Alpha-sitosterol: a new antiviral agent produced by Streptomyces misakiensis and its potential activity against Newcastle disease virus.

BACKGROUND: Newcastle Disease Virus (NDV) causes severe economic losses in the poultry industry worldwide. Hence, this study aimed to discover a novel bioactive antiviral agent for controlling NDV. Streptomyces misakiensis was isolated from Egyptian soil and its secondary metabolites were identified using infrared spectroscopy (IR), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy. The inhibitory activity of bioactive metabolite against NDV were examined. Three experimental groups of 10-day-old specific pathogen-free embryonated chicken eggs (SPF-ECEs), including the bioactive metabolite control group, NDV control positive group, and α-sitosterol and NDV mixture-treated group were inoculated. RESULTS: α-sitosterol (Ethyl-6-methylheptan-2-yl]-10,13-dimethyl-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol), a secondary metabolite of S. misakiensis, completely inhibited hemagglutination (HA) activity of the NDV strain. The HA activity of the NDV strain was 8 log2 and 9 log2 for 0.5 and 0.75% RBCs, respectively. The NDV HA activity for the two concentrations of RBCs was significantly (P < 0.0001) inhibited after α-sitosterol treatment. There was a significant (P < 0.0001) decrease in the log 2 of HA activity, with values of - 0.500 (75%, chicken RBCs) before inoculation in SPF-ECEs and - 1.161 (50%, RBCs) and - 1.403 (75%, RBCs) following SPF-ECE inoculation. Compared to ECEs inoculated with NDV alone, the α-sitosterol-treated group showed improvement in histological lesion ratings for chorioallantoic membranes (CAM) and hepatic tissues. The CAM of the α-sitosterol- inoculated SPF-ECEs was preserved. The epithelial and stromal layers were noticeably thicker with extensive hemorrhages, clogged vasculatures, and certain inflammatory cells in the stroma layer in the NDV group. However, mild edema and inflammatory cell infiltration were observed in the CAM of the treated group. ECEs inoculated with α-sitosterol alone showed normal histology of the hepatic acini, central veins, and portal triads. Severe degenerative alterations, including steatosis, clogged sinusoids, and central veins, were observed in ECEs inoculated with NDV. Mild hepatic degenerative alterations, with perivascular round cell infiltration, were observed in the treated group. CONCLUSION: To the best of our knowledge, this is the first study to highlight that the potentially bioactive secondary metabolite, α-sitosterol, belonging to the terpene family, has the potential to be a biological weapon against virulent NDV. It could be used for the development of innovative antiviral drugs to control NDV after further clinical investigation.

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.

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.

In silico, in ovo and in vitro antiviral efficacy of phosphorylated derivatives of abacavir: an experimental approach.

Outstanding increase of oral absorption, bioavailability, and antiviral efficacy of phosphorylated nucleosides and basic antiviral influence of abacavir is the central idea for the development of new series of phosphorylated abacavir (ABC) derivatives. The designed compounds were primarily screened for antiviral nature against HN protein of NDV and VP7 protein of BTV using the molecular environment approach. Out of all the designed compounds, the compounds which are having higher binding energies against these two viral strains were prompted for the synthesis of the target compounds (5A-K). Among the synthesized title compounds (5A-K), the compounds which have exhibited higher dock scores akin to the rest of the compounds were then selected and screened for the antiviral activity against NDV and BTV infected embryonated eggs and BHK 21 cell lines through the in ovo and in vitro approaches. The results revealed that all the designed compounds have formed higher binding energies against both the targets. Among all, the compounds which are selected based on their dock scores such as 5A, 5F, 5G, 5H, 5I, and 5K against NDV and 5J, 5E, 5I, 5C, 5A, and 5K against BTV have shown significant antiviral activity against HN protein of NDV, VP7 protein of Bluetongue virus in both NDV- and BTV-treated embryonated eggs and BHK 21 cell lines. Hence, it is concluded that, the best lead compounds will stand as the potential antiviral agents and prompted them as virtuous therapeutics against NDV and BTV in future.

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.

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.

Status updates of Newcastle disease and amelioration effects of medicinal plants against Newcastle disease virus: A review.

Recently, medicinal plants are achieving great interest because of their use in ethno medicine treatment of different common diseases and also other medicinal assertions are now reinforced by comprehensive scientific evidence. Almost 82 research articles and abstracts published, so far, were screened for evaluating antiviral efficiency of various plant samples and 23 different plants were found to be traditionally used against Newcastle disease (ND). ND is a most transmissible viral disease of avian species caused by virulent strain of Avula virus from the Paramyxoviridae family. The first epidemic of ND was perceived in Java, Indonesia and England in year 1926. ND causes great economic loses to the commercial poultry farmers around the world. Medicinal plants are traditionally used in the control of viral or other diseases and infections. Plants have been found useful in treating many microbial diseases in man and animals caused by bacteria and viruses. The ability to synthesize compounds retaining antiviral potential by secondary metabolism makes plants a vital source of pharmaceutical and therapeutic products, which can reduce chemotherapeutic load in birds. Current studies signify that the natural products posses a rich potential source of new antiviral compounds. Further ethnobotanical studies and laboratory investigations are established to identify species having potential to improve ND control.

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.

Vitamin A dietary supplementation reduces the mortality of velogenic Newcastle disease significantly in cockerels.

This project was undertaken to find ways of reducing mortalities and economic losses due to velogenic Newcastle disease (VND) in areas where the disease is enzootic. Four groups of cockerels of 44 birds each were used for this experiment. The birds in groups 1 and 2 received no dietary vitamin A supplementation, whereas groups 3 and 4 received 300 iu and 600 iu of vitamin A per kilogram of commercial feed, respectively, from 1 week of age till the end of the experiment. At 6 weeks of age, the birds in groups 2, 3 and 4 were inoculated intraocularly with a VND virus (duck/Nigeria/Plateau/Kuru/113/1991). The birds in Group 1 were given phosphate-buffered saline intraocularly. Clinical signs appeared in Group 2 birds on day 3 PI and in groups 3 and 4 on day 5 PI. The clinical signs included a drop in feed and water consumption, depression, diarrhoea, torticollis and paralysis in all the infected groups. The average body weights of all groups were significantly different from one another on day 14 PI with Group 2 birds having the lowest body weight. Mortalities were highest in Group 2 birds (0%, 93.18%, 72.73% and 56.82% in groups 1, 2, 3 and 4 respectively). The antibody response in all the groups was significantly different from one another on days 14 and 21 PI. Group 2 birds had the lowest titres on those 2 days and showed more severe atrophy of the bursa, spleen, thymus and fibrin deposition in the spleen and thymus than the birds in groups 3 and 4. The above observations show that vitamin A dietary supplementation delayed the onset of clinical signs and significantly reduced body weight loss, atrophy of the bursa, spleen and thymus, and mortalities by 36%. It also significantly potentiated haemagglutination inhibition antibody response.

Immunomodulatory effects of Taishan Pinus massoniana pollen polysaccharide and propolis on immunosuppressed chickens.

Co-infection of reticuloendotheliosis virus (REV) and avian leukosis virus subgroup J (ALV-J), which can cause suppressed immunity and vaccination failure, frequently occurs in chicken flocks in China. Taishan Pinus massoniana pollen polysaccharide (TPPPS) and propolis (PP) have been proven to possess immune modulatory effects and improve the immune effects of vaccines. This study aimed to investigate the immune modulatory ability of TPPPS and PP on chickens co-infected with immunosuppressive viruses. Prior to the study, chickens were artificially established as REV and ALV-J co-infection models. Four randomly assigned groups of these immunosuppressed chickens were successively administered with TPPPS, PP, mixture of TPPPS and PP (TPPPS-PP), or phosphate-buffered saline (PBS) for three days. At nine days old, the four immunosuppressed groups, as well as one normal group, were inoculated with the attenuated Newcastle disease (ND) vaccine. During the monitoring period, the indices of immune organ weight, lymphocyte transformation rates, CD4(+) and CD8(+) T-lymphocyte counts in peripheral blood, IL-2 and IFN-γ secretions, serum antibody titers of ND vaccine, and viral loads in spleens were determined. The results showed that chickens administered with TPPPS, PP, or TPPPS-PP could significantly enhance the levels of the above immune parameters compared to chickens in the PBS group. We observed the strongest immunity in the TPPPS-PP group, which indicates that the combination of TPPPS and PP versus TPPPS or PP alone, could generate better effects on improving the immune system effectiveness of immunosuppressed chickens.

A cholesterol tag at the N terminus of the relatively broad-spectrum fusion inhibitory peptide targets an earlier stage of fusion glycoprotein activation and increases the peptide's antiviral potency in vivo.

In previous work, we designed peptides that showed potent inhibition of Newcastle disease virus (NDV) and infectious bronchitis virus (IBV) infections in chicken embryos. In this study, we demonstrate that peptides modified with cholesterol or 3 U of polyethylene glycol (PEG3) conjugated to the peptides' N termini showed even more promising antiviral activities when tested in animal models. Both cholesterol- and cholesterol-PEG3-tagged peptides were able to protect chicken embryos from infection with different serotypes of NDV and IBV when administered 12 h prior to virus inoculation. In comparison, the untagged peptides required intervention closer to the time of viral inoculation to achieve a similar level of protection. Intramuscular injection of cholesterol-tagged peptide at 1.6 mg/kg 1 day before virus infection and then three times at 3-day intervals after viral inoculation protected 70% of the chickens from NDV infection. We further demonstrate that the cholesterol-tagged peptide has an in vivo half-life greater than that of untagged peptides. It also has the potential to cross the blood-brain barrier to enter the avian central nervous system (CNS). Finally, we show that the cholesterol-tagged peptide could play a role before the viral fusion peptide's insertion into the host cell and thereby target an earlier stage of fusion glycoprotein activation. Our findings are of importance for the further development of antivirals with broad-spectrum protective effects.

Antiviral activity of crude extracts from Commiphora swynnertonii against Newcastle disease virus in ovo.

Studies were carried out to investigate the effect of crude extracts from resin, leaves, stem barks and root barks of Commiphora swynnertonii against Newcastle disease virus (NDV) using an in ovo assay. Nine-day-old embryonated chicken eggs were divided into seven groups (n = 6) and received various treatments. Six groups were inoculated with velogenic NDV strain; five groups out of these were treated with different concentrations of the four extracts or a diluent, dimethylsulphoxide. The uninoculated and inoculated groups were left as negative and positive controls, respectively. Embryo survival was observed daily and embryo weights were measured day 5 post-inoculation; a few eggs from selected groups were left to hatch. Allantoic fluid from treated eggs and serum from hatched chicks were collected for hemagglutination and hemagglutination inhibition (HI) tests to detect NDV in the eggs and antibodies against NDV in the hatched chicks respectively. Results showed that embryo survival and mean embryo weight were significantly higher (p < 0.001) in those groups which were treated with the crude extracts from C. swynnertonii than the positive control group. Also the extracts significantly (p < 0.001) reduced virus titres, whereas no viruses were detected in the allantoic fluids of the resin-treated group at the highest concentration of 500 µg/mL. Furthermore, the HI test results showed very low levels of antibodies against NDV in chicks hatched from resin and root bark extract-treated eggs suggesting that these plant materials were capable of destroying the NDV before stimulating the developing chick's immunity. The current findings have clearly demonstrated that crude extracts especially that of resin from C. swynnertonii have strong antiviral activity against NDV in ovo. In vivo trials are needed to validate the use of resin from the tree in controlling Newcastle disease in chickens.

Anti-Newcastle Disease Virus activity of 3ß and 3α Friedelanol Triterpenoids from the leaves of Synadenium glaucescens Pax.

Newcastle Disease (ND) is a highly pathogenic disease of avian species which is caused by Newcastle Disease Virus (NDV). It is one of the major causes of mortality and morbidity to poultry industry in the third world countries. Currently, there is no treatment measures against ND; the only existing measure is vaccination, though it is incapable to offer 100% immunity. In Tanzania, the leaves of Synadenium glaucescens Pax. are traditionally used for treatment of various ailments including ND. Previously, its leaves extract has been scientifically confirmed to exhibit anti-NDV activity though bioactive compound(s) responsible for this activity is/are unknown. Therefore, this study was aimed to evaluate anti-NDV activity of 3ß-Friedelanol (1) and 3α-friedelanol (2) isolated from its leaves extract. Isolation of these compounds was achieved by column chromatography method whereas, their chemical structures were determined by Nuclear Magnetic Resonance (NMR) data and by comparing with the available literature NMR data. Anti-NDV activity study was done in embryonated chicken eggs (ECEs). Treatment of NDV inoculated ECEs with 3ß-Friedelanol (1) reduced the viral load to zero and maintained the survival of embryos, this was revealed by continuous organs formation and increase in embryo weights with no significant different (p > 0.05) from un-inoculated ECE. These effects suggest that, 3ß-Friedelanol (1) possesses anti-NDV activity. Therefore, existence of 3ß-Friedelanol (1) in the leaves of S. glaucescens may justify its earlier described anti-NDV activity and traditional use in the treatment of ND. Hence, its leaves extract may be considered for development of anti-NDV herbal formulation while 3ß-Friedelanol could either serve as a drug or lead compound for synthesis of anti-NDV drugs.

Assessment of antiviral activity and mechanism of rhein on newcastle disease virus (La Sota strain IV) in vitro.

Current research is focused on the development of drug candidates from natural products. Rhein a Traditional Chinese Medicine (TCM) from Polygonaceae (rhubarb) has exhibited antioxidant, anti-inflammatory and anticancer activities, however no work has reported its antiviral potential, thus this study was performed to investigate the antiviral activities of rhein on new castle disease virus (NDV) in vitro.NDV infection of chicken embryo fibroblasts (CEFs) was prepared using 10-day-old specific pathogen free chicken embryos. Cytotoxicity and anti-viral activities of rhein were assessed using the MTT method. The interaction between NDV and cell membrane proteins were also detected using virus overlay protein binding assay (VOPBA). In addition NDV genes expressions in CEFs were measured using real-time fluorescent quantitative (RTFQ) PCR.The results showed that rhein effectively inhibit NDV activities maximal safe concentration of 0.125 mg/ml. This finding indicated that, rhein could be used as future antiviral drug against NDV.[Formula: see text].

Lithium chloride functions as Newcastle disease virus-induced ER-stress modulator and confers anti-viral effect.

Newcastle disease is a severe clinical manifestation of avian species caused by Newcastle disease virus (NDV). Although several vaccination strategies are available to protect poultry against NDV infection, even then, outbreaks have been reported in the vaccinated birds. The lack of therapeutics against NDV makes the need for effective anti-viral drugs is of utmost importance. Lithium Chloride (LiCl) is a widely prescribed drug for the treatment of bipolar disorder, acute brain injuries, and chronic neurodegenerative diseases. Also, LiCl has been repurposed as an effective anti-viral drug for some viral infections. In the present work, we have investigated the efficacy of LiCl to inhibit NDV replication using in vitro, in ovo, and in vivo models. Our results collectively showed the modulation of NDV replication after the LiCl treatment. We also demonstrated that NDV induces endoplasmic reticulum stress (ER-stress), and a stress-inducible ER chaperone, glucose-regulating protein 78 (GRP78), was found to be over-expressed after NDV infection. Subsequently, the treatment of NDV infected cells with LiCl significantly reduced the transcript and protein levels of GRP78. Finally, we concluded that LiCl treatment protects the cells from ER-stress induced by the NDV infection.

In vitro and in vivo experimental trials to assess the modulatory influence of ß-caryophyllene on NDV replication and immunopathogenesis.

A trial was conducted to evaluate the antiviral activity and immunomodulatory effect of B-Caryophyllene (BCP) using NDV as a viral model. First, an in ovo experiment was conducted to estimate the antiviral mechanism of BCP. Next, an in vivo experiment was designed to confirm its antiviral efficacy as well as its immunomodulatory and growth promoting ability. According to the in ovo experiment, BCP possesses antiviral influence up to 61.7% when treated before or during NDV infection. Oral supplementation of chickens with two doses of BCP (200 and 400 µg/bird) resulted in a significant increase in the NDV HI-Ab responses and a significant increase in interferon-α signaling cytokines. These obvious immunomodulatory effects improved the bird clinical protection against virulent NDV challenge. To conclude, we introduced a new compound for the poultry industry sector that has antiviral and immunostimulant properties when supplemented orally before or during NDV infection.

RETRACTED: Evaluation of imidazole and its derivative against Newcastle disease virus infection in chicken: A drug repurposing approach.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief and Author as, in addition to the Corrigendum already published in regards to this paper, many of the images were duplicated throughout the paper:­ Figure 1b: all four images of the 36hrs imidazole treatment group 10mM, 20mM, 30mM and 40mM, are the same as the images given in Figure 2C imidazole+virus group 10mM, 20mM, 30mM and 40mM. ­ Figure 2b: GFP image of 12hrs NDV+IMD is the same as the image given in Figure 2c 30mM GFP. ­ Figure 2h: all brightfield images for the first four panels are the same. ­ Figure 3b: plaques in the fourth and fifth panel are same. ­ Figure 3d: gross embryo image in the control (1st) is the same as NDV+ALB (4th panel) group. ­ Figure 4a: gross image 1 and 5 are the same.

An evaluation of the impact of aloe vera and licorice extracts on the course of experimental pigeon paramyxovirus type 1 infection in pigeons.

The progressive decrease in the efficiency of synthetic drugs has prompted research into phytogenic feed additives with potentially immunomodulatory and anti-infective properties. Complex diseases with a mixed etiology, including viral, pose a growing problem in domestic pigeons. The aim of this study was to determine the effectiveness of various doses of aloe vera and licorice extracts on the course of experimental PPMV-1 infection in pigeons. The experiment was performed on pigeons divided into 5 groups, including one control group and 4 experimental groups, which were orally administered aloe vera or licorice extracts at 300 or 500 mg/kg BW for 7 d after experimental inoculation with PPMV-1. On d 4, 7, and 14 after inoculation, cloacal swabs and samples of organs were collected from 4 birds in each group. The samples were analyzed to determine the copy number of PPMV-1 RNA by TaqMan qPCR. The results indicate that licorice and aloe vera extracts inhibited PPMV-1 replication by decreasing viral RNA copy numbers in the examined organs. The most inhibitory effect was observed in pigeons receiving aloe vera extract at 300 mg/kg BW, for which PPMV-1 RNA copy numbers were approximately 7-fold lower (brain), 9-fold lower (kidneys), and 14-fold lower (liver) than in the control group. The results of this study point to the potentially antiviral effects of aloe vera and licorice extracts in pigeons infected with PPMV-1. To the best of our knowledge, this is the first study to investigate the antiviral properties of aloe vera and licorice extracts in domestic pigeons.