Anti-adenovirus Activity Research Articles

Dietary oxyclozanide influences antioxidant enzyme activities and damages DNA in Galleria mellonella (Lepidoptera: Pyralidae).

Oxyclozanide (OXY) is an anthelmintic widely used in the treatment of flatworm infection and fasciolosis. It also has antiadenovirus, antibiofilm, antifungal, and antibacterial activities. Various chemicals have been suggested as alternative chemicals in insect pest management. Here, the oxidative and genotoxic effects of OXY on 7th instars, pupae and adults of the model organism Galleria mellonella (Linnaeus) (Lepidoptera: Pyralidae) were examined. First-instar larvae were reared on 0.003, 0.03, 0.3, and 1.5 g OXY per 100 g artificial diets. Compared with all tested OXY concentrations and controls without OXY, dietary OXY led to increased antioxidant capacity and genotoxic effects. Concentrations of malondialdehyde, an oxidative stress marker, were significantly increased in adults of larvae reared on OXY-charged diets at 0.3 and 1.5 g/100 g compared to the adult control group. We also recorded a significant increase in the genotoxic test data (Tail length, Tail DNA %, Tail moment) at the same stages and concentrations. We recorded significant increases in glutathione-S-transferase, superoxide dismutase (SOD) and glutathione peroxidase activities in larvae fed high OXY concentrations. SOD and catalase activities were also significantly increased at the concentration of 0.03 g/100 g of OXY in the pupal and adult stages. Cytochrome P450 monooxygenase activity was significantly increased at the highest concentration of OXY in the larval and pupal stages. Also, our regression analysis indicates a correlation between the markers of oxidative stress, antioxidant enzymes and comet parameters. These data indicate that OXY induces oxidative stress and antioxidative enzyme response.

The in vitro Evaluation of the Activity of COVID-19 Antiviral Drugs Against Adenovirus.

PurposePresently, there is no approved antiviral therapy for adenovirus (HAdV) ocular infections. During the COVID-19 pandemic, increased attention has been focused on antiviral treatments. Remdesivir, hydroxychloroquine, ivermectin, and umifenovir (Arbidol) have been touted as potential antiviral treatments for COVID-19. The goal of the current study was to determine whether these potential COVID-19 antivirals produce in vitro antiviral activity against a panel of ocular adenovirus types.MethodsThe 50% effective concentrations (EC50) of remdesivir (REM), hydroxychloroquine (HCQ), ivermectin (IVM), umifenovir (UMF) and cidofovir (CDV) (positive antiviral control) were determined for the human HAdV types HAdV3, HAdV4, HAdV5, HAdV7a, HAdV8, HAdV19/64 and HAdV37 using standard plaque-reduction assays in A549 cells.ResultsThe range of mean in vitro EC50 concentrations for each antiviral across the range of HAdV types is as follows: The positive antiviral control, CDV, ranged from 0.47 to 9.62 µM; REM ranged from 0.21 to 11.27 µM; UMF ranged from 3.72 to 64.8 µM; IVR ranged from 2.60 to 201.3 µM; and HCQ was >10 µM for all Ad types because of toxicity to the A549 cells. REM produced lower EC50 concentrations than CDV for 6 of 7 HAdV types. Potency increases with lower EC50 concentrations.ConclusionREM demonstrated anti-adenovirus activity in a range similar to that demonstrated by cidofovir. UMF and IVR demonstrated larger ranges of antiviral activity than CDV and REM across the panel of HAdV types. The anti-adenovirus activity of HCQ could not be determined due to cytotoxicity. Further investigation of REM, UMF, and IVR as antivirals for adenovirus is indicated.

Anti-Adenovirus Activity of the Medical Intranasal Drug Nazoferon

Currently, 90 different types of human adenoviruses (HAdV) are known, which have been classified into seven species from A to G and new adenovirus types continue to emerge. Antigenic diversity of viruses inhibits the process of creating universal vaccines and causes the development of resistance to direct-acting antiviral drugs. In addition to the rapid development of drug resistance, too narrow a range of existing drugs and a significant number of side effects limits the treatment of adenoviral infections. There is currently no specific etiotropic antiviral drug. Therefore, the development of new effective drugs and the selection of the optimal drug for the treatment of infections caused by adenoviruses remain relevant. The aim of the study was to investigate the antiviral properties of the drugs Nazoferon spray and Nazoferon drops in a model of human adenovirus serotype 3. Methods. Determination of cytotoxicity and antiviral action of drugs was performed by standard colorimetric method using MTT. The titer of the virus, synthesized in the presence of drugs was determined by the end point of dilution of the virus, which causes 50% development of the cytopathic effect of the virus on cells (СPE). Results. Low cytotoxicity of Nazoferon spray and Nazoferon drops (manufactured by JSC Farmak, Ukraine) was shown, CC50 is 53854 IU/ml and 54357 IU/ml, respectively. Quantitative and qualitative composition of excipients had no cytotoxic effect. In prophylactic regimens, interferon preparations did not inhibit the reproduction of adenovirus in vitro. Taking into account that most of the virions remain associated with the cells during the reproduction of adenovirus in the cell, we used test to determine infectivity lysates of infected and treated cells. The infectious titer of the synthesized HAdV3 was reduced by 3.2 log10 and 3.7 log10 for Nazoferon spray and drops, respectively. Conclusions. Nazoferon spray and drops can be recommended as anti-adenoviral drugs that block the reproduction of adenovirus, and due to their bioavailability and low cost have significant advantages in the treatment of acute respiratory infections (ARIs) caused by human adenoviruses.

Filociclovir Is an Active Antiviral Agent against Ocular Adenovirus Isolates In Vitro and in the Ad5/NZW Rabbit Ocular Model.

Presently, there is no FDA- or EMA-approved antiviral for the treatment of human adenovirus (HAdV) ocular infections. This study determined the antiviral activity of filociclovir (FCV) against ocular HAdV isolates in vitro and in the Ad5/NZW rabbit ocular model. The 50% effective concentrations (EC50) of FCV and cidofovir (CDV) were determined for several ocular HAdV types using standard plaque reduction assays. Rabbits were topically inoculated in both eyes with HAdV5. On day 1, the rabbits were divided into four topical treatment groups: (1) 0.5% FCV 4x/day × 10 d; (2) 0.1% FCV 4x/day × 10 d; (3) 0.5% CDV 2x/day × 7 d; (4) vehicle 4x/day × 10 d. Eyes were cultured for virus on days 0, 1, 3, 4, 5, 7, 9, 11, and 14. The resulting viral eye titers were determined using standard plaque assays. The mean in vitro EC50 for FCV against tested HAdV types ranged from 0.50 to 4.68 µM, whereas those treated with CDV ranged from 0.49 to 30.3 µM. In vivo, compared to vehicle, 0.5% FCV, 0.1% FCV, and 0.5% CDV produced lower eye titers, fewer numbers of positive eye cultures, and shorter durations of eye infection. FCV demonstrated anti-adenovirus activity in vitro and in vivo.

Oligopeptide-modified poly(beta-amino ester)s-coated AdNuPARmE1A: Boosting the efficacy of intravenously administered therapeutic adenoviruses.

Oncolytic adenoviruses are used as agents for the treatment of cancer. However, their potential is limited due to the high seroprevalence of anti-adenovirus neutralizing antibodies (nAbs) within the population and the rapid liver sequestration when systemically administered. To overcome these challenges, we explored using nanoparticle formulation to boost the efficacy of systemic oncolytic adenovirus administration.Methods: Adenovirus were conjugated with PEGylated oligopeptide-modified poly(β-amino ester)s (OM-pBAEs). The resulting coated viral formulation was characterized in terms of surface charge, size, aggregation state and morphology and tested for anti-adenovirus nAbs evasion and activity in cancer cells. In vivo pharmacokinetics, biodistribution, tumor targeting, and immunogenicity studies were performed. The antitumor efficacy of the oncolytic adenovirus AdNuPARmE1A coated with OM-pBAEs (SAG101) in the presence of nAbs was evaluated in pancreatic ductal adenocarcinoma (PDAC) mouse models. Toxicity of the coated formulation was analyzed in vivo in immunocompetent mice.Results: OM-pBAEs conjugated to adenovirus and generated discrete nanoparticles with a neutral charge and an optimal size. The polymeric coating with the reporter AdGFPLuc (CPEG) showed enhanced transduction and evasion of antibody neutralization in vitro. Moreover, systemic intravenous administration of the formulation showed improved blood circulation and reduced liver sequestration, substantially avoiding activation of nAb production. OM-pBAEs coating of the oncolytic adenovirus AdNuPARmE1A (SAG101) improved its oncolytic activity in vitro and enhanced antitumor efficacy in PDAC mouse models. The coated formulation protected virions from neutralization by nAbs, as antitumor efficacy was preserved in their presence but was completely lost in mice that received the non-formulated AdNuPARmE1A. Finally, coated-AdNuPARmE1A showed reduced toxicity when high doses of the formulation were administered.Conclusions: The developed technology represents a promising improvement for future clinical cancer therapy using oncolytic adenoviruses.

In vitro anti-adenoviral activities of ethanol extract, fractions, and main phenolic compounds of pomegranate (Punica granatum L.) peel.

BackgroundAdenovirus causes a number of diseases in human, and can cause serious infection in severely immunosuppressed individuals. Despite the seriousness of adenovirus infection, there is no definitely approved anti-adenoviral therapy. Many studies have shown that compounds derived from medicinal plants have antiviral activity. Therefore, this study evaluated in vitro anti-adenoviral activity of ethanol extract, fractions, and main phenolic compounds of pomegranate peel.MethodsThe ethanol extract of pomegranate peel was prepared with maceration method and fractionated by consecutive liquid/liquid partition. The cytotoxic and anti-adenovirus activities of the extract, fractions, and main phenolic compounds (ellagic acid, punicalagin and gallic acid) were evaluated on Hep-2 cell line using MTT assay. Inhibitory effect on adsorption and post-adsorption phases of the virus replication cycle was also evaluated.ResultsPomegranate peel extract had a desirable effect against adenovirus with IC50 of 5.77 µg/mL and selectivity index of 49.9. Among the fractions and compounds, the n-butanol fraction and gallic acid had the highest anti-adenoviral activity with IC50 of 2.16 µg/mL and 4.67 µM and selectivity indices of 122.5 and 10.5, respectively. The crude extract, n-butanol fraction and gallic acid inhibited the virus replication in post-adsorption phase (p < 0.01).ConclusionPomegranate peel extract, especially its n-butanol fraction, could serve as a new promising anti-adenovirus agent due to high inhibitory effect against adenovirus replication. The effect of the n-butanol fraction may be related to the synergistic effect or other compounds of this fraction. Further understanding of the bioassay guided isolation of natural compounds of this fraction seems essential.

Acute and Subacute Toxicity Assessment of Oxyclozanide in Wistar Rats.

Oxyclozanide is an effective anthelmintic and has shown good properties in other ways including anti-adenovirus, anti-biofilm, antifungal, and antibacterial activity. This study aimed to investigate the acute and subacute 28-days repeated dose oral toxicity of an oxyclozanide suspension in Wistar rats. A high oral lethal dose (LD50) of 3,707 mg/kg was observed in the acute toxicity test. During the 28-days time period, no obvious adverse effects or death were detected. Histopathological changes were observed in the heart, liver, and kidney of animals treated with high dose of oxyclozanide. Based on the hematological parameters, there were no statistical differences between the oxyclozanide-treated group and the control group. For biochemistry assays, ALP, AST, GLU, TBIL, GLO, TG, BUN, UA, LDH, and CK were statistically changed in the treatment groups. These data suggested that the LD50 of oxyclozanide was ~3,707 mg/kg body weight (BW), and the lowest observed adverse effect level (LOAEL) of oxyclozanide was at a dose of 74 mg/kg in rats.

Antiviral Activity of Exopolysaccharides Produced by Lactic Acid Bacteria of the Genera Pediococcus, Leuconostoc and Lactobacillus against Human Adenovirus Type 5

Background and objectives: The use of antagonistic probiotic microorganisms and their byproducts represents a promising approach for the treatment of viral diseases. In the current work, the effect of exopolysaccharides (EPSs) produced by lactic acid bacteria from different genera on the structural and functional characteristics of cells and the development of adenoviral infection in vitro was studied. Materials and Methods: Cytotoxicity of six EPSs of lactic acid bacteria of the genera Lactobacillus, Leuconostoc and Pediococcus was determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The influence of the EPSs on the infectivity of human adenovirus type 5 (HAdV-5) and on the cell cycle under a condition of adenovirus infection was studied using plaque reduction assay and flow cytometric analysis, respectively. Results: It was shown that exopolysaccharides were non-toxic to Madin-Darby bovine kidney cells (MDBK) as they reduced their viability by 3–17%. A change in the distribution of the cell cycle phases in the non-infected cell population treated with EPSs was observed. The analysis demonstrated an increase in the number of cells in the S phase by 47% when using EPSs 15a and a decrease in the number of cells in the G1 phase by 20–27% when treated with the EPSs 15a, 33a, and 19s. The use of EPSs did not led to the normalization of the life cycle of HAdV-5 infected cells to the level of non-infected cells. The EPSs showed low virucidal activity and reduced the HAdV-5 infectivity to 85%. Among the studied exopolysaccharides, anti-adenovirus activity was found for EPS 26a that is produced by Lactobacillus spp. strain. The treatment of cells with the EPS following virus adsorption completely (100%) suppressed the formation and release of HAdV-5 infectious. Conclusions: EPS 26a possessed distinct anti-HAdV-5 activity and the obtained data demonstrate the potential of using exopolysaccharides as anti-adenoviral agents.

Repositioning salicylanilide anthelmintic drugs to treat adenovirus infections

The repositioning of drugs already approved by regulatory agencies for other indications is an emerging alternative for the development of new antimicrobial therapies. The repositioning process involves lower risks and costs than the de novo development of novel antimicrobial drugs. Currently, infections by adenovirus show a steady increment with a high clinical impact in immunosuppressed and immunocompetent patients. The lack of a safe and efficacious drug to treat these infections supports the search for new antiviral drugs. Here we evaluated the anti-adenovirus activity of niclosanide, oxyclozanide, and rafoxanide, three salicylanilide anthelmintic drugs. Also, we carried out the cytotoxicity evaluation and partial characterization of the mechanism of action of these drugs. The salicylanilide anthelmintic drugs showed significant anti-adenovirus activity at low micromolar concentrations with little cytotoxicity. Moreover, our mechanistic assays suggest differences in the way the drugs exert anti-adenovirus activity. Niclosamide and rafoxanide target transport of the HAdV particle from the endosome to the nuclear envelope, whilst oxyclozanide specifically targets adenovirus immediately early gene E1A transcription. Data suggests that the studied salicylanilide anthelmintic drugs could be suitable for further clinical evaluation for the development of new antiviral drugs to treat infections by adenovirus in immunosuppressed patients and in immunocompetent individuals with community-acquired pneumonia.

Anti-adenovirus activity, antioxidant potential, and phenolic content of dried flower buds of Syzygium aromaticum extract in HEp2 cell line

The aim of this study is to evaluate in vitro anti-adenovirus property, antioxidant potential, and total phenolic content of dried flowers buds of Syzygium aromaticum crude extract. The crud extract was prepared and its anti-adenovirus activity was investigated on HEp2 cell line using MTT (3-[4,5-dimethylthiazol–2-yl]-2,5-diphenyltetrazolium bromide) assay. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, Folin-Ciocalteu method and aluminum chloride colorimetric method was used to determine antioxidant activity, total phenol content, flavonoids and flavonols content of the extract, respectively. Based on results, the 50% cytotoxicity concentration (CC50) and the 50% inhibitory concentration (IC50) of the extract were 97.66±11.4 and 4.73±1.6 μg/ml, respectively, with the selectivity index (SI) of 20.64. The crud extract inhibited adenovirus replication in post-adsorption step (p<0.05). The extract showed remarkable scavenging activity with IC50 values of 10.05±1.93 μg/ml. Total phenolic, flavonoid and flavonol content of the crude extract was 255.8±3.95 mg GAE/g, 63.9±2.35 mg RUT/g and 62±2.35 mg RUT/g, respectively. The results of the present study indicated that S. aromaticum crude extract exhibited anti-adenovirus activity with inhibitory effect on adenovirus replication

Anti-adenovirus activity, antioxidant potential, and phenolic content of black tea (Camellia sinensis Kuntze) extract.

BackgroundAdenovirus (ADV) causes a number of diseases in human, and to date, no specific antiviral therapy is approved against this virus. Thus, searching for effective anti-ADV agents seems to be an urgent requirement. Many studies have shown that components derived from medicinal plants have antiviral activity. Therefore, the present study was aimed to evaluate in vitro anti-ADV activity and also antioxidant potential and total phenolic compounds of black tea (Camellia sinensis) crude extract. MethodsIn this study, the hydroalchoholic extract of black tea was prepared and its anti-ADV activity was evaluated on HEp2 cell line using MTT [3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide] assay. The 50 % inhibitory concentration (IC50) and 50 % cytotoxicity concentration (CC50) of the extract were determined using regression analysis. Its inhibitory effect on adsorption and/or post-adsorption stages of the virus replication cycle was evaluated. To determine antioxidant activity, total phenol content, and flavonoids content of the extract, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, Folin-Ciocalteu method, and aluminum chloride colorimetric method were used, respectively. ResultsThe CC50 and the IC50 of the extract were 165.95±12.7 and 6.62±1.4 µg/mL, respectively, with the selectivity index (SI) of 25.06. This extract inhibited ADV replication in post-adsorption stage. The IC50 of DPPH radical was 8±1.41 μg/mL, compared with butylated hydroxytoluene, with IC50 of 25.41±1.89 μg/mL. The total phenol and flavonoid contents of the extract were 341.8±4.41 mg gallic acid equivalent per gram and 21.1±2.11 mg/g, respectively. ConclusionsHaving SI value of 25.06 with inhibitory effect on ADV replication, particularly during the post-adsorption period, black tea extract could be considered as a potential anti-ADV agent. The antiviral activity of this extract could be attributed to its phenolic compounds.

An unusual indole alkaloid with anti-adenovirus and anti-HSV activities from Alstonia scholaris

A novel alkaloid, 17-nor-excelsinidine (1), possessing an unusual 1-azoniatricyclo [4.3.3.0] undecane moiety was isolated from the twigs and leaves of Alstonia scholaris alongside its biogenetically related strictamine (2). The structure and absolute stereochemistry of compound 1 were rigorously determined by a combination of NMR spectroscopy and X-ray crystallography. The 17-nor-excelsinidine (1) and strictamine (2) showed significant inhibitory activity against herpes simplex virus (HSV) and adenovirus (ADV).

Crystal structure of adenovirus E3-19K bound to HLA-A2 reveals mechanism for immunomodulation.

E3-19K binds to and retains MHC class I molecules in the endoplasmic reticulum, suppressing anti-Adenovirus (Ad) activities of T-cells. We determined the structure of the Ad serotype 2 (Ad2, species C) E3-19K–HLA-A2 complex to 1.95 Å resolution. Ad2 E3-19K binds to the N-terminus of the HLA-A2 groove, contacting the α1-, α2-, and α3-domains and β2m. Ad2 E3-19K has a unique structure comprised of a large N-terminal domain, formed by two partially overlapping β-sheets arranged in a V-shape, a C-terminal α-helix and tail. The structure reveals determinants in E3-19K and HLA-A2 that are important for complex formation; conservation of some of these determinants in E3-19K proteins of different species and MHC I of different loci suggests a universal binding mode for all E3-19K proteins. Our structure is important for understanding the immunomodulatory function of E3-19K.

Evaluation of anti-adenovirus activity of some plants from Lamiaceae family grown in Iran in cell culture

The family Lamiaceae included some plants such as thyme species which have a lot of medical properties even in the Iranian traditional medicine. Some of these properties have not been approved by this original article. The aim of this study was to evaluate the anti-adenovirus effect of the three plants from Lamiaceae family ( Thymus daenensis, Thymus vulgaris, Zataria multiflora ) that was grown in Iran. The aqueous extracts of the plants were prepared and the essential oil of T. vulgaris was purchased. Cytotoxicity effects of the tested compounds were determined. The anti-adenovirus effects of maximum non-cytotoxic concentration of tested compounds were evaluated in cell culture with 100 TCID50 of adenovirus type 5 by three methods: Simultaneous, pre-treatment and post-treatment. For antiviral effect, only those concentrations were accepted that completely inhibit cytopathic effect of virus in cell culture. In simultaneous and post-treatment methods, minimum concentration that showed antiadenovirus activity was 12.5, 12.5, 25 and 50 μg/ml for T. daenensis, T. vulgaris , and Z. multiflora aqueous extracts and thyme essential oil, respectively. None of the tested compounds had shown antiadenovirus effect in pre-treatment method. These results have suggested the potential use of these compounds for the treatment of the adenovirus infections. Keywords : Adenovirus, antiviral effect, essential oil, extract, Lamiaceae family, Thymus daenensis, Thymus vulgaris, Zataria multiflora.

Anti-adenovirus Activities of Shikonin, a Component of Chinese Herbal Medicine in Vitro

Radix Lithosperm eyrthrorhizon is a common prescription compound in traditional Chinese medicine. Shikonin is a major component of Radix Lithospermi and has various biological activities. We have investigated the inhibitory effect of shikonin on the growth of adenovirus type 3 (AdV3) in vitro. The antiviral function of shikonin against AdV3 and its virus inhibition ratio were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method (MTT). The expression of hexon protein in AdV3 was determined by immunofluorescence assay using laser scanning confocal microscopy (LSCM) and Western blot analysis. In addition, the rate of apoptosis in cells infected by AdV3 was determined by flow cytometry. Shikonin (0.0156-1 µM) inhibited growth of AdV3 in a concentration-dependent manner with a virus inhibition rate of 23.8-69.1%. Expression of hexon protein in AdV3 was higher in the virus control group than in the shikonin-treated groups as determined by immunofluorescence assay and Western blotting (p<0.05). The rate of shikonin-treated HeLa cell apoptosis had a statistically significant decrease with increasing concentration of drug (p<0.05). Our data demonstrate that shikonin possesses anti-AdV3 capabilities and that the potential antiviral mechanism might involve inhibiting the degree of apoptosis and hexon protein expression of AdV.

Anti-Adenovirus Activity of Epiandrosterone and Dehydroepiandrosterone Derivatives

Background: Dehydroepiandrosterone (DHEA) exhibits a wide range of biological functions including antiviral activity. In this work, we present in vitro anti-adenovirus (AdV) activity of seven DHEA and twelve epiandrosterone (EA) analogues. Methods: The cytotoxic effect of the compounds was determined by the MTT assay and the antiviral activity by a virus yield inhibition assay. The mode of antiviral activity was examined using time-of-addition experiments, adsorption and internalization assays and Western blot analysis. Results: EA, DHEA, and two synthetic derivatives inhibit virus replication with selectivity indices ranging between 42 and 83. Virus adsorption and internalization are not the target of the inhibitory action; meanwhile, AdV protein synthesis was diminished in the presence of DHEA. Conclusions: DHEA and some synthetic derivatives present antiviral activity similar to cidofovir, which was used as reference drug. These steroidal compounds adversely affect virus protein synthesis and viral mature particle formation.

The In Vitro and In Vivo Evaluation of ddC as a Topical Antiviral for Ocular Adenovirus Infections

To evaluate the antiviral activity of 2', 3'-dideoxycytidine (ddC) in vitro against a panel of ocular adenovirus serotypes and in vivo in the ocular Ad5/NZW rabbit replication model. In vitro, the 50% inhibitory concentrations (IC(50)) of ddC and cidofovir were determined using standard plaque-reduction assays. In vivo, 40 rabbits were topically inoculated in both eyes with Ad5 after corneal scarification. On day 1, the rabbits were equally divided into four topical treatment groups: 3% ddC; 2% ddC; 0.5% cidofovir; and saline. ddC and saline eyes were treated four times daily for 7 days, and cidofovir-treated eyes were treated twice daily for 7 days. Eyes were cultured for virus a multiple times over 2 weeks. The in vitro IC(50) for ddC ranged from 0.18 to 1.85 microg/mL, whereas those for cidofovir ranged from 0.018 to 5.47 microg/mL. ddC was more potent than cidofovir for seven of nine serotypes. In vivo, 3% ddC, 2% ddC, and 0.5% cidofovir significantly reduced the number of Ad5-positive cultures per total (days 1-14), mean Ad5 ocular titer (days 1-5), and duration of shedding (among other outcome measures) compared with the saline control. The 3% and 2% ddC treatments were significantly more efficacious than the 0.5% cidofovir treatment in the parameters listed above. ddC demonstrated potent antiadenovirus activity in vitro and in vivo. Systemic safety studies after topical ocular administration are needed to evaluate ddC as a topical antiviral treatment for adenoviral ocular infections in the target population.

Efficacy of topical cobalt chelate CTC-96 against adenovirus in a cell culture model and against adenovirus keratoconjunctivitis in a rabbit model.

BackgroundAdenovirus (Ad), associated with significant morbidity, has no topical treatment. A leading CTC compound (CTC-96), a CoIII chelate, was found to have potent in vitro and in vivo antiviral efficacy against herpes viruses. In this study CTC-96 is being tested for possible anti-Adenovirus activity.MethodsThe biological anti-adenovirus activity of CTC-96 in concentrations from 5 to 250 ug/ml, was evaluated initially by viral inactivation (viral exposure to CTC-96 followed by dilution and inoculation of cells), virucidal (viral exposure to CTC-96 and inoculation of cells without dilution) and antiviral (effect of CTC-96 on previously adsorbed virus) plaque assays on HeLa (human cervical carcinoma), A549 (human lung carcinoma) and SIRC (rabbit corneal) cells. After verifying the antiviral activity, New Zealand White rabbits were infected with Ad-5 into: 1) the anterior cul-de-sac scarifying the conjunctiva (Group "C+"); 2) the anterior cul-de-sac scarifying the conjunctiva and cornea (Group "CC+"); 3) the stroma (Group "CI+"). Controls were sham-infected ("C-", "CC-", "CI-"). Other rabbits, after "CC", were treated for 21 days with: 1) placebo, 9x/day ("-"); 2) CTC-96, 50 ug/ml, 9x/day ("50/9"); CTC-96, 50 ug/ml, 6x/day ("50/6"); CTC-96, 25 ug/ml, 6x/day ("25/6"). All animals were monitored via examination and plaque assays.ResultsIn vitro viral inactivation, virucidal and antiviral assays all demonstrated CTC-96 to be effective against Adenvirus type 5 (ad-5). The in vivo model of Ad keratoconjunctivitis most similar to human disease and producing highest viral yield was "CC". All eyes (6/6) developed acute conjunctivitis. "CI" yielded more stromal involvement (1/6) and iritis (5/6), but lower clinical scores (area × severity). Infection via "C" was inconsistent (4/6). Fifty (50) ug/ml was effective against Ad-5 at 6x, 9x dosings while 25 ug/ml (6x) was only marginally effective.ConclusionCTC-96 demonstrated virucidal activity against Ad5 in tissue culture with HeLa, A549 and SIRC cell lines.Animal Model Development: 1) "CC" produced conjunctival infection with occasional keratitis similar to human disease; "CI" yielded primarily stromal involvement; 2) "C" consistently produced neither conjunctivitis nor keratitis.CTC Testing: 1) Conjunctivitis in all eyes; 2) Resolution fastest in "50/9" ("50/9". "50/6" > "25/6" > "-"); 3) Efficacy in "50/6" was not statistically different than "50/9"; 4) Conjunctival severity was lower in treatment groups then controls; 5) Little corneal or intra-ocular changes were noted.

In Vitro Antiviral Activity of Marine Sponges Collected Off Brazilian Coast

This paper describes the in vitro antiviral evaluation of 27 different marine sponges (Porifera) collected off Brazilian coastline in the search for novel drug leads. With these sponges aqueous and organic extracts were prepared and tested for anti-herpetic (HSV-1, KOS strain), anti-adenovirus (human AdV serotype 5) and anti-rotavirus (simian RV SA11) activities. The evaluation of the cytotoxicity and potential antiviral activity of these extracts were performed by using MTT assay. Results were expressed as 50% cytotoxicity (CC50) and 50% effective (EC50) concentrations, respectively, in order to calculate the selectivity indices (SI=CC50/EC50) of each extract. From the 40 sponge extracts tested, 17 extracts showed antiviral action in different degrees. The results concerning the antiviral activity were obtained by using three different strategies: (1) simultaneous assay, when sponge extracts were added to the cells at the same time of the viruses; (2) pre treatment assay, when sponge extracts were added to the cells 15 h prior to the viruses infection; and (3) post treatment assay, when the viruses were added to the cells and remained during 2 h prior to the addition of sponge extracts. The antiviral assays with HSV-1/KOS and AdV-5 showed more promising results when the pre treatment test was employed. In relation to the RV-SA11 virus, only the simultaneous assay showed antiviral activity. The extracts presenting the most promising results were the aqueous extracts of Cliona sp., Agelas sp.2, Tethya sp., Axinella aff corrugata, Polymastia janeirensis and Protosuberites sp., and these extracts deserve special attention in further studies.

Antiadenovirus Activities of Several Classes of Nucleoside and Nucleotide Analogues

The absence of any formally licensed antiadenovirus drugs and the increasing incidence of life-threatening adenovirus infections in immunosuppressed patients warrant the development of effective antiadenovirus compounds. A detailed study was performed on the antiadenovirus activities of several classes of nucleoside and nucleotide analogues in human embryonic lung fibroblast cells. The antiadenovirus activities were evaluated by three methods, viz., evaluating the adenoviral cytopathic effect, monitoring cell viability by a colorimetric assay, and real-time PCR quantitation of viral DNA as a direct parameter for virus replication. The most active and selective compounds were the acyclic nucleoside phosphonate analogues cidofovir, its adenine analogue (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(S)-HPMPA], and the new derivative (S)-2,4-diamino-6-[3-hydroxy-2-(phosphonomethoxy)propoxy]pyrimidine [(S)-HPMPO-DAPy]; the N7-substituted acyclic derivative 2-amino-7-(1,3-dihydroxy-2-propoxymethyl)purine (S-2242); and the 2',3'-dideoxynucleoside analogues zalcitabine and alovudine. No antiadenovirus activity was observed for the antiviral drugs ribavirin, foscarnet, acyclovir, penciclovir, and brivudin, while ganciclovir displayed modest activity. However, in human osteosarcoma cells transfected with herpes simplex virus thymidine kinase, ganciclovir demonstrated highly potent antiadenovirus activity, suggesting that the efficacy of ganciclovir against adenovirus is limited by inefficient phosphorylation in adenovirus-infected cells, rather than by insufficient inhibition at the viral DNA polymerase level. Collectively, our antiviral data show that the adenovirus DNA polymerase exhibits sensitivity to a relatively broad spectrum of inhibitors and should be studied further as an antiviral target in antiadenovirus drug development programs.