The improved antiviral activities of amino-modified chitosan derivatives on Newcastle virus.

Chitosan is widely used as a medical material because of its excellent biological activities. However, the low solubility of natural chitosan limited its medicinal activity to some extent. The solubility can be improved by introducing more active groups and lowering molecular weight. Therefore, 6-amine chitosan derivatives were synthesized in this paper since more active groups were introduced to increase the medicinal activity. Those derivatives were characterized by elemental analysis, HPLC, and FT-IR and the antiviral activity was tested by hemagglutination tests. Finally, 6-amine chitosan derivatives improved the antiviral activity, especially after the introduction of bromine ion. When 6-deoxy-6-bromo-N-phthaloyl chitosan was 1 g/L, they reduced the hemagglutination titer of virus to zero. The RT-PCR result showed that the expression level of TNF-α and IFN-ß increased significantly, which indicated that the antiviral activity of amino-modified chitosan worked through the stimulation of immune response.

Evaluation of Chitosan Derivatives Modified Mesoporous Silica Nanoparticles as Delivery Carrier.

Chitosan is a non-toxic biological material, but chitosan is insoluble in water, which hinders the development and utilization of chitosan. Chitosan derivatives N-2-Hydroxypropyl trimethyl ammonium chloride (N-2-HACC) and carboxymethyl chitosan (CMCS) with good water solubility were synthesized by our laboratory. In this study, we synthesized mesoporous SiO2 nanoparticles by the emulsion, and then the mesoporous SiO2 nanoparticles were modified with γ-aminopropyltriethoxysilane to synthesize aminated mesoporous SiO2 nanoparticles; CMCS and N-2-HACC was used to cross-link the aminated mesoporous SiO2 nanoparticles to construct SiO2@CMCS-N-2-HACC nanoparticles. Because the aminated mesoporous SiO2 nanoparticles with positively charged can react with the mucous membranes, the virus enters the body mainly through mucous membranes, so Newcastle disease virus (NDV) was selected as the model drug to evaluate the performance of the SiO2@CMCS-N-2-HACC nanoparticles. We prepared the SiO2@CMCS-N-2-HACC nanoparticles loaded with inactivated NDV (NDV/SiO2@CMCS-N-2-HACC). The SiO2@CMCS-N-2-HACC nanoparticles as delivery carrier had high loading capacity, low cytotoxicity, good acid resistance and bile resistance and enteric solubility, and the structure of NDV protein encapsulated in the nano vaccine was not destroyed. In addition, the SiO2@CMCS-N-2-HACC nanoparticles could sustain slowly released NDV. Therefore, the SiO2@CMCS-N-2-HACC nanoparticles have the potential to be served as delivery vehicle for vaccine and/or drug.

Identification of nucleoporin 93 (Nup93) that mediates antiviral innate immune responses.

RIG-I-like receptors (RLRs) are cytoplasmic sensors for viral RNA that elicit antiviral innate immune responses. RLR signaling culminates in the activation of the protein kinase TBK1, which mediates phosphorylation and nuclear translocation of IRF3 that regulates expression of type I interferon genes. Here, we found that Nucleoporin 93 (Nup93), components of nuclear pore complex (NPC), plays an important role in RLR-mediated antiviral responses. Nup93-deficient RAW264.7 macrophage cells exhibited decreased expression of Ifnb1 and Cxcl10 genes after treatment with a synthetic RLR agonist stimulation as well as Newcastle Disease Virus infection. Silencing Nup93 in murine primary macrophages and embryonic fibroblasts also resulted in reduced expression of these genes. IRF3 nuclear translocation during RLR signaling was impaired in Nup93-deficient RAW264.7 cells. Notably, the activation of TBK1 during RLR signaling was also decreased in Nup93-deficient cells. We found that Nup93 formed a complex with TBK1, and Nup93 overexpression enhanced TBK1-mediated IFNß promoter activation. Taken together, our findings suggest that Nup93 regulates antiviral innate immunity by enhancing TBK1 activity and IRF3 nuclear translocation.

Host CARD11 Inhibits Newcastle Disease Virus Replication by Suppressing Viral Polymerase Activity in Neurons.

Host factors play multiple essential roles in the replication and pathogenesis of mammalian neurotropic viruses. However, the cellular proteins of the central nervous system (CNS) involved in avian neurotropic virus infection have not been completely elucidated. Here, we employed a gene microarray to identify caspase recruitment domain-containing protein 11 (CARD11), a lymphoma-associated scaffold protein presenting brain-specific upregulated expression in a virulent neurotropic Newcastle disease virus (NDV)-infected natural host. Chicken primary neuronal cells infected with NDV appeared slightly syncytial and died quickly. CARD11 overexpression inhibited viral replication and delayed cytopathic effects; conversely, depletion of CARD11 enhanced viral replication and cytopathic effects in chicken primary neuronal cells. The inhibition of viral replication by CARD11 could not be blocked with CARD11-Bcl10-MALT1 (CBM) signalosome and NF-κB signaling inhibitors. CARD11 was found to interact directly with the viral phosphoprotein (P) through its CC1 domain and the X domain of P; this X domain also mediated the interaction between P and the viral large polymerase protein (L). The CARD11 CC1 domain and L competitively bound to P via the X domain that hindered the P-L interaction of the viral ribonucleoprotein (RNP) complex, resulting in a reduction of viral polymerase activity in a minigenome assay and inhibition of viral replication. Animal experiments further revealed that CARD11 contributed to viral replication inhibition and neuropathology in infected chicken brains. Taken together, our findings identify CARD11 as a brain-specific antiviral factor of NDV infection in avian species.IMPORTANCE Newcastle disease virus (NDV) substantially impacts the poultry industry worldwide and causes viral encephalitis and neurological disorders leading to brain damage, paralysis, and death. The mechanism of interaction between this neurotropic virus and the avian central nervous system (CNS) is largely unknown. Here, we report that host protein CARD11 presented brain-specific upregulated expression that inhibited NDV replication, which was not due to CARD11-Bcl10-MALT1 (CBM) complex-triggered activation of its downstream signaling pathways. The inhibitory mechanism of viral replication is through the CARD11 CC1 domain, and the viral large polymerase protein (L) competitively interacts with the X domain of the viral phosphoprotein (P), which hampers the P-L interaction, suppressing the viral polymerase activity and viral replication. An in vivo study indicated that CARD11 alleviated neuropathological lesions and reduced viral replication in chicken brains. These results provide insight into the interaction between NDV infection and the host defense in the CNS and a potential antiviral target for viral neural diseases.

Resiquimod inhibits Newcastle disease virus replication by modulating host cytokines: An understanding towards its possible therapeutics.

Newcastle disease virus (NDV) infects domestic and wild avian species with high mortality and morbidity worldwide. Although this disease is mainly controlled through NDV vaccines, alternative use of antiviral compounds is increasingly under study. Resiquimod (R-848), an imidazoquinoline compound is a potent synthetic agonist of Toll-like receptor 7 (TLR7). Until now reports regarding the adjuvant potential of resiquimod is well established against human viruses but has been less explored against avian viruses. In the present study, we have analysed the anti-NDV effect of resiquimod in chicken embryo fibroblast cells (DF-1) and embryonated chicken eggs. About 70% reduction in NDV replication was observed 48 h and 72 h post-resiquimod treatment in DF-1 cells. Furthermore, differential host genes expression was observed in resiquimod treated DF-1 cells, PBMCs, and tissue sample of chicken embryos at a different time point. Among all the analyzed genes, significant up-regulation of viperin, IFNα, IFNγ, IL-1ß, TNFα, IL18 were observed in its transcriptional level. Furthermore, resiquimod treatment showed NDV reduction in two weeks old chickens. About 61% and 38% reduction in NDV replication was observed 72 h post-infection in lungs and spleen, respectively. The study suggests the modulation of host innate immunity regulatory genes by resiquimod, which eventually modulates the NDV replication. The result of the study could be explored further to establish resiquimod as an alternative antiviral compound against NDV.

Therapeutic potential of Nitazoxanide against Newcastle disease virus: A possible modulation of host cytokines.

Newcastle disease (ND) is prevalent among the domesticated and the wild birds and is caused by the avian paramyxovirus serotype-I (APMV-I). It is commonly known to affect chicken, pheasant, ostrich, pigeon and waterfowl. Depending on the virulence, the velogenic NDV strains cause severe respiratory and nervous disorders with a high mortality rate. The live and killed vaccines are available for the prevention of infection in the market, but the drug for the treatment is not available. Nitazoxanide (NTZ), a member of thiazolides, is an antiparasitic drug. In the present study, the effect of NTZ on the NDV replication was explored. The experiments were conducted in chicken fibroblast cells (DF-1), PBMC, embryonated chicken eggs, and two-week old chickens. The inhibition of the NDV was observed upon post-treatment of NTZ at a concentration of ~12.5 µM. Cytokine profiling of the DF-1, PBMC, and chicken embryonic tissue treated with NTZ revealed significant upregulation in all the cytokines studied except for IL-1ß in DF-1 cells. It is plausible that NTZ is involved in causing immune-modulatory effects in poultry. NTZ treatment in two weeks old chicken showed significant reduction in NDV replication in trachea, and lungs, respectively, at 72 h post-infection. Encouraging results from the present study warrants repurposing NTZ as a drug for the treatment of viral infection in poultry. It will also pave the way towards understanding of similar effect against other animal pathogens.

2ß-3,4-Unsaturated sialic acid derivatives: Synthesis optimization, and biological evaluation as Newcastle disease virus hemagglutinin-neuraminidase inhibitors.

The optimization of the synthetic protocol to obtain the 3,4-unsaturated sialic acid derivatives, through the fine-tuning of both the Ferrier glycosylation conditions and the subsequent hydrolysis work-up, is herein reported. The accomplishment of the desired ß-anomers and some selected α-ones, in pure form, led us to evaluate their specific inhibitory activity towards NDV-HN and human sialidase NEU3. Importantly, the resulting data allowed the identification, for the first time, of three active 3,4-unsaturated sialic acid analogs, showing IC50 values against NDV-HN in the micromolar range.

Antiviral activity of green silver nanoparticles produced using aqueous buds extract of Syzygium aromaticum.

In the present study, we synthesized silver (Ag) nanoparticles using aqueous extracts of clove (Syzygium aromaticum) (SAE). This synthesis of green silver nanoparticles (AgNP) was a novel and effectual tool against the Newcastle Viral Disease (NDV). Syzygium aromaticum extract was used as reducing and stabilizing agent for synthesis of silver nanoparticles. AgNP were characterized using diversity of biophysical methods inclusive of Fourier transform infrared spectroscopy (FTIR), UV-VIS spectroscopy and Transmission electron microscopy (TEM) for morphology and size. Furthermore, XRD analysis confirmed the crystalline nature of the particles. In current investigations, the antiviral activity of clove buds silver nanoparticles was inspected in-vitro and in-ovo. Embryonated chicken eggs were used to perform the cytotoxicity assay of the clove extract silver nanoparticles (CESN). CESN showed in vitro antiviral activity against NDV in embryonated eggs.

Antiviral activities of extremophilic actinomycetes extracts from Kazakhstan's unique ecosystems against influenza viruses and paramyxoviruses.

BACKGROUND: Commercially available antiviral drugs, when used in the treatment of viral infections, do not always result in success. This is an urgent problem currently that needs to be addressed because several viruses including influenza and paramyxoviruses are acquiring multi-drug resistance. A potential solution for this emerging issue is to create new antiviral drugs from available compounds of natural products. It is known that the majority of drugs have been developed using compounds derived from actinomycetes, which are naturally occurring gram-positive bacteria. The purpose of this study was to investigate the antiviral properties of extremophilic actinomycetes extracts from strains that were isolated from extreme environments in Kazakhstan. METHODS: Five strains of extremophilic actinomycetes isolated from the unique ecosystems of Kazakhstan were extracted and tested for antiviral activity against influenza viruses (strains H7N1, H5N3, H1N1 and H3N2) and paramyxoviruses (Sendai Virus and Newcastle Disease Virus). The antiviral activity of these selected extracts was tested by checking their effect on hemagglutination and neuraminidase activities of the studied viruses. Additionally, actinomycetes extracts were compared with commercially available antiviral drugs and some plant preparations that have been shown to exhibit antiviral properties. RESULTS: The main findings show that extracts from strains K-192, K-340, K-362, K-522 and K525 showed antiviral activities when tested using influenza viruses, Sendai Virus, and Newcastle Disease Virus. These activities were comparable to those shown by Rimantadine and Tamiflu drugs, and "Virospan" and "Flavovir" plant preparations. CONCLUSIONS: We identified several extracts with antiviral activities against several strains of influenza viruses and paramyxoviruses. Our research findings can be applied towards characterization and development of new antiviral drugs from the active actinomycetes extracts.

Virus-Triggered ATP Release Limits Viral Replication through Facilitating IFN-ß Production in a P2X7-Dependent Manner.

Accumulating evidence shows that innate immune responses are associated with extracellular nucleotides, particularly ATP. In this article, we demonstrate extensive protection of ATP/P2X7 signaling in a host against viral infection. Interestingly, we observed a significant increase in ATP as a danger signal in vesicular stomatitis virus (VSV)-infected cell supernatant and VSV-infected mice in an exocytosis- and pannexin channel-dependent manner. Furthermore, extracellular ATP reduces the replication of VSV, Newcastle disease virus, murine leukemia virus, and HSV in vivo and in vitro through the P2X7 receptor. Meanwhile, ATP significantly increases IFN-ß expression in a concentration- and time-dependent manner. Mechanistically, ATP facilitates IFN-ß secretion through P38/JNK/ATF-2 signaling pathways, which are crucial in promoting antiviral immunity. Taken together, these results demonstrate the protective role of extracellular ATP and P2X7 in viral infection and suggest a potential therapeutic role for ATP/P2X7 in viral diseases.

Phosphorylated abacavir analogue (ABC-1) has ameliorative action against Newcastle disease virus induced pathogenesis in chicken.

Newcastle disease virus (NDV) causes huge economic loss to the poultry industry due to high mortality and morbidity. The present study aimed to assess the protective role of novel phosphorylated analogue ABC-1 in vivo in NDV-infected chickens through the inhibition of fusion protein. Both NDV-induced oxidative damage and protective role of novel phosphorylated ABC-1 were evaluated in vital organs such as the liver and lung of chickens. Enzyme linked immunosorbent assay (ELISA) results showed that protein oxidation and nitration levels were significantly raised in NDV-infected tissues compared to healthy controls, whereas these levels were reduced significantly (P < 0.05) in birds treated with phosphorylated compounds compared to the NDV-infected group alone. Additional investigation with double immunofluorescence showed that the large amount of immuno colocalization and Western blot analysis also confirmed this observation through its band pattern in NDV-infected birds compared to healthy birds, whereas these alterations were reduced in treatment with novel phosphorylated ABC-1. The expression of fusion glycoprotein was studied by immuno colocalization, PCR, and flow cytometry, and results demonstrated that the novel phosphorylated analogues reduced the expression of fusion glycoprotein. These results put forth that novel phosphorylated ABC-1 protects chickens from NDV-induced pathogenesis, protein oxidation/nitration, and exerts potent antiviral activity.

Protocatechuic acid (PCA) induced a better antiviral effect by immune enhancement in SPF chickens.

Protocatechuic acid (PCA) is an antiviral agent against Avian Influenza virus (AIV) and Infectious Bursal Disease (IBD) virus, but its antiviral mechanism is unknown. In this study, we evaluated the humoral and cellular responses to PCA in specific pathogen-free (SPF) chickens. One hundred forty 35-day-old SPF chickens were randomly divided into 7 groups. The birds were inoculated with the commercial, attenuated Newcastle Disease Virus (NDV) vaccine and then received orally with 10, 20 or 40 mg/kg body weight of PCA for 30 days. Immune organ indexes, anti-Newcastle Disease Virus (NDV) antibodies and lymphocyte proliferation, but not body weight, were significantly increased in chicken treated with 40 mg/kg PCA, compared to the control birds treated with Astragalus polysaccharide (ASP). Survival rate was 70% and 60%, respectively, in the chickens with 40 mg/kg PCA, 20 mg/kg PCA while 50% survival was found in the birds treated with 125 mg/kg ASP. PCA treatment resulted in significantly lower viral load and reduced shedding. These results indicate that PCA may improve poultry health by enhancing both the humoral and cellular immune response.

Saponin-adjuvanted vaccine protects chickens against velogenic Newcastle disease virus.

Despite extensive vaccination campaigns, Newcastle disease virus (NDV) remains endemic in many countries worldwide, and factors that contribute to this failure include mismatched vaccines, partial immunization, and poor husbandry practices. In order to overcome the problem of genetic divergence between circulating field strains and vaccine strains, we saponin-adjuvanted an Egyptian field strain and assessed its safety and immunogenicity in chickens. Immunization of chickens with the vaccine followed by challenge with a velogenic reference strain revealed the potential of the saponin-adjuvanted vaccine to induce a strong immune response that resulted in complete protection of chickens. Importantly, in vaccinated chickens, virus shedding was abolished, providing an added advantage over the currently available commercial live-attenuated and inactivated vaccines, which are unable to prevent shedding. A histopathological investigation demonstrated that the vaccinated chickens had less-severe lesions than challenged unvaccinated and mock-vaccinated chickens. We propose using this formulation as an alternative and improved NDV vaccine platform that can be exploited to control disease not only in Egypt but also in other disease-endemic countries.

Biosurfactants production potential of native strains of Bacillus cereus and their antimicrobial, cytotoxic and antioxidant activities.

Present study was designed to evaluate the biosurfactant production potential by native strains of Bacillus cereus as well as determine their antimicrobial and antioxidant activities. The strains isolated from garden soil were characterized as B. cereus MMIC 1, MMIC 2 and MMIC 3. Biosurfactants were extracted as grey white precipitates. Optimum conditions for biosurfactant production were 37°C, the 7th day of incubation, 0.5% NaCl, pH 7.0. Moreover, corn steep liquor was the best carbon source. Biuret test, Thin Layer Chromatography (TLC), agar double diffusion and Fourier Transform Infrared Spectroscopy (FTIR) characterized the biosurfactants as cationic lipopeptides. Biosurfactants exhibited significant antibacterial and antifungal activity against S. aureus, E. coli, P. aeruginosa, K. pneumoniae, A. niger and C. albicans at 30 mg/ml. Moreover, they also possessed antiviral activity against NDV at 10 mg/ml. Cytotoxicity assay in BHK-21 cell lines revealed 63% cell survival at 10 mg/ml of biosurfactants and thus considered as safe. They also showed very good antioxidant activity by ferric-reducing activity and DPPH scavenging activity at 2 mg/ml. Consequently, the study offers an insight for the exploration of new bioactive molecules from the soil. It was concluded that lipopeptide biosurfactants produced from native strains of B. cereus may be recommended as safe antimicrobial, emulsifier and antioxidant agent.

Virus inactivation under the photodynamic effect of phthalocyanine zinc(II) complexes.

Various metal phthalocyanines have been studied for their capacity for photodynamic effects on viruses. Two newly synthesized water-soluble phthalocyanine Zn(II) complexes with different charges, cationic methylpyridyloxy-substituted Zn(II)- phthalocyanine (ZnPcMe) and anionic sulfophenoxy-substituted Zn(II)-phthalocyanine (ZnPcS), were used for photoinactivation of two DNA-containing enveloped viruses (herpes simplex virus type 1 and vaccinia virus), two RNA-containing enveloped viruses (bovine viral diarrhea virus and Newcastle disease virus) and two nude viruses (the enterovirus Coxsackie B1, a RNA-containing virus, and human adenovirus 5, a DNA virus). These two differently charged phthalocyanine complexes showed an identical marked virucidal effect against herpes simplex virus type 1, which was one and the same at an irradiation lasting 5 or 20 min (Δlog=3.0 and 4.0, respectively). Towards vaccinia virus this effect was lower, Δlog=1.8 under the effect of ZnPcMe and 2.0 for ZnPcS. Bovine viral diarrhea virus manifested a moderate sensitivity to ZnPcMe (Δlog=1.8) and a pronounced one to ZnPcS at 5- and 20-min irradiation (Δlog=5.8 and 5.3, respectively). The complexes were unable to inactivate Newcastle disease virus, Coxsackievirus B1 and human adenovirus type 5.

Ethanol extract and chromatographic fractions of Tamarindus indica stem bark inhibits Newcastle disease virus replication.

CONTEXT: The plethora of ethnomedicinal applications of Tamarindus indica Linn. (Leguminosae), tamarind, includes treatment of human and livestock ailments; preparations are recognized antipyretics in fevers, laxatives and carminatives. African folklore has various applications of tamarind. However, in Nyasaland, domestic fowl are fed with preparations for prophylactic properties. OBJECTIVES: The objective of this study is to evaluate the antiviral properties of T. indica extract. MATERIALS AND METHODS: Tamarindus indica stem bark was extracted through ethanol maceration over 24 h, and the crude extract was fractionated by gravity-propelled column chromatography. Newcastle disease virus (NDV) inhibitory activity of extract and fractions were evaluated in vivo using 10-d-old embryonated chicken egg (ECE) as the medium for virus cultivation and antivirus assay. About 240 ECE were grouped into eight (three controls and five experimental) and, 200 µL of the extract and fractions respectively inoculated into NDV pre-infected eggs and incubated at 37 °C. Allantoic fluid was harvested 5 d post-virus infection and assayed for haemagglutination (HA). RESULTS: Anti-NDV assessment showed 62.5 mg/mL of crude extract and fractions: TiA, TiC and TiD to yield a HA titre of 1:128 each, while TiB showed 1:64 HA titre. At 125 mg/mL, a titre of 1:16 was recorded against TiB and TiD and, 1:8 against TiA. Similarly, crude extract and TiC, each recorded 1:4 HA titre. However, the minimum concentrations of extract and fraction for virus inactivation were 0.24 mg/mL and 0.49 mg/mL, respectively. CONCLUSION: The antiviral activity shown by T. indica portends novel antiviral drugs and, perhaps, as scaffold for new drugs.

In vivo antiviral potential of Glycyrrhiza glabra extract against Newcastle disease virus.

Newcastle disease is highly infectious viral disease causing huge economic losses worldwide. These losses can be prevented by control of viral diseases. Medicinal plants have been traditionally used for treatment of different diseases since long. In this study the effect of extracts from Glycyrrhiza glabra leaves are investigated against Newcastle disease virus (NDV) by an in-vivo assay. Seven groups of nine-day-old embryonated chicken eggs were inoculated with various treatments of different plant extracts. All the groups except uninoculated negative control group were inoculated with velogenic NDV strain; five groups received different concentrations of the three extracts. Daily observe the rate of embryo survival. Allantoic fluid from treated eggs was collected for hem agglutination test. Results showed that embryo survival rate was higher 300µg/mL treated group as all the extracts showed antiviral activity. Similarly, the plant extracts effectively control virus as no viruses were identified in the allantoic fluids of all groups treated with low doses of plant. The current results have clearly verified that all the extracts especially that of methanol 300µg/mL from leaves of Glycyrrhiza glabra have strong antiviral activity against NDV in vivo.

The LXR ligand GW3965 inhibits Newcastle disease virus infection by affecting cholesterol homeostasis.

Newcastle disease (ND) is a contagious disease that affects most species of birds. Its causative pathogen, Newcastle disease virus (NDV), also exhibits considerable oncolytic activity against mammalian cancers. A better understanding of the pathogenesis of NDV will help us design efficient vaccines and novel anticancer strategies. GW3965, a widely used synthetic ligand of liver X receptor (LXR), induces the expression of LXRs and its downstream genes, including ATP-binding cassette transporter A1 (ABCA1). ABCA1 regulates cellular cholesterol homeostasis. Here, we found that GW3965 inhibited NDV infection in DF-1 cells. It also inhibited NF-κB activation and reduced the upregulation of proinflammatory cytokines induced by the infection. Further studies showed that GW3965 exerted its inhibitory effects on virus entry and replication. NDV infection increased the mRNA levels of several lipogenic genes but decreased the ABCA1 mRNA level. Overexpression of ABCA1 inhibited NDV infection and reduced the cholesterol content in DF-1 cells, but when the cholesterol was replenished, NDV infection was restored. GW3965 treatment prevented cholesterol accumulation in the perinuclear area of the infected cells. In summary, our studies suggest that GW3965 inhibits NDV infection, probably by affecting cholesterol homeostasis.

Synthesis and Antiviral Activity of Novel Phosphorylated Derivatives of Didanosine Against Newcastle Disease Virus in Chicken.

A series of novel phosphorylated derivatives of didanosine were designed and docking studies were performed with a fusion protein of the Newcastle disease virus (NDV), to develop antiviral compounds against NDV. Based on the docking scores and binding affinities, three derivatives were selected. These compounds were synthesized and characterized by IR, (1) H, (13) C, (31) P, and CHN analysis and mass spectra. They were assessed for their in vitro antiviral activity in DF-1 cells; DDI-10 showed better antiviral activity as evidenced by significant reduction in plaque formation and cytopathic effects. DDI-10 was further evaluated in NDV-infected chicken; the survival rates and antioxidant enzyme levels in brain, liver, and lung tissues were estimated. Superoxide dismutase and catalase were significantly raised, and lipid peroxidation and HA titer levels were decreased upon treatment with 1.5 mg/kg body weight of DDI-10 than with 3 mg/kg body weight of DDI. Further histopathological alterations in NDV-infected tissues were restored in chicken treated with DDI-10. Thus, based on the results from in silico, in vitro, and in vivo assays, the novel phosphorylated DDI-10 might be considered as potent antiviral compound for NDV infection in chicken.

The screening and evaluation of herbs and identification of herbal combinations with anti-viral effects on Newcastle disease virus.

A total of 25 "heat-clearing and detoxifying" herbs used in Chinese medicine were investigated for their cytopathic effects on the growth of Newcastle Disease virus (NDV) in a chicken fibroblast cell line. The 5 herbs with the highest virus inhibitory effects were Herba agastaches, Flos chrysanthemi indici, Rhizoma anemarrhenae, Astragalus root and Baikal skullcap root and these were used in herbal formulations. Anti-NDV activities of 4 formulations were tested on the growth of NDV in the DF-1 fibroblast cell line. Formulation II, containing Baikal skullcap root, Astragalus root, Anemarrhena rhizome (1:1:2) and formulation IV containing Anemarrhena rhizome, Astragalus root and Flos chrysanthemi indici (1:1:1), which had strong anti-NDV activity in vitro, were used to determine the in vivo inhibitory effects of NDV-infection in chickens. After treatment with the two formulations serum IgY titres against NDV were improved, and morbidity was reduced in the NDV-infected chickens. The results suggest that the components in formulations II and IV acted synergistically to improve resistance to Newcastle disease and provide a basis for the developing an anti-NDV herbal medicine.