scholarly journals First report of antiviral activity of nordihydroguaiaretic acid against Fort Sherman-like virus (Orthobunyavirus)

2020 ◽  
Author(s):  
Florencia Martinez ◽  
María Laura Mugas ◽  
Juan Javier Aguilar ◽  
Juliana Marioni ◽  
Marta Silvia Contigiani ◽  
...  

AbstractThe genus Orthobunyavirus are a group of viruses within arbovirus, with a zoonotic cycle, some of which could lead to human infection. A characteristic of these viruses is their lack of antiviral treatment or vaccine for its prevention. The objective of this work was to study the in vitro antiviral activity of nordihydroguaiaretic acid (NDGA), the most important active compound of Larrea divaricata Cav. (Zigophyllaceae), against Fort Sherman-like virus (FSV-like) as a model of Orthobunyavirus genus. At the same time, the effect of NDGA as a lipolytic agent on the cell cycle of this viral model was assessed. The method of reducing plaque forming units on LLC-MK2 cells was used to detect the action of NDGA on CbaAr426 and SFCrEq231 isolates of FSV-like. NDGA did not show virucidal effect, but it had antiviral activity with a similar inhibition in both isolates, which was dose dependent. It was established that the NDGA has a better inhibition one-hour post infection (p.i.), showing a different behavior in each isolate, which was dependent upon the time p.i. Since virus multiplication is dependent on host cell lipid metabolism, the antiviral effect of NDGA has been previously related to its ability to disturb the lipid metabolism, probably by interfering with the sterol regulatory element-binding proteins (SREBP) pathway and the 5-lipoxigenase (5-LOX). We determined by using caffeic acid, a 5-LOX inhibitor, that the inhibition of this enzyme negatively affected the FSV-like replication; and by the use of resveratrol, a SREBP1 inhibitor, it was showed that the negative regulation of this pathway only had action on the SFCrEq231 reduction. In addition, it was proved that the NDGA acts intracellularly, since it showed the ability to incorporate into LLC-MK2 cells. The information provided in this work converts the NDGA in a good antiviral candidate, especially for Orthobunyavirus infections, and a useful tool for the biochemical study of FSV-like that causes an infection poorly studied and potentially dangerous.

2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Teresa Merino-Ramos ◽  
Nereida Jiménez de Oya ◽  
Juan-Carlos Saiz ◽  
Miguel A. Martín-Acebes

ABSTRACT Flaviviruses are positive-strand RNA viruses distributed all over the world that infect millions of people every year and for which no specific antiviral agents have been approved. These viruses include the mosquito-borne West Nile virus (WNV), which is responsible for outbreaks of meningitis and encephalitis. Considering that nordihydroguaiaretic acid (NDGA) has been previously shown to inhibit the multiplication of the related dengue virus and hepatitis C virus, we have evaluated the effect of NDGA, and its methylated derivative tetra-O-methyl nordihydroguaiaretic acid (M4N), on the infection of WNV. Both compounds inhibited the infection of WNV, likely by impairing viral replication. Since flavivirus multiplication is highly dependent on host cell lipid metabolism, the antiviral effect of NDGA has been previously related to its ability to disturb the lipid metabolism, probably by interfering with the sterol regulatory element-binding proteins (SREBP) pathway. Remarkably, we observed that other structurally unrelated inhibitors of the SREBP pathway, such as PF-429242 and fatostatin, also reduced WNV multiplication, supporting that the SREBP pathway may constitute a druggable target suitable for antiviral intervention against flavivirus infection. Moreover, treatment with NDGA, M4N, PF-429242, and fatostatin also inhibited the multiplication of the mosquito-borne flavivirus Zika virus (ZIKV), which has been recently associated with birth defects (microcephaly) and neurological disorders. Our results point to SREBP inhibitors, such as NDGA and M4N, as potential candidates for further antiviral development against medically relevant flaviviruses.


2021 ◽  
Author(s):  
Israa Elbashir ◽  
Aisha Aisha Nasser J M Al-Saei ◽  
Paul Thornalley ◽  
Naila Rabbani

Background and aims: In 2020 a global pandemic was declared caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2). The pandemic is still ongoing and continues to cause considerable mortality and morbidity world-wide and new variants of the virus are emerging. Rapid development and rollout of vaccines for SARS-CoV-2 is in progress to counter the pandemic but has been tempered by the emergence of new SARS-CoV-2 variants, many of which exhibit reduced vaccine effectiveness. To date there is no approved antiviral treatment for coronavirus disease 2019 (COVID-19). Several studies have shown that Manuka honey has virucidal/antiviral effect. Methylglyoxal (MG), a bioactive component in Manuka honey, has antiviral activity in vitro. MG may modify arginine residues in the functional domains of viral spike and nucleocapsid proteins, resulting in loss of charge, protein misfolding and inactivation. The aim of this study was to characterize the antiviral activity of Manuka honey against SARS-CoV-2 in vitro Materials and methods: Wild-type SARS-CoV-2 with titers of multiplicities of infection (MOI) 0.1 and 0.05 were incubated with 2-fold serial dilutions of 250+ Manuka honey (equivalent to 250 to 31 µM) in infection medium (Dulbecco's Modified Eagle Medium + 2% fetal bovine serum + 100 units/ml penicillin + 100 µg/ml streptomycin) for 3 h. Manuka honey treated and untreated control SARS-CoV-2 was incubated with confluent cultures of Vero cells in vitro for 1 h, cultures washed with phosphate-buffered saline and incubated in fresh infection medium at 37°C for 4 - 5 days until 70% of virus control cells displayed cytopathic effect. We also studied the effect of scavenging MG in Manuka Honey with aminoguanidine (AG; 500 µM) on virucidal activity. The antiviral activity of MG was judged by median tissue culture infectious dose (TCID50) assays. Data analysis was by logistic regression. TCID50 (mean ± SD) was deduced by interpolation. Results: Diluted Manuka honey inhibited SARS-CoV-2 replication in Vero cells. SARS-CoV-2 was incubated in diluted Manuka honey in medium at 37°C for 3 h before adding to Vero cells. Manuka honey dilutions down to 125 µM MG equivalents completely inhibited cytopathic effect of SARS-CoV-2 whereas 31.25 µM and 62.5 µM MG equivalents had limited effect. Logistic regression and interpolation of the cytopathic effect indicated that the TCID50 = 72 ± 2 µM MG equivalents for MOI of 0.1. Prior scavenging of MG by addition of AG resulted in virus replication levels equivalent to those seen in the virus control without AG. Conclusion: Manuka honey has antiviral activity against SARS-CoV-2 when incubated with the virus in cell-free media at no greater than ca. 40-fold dilutions of 250+ grade. Anti-viral activity was inhibited by AG, consistent with the anti-viral effect being mediated by MG. Manuka honey dilutions in MG equivalents had similar antiviral effect compared to authentic MG, also consistent with MG content of Manuka honey mediating the antiviral effect. Whilst Manuka honey may inactivate SARS-CoV-2 in cell-free culture medium, its antiviral activity in vivo for other than topical application may be limited because of the rapid metabolism of MG by the glyoxalase system and limited bioavailability of oral MG.


Author(s):  
Jainey James ◽  
Divya Jyothi ◽  
Sneh Priya

Aims: The present study aim was to analyse the molecular interactions of the phytoconstituents known for their antiviral activity with the SARS-CoV-2 nonstructural proteins such as main protease (6LU7), Nsp12 polymerase (6M71), and Nsp13 helicase (6JYT). The applied in silico methodologies was molecular docking and pharmacophore modeling using Schrodinger software. Methods: The phytoconstituents were taken from PubChem, and SARS-CoV-2 proteins were downloaded from the protein data bank. The molecular interactions, binding energy, ADMET properties and pharmacophoric features were analysed by glide XP, prime MM-GBSA, qikprop and phase application of Schrodinger respectively. The antiviral activity of the selected phytoconstituents was carried out by PASS predictor, online tools. Results: The docking score analysis showed that quercetin 3-rhamnoside (-8.77 kcal/mol) and quercetin 3-rhamnoside (-7.89 kcal/mol) as excellent products to bind with their respective targets such as 6LU7, 6M71 and 6JYT. The generated pharmacophore hypothesis model validated the docking results, confirming the hydrogen bonding interactions of the amino acids. The PASS online tool predicted constituent's antiviral potentials. Conclusion: The docked phytoconstituents showed excellent interactions with the SARS-CoV-2 proteins, and on the outset, quercetin 3-rhamnoside and quercetin 7-rhamnoside have well-interacted with all the three proteins, and these belong to the plant Houttuynia cordata. The pharmacophore hypothesis has revealed the characteristic features responsible for their interactions, and PASS prediction data has supported their antiviral activities. Thus, these natural compounds could be developed as lead molecules for antiviral treatment against SARS-CoV-2. Further in-vitro and in-vivo studies could be carried out to provide better drug therapy.


2021 ◽  
Author(s):  
Dong-Kyun Ryu ◽  
Hye-Min Woo ◽  
Bobin Kang ◽  
Hanmi Noh ◽  
Jong-In Kim ◽  
...  

The Delta variant originally from India is rapidly spreading across the world and causes to resurge infections of SARS-CoV-2. We previously reported that CT-P59 presented its in vivo potency against Beta and Gamma variants, despite its reduced activity in cell experiments. Yet, it remains uncertain to exert the antiviral effect of CT-P59 on the Delta and its associated variants (L452R). To tackle this question, we carried out cell tests and animal study. CT-P59 showed reduced antiviral activity but enabled neutralization against Delta, Epsilon, and Kappa variants in cells. In line with in vitro results, the mouse challenge experiment with the Delta variant substantiated in vivo potency of CT-P59 showing symptom remission and virus abrogation in the respiratory tract. Collectively, cell and animal studies showed that CT-P59 is effective against the Delta variant infection, hinting that CT-P59 has therapeutic potency for patients infected with Delta and its associated variants.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Xianghe Meng ◽  
Darong Yang ◽  
Rong Yu ◽  
Haizhen Zhu

It has been reported that IFN-λs inhibit HCV replication in vitro. But the mechanisms of how IL-28A conducts antiviral activity and the functions of IL-28A-induced ISGs (IFN-stimulated genes) are not fully understood. In this study, we found that IL-28A has the antiviral effect on HCV life cycle including viral replication, assembly, and release. IL-28A and IFN-αsynergistically inhibit virus replication. EPSTI1 (epithelial-stromal interaction 1), one of IL-28A-induced ISGs, plays a vital role in IL-28A-mediated antiviral activity. Furthermore, forced expression of EPSTI1 effectively inhibits HCV replication in the absence of interferon treatment, and knockdown of EPSTI1 contributes to viral enhancement. EPSTI1 can activate PKR promoter and induce several PKR-dependent genes, including IFN-β, IFIT1, OAS1, and RNase L, which is responsible for EPSTI1-mediated antiviral activity.


2006 ◽  
Vol 290 (5) ◽  
pp. F1065-F1073 ◽  
Author(s):  
Yahua Zhang ◽  
Xiaoyan Zhang ◽  
Lihong Chen ◽  
Jing Wu ◽  
Dongming Su ◽  
...  

Liver X receptors (LXRs), including LXRα and LXRβ, are intracellular sterol sensors that regulate expression of genes controlling fatty acid and cholesterol absorption, excretion, catabolism, and cellular efflux. Because the kidney plays an important role in lipid metabolism and dyslipidemia accelerates renal damage, we investigated the effect of TO-901317, an LXR agonist, on the gene expression profile in mouse kidney. Treatment of C57 Bl/6 mice with TO-901317 (3 mg·kg−1·day−1) for 3 days resulted in 51 transcripts that were significantly regulated in the kidney. Among them, the stearoyl-CoA desaturase-1 (SCD1) was upregulated most dramatically. Northern blot analysis revealed that SCD1 mRNA levels were markedly higher than that in control kidneys. Enhanced SCD1 expression by TO-901317 also resulted in increased fatty acid desaturation in the kidney. In control mice, constitutive renal SCD1 expression was low; however, TO-901317 treatment markedly increased SCD1 expression in the outer stripe of the outer medulla as assessed by both in situ hybridization and immunostain. Double-labeling studies further indicated that SCD1 mRNA was selectively expressed in proximal straight tubules negative for aquaporin-2 and Tamm-Horsfall protein. In vitro studies in cultured murine proximal tubule cells further demonstrated that LXR activation enhanced SCD1 transcription via increased sterol regulatory element binding protein-1. Taken together, these data suggest LXR activation of SCD1 expression may play an important role in regulating lipid metabolism and cell function in renal proximal straight tubules.


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1602
Author(s):  
Marina Plotnikova ◽  
Alexey Lozhkov ◽  
Ekaterina Romanovskaya-Romanko ◽  
Irina Baranovskaya ◽  
Mariia Sergeeva ◽  
...  

Type III interferons (lambda IFNs) are a quite new, small family of three closely related cytokines with interferon-like activity. Attention to IFN-λ is mainly focused on direct antiviral activity in which, as with IFN-α, viral genome replication is inhibited without the participation of immune system cells. The heterodimeric receptor for lambda interferons is exposed mainly on epithelial cells, which limits its possible action on other cells, thus reducing the likelihood of developing undesirable side effects compared to type I IFN. In this study, we examined the antiviral potential of exogenous human IFN-λ1 in cellular models of viral infection. To study the protective effects of IFN-λ1, three administration schemes were used: ‘preventive’ (pretreatment); ‘preventive/therapeutic’ (pre/post); and ‘therapeutic’ (post). Three IFN-λ1 concentrations (from 10 to 500 ng/mL) were used. We have shown that human IFN-λ1 restricts SARS-CoV-2 replication in Vero cells with all three treatment schemes. In addition, we have shown a decrease in the viral loads of CHIKV and IVA with the ‘preventive’ and ‘preventive/therapeutic’ regimes. No significant antiviral effect of IFN-λ1 against AdV was detected. Our study highlights the potential for using IFN-λ as a broad-spectrum therapeutic agent against respiratory RNA viruses.


2021 ◽  
Author(s):  
Bernadett Palyi ◽  
Zoltan Kis ◽  
Polett Hajdrik ◽  
Noemi S Kovacs ◽  
Daniel S Veres ◽  
...  

Humic substances are well known human nutritional supplement materials and play important performance-enhancing roles as animal feed additives, too. For decades, ingredients of humic substances have also been proven to carry potent antiviral effects against different viruses. Here, the antiviral activity of a humic substance containing ascorbic acid, Se- and Zn2+ ions intended as a nutritional supplement material was investigated against SARS-CoV-2 virus B1.1.7 Variant of Concern (Alpha Variant) in a VeroE6 cell line. Results show that this combination has a significant in vitro antiviral effect at a very low concentration range of its intended active ingredients. Even picomolar concentration ranges of humic substances, vitamin C and Zn/Se ions in the given composition were enough to achieve fifty percent viral replication inhibition in the applied SARS-CoV-2 virus inhibition test. Keywords: SARS-CoV-2, humic acid, fulvic acid, Zn-Se-ascorbic acid complex, antiviral activity, RT-PCR


2021 ◽  
Vol 8 ◽  
Author(s):  
Manuel Gómez-García ◽  
Héctor Puente ◽  
Héctor Argüello ◽  
Óscar Mencía-Ares ◽  
Pedro Rubio ◽  
...  

Organic acid and essential oils (EOs), well-known antimicrobials, could also possess antiviral activity, a characteristic which has not been completely addressed up to now. In this study, the effect of two organic acids (formic acid and sodium salt of coconut fatty acid distillates) and two single EO compounds (thymol and cinnamaldehye) was evaluated against porcine epidemic diarrhea virus (PEDV). The concentration used for each compound was established by cytotoxicity assays in Vero cells. The antiviral activity was then evaluated at three multiplicities of infection (MOIs) through visual cytopathic effect (CPE) evaluation and an alamarBlue assay as well as real-time reverse-transcription PCR (RT-qPCR) and viral titration of cell supernatants. Formic acid at at a dose of 1,200 ppm was the only compound which showed antiviral activity, with a weak reduction of CPE caused by PEDV. Through the alamarBlue fluorescence assay, we showed a significant anti-CPE effect of formic acid which could not be observed by using an inverted optical microscope. RT-qPCR and infectivity analysis also showed that formic acid significantly reduced viral RNA and viral titers in a PEDV MOI-dependent manner. Our results suggest that the antiviral activity of formic acid could be associated to its inhibitory effect on viral replication. Further studies are required to explore the anti-PEDV activity of formic acid under field conditions alone or together with other antiviral agents.


2021 ◽  
Author(s):  
Fei Liu ◽  
Amy C.H Lee ◽  
Fang Guo ◽  
Andrew S. Kondratowicz ◽  
Holly M Micolochick Steuer ◽  
...  

Noncanonical poly(A) polymerases PAPD5 and PAPD7 (PAPD5/7) stabilize HBV RNA via the interaction with the viral post-transcriptional regulatory element (PRE), representing new antiviral targets to control HBV RNA metabolism, HBsAg production and viral replication. Inhibitors targeting these proteins are being developed as antiviral therapies, therefore it is important to understand how PAPD5/7 coordinate to stabilize HBV RNA. Here, we utilized a potent small-molecule AB-452 as a chemical probe, along with genetic analyses to dissect the individual roles of PAPD5/7 in HBV RNA stability. AB-452 inhibits PAPD5/7 enzymatic activities and reduces HBsAg both in vitro (EC50 ranged from 1.4 to 6.8 nM) and in vivo by 0.93 log10. Our genetic studies demonstrate that the stem-loop alpha sequence within PRE is essential for both maintaining HBV poly(A) tail integrity and determining sensitivity towards the inhibitory effect of AB-452. Although neither single knock-out (KO) of PAPD5 nor PAPD7 reduces HBsAg RNA and protein production, PAPD5 KO does impair poly(A) tail integrity and confers partial resistance to AB-452. In contrast, PAPD7 KO could not result in any measurable phenotypic changes, but displays a similar antiviral effect as AB-452 treatment when PAPD5 is depleted simultaneously. PAPD5/7 double KO confers complete resistance to AB-452 treatment. Our results thus indicate that PAPD5 plays a dominant role in stabilizing viral RNA by protecting the integrity of its poly(A) tail, while PAPD7 serves as a second line of protection. These findings inform PAPD5 targeted therapeutic strategies and open avenues for further investigating PAPD5/7 in HBV replication.


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