydrogenase ◽  
Cell Viability ◽  
Gastric Adenocarcinoma ◽  
Cell Lines ◽  
Dependent Manner ◽  
Ethanol Treatment ◽  
Adenocarcinoma Cell ◽  
Low Concentrations ◽  
Adenocarcinoma Cells ◽  
Dose Dependent

Chronic alcohol consumption has been identified as a significant risk factor for cancer in humans. The aim of the study was to analyze the influence of low concentrations of ethanol on gastric adenocarcinoma cell viability, apoptosis, and changes in the expression of alcohol dehydrogenase with ethanol treatment. Gastric adenocarcinoma cell lines (MGC803, MGC823 and SGC7901) were treated with different concentrations of ethanol (0.03125%, 0.0625%, 0.125%, 0.25%, 0.5%, 1%, 2%, and 4%). An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and flow cytometry were used to analyze the effect of ethanol treatment on cell viability and apoptosis. Western blotting was used to analyze the expression of alcohol dehydrogenase in gastric carcinoma cells. Ethanol treatment inhibited cell proliferation in gastric adenocarcinoma cell lines in a significant dose-dependent manner. Ethanol was also able to induce the apoptosis of gastric adenocarcinoma cells in a dose-dependent manner. Alcohol dehydrogenase activity of gastric adenocarcinoma cells increased with the increase in the concentration of ethanol. Ethanol inhibited cell viability and growth of gastric adenocarcinoma cell lines. Low concentrations of ethanol also induced apoptosis and increased the expression of alcohol dehydrogenase of the gastric adenocarcinoma cell lines.

AV513 Enhances Tissue Factor Activity by Inhibiting TFPI in Hemophilia A Plasma: Potential TFPI Target Sites and Potentiation of Factor VIII Activity.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 497-497 ◽  
Author(s):  
Sabine Knappe ◽  
Nicholas Kripalani ◽  
Susannah Patarroyo-White ◽  
Kirk W. Johnson ◽  
Srinivasa Prasad
Keyword(s):  
Human Plasma ◽  
Tissue Factor ◽  
Thrombin Generation ◽  
Hemophilia A ◽  
Brown Seaweed ◽  
Full Length ◽  
Dependent Manner ◽  
Severe Hemophilia ◽  
Low Concentrations ◽  
Dose Dependent

Abstract AV513, a sulfated polysaccharide prepared from brown seaweed and enriched for fucoidan accelerates clotting in hemophilia A and B plasma. Prior studies have demonstrated that AV513 functions mainly by inhibiting TFPI activity. In this report, we have further studied AV513 mechanism of action using human plasma thromboelastography (TEG) model and a thrombin generation assay in FVIII deficient plasma. In the TEG assay, AV513 enhanced tissue factor (TF) induced clotting in human hemophilia A pooled plasma in a dose-dependent manner. A dose-dependent potentiation effect by AV513 was observed with reduction of TEG R time to normal levels at 0.5 μg/mL of AV513. An AV513 dose dependent increase in thrombin generation was observed in hemophilia A pooled plasma with a 3-fold increase in peak thrombin generation at 2.5 μg/mL AV513 (basal: 40 nM vs. treated: 140 nM). When TFPI was immunodepleted from hemophilia A plasma (FVIII/TFPI deficient), sub-optimal concentrations of TF enhanced thrombin generation which was not further enhanced by addition of AV513. The increase in thrombin generation in FVIII /TFPI deficient plasma was inhibited by 93% after the addition of exogenous full-length TFPI or by 47% after the addition of truncated rTFPI (amino acids 1–161) that lacks the Kunitz 3 domain and the C-terminal tail. AV513 at low concentrations reversed exogenous full length TFPI activity almost completely in FVIII/TFPI-deficient plasma but had only a small effect on truncated TFPI. In a human plasma TEG combination study of AV513 and low concentrations of rFVIII (ReFacto), AV513 at a concentration of 0.25 μg/mL reduced the TEG R time by 35% in severe hemophilia A plasma compared to 10 mU/mL of rFVIII alone. These results indicate that AV513 functions as a pro-coagulant by inhibiting TFPI at least in part via targeting the C-terminal region. Moreover, AV513, in the presence of low rFVIII (ReFacto) levels, improves severe hemophilia A plasma clotting - as measured by TEG - beyond that observed with either agent alone.

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