Antiherpes Virus Effect of the Red Marine Alga Polysiphonia denudata

2000 ◽  
Vol 55 (9-10) ◽  
pp. 830-835 ◽  
Author(s):  
Julia Serkedjieva
Keyword(s):  
Marine Alga ◽  
Water Extract ◽  
Antiviral Effect ◽  
Inhibitory Effect ◽  
Extracellular Virus ◽  
Black Sea Coast ◽  
Red Marine Alga ◽  
Replicative Cycle

Abstract The water extract from the red marine alga Polysiphonia denudata (Dillwyn) Kütz. from the Bulgarian Black Sea coast selectively inhibited the reproduction of herpes virus type 1 and type 2 in cell cultures (EC50 = 8.7 to 47.7 mg/ml) as shown by the reduction of virusinduced cytopathic effect and viral infectivity. The virus-inhibitory effect was dose-related, strain-specific and depended on virus inoculum. The inhibition affected adsorption as well as the intracellular stages of viral replication. The presence of the extract throughout the whole replicative cycle was necessary for the full expression of the antiviral effect. In higher concentrations (MIC90 = 6.5 mg/ml) the extract exhibited strong extracellular virus inactivating activity.

Two types of leptin-responsive gastric vagal afferent terminals: an in vitro single-unit study in rats

1997 ◽  
Vol 273 (2) ◽  
pp. R833-R837 ◽  
Author(s):  
Y. H. Wang ◽  
Y. Tache ◽  
A. B. Sheibel ◽  
V. L. Go ◽  
J. Y. Wei
Keyword(s):  
Inhibitory Effect ◽  
Vagal Afferents ◽  
Neural Signals ◽  
Excitatory Effect ◽  
Leptin Sensitivity ◽  
Before And After ◽  
Afferent Terminals

In vitro gastric vagal afferents' (GVAs) unit activities were recorded from the ventral GVA nerve strands in rats. The responsiveness of 16 GVA terminals to close intra-arterial injection of vehicle (0.1 ml), leptin (350 pmol), and cholecystokinin (CCK)-8 (10 pmol) was analyzed to generate a spike count-versus-time histogram. Data of 5-min spike counts before and after each treatment were normalized by dividing the latter by the former. A quotient (Q) > 1 indicates an excitatory effect, Q < 1 indicates an inhibitory effect, and Q close to 1 indicates no effect. Two types of GVA terminals were identified. Type 1 (n = 8) responded to leptin with Q > 1; CCK-8 pretreatment did not consistently alter leptin sensitivity. In contrast, Type 2 (n = 8) responded to leptin with Q < 1 or close to 1, and CCK-8 pretreatment increased the leptin sensitivity so that the terminals responded to subsequent leptin with Q > 1. These data suggest that Type 1 and Type 2 GVA terminals may provide afferent neural signals, which, in turn, will be involved in body weight and food intake control systems, respectively.

Antiviral Effect of Brassinosteroids against Herpes Virus and Arenaviruses

2000 ◽  
Vol 11 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Mónica B Wachsman ◽  
Elsa MF López ◽  
Javier A Ramirez ◽  
Lydia R Galagovsky ◽  
Celia E Coto
Keyword(s):  
Cell Culture ◽  
Antiviral Effect ◽  
Selectivity Index ◽  
Synthetic Compounds ◽  
Late Step ◽  
Simplex Virus ◽  
Synthetic Derivatives ◽  
Replicative Cycle ◽  
Hsv 1

A natural brassinosteroid and a series of synthetic derivatives were found to be good inhibitors of herpes simplex virus type 1 (HSV-1) and arenavirus replication in cell culture. The synthetic compounds tested were analogues of the 24(S) ethylbrassinone. Compounds (22R,23R,24S)-2α, 3α,5α,22,23-pentahydroxy-stigmastan-6-one and (22R,23R,24S)-3β-bromo-5α,22,23-trihydroxy stigmastan-6-one were cytotoxic at concentrations of 20–40 µM. (22S,23S,24S)-2α,3α,22,23-tetrahydroxy-5α,stigmastan-6-one, (22R,23R,24S)-3β-acetoxy-22,23-dihydroxy-5α-cholestan-6-one, (22S,23S,24S)-3β-bromo-22,23-dihydroxy-5α-cholestan-6-one and (22S,23S,24S)-3β-bromo-5α,22,23-trihydroxy-stigmastan-6-one were the most active of the series against HSV-1, with selectivity index (SI) values (CC50/EC50) ranging from 10.6 to 16.5. The majority of the compounds were potent inhibitors of arenaviruses, (22S,23S,24S)-3β-bromo-5α,22,23-trihydroxy-stigmastan-6-one being the most active, with SI values of 307.8 and 692.5 for Tacaribe and Junin viruses, respectively. The antiviral activity of brassinosteroid derivatives was not because of direct inactivation; time-of-addition experiments suggested that a late step in HSV-1 multiplication was affected, whereas arenaviruses remained susceptible to the compounds throughout the replicative cycle.

scholarly journals Localized accumulation of angiotensin II and production of angiotensin-(1–7) in rat luteal cells and effects on steroidogenesis

2006 ◽  
Vol 291 (2) ◽  
pp. E221-E233 ◽  
Author(s):  
John R. Pepperell ◽  
Gabor Nemeth ◽  
Yuji Yamada ◽  
Frederick Naftolin ◽  
Maricruz Merino
Keyword(s):  
Angiotensin Ii ◽  
Inhibitory Effect ◽  
Ang Ii ◽  
Luteal Cells ◽  
Permeabilized Cells ◽  
Production Studies ◽  
Progesterone Production ◽  
Angiotensin Peptides

These studies aim to investigate subcellular distribution of angiotensin II (ANG II) in rat luteal cells, identify other bioactive angiotensin peptides, and investigate a role for angiotensin peptides in luteal steroidogenesis. Confocal microscopy showed ANG II distributed within the cytoplasm and nuclei of luteal cells. HPLC analysis showed peaks that eluted with the same retention times as ANG-(1–7), ANG II, and ANG III. Their relative concentrations were ANG II ≥ ANG-(1–7) > ANG III, and accumulation was modulated by quinapril, an inhibitor of angiotensin-converting enzyme (ACE), Z-proprolinal (ZPP), an inhibitor of prolyl endopeptidase (PEP), and parachloromercurylsulfonic acid (PCMS), an inhibitor of sulfhydryl protease. Phenylmethylsulfonyl fluoride (PMSF), a serine protease inhibitor, did not affect peptide accumulation. Quinapril, ZPP, PCMS, and PMSF, as well as losartan and PD-123319, the angiotensin receptor type 1 (AT1) and type 2 (AT2) receptor antagonists, were used in progesterone production studies. ZPP significantly reduced luteinizing hormone (LH)-dependent progesterone production ( P < 0.05). Quinapril plus ZPP had a greater inhibitory effect on LH-stimulated progesterone than either inhibitor alone, but this was not reversed by exogenous ANG II or ANG-(1–7). Both PCMS and PMSF acutely blocked LH-stimulated progesterone, and PCMS blocked LH-sensitive cAMP accumulation. Losartan inhibited progesterone production in permeabilized but not intact luteal cells and was reversed by ANG II. PD-123319 had no significant effect on luteal progesterone production in either intact or permeabilized cells. These data suggest that steroidogenesis may be modulated by angiotensin peptides that act in part through intracellular AT1 receptors.

scholarly journals PPARγAgonist Rosiglitazone Suppresses Renal mPGES-1/PGE2 Pathway in db/db Mice

PPAR Research ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ying Sun ◽  
Zhanjun Jia ◽  
Gang Liu ◽  
Li Zhou ◽  
Mi Liu ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Inhibitory Effect ◽  
Peroxisome Proliferator ◽  
Glomerular Injury ◽  
Peroxisome Proliferator Activated Receptor ◽  
Protein Expressions ◽  
Pg E2 ◽  
Cox 1

Evidence had shown the detrimental effect of prostaglandin (PG) E2 in diabetic nephropathy (DN) of STZ-induced type-1 diabetes but its role in the development of DN of type-2 diabetes remains uncertain. The present study was undertaken to investigate the regulation of PGE2 synthetic pathway and the interaction between peroxisome proliferator-activated receptor (PPAR)γand PGE2 synthesis in the kidneys of db/db mice. Strikingly, urinary PGE2 was remarkably elevated in db/db mice paralleled with the increased protein expressions of COX-2 and mPGES-1. In contrast, the protein expressions of COX-1, mPGES-2, cPGES, and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) were not altered. Following 1-week rosiglitazone (Rosi) therapy, urinary PGE2, but not other prostanoids, was reduced by 57% in parallel with significant reduction of mPGES-1 protein and EP4 mRNA expressions. By immunohistochemistry, mPGES-1 was significantly induced in the glomeruli of db/db mice, which was almost entirely abolished by Rosi. In line with the reduction of glomerular mPGES-1, the glomerular injury score showed a tendency of improvement after 1 week of Rosi therapy. Collectively, the present study demonstrated an inhibitory effect of PPARγactivation on renal mPGES-1/PGE2/EP4 pathway in type-2 diabetes and suggested that mPGES-1 may potentially serve as a therapeutic target for treating type-2 diabetes-associated DN.

scholarly journals Deiodinase type 1 activity is expressed in the prostate of pubescent rats and is modulated by thyroid hormones, prolactin and sex hormones

2006 ◽  
Vol 190 (2) ◽  
pp. 363-371 ◽  
Author(s):  
Brenda Anguiano ◽  
Alejandra López ◽  
Guadalupe Delgado ◽  
Carlos Romero ◽  
Carmen Aceves
Keyword(s):  
Thyroid Hormones ◽  
Enzymatic Activity ◽  
Mrna Expression ◽  
Sex Hormones ◽  
Inhibitory Effect ◽  
Preferential Expression ◽  
Gold Thioglucose ◽  
17Β Estradiol

The aim of this study was to characterize the type of 5′-deiodinase activity in the prostate of pubescent rats (7–8 weeks), to establish its distribution in the lobes (ventral, dorsolateral, and anterior), and to analyze its modulation by prolactin (PRL), testosterone, dihydrotestosterone (DHT), and 17β-estradiol (E2). Our results showed that the enzymatic activity was highly susceptible to inhibition by 6-n-propyl-2-thiouracil and gold thioglucose, its preferential substrate was reverse tri-iodothyronine (rT3), it exhibited a low dithiothreitol requirement (5 mM), and the apparent Km and Vmax values for substrate (rT3) were approximately 0.25 μM and 9.0 pmol liberated/mg protein per hour, respectively. All these characteristics indicate the preferential expression of type 1 deiodinase (D1), which was corroborated by demonstrating the presence of D1 mRNA in prostate. D1 activity was detected in all lobes and was most abundant in the dorsolateral. Although we detected type 2 deiodinase (D2) mRNA expression, the D2 activity was almost undetectable. D1 activity was enhanced in animals with hyperthyroidism and hyperprolactinemia, in intact animals treated with finasteride (inhibitor of local DHT production), and in castrated animals with E2 replacement. In contrast, activity diminished in castrated animals with testosterone replacement. Our results suggest that thyroid hormones, PRL, and E2 exert a positive modulation on D1 activity, while testosterone and DHT exhibit an inhibitory effect. D1 activity may be associated with prostate maturation and/or function.

scholarly journals Porcine Reproductive and Respiratory Syndrome Virus Antagonizes PCSK9’s Antiviral Effect via Nsp11 Endoribonuclease Activity

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 655
Author(s):  
Yujiao Zhang ◽  
Fei Gao ◽  
Liwei Li ◽  
Kuan Zhao ◽  
Shan Jiang ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Alveolar Macrophages ◽  
Antiviral Effect ◽  
Respiratory Syndrome Virus ◽  
Nonstructural Proteins ◽  
Swine Industry ◽  
Virus Receptor ◽  
Endoribonuclease Activity

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important pathogens in the swine industry worldwide. Our previous study had indicated that proprotein convertase subtilisin/kexin type 9 (PCSK9) was a responsive gene in porcine alveolar macrophages (PAMs) upon PRRSV infection. However, whether PCSK9 impacts the PRRSV replication and how the PRRSV modulates host PCSK9 remains elusive. Here, we demonstrated that PCSK9 protein suppressed the replication of both type-1 and type-2 PRRSV species. More specifically, the C-terminal domain of PCSK9 was responsible for the antiviral activity. Besides, we showed that PCSK9 inhibited PRRSV replication by targeting the virus receptor CD163 for degradation through the lysosome. In turn, PRRSV could down-regulate the expression of PCSK9 in both PAMs and MARC-145 cells. By screening the nonstructural proteins (nsps) of PRRSV, we showed that nsp11 could antagonize PCSK9’s antiviral activity. Furthermore, mutagenic analyses of PRRSV nsp11 revealed that the endoribonuclease activity of nsp11 was critical for antagonizing the antiviral effect of PCSK9. Collectively, our data provide further insights into the interaction between PRRSV and the cell host and offer a new potential target for the antiviral therapy of PRRSV.

scholarly journals Antiinfluenza Virus Effect of Extracts from Marine Algae and Invertebrates

2000 ◽  
Vol 55 (1-2) ◽  
pp. 87-93 ◽  
Author(s):  
Julia Serkedjieva ◽  
Monika Konaklieva ◽  
Stefka Dimitrova-Konaklieva ◽  
Veneta Ivanova ◽  
Kamen Stefanov ◽  
...  
Keyword(s):  
Marine Algae ◽  
Influenza Infection ◽  
Antiviral Effect ◽  
Inhibitory Effect ◽  
Influenza Viruses ◽  
Virus Infectivity ◽  
Tissue Cultures ◽  
Black Sea Coast ◽  
Sea Coast ◽  
Experimental Influenza

Abstract Sixty products, derived from marine organisms, typical of the Bulgarian Black Sea coast, were examined for inhibitory activity on the reproduction of influenza viruses in tissue cultures. The antiviral effect was investigated by the reduction of virus infectivity. Using representative strains of influenza virus it was shown that apparently the inhibitory effect was strain-specific. The most effective products were further studied in fertile hen’s eggs and in experimental influenza infection in white mice.

Side-Chain Derivatives of Biologically Active Nucleosides. Part 2: Synthesis and anti-HIV Activity of 5′-C-Methyl Derivatives of 3′-Fluoro-3′-Deoxythymidine

1996 ◽  
Vol 7 (3) ◽  
pp. 173-177 ◽  
Author(s):  
J. Hiebl ◽  
E. Zbiral ◽  
M. von Janta-Lipinski ◽  
J. Balzarini ◽  
E. De Clercq
Keyword(s):  
Inhibitory Effect ◽  
Biologically Active ◽  
Side Chain ◽  
Dna Viruses ◽  
Immunodeficiency Virus ◽  
Methyl Derivatives ◽  
Derivatives Of ◽  
Anti Hiv

1-(3′-Fluoro-2′,3′,6′-trideoxy-β-D-allofuranosyl)thymine [7] and 1-(3′-fluoro-2′,3′,6′-trideoxy-α-L-talofuranosyl) thymine [8] were synthesized starting from the corresponding 2,3′-anhydro nucleoside derivatives. The fluorine was introduced stereoselectively by opening of the anhydro bridge in the presence of HF/AIF3. The 5′-C-methyl derivatives, [7] and [8], of 3′-fluoro-3′-deoxythymidine (FLT) were evaluated for their inhibitory effect against human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2). The compounds [7] and [8] had antiviral activity which was three orders of magnitude lower than the reference compound 3′-fluoro-3′-deoxythymidine. None of the compounds showed appreciable activity against other RNA or DNA viruses at subtoxic concentrations.

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