valacyclovir and Disease-Models--Animal

Although the seroprevalence of Herpes simplex virus type 1 (HSV-1) currently amounts to ∼ 67% worldwide, the annual incidence of a severe disease progression, particularly herpes encephalitis, is approximately 2-4 cases per 1,000,000 infections. Nucleoside analogues, such as acyclovir (ACV), valacyclovir (VACV) or famciclovir, are still the therapeutic treatment of choice for HSV infections. However, nucleoside drugs have limited efficacy against severe HSV disease and for treatment of nucleoside-resistant viral strains, alternative therapies such as helicase-primase inhibitors (HPIs) which are highly potent by inhibiting viral replication are under development. In preclinical studies we analyzed the antiviral efficacy of drug candidates of a novel compound class of HPIs for the treatment of HSV to identify the most active eutomer structure in an intranasal infection mouse lethal challenge model. HSV-1 infected BALB/c mice treated with vehicle control developed fatal disease according to humane endpoints after 5-7 days. In contrast, the animals dosed orally once daily with the HPI compounds at 10 or 4 mg/kg/day showed a significantly increased survival (70% and 100% for 10 mg/kg/day; 90% and 100% for 4 mg/kg/day, respectively) compared to the vehicle treatment (0-10%), when therapy was initiated 6 h post HSV-1 inoculation. We observed a significantly improved outcome in clinical parameters and survival over 21 days in the group receiving novel HPI candidates using even the lowest dose of 4 mg/kg/day. With VACV treatment of 75 mg/kg daily survival was also significantly increased (80%-90% for 75 mg/kg/day) but to lesser extent. Initial IM-250 therapy at 10 mg/kg/day could be delayed up to 72 h resulting in significantly increased survival compared to the vehicle control. Furthermore, we detected significantly fewer viral genome copies in the lungs and brains of HPI treated animals compared to vehicle (440-fold reduction for 4 mg/kg/day IM-250 in the brain) or VACV controls by quantitative PCR. In conclusion the preclinical studies of the novel HPI compounds showed superior efficacy in comparison to the current standard HSV treatment represented by VACV with respect to the survival according humane endpoints, the clinical score and virus load in lungs and brains. Thus, candidates of this new drug class are promising antivirals of HSV infections and further translation into clinical trials is warranted.

Topics: Acyclovir; Animals; Antiviral Agents; Chlorocebus aethiops; Disease Models, Animal; DNA Helicases; DNA Primase; Female; Herpes Simplex; Herpesvirus 1, Human; Mice; Mice, Inbred BALB C; Survival Rate; Valacyclovir; Vero Cells; Viral Load

Despite the availability of more than 20 clinical antiepileptic drugs, approximately 30% of patients with epilepsy do not respond to antiepileptic drug treatment. Therefore, it is important to develop antiepileptic products that function via novel mechanisms. In the present study, we evaluated data from one of the largest global databases to identify drugs with antiepileptic effects, and subsequently attempted to understand the effect of the combination of antiepileptic drugs and valacyclovir in epileptic seizures using a kindling model. To induce kindling in mice, pentylenetetrazol at a dose of 40 mg/kg was administered once every 48 h. Valacyclovir was orally administered 30 min before antiepileptic drug injection in kindled mice, and behavioral seizures were monitored for 20 min following pentylenetetrazol administration. Additionally, c-Fos expression in the hippocampal dentate gyrus was measured in kindled mice. Valacyclovir showed inhibitory effects on pentylenetetrazol-induced kindled seizures. In addition, simultaneous use of levetiracetam and valacyclovir caused more potent inhibition of seizure activity, and neither valproic acid nor diazepam augmented the anti-seizure effect in kindled mice. Furthermore, kindled mice showed increased c-Fos levels in the dentate gyrus. The increase in c-Fos expression was significantly inhibited by the simultaneous use of levetiracetam and valacyclovir. The findings of the present study indicate that a combination of levetiracetam and valacyclovir had possible anticonvulsive effects on pentylenetetrazol-induced kindled epileptic seizures. These results suggest that valacyclovir may have an antiseizure effect in patients with epilepsy.

Topics: Animals; Anticonvulsants; Cefepime; Databases, Factual; Disease Models, Animal; Drug Repositioning; Drug Therapy, Combination; Hippocampus; Humans; Kindling, Neurologic; Levetiracetam; Male; Mice; Pentylenetetrazole; Proto-Oncogene Proteins c-fos; Seizures; Valacyclovir

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

Aciclovir (ACV), valaciclovir (VACV) and famciclovir (FCV) are used for systemic infections caused by herpes virus. In Japan, only topical ACV is permitted for use against herpetic keratitis. We investigated the effectiveness of topical ACV, oral VACV and oral FCV on mouse epithelial herpetic keratitis.. C57/BL76 mice were inoculated with HSV-1 McKrae strain in the cornea. Once infection was confirmed 4 days after inoculation, topical ACV, oral VACV and FCV were started and administered for 5 days. Control groups were given either topical or oral saline. On days 2, 4, 6 and 10 after medication started, tears, eyeballs, and trigeminal ganglia were examined using viral culture and real-time PCR.. Viral culture of tears detected no HSV in the topical ACV group on day 4 after administration start; with similar results for the oral VACV group on day 4; and the oral FCV group on day 6. Real-time PCR of the eyeballs showed significant decrease of HSV DNA copy number in the topical ACV group on days 4 and 6 compared to the topical saline group. Real-time PCR of the trigeminal ganglia showed significant decrease of HSV DNA copy number in the oral VACV group on days 4 and 6, and in the oral FCV group on day 6 compared to the oral saline group.. We suggest that 5-day administration of topical ACV, oral VACV and oral FCV are effective for mouse epithelial herpetic keratitis and sufficiently decrease HSV amounts in the ocular surface and eyeballs.

Topics: 2-Aminopurine; Acyclovir; Administration, Oral; Administration, Topical; Animals; Antiviral Agents; Disease Models, Animal; DNA Copy Number Variations; DNA, Viral; Epithelium, Corneal; Eye Infections, Viral; Famciclovir; Female; Herpesvirus 1, Human; Keratitis, Herpetic; Mice; Mice, Inbred C57BL; Real-Time Polymerase Chain Reaction; Tears; Trigeminal Nerve; Valacyclovir; Valine

Despite antiviral therapy, the mortality rate of herpes simplex virus encephalitis (HSE) remains high and many surviving patients harbor neurological sequelae. Although viral replication is responsible for substantial neurological damages, an exaggerated inflammatory response could also contribute to this process. Artesunate (ART) and rapamycin (RAPA) have shown some benefits in the treatment of herpes simplex virus infections. Herein, we evaluated the benefit of combining ART or RAPA with valacyclovir (VACV) in a murine model of HSE. Infected mice were treated with VACV (1mg/mL in drinking water) from day 3 post-infection (p.i.) combined or not with daily intraperitoneal administration of ART (30mg/kg) or RAPA (20mg/kg) from days 4 to 13 p.i. Viral load, infectious titers, cytokine and chemokine levels were measured in brain homogenates on days 5, 7 and 9. The survival rates of mice treated with VACV and ART or RAPA were higher than with VACV alone (71.9% versus 43.2% for ART and 66.7% versus 43.2% for RAPA; both P⩽0.05) but no significant difference was seen in the brain viral loads. Levels of IL-1β, IL-2 (both P⩽0.05), IL-6, IFN-γ (both P⩽0.01), CCL2 (P⩽0.01), CCL3 and CCL4 (both P⩽0.05) were reduced in mice treated with VACV combined with ART versus VACV alone. Levels of IL-6, IL-1β and IFN-γ slightly increased on day 7 in mice treated with VACV combined with RAPA compared to VACV alone and then decreased on day 9. Our results suggest that immunomodulatory compounds such as ART or RAPA could benefit antiviral therapy in HSE.

Topics: Acyclovir; Administration, Oral; Animals; Antiviral Agents; Artemisinins; Artesunate; Brain; Cytokines; Disease Models, Animal; Drug Therapy, Combination; Encephalitis, Herpes Simplex; Female; Immunologic Factors; Injections, Intraperitoneal; Mice, Inbred BALB C; Sirolimus; Survival Analysis; Treatment Outcome; Valacyclovir; Valine; Viral Load

To determine the efficacy of a new helicase-primase inhibitor, ASP2151, for treating herpetic keratitis.. Murine corneas were infected with herpes simplex virus type 1 (HSV-1). ASP2151 was administered orally or topically, and the severity of epithelial dendritic keratitis was determined. The effectiveness of ASP2151 was compared with that of acyclovir and valacyclovir. The reduction of the amount of HSV in tears, enucleated eyes and trigeminal ganglia was determined by real-time PCR or plaque assay.. Orally administered ASP2151 reduced the epithelial keratitis score significantly more than that of the vehicle-treated group (p<0.01). It also lowered the HSV-DNA levels in the tears significantly more than that by valacyclovir (p<0.01). ASP2151 ointment resulted in the same reduction of the keratitis score as acyclovir ointment, and lowered the HSV DNA in tears more than acyclovir ointment. Topical instillation of ASP2151 improved the herpetic dendritic keratitis score significantly and reduced the titre of HSV DNA in the tears in a dose-responsive way.. ASP2151 had significantly better anti-HSV activity against herpes simplex keratitis than valacyclovir and acyclovir after systemic or topical use. These findings indicate that ASP2151 should be considered as an alternative treatment for herpes simplex keratitis.

Topics: Acyclovir; Administration, Oral; Administration, Topical; Animals; Disease Models, Animal; DNA Helicases; DNA Primase; DNA, Viral; Herpesvirus 1, Human; Keratitis, Herpetic; Mice; Mice, Inbred BALB C; Oxadiazoles; Real-Time Polymerase Chain Reaction; Tears; Treatment Outcome; Valacyclovir; Valine; Viral Proteins

The study aimed to predict effective human jejunal permeability (P(eff)) using a biophysical model based on parametrized paracellular, aqueous boundary layer, and transcellular permeabilities, and the villus-fold surface area expansion factor (k(VF)). Published human jejunal data (119 P(eff), 53 compounds) were analyzed by a regression procedure incorporating a dual-pore size paracellular model. Transcellular permeability, scaled by k(VF), was equated to that of Caco-2 at pH 6.5. The biophysical model predicted human jejunal permeability data within the experimental uncertainty. This investigation revealed several surprising predictions: (i) many molecules permeate predominantly (but not exclusively) by the paracellular route, (ii) the aqueous boundary layer thickness in the intestinal perfusion experiments is larger than expected, (iii) the mucosal surface area in awake humans is apparently nearly entirely accessible to drug absorption, and (iv) the relative "leakiness" of the human jejunum is not so different from that observed in a number of published Caco-2 studies.

Topics: Animals; Disease Models, Animal; Dogs; Humans; Jejunal Diseases; Kidney Diseases; Models, Biological; Permeability; Porosity; Regression Analysis

To examine the efficacy of valaciclovir (VACV) oral formulation as an alternative to topical treatments in a case of herpetic keratitis.. The patient was a 61-year-old man who presented with dendritic keratitis in his left eye. After recognizing his difficulty in using eye ointment, we prescribed oral VACV 500 mg tablets twice daily for 7 days. We also describe our experiments with orally administered VACV in a mouse model of this disease. In this study, 143 Balb/c mice were inoculated with herpes simplex virus type 1 (HSV)-1 in each eye and treated with oral VACV 50 or 100 mg/kg twice daily, oral acyclovir (ACV) 50 mg/kg 5 times/d, 3% ACV eye ointment (ACV-O) 5 times/d, 3% ACV eye drops 5 times/d, or control for 5 days.. After 7 days, the patient's lesion was observed healed. Corrected left visual acuity was also improved, and HSV DNA was below detectable level. In the mouse study, slit-lamp examination on days 3, 4, 5, and 7 revealed that all 5 ACV and VACV treatment groups were significantly more effective in improving symptoms of herpetic epithelial keratitis versus control (P < 0.05). Moreover, VACV 100 mg/kg was superior to other treatments. Viral titers in mouse eyeball and trigeminal ganglia were lowest in the VACV 100 mg/kg group versus other treatment groups.. Our case example suggests that when frequent application, blurred vision, and foreign body sensation after ACV-O application cause difficulty for patients to follow treatment, oral VACV might be an effective and safe option for patients with herpetic keratitis.

Topics: Acyclovir; Administration, Oral; Animals; Antiviral Agents; Cornea; Disease Models, Animal; DNA, Viral; Gene Dosage; Herpesvirus 1, Human; Humans; Keratitis, Dendritic; Keratitis, Herpetic; Male; Mice; Mice, Inbred BALB C; Middle Aged; Polymerase Chain Reaction; Prodrugs; Valacyclovir; Valine

An adult mouse model for studies of latency and recurrence after vaginal HSV-2 infection is not available at present, largely because the infection kills most mice within 14 days. We describe here an antiviral therapy that rescues most vaginally infected mice from death. Vaginally infected mice were nearly all rescued by combined treatment with one dose of monoclonal anti-HSV glycoprotein D 3 days after infection plus valacyclovir in the drinking water on days 3, 4, 5, 7, 9, 11, 13, and 15 after infection. At 60 days after infection, PCR measurements revealed that most rescued mice had viral DNA in their lumbosacral dorsal root ganglia, lumbosacral spinal cords, and paracervical autonomic ganglia, consistent with the possibility that latent infections were established. At this time, immunolabeling revealed CD45+ lymphoid cells in these neural tissues in rescued mice but not in normal control mice. In vivo depletion of T lymphocytes with monoclonal antibodies caused a recurrence of herpes illness symptoms earlier and in a larger proportion of rescued mice than was observed in non-depleted rescued mice. Interestingly, many rescued mice (46/114) spontaneously developed a syndrome of typical herpes illness symptoms that began with ruffled fur on a mouse that previously had sleek fur and progressed to arched backs, feeble gait, hindlimb paralysis, and death or euthanasia, or in some cases to recovery to health. This high incidence of apparent spontaneous recurrence of HSV-2 infection in rescued mice suggests that it may be possible, with some refinement of the procedure, to obtain an effective adult mouse model for studies of therapeutic vaccination to inhibit or prevent HSV-2 recurrence after genital tract infection.

Topics: Acyclovir; Administration, Oral; Animals; Antibodies, Monoclonal; Antibodies, Viral; Antiviral Agents; Disease Models, Animal; Drug Therapy, Combination; Female; Herpes Genitalis; Herpesvirus 2, Human; Injections, Intraperitoneal; Mice; Mice, Inbred BALB C; Secondary Prevention; Valacyclovir; Valine; Viral Envelope Proteins; Virus Latency

A dipeptide prodrug of the antiviral nucleoside acyclovir (ACV), val-val-ACV (VVACV), was evaluated in vivo as a potential drug candidate for improving antiviral efficacy against herpetic epithelial and stromal keratitis.. The effect of 1% VVACV on epithelial keratitis induced by inoculation of HSV-1 strain McKrae (25 microL of 10(5) plaque-forming units [PFU]) in the scarified rabbit cornea and stromal keratitis induced by intrastromal injection of HSV-1 strain RE (10 microL of 10(5) PFU) was compared with that of 1% trifluorothymidine (TFT) and balanced salt solution as the vehicle control. Both eyes of 10 rabbits were used in each treatment group. Lesions were evaluated by slit lamp examinations over a 2-week period after infection. Aqueous humor samples and corneas were analyzed for drug concentrations at the end of each experiment. Cytotoxicity of VVACV in comparison with val-acyclovir (VACV), ACV, and TFT was evaluated in cellular proliferation assays.. The dipeptide prodrug VVACV demonstrated excellent activity against HSV-1 in the rabbit epithelial and stromal keratitis models: 1% VVACV was as effective as 1% TFT. The prodrug was also less cytotoxic than TFT, which is the only effective drug currently licensed and routinely used for topical treatment of ocular herpes infections in the United States.. The less cytotoxic and highly water-soluble prodrug VVACV, which showed excellent in vivo activity against HSV-1 in rabbit epithelial and stromal keratitis, is a promising drug candidate for treatment of ocular HSV infections.

Topics: Acyclovir; Animals; Antiviral Agents; Aqueous Humor; Biological Availability; Chlorocebus aethiops; Cornea; Corneal Stroma; Disease Models, Animal; Drug Evaluation, Preclinical; Epithelium, Corneal; Herpesvirus 1, Human; Keratitis, Herpetic; Prodrugs; Rabbits; Trifluridine; Valacyclovir; Valine

Mouse models of herpes simplex virus type 1 (HSV-1) infection provide significant insights into viral and host genes that regulate disease pathogenesis, but conventional methods to determine the full extent of viral spread and replication typically require the sacrifice of infected animals. To develop a noninvasive method for detecting HSV-1 in living mice, we used a strain KOS HSV-1 recombinant that expresses firefly (Photinus pyralis) and Renilla (Renilla reniformis) luciferase reporter proteins and monitored infection with a cooled charge-coupled device camera. Viral infection in mouse footpads, peritoneal cavity, brain, and eyes could be detected by bioluminescence imaging of firefly luciferase. The activity of Renilla luciferase could be imaged after direct administration of substrate to infected eyes but not following the systemic delivery of substrate. The magnitude of bioluminescence from firefly luciferase measured in vivo correlated directly with input titers of recombinant virus used for infection. Treatment of infected mice with valacyclovir, a potent inhibitor of HSV-1 replication, produced dose-dependent decreases in firefly luciferase activity that correlated with changes in viral titers. These data demonstrate that bioluminescence imaging can be used for noninvasive, real-time monitoring of HSV-1 infection and therapy in living mice.

Topics: Acyclovir; Animals; Antiviral Agents; Disease Models, Animal; Female; Genes, Reporter; Herpes Simplex; Herpesvirus 1, Human; Keratitis, Herpetic; Luciferases; Luminescent Measurements; Mice; Organ Specificity; Time Factors; Valacyclovir; Valine

Levels of bystander death occurring in herpes simplex virus type 1 (HSV-1)-infected mouse brain stems were studied, as well as the extent to which bystander death is influenced by guanosine nucleoside analogue treatment. Consecutive sections from brain stems of HSV-1-infected mice were stained alternately for (i) viral infection and (ii) cell death (TUNEL assay). Virus antigen was detectable in brain stems on day 3 of infection, while TUNEL staining was comparatively lower. An increase in the extent of TUNEL staining was observed on day 4 of infection. Despite this increase, however, the ratio of TUNEL-stained to infection marker-stained tissue still indicated that the amount of TUNEL staining remained lower than infection staining at this time point. On days 5 and 6 of infection, TUNEL staining continued to increase and the TUNEL/infection marker ratio switched on day 6 in favour of excess TUNEL staining, which was observed in and around the foci of infection, suggesting bystander death. The excess TUNEL staining on day 6 of infection was further increased on treatment with antivirals. The significance and implications of these results are discussed with respect to the nature and mechanism of action of the TUNEL assay, dynamics of primary HSV-1 infection, immunological influences and potential effects of antiviral treatment. The potential problems of the TUNEL assay are considered in the context of viral infection and the TUNEL assay, in combination with infection marker staining, may potentially provide a model system for quantitative analysis of true bystander death during HSV infection in vivo.

Topics: 2-Aminopurine; Acyclovir; Animals; Antiviral Agents; Apoptosis; Brain Stem; Disease Models, Animal; DNA Fragmentation; Famciclovir; Female; Ganciclovir; Guanine; Herpes Simplex; Herpesvirus 1, Human; Humans; In Situ Nick-End Labeling; Mice; Mice, Inbred BALB C; Valacyclovir; Valine

Topics: 2-Aminopurine; Acyclovir; Animals; Antiviral Agents; Disease Models, Animal; Famciclovir; Herpes Simplex; Herpesvirus 1, Human; Mice; Recurrence; Valacyclovir; Valine; Virus Latency

The animal model of necrotic hepatitis caused by HSV-1 infection in juvenile mice was used to compare the efficacies of the oral antiherpes agents famciclovir (FCV), valaciclovir (VACV) and brivudin (BVDU). The experimental infection allows the measurement of viral replication in the liver by macroscopic lesions and the evaluation of mortality from encephalitis. Mice intravenously inoculated with a highly virulent clinical HSV-1 isolate were orally treated by gavage over a period of 3 days starting on day 2 post infection. The reference drug acyclovir (ACV) was administered subcutaneously. Necrotic hepatitis was significantly (p < 0.01) reduced by treatment with FCV, VACV and ACV at a dose of 50 mg/kg per day divided into 3 doses. No significant effect was achieved with BVDU at 200 mg/kg per day. Treatment with FCV at 50 mg/kg per day, ACV at 100 mg/kg per day, and VACV at 200 mg/kg per day significantly (p < 0.001) decreased mortality in mice. BVDU treatment at 200 mg/kg per day did not reduce mortality but significantly prolonged (p < 0.05) the survival time.

Topics: 2-Aminopurine; Acyclovir; Animals; Antiviral Agents; Bromodeoxyuridine; Cell Line; Disease Models, Animal; Famciclovir; Hepatitis, Animal; Herpes Zoster; Herpesvirus 1, Human; Liver; Mice; Mice, Inbred BALB C; Valacyclovir; Valine; Viral Plaque Assay; Virus Replication

The ability of famciclovir and valaciclovir to affect the establishment and maintenance of latency in mice with a cutaneous herpes simplex type 1 (HSV-1) infection was examined. Mice were treated via drinking water starting at various times between days 1 and 5 and terminating on day 10 after inoculation. Clinical signs and viral replication in the target tissues were monitored. Three to four months later, trigeminal and dorsal root ganglia were explanted from groups of 16 mice and examined for latent virus by cocultivation. The two compounds differed in their effects on the acute neural infection, and ganglia explanted from famciclovir-treated mice were markedly reduced in their ability to reactivate virus, although neither drug affected latency if treatment was delayed for several months. The difference between the compounds is likely to reflect differences in the metabolism of their respective products, penciclovir and acyclovir, in infected neurons.

Topics: 2-Aminopurine; Acute Disease; Acyclovir; Animals; Antiviral Agents; Brain Stem; Disease Models, Animal; Ear, External; Famciclovir; Female; Ganglia, Spinal; Herpes Simplex; Herpesvirus 1, Human; Mice; Mice, Inbred BALB C; Prodrugs; Trigeminal Ganglion; Valacyclovir; Valine; Virus Activation; Virus Latency; Virus Replication