scholarly journals Anti-influenza Sesquiterpene from the Roots of Reynoutria japonica

2014 ◽  
Vol 9 (3) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Nguyen Xuan Nhiem ◽  
Phan Van Kiem ◽  
Chau Van Minh ◽  
Nguyen Thi Hoai ◽  
Ho Viet Duc ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Mdck Cells ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Therapeutic Index ◽  
Reynoutria Japonica ◽  
Influenza Activity ◽  
Oseltamivir Phosphate

One new flavonol glycoside, 4′- O-methylmyricitrin 3′- O-β-D-glucopyranoside (1), one new sesquiterpene, reynoudiol (11), as well as the 12 known compounds (2–10, 12–14) quercetin 3- O-methyl ether (2), quercitrin (3), isorhamnetin 3- α-L-rhamnopyranoside (4), tamarixetin 3- α-L-rhamnopyranoside (5), myricitrin (6), 4′- O-methylmyricitrin (7), isorhamnetin 3- O-β-D-xylopyranosyl (1→2)- O-β-D-glucopyranoside (8), isorhamnetin 3- O-β-D-apiofuranosyl-(1→2)- O-β-D-glucopyranoside (9), (+)-catechin (10), 7-drimene-3,11,12-triol (12), clovane-2 β,9 α-diol (13), and α-cadinol (14), were isolated from the methanol extract of Reynoutria japonica roots. Based on in vitro screening of the anti-influenza activity of the isolated compounds, reynoudiol showed significantly higher activity than that of oseltamivir phosphate at the same concentration, and did not induce any detectable cytopathic effect in MDCK cells. The CC50 of reynoudiol was above 50 μM and could inhibit influenza virus infection with an IC50 of 0.29 ± 0.01 μM. The therapeutic index (TI) of reynoudiol against influenza infection was 172.4, and thus, this compound can be potentially used to treat oseltamivir-resistant influenza virus infection.

scholarly journals Mouse Saliva Inhibits Transit of Influenza Virus to the Lower Respiratory Tract by Efficiently Blocking Influenza Virus Neuraminidase Activity

2017 ◽  
Vol 91 (14) ◽  
Author(s):  
Brad Gilbertson ◽  
Wy Ching Ng ◽  
Simon Crawford ◽  
Jenny L. McKimm-Breschkin ◽  
Lorena E. Brown
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Respiratory Tract ◽  
Active Site ◽  
Lower Respiratory Tract ◽  
Mdck Cells ◽  
Influenza Virus Infection ◽  
Natural Form ◽  
Influenza Virus Neuraminidase

ABSTRACT We previously identified a novel inhibitor of influenza virus in mouse saliva that halts the progression of susceptible viruses from the upper to the lower respiratory tract of mice in vivo and neutralizes viral infectivity in MDCK cells. Here, we investigated the viral target of the salivary inhibitor by using reverse genetics to create hybrid viruses with some surface proteins derived from an inhibitor-sensitive strain and others from an inhibitor-resistant strain. These viruses demonstrated that the origin of the viral neuraminidase (NA), but not the hemagglutinin or matrix protein, was the determinant of susceptibility to the inhibitor. Comparison of the NA sequences of a panel of H3N2 viruses with differing sensitivities to the salivary inhibitor revealed that surface residues 368 to 370 (N2 numbering) outside the active site played a key role in resistance. Resistant viruses contained an EDS motif at this location, and mutation to either EES or KDS, found in highly susceptible strains, significantly increased in vitro susceptibility to the inhibitor and reduced the ability of the virus to progress to the lungs when the viral inoculum was initially confined to the upper respiratory tract. In the presence of saliva, viral strains with a susceptible NA could not be efficiently released from the surfaces of infected MDCK cells and had reduced enzymatic activity based on their ability to cleave substrate in vitro. This work indicates that the mouse has evolved an innate inhibitor similar in function, though not in mechanism, to what humans have created synthetically as an antiviral drug for influenza virus. IMPORTANCE Despite widespread use of experimental pulmonary infection of the laboratory mouse to study influenza virus infection and pathogenesis, to our knowledge, mice do not naturally succumb to influenza. Here, we show that mice produce their own natural form of neuraminidase inhibitor in saliva that stops the virus from reaching the lungs, providing a possible mechanism through which the species may not experience severe influenza virus infection in the wild. We show that the murine salivary inhibitor targets the outer surface of the influenza virus neuraminidase, possibly occluding entry to the enzymatic site rather than binding within the active site like commercially available neuraminidase inhibitors. This knowledge sheds light on how the natural inhibitors of particular species combat infection.

Screening of the essential oil effects on human H1N1 influenza virus infection: an in vitro study in MDCK cells

2021 ◽  
pp. 1-4
Author(s):  
Basma Najar ◽  
Valeria Nardi ◽  
Maria Alfreda Stincarelli ◽  
Samuele Patrissi ◽  
Luisa Pistelli ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Essential Oil ◽  
Mdck Cells ◽  
Influenza Virus Infection ◽  
In Vitro Study ◽  
H1n1 Influenza ◽  
Vitro Study ◽  
H1n1 Influenza Virus

scholarly journals Role of CXCL5 in Regulating Chemotaxis of Innate and Adaptive Leukocytes in Infected Lungs Upon Pulmonary Influenza Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Lei Guo ◽  
Nan Li ◽  
Zening Yang ◽  
Heng Li ◽  
Huiwen Zheng ◽  
...  
Keyword(s):  
Immune Response ◽  
Influenza Virus ◽  
Virus Infection ◽  
B Cell ◽  
B Lymphocyte ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Neutrophil Infiltration ◽  
Cell Immune Response

Respirovirus such as influenza virus infection induces pulmonary anti-viral immune response, orchestration of innate and adaptive immunity restrain viral infection, otherwise causes severe diseases such as pneumonia. Chemokines regulate leukocyte recruitment to the inflammation site. One chemokine CXCL5, plays a scavenging role to regulate pulmonary host defense against bacterial infection, but its role in pulmonary influenza virus infection is underdetermined. Here, using an influenza (H1N1) infected CXCL5-/- mouse model, we found that CXCL5 not only responds to neutrophil infiltration into infected lungs at the innate immunity stage, but also affects B lymphocyte accumulation in the lungs by regulating the expression of the B cell chemokine CXCL13. Inhibition of CXCL5-CXCR2 axis markedly induces CXCL13 expression in CD64+CD44hiCD274hi macrophages/monocytes in infected lungs, and in vitro administration of CXCL5 to CD64+ alveolar macrophages suppresses CXCL13 expression via the CXCL5-CXCR2 axis upon influenza challenge. CXCL5 deficiency leads to increased B lymphocyte accumulation in infected lungs, contributing to an enhanced B cell immune response and facilitating induced bronchus-associated lymphoid tissue formation in the infected lungs during the late infection and recovery stages. These data highlight multiple regulatory roles of CXCL5 in leukocyte chemotaxis during pulmonary influenza infection.

scholarly journals Protective essential oil attenuates influenza virus infection: An in vitro study in MDCK cells

2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shuhua Wu ◽  
Krupa B Patel ◽  
Leland J Booth ◽  
Jordan P Metcalf ◽  
Hsueh-Kung Lin ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Essential Oil ◽  
Mdck Cells ◽  
Influenza Virus Infection ◽  
In Vitro Study ◽  
Vitro Study

scholarly journals Performance of case definitions and clinical predictors for influenza surveillance among patients followed in a rural cohort in Senegal

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mamadou Aliou Barry ◽  
Florent Arinal ◽  
Cheikh Talla ◽  
Boris Gildas Hedible ◽  
Fatoumata Diene Sarr ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Sore Throat ◽  
Predictive Value ◽  
Influenza Infection ◽  
Clinical Signs ◽  
Influenza Virus Infection ◽  
Nasal Discharge ◽  
Age Group ◽  
Case Definitions

Abstract Background Influenza is a major cause of morbidity and mortality in Africa. However, a lack of epidemiological data remains for this pathology, and the performances of the influenza-like illness (ILI) case definitions used for sentinel surveillance have never been evaluated in Senegal. This study aimed to i) assess the performance of three different ILI case definitions, adopted by the WHO, USA-CDC (CDC) and European-CDC (ECDC) and ii) identify clinical factors associated with a positive diagnosis for Influenza in order to develop an algorithm fitted for the Senegalese context. Methods All 657 patients with a febrile pathological episode (FPE) between January 2013 and December 2016 were followed in a cohort study in two rural villages in Senegal, accounting for 1653 FPE observations with nasopharyngeal sampling and influenza virus screening by rRT-PCR. For each FPE, general characteristics and clinical signs presented by patients were collected. Sensitivity, Specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) for the three ILI case definitions were assessed using PCR result as the reference test. Associations between clinical signs and influenza infection were analyzed using logistic regression with generalized estimating equations. Sore throat, arthralgia or myalgia were missing for children under 5 years. Results WHO, CDC and ECDC case definitions had similar sensitivity (81.0%; 95%CI: 77.0–85.0) and NPV (91.0%; 95%CI: 89.0–93.1) while the WHO and CDC ILI case definitions had the highest specificity (52.0%; 95%CI: 49.1–54.5) and PPV (32.0%; 95%CI: 30.0–35.0). These performances varied by age groups. In children < 5 years, the significant predictors of influenza virus infection were cough and nasal discharge. In patients from 5 years, cough, nasal discharge, sore throat and asthenia grade 3 best predicted influenza infection. The addition of “nasal discharge” as a symptom to the WHO case definition decreased sensitivity but increased specificity, particularly in the pediatric population. Conclusion In summary, all three definitions studies (WHO, ECDC & CDC) have similar performance, even by age group. The revised WHO ILI definition could be chosen for surveillance purposes for its simplicity. Symptomatic predictors of influenza virus infection vary according the age group.

scholarly journals Routine blood parameters are helpful for early identification of influenza infection in children

2020 ◽  
Author(s):  
Ronghe Zhu ◽  
Cuie Chen ◽  
Qiu Wang ◽  
Xixi Zhang ◽  
Chaosheng Lu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Early Identification ◽  
Influenza A ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Cutoff Value ◽  
Routine Blood ◽  
Influenza A Virus Infection

Abstract Purpose Routine blood parameters, such as the lymphocyte (LYM) count, platelet (PLT) count, lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), LYM*PLT and mean platelet volume-to-platelet ratio (MPV/PLT), are widely used to predict the prognosis of infectious diseases. We aimed to explore the value of these parameters in the early identification of influenza virus infection in children.Methods We conducted a single-center, retrospective, observational study of fever with influenza-like symptoms in pediatric outpatients from different age groups and evaluated the predictive value of various routine blood parameters measured within 48 hours of the onset of fever for influenza virus infection.Results The LYM count, PLT count, LMR and LYM*PLT were lower, and the NLR and MPV/PLT were higher in children with an influenza infection (PCR-confirmed and symptomatic). The LYM count, LMR and LYM*PLT in the influenza infection group were lower in the 1- to 6-year-old subgroup, and the LMR and LYM*PLT in the influenza infection group were lower in the >6-year-old subgroup. In the 1- to 6-year-old subgroup, the cutoff value of the LMR for predicting influenza A virus infection was 3.75, the sensitivity was 81.87%, the specificity was 84.31%, and the area under the curve (AUC) was 0.886; the cutoff value of the LMR for predicting influenza B virus infection was 3.71, the sensitivity was 73.58%, the specificity was 84.31%, and the AUC was 0.843. In the >6-year-old subgroup, the cutoff value of the LMR for predicting influenza A virus infection was 3.05, the sensitivity was 89.27%, the specificity was 89.61%, and the AUC was 0.949; the cutoff value of the LMR for predicting influenza B virus infection was 2.88, the sensitivity was 83.19%, the specificity was 92.21%, and the AUC was 0.924.Conclusions Routine blood tests are simple, inexpensive and easy to perform, and they are useful for the early identification of influenza virus infection in children. The LMR had the strongest predictive value for influenza virus infection in children older than 1 year, particularly influenza A virus infection.

scholarly journals Linear polysialoside outperforms dendritic analogs for inhibition of influenza virus infection in vitro and in vivo

Biomaterials ◽  
2017 ◽  
Vol 138 ◽  
pp. 22-34 ◽  
Author(s):  
Sumati Bhatia ◽  
Daniel Lauster ◽  
Markus Bardua ◽  
Kai Ludwig ◽  
Stefano Angioletti-Uberti ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza Virus Infection

scholarly journals Brugada-Like Electrocardiographic Changes during Influenza Infection

2003 ◽  
Vol 31 (3) ◽  
pp. 244-246 ◽  
Author(s):  
K Kusaka ◽  
J Yamakawa ◽  
K Kawaura ◽  
T Itoh ◽  
T Takahashi ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Viral Infection ◽  
Brugada Syndrome ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Ecg Changes ◽  
Early Repolarization ◽  
Electrocardiographic Changes

We describe a 32-year-old man with electrocardiographic (ECG) changes consistent with Brugada syndrome and influenza virus infection. The ECG pattern changed after 1 week to one of early repolarization in V1 and V2. This case suggests an association between Brugada syndrome and viral infection.

scholarly journals Increased Plasma Matrix Metalloproteinase-9 Levels Contribute to Intracerebral Hemorrhage during Thrombolysis after Concomitant Stroke and Influenza Infection

2016 ◽  
Vol 6 (2) ◽  
pp. 50-59 ◽  
Author(s):  
Sajjad Muhammad ◽  
Oliver Planz ◽  
Markus Schwaninger
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Matrix Metalloproteinase ◽  
Intracerebral Hemorrhage ◽  
Acute Stroke ◽  
Plasma Levels ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Concomitant Infection ◽  
Metalloproteinase 9

Background: Thrombolysis is the only approved therapy for acute stroke. However, life-threatening complications such as intracerebral hemorrhage (ICH) can develop after intravenous administration of tissue plasminogen activator (tPA). Both infection and thrombolysis during cerebral ischemia disrupt the blood-brain barrier (BBB). tPA can induce matrix metalloproteinase-9 (MMP-9), which is known to be involved in BBB disruption. However, it has still not been investigated whether preexisting influenza virus infection during thrombolysis after acute stroke affects systemic levels of MMP-9 and its inhibitor TIMP-1 and whether increased systemic MMP-9 levels affect ICH. This study aimed to investigate the influence of influenza virus infection on plasma levels of MMP-9 and TIMP-1 after thrombolysis in acute stroke, and to determine whether the infection correlates with intracerebral bleeding. Methods: C57BL/6 mice were infected by administering 1 × 105 plaque-forming units of human influenza (H1N1) virus intranasally. After 3 days of infection the middle cerebral artery was occluded for 45 min and then reperfused. Intravenous tPA (10 mg/kg) treatment was started 10 min after stroke onset. Twenty-four hours after stroke onset, mice were deeply anesthetized with ketamine, venous blood was drawn from the caval vein and centrifuged at 2,000 rpm, and the supernatant was collected and frozen at -80°C. Plasma levels of MMP-9 and TIMP-1 were quantified by using ELISA. Results: After stroke, plasma MMP-9 was significantly increased in mice with a concomitant influenza infection that were treated with tPA (9.99 ± 0.62 ng/ml, n = 7) as compared to noninfected control mice that were treated with tPA (4.74 ± 0.48 ng/ml, n = 8). Moreover, plasma levels of TIMP-1, an inhibitor of MMP-9, were also significantly increased in mice treated with tPA after concomitant infection and stroke (42.17 ± 7.02 ng/ml, n = 7) as compared to noninfected control mice that were treated with tPA after stroke (20.22 ± 2.12 ng/ml, n = 8). MMP-9 values significantly correlated with intracerebral hemoglobin levels in animals treated with tPA after stroke (p = 0.028, r = 0.76, n = 8) and after concomitant stroke and infection (p = 0.039, r = 0.78, n = 7). Conclusion: Preexisting influenza A virus infection led to increased plasma MMP-9 and TIMP-1 levels in mice undergoing thrombolysis after induced stroke. MMP-9 levels closely correlated with intracerebral bleeding after thrombolysis during concomitant infection and stroke. Thus, our data indicate that thrombolysis may be dangerous during influenza infection. MMP-9 inhibitors might be considered to reduce the side effects of thrombolysis during concomitant infection and stroke.

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