sorivudine and Herpes-Simplex

Antiviral treatment of herpesvirus infections is rapidly changing since the advent of new drugs with improved oral availability. The efficacy of valaciclovir, the prodrug of aciclovir, and famciclovir, the prodrug of penciclovir, in the treatment of herpes genitalis and acute herpes zoster has been well documented in large clinical trials. Both drugs are effective on zoster-associated pain. Brivudin and sorivudine which are the most active compounds against varicella-zoster virus (VZV) in cell culture have also been successful in the treatment of herpes zoster. Aciclovir is still the standard therapy of severe herpes simplex virus (HSV) and varicella virus infections. In patients treated with aciclovir, the mortality of herpes encephalitis has been reduced to about 25%. The development of resistance against aciclovir and the other nucleoside analogues has not been a problem to date in the treatment of immunocompetent individuals. However, in immunocompromised patients, aciclovir-resistant HSV strains often emerge. In such cases, intravenous foscarnet is the current treatment of choice.

Topics: 2-Aminopurine; Acyclovir; Administration, Oral; Antiviral Agents; Arabinofuranosyluracil; Bromodeoxyuridine; Chickenpox; Drug Resistance, Microbial; Encephalitis, Viral; Famciclovir; Herpes Genitalis; Herpes Labialis; Herpes Simplex; Herpes Zoster; Humans; Immunocompromised Host; Prodrugs; Simplexvirus; Valacyclovir; Valine

Topics: 2-Aminopurine; Acyclovir; Antiviral Agents; Arabinofuranosyluracil; Chickenpox; Drug Resistance, Microbial; Famciclovir; Herpes Simplex; Herpes Zoster; Humans; Valacyclovir; Valine

A recombinant of herpes simplex virus (HSV) was constructed in which the HSV thymidine kinase (TK) gene was deleted and the varicella-zoster virus (VZV) TK gene was introduced into the US5 region under the control of the human cytomegalovirus IE promoter. Infection with the recombinant (R18) led to the induction of TK although the kinetics of synthesis resembled those of a 'late' gene product. The recombinant was virulent in the zosteriform mouse model with the pattern of pathogenesis similar to that of wild-type HSV-1. The sensitivity of the recombinant to several nucleoside analogues was assessed and in most cases (BVaraU, ACV and GCV) it resembled VZV rather than HSV. The enhanced sensitivity of the recombinant to BVaraU compared with wild-type HSV resulted in a far greater response to treatment with BVaraU as assessed in the mouse model.

Topics: Acyclovir; Animals; Antiviral Agents; Arabinofuranosyluracil; Base Sequence; Cytomegalovirus; Drug Evaluation, Preclinical; Ganciclovir; Herpes Simplex; Herpesvirus 1, Human; Herpesvirus 3, Human; Humans; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Promoter Regions, Genetic; Thymidine Kinase; Transformation, Genetic; Virulence; Virus Latency

We compared the in vitro and in vivo antiviral effects against herpes simplex virus type 1 (HSV-1) and other biological properties of 1-beta-D-arabinofuranosyl-5-[(E)-2-chlorovinyl]uracil (CV-araU) and 1-beta-D-arabinofuranosyl-5-[(E)-2-bromovinyl]uracil (BV-araU, sorivudine). Both CV-araU and BV-araU exhibited antiviral activities against HSV-1 in the cell culture derived from mouse, though the activities were lower than those seen in human cells. For intraperitoneal and intracerebral infections in mice with HSV-1 strain WT-51, both compounds, administered twice daily, were effective in increase in the survival rate at doses of 15 mg/kg and 30 mg/kg, respectively. In pharmacokinetic analysis, both drugs were absorbed well in the rat gastrointestinal tract following oral administration. There was no difference between the metabolism of orally administered CV-araU and BV-araU in rats. High levels of the corresponding base were found in plasma after oral administration of CV-araU and BV-araU, but much lower base levels were seen after intravenous doses. Both drugs were resistant to degradation by rat liver enzymes.

Topics: 3T3 Cells; Animals; Antiviral Agents; Arabinofuranosyluracil; Bromine; Cell Line; Chlorine; Encephalitis, Viral; Herpes Simplex; Humans; Male; Mice; Rats

Effect of topical treatments with BV-araU was tested in cutaneous infections of shaved Balb/c mice with herpes simplex virus type 1. Evolution of zosteriform skin lesions associated with infection with a low virulent KOS(S) strain was almost completely suppressed by treatments with 5% BV-araU cream given 4 times daily for 5 days starting 1 day after inoculation. This effect was equivalent to that of Zovirax Cream including 5% acyclovir. One percent BV-araU cream was also effective in inhibiting progression of symptoms, while 0.2% cream was not effective. Five percent BV-araU cream significantly suppressed progression of skin lesion even if initiation of treatment was delayed to 2 days after infection. However, the efficacy was diminished by further delay in starting treatment. The effect of BV-araU cream was also evident during infection of immunosuppressed mice. Virus titers in the skin tissue encompassing the inoculation site of mice decreased the day after the first treatment. In the lower flank site, virus replication was almost completely suppressed by the treatment beginning 1 day postinfection. Topical application of BV-araU may be useful therapy for HSV-1 infections in humans, including immunocompromised patients.

Topics: Administration, Topical; Animals; Antiviral Agents; Arabinofuranosyluracil; Cyclophosphamide; Dose-Response Relationship, Drug; Herpes Simplex; Immune Tolerance; Immunocompetence; Immunocompromised Host; Male; Mice; Mice, Inbred BALB C; Simplexvirus; Skin Diseases, Viral; Time Factors

The effect of oral BV-araU was tested in cutaneous model infections of shaved Balb/c mice with herpes simplex virus type 1 (HSV-1). Progression of cutaneous symptoms associated with cutaneous infection with HSV-1 F strain was inhibited by BV-araU at doses of 20 and 50 mg/kg twice daily, beginning one day post-infection, resulting in significant increase in the survival rate. Onset of disease was suppressed in most animals receiving 100 mg of BV-araU per kg. BV-araU (20 mg/kg or more) also significantly increased the survival rate of mice infected with HSV-1 WT-51 strain. The efficacy of BV-araU was not affected by gender or age (6-9 weeks) of the mice. BV-araU was effective even when the treatment was started 2.5 days post-infection. The efficacy of BV-araU against F strain infection was comparable to that of acyclovir, but acyclovir showed therapeutic effects at lower doses compared with BV-araU against WT-51 strain infection. Against infection of cyclophosphamide-treated immunosuppressed mice with HSV-1 KOS(S) strain, BV-araU decreased the morbidity rate and severity of symptoms at doses of 200 and 100 mg/kg, respectively, and all mice given 50 mg of BV-araU or more per kg survived, suggesting oral efficacy can be achieved against HSV-1 infections in immunosuppressed individuals.

Topics: Acyclovir; Administration, Oral; Animals; Antiviral Agents; Arabinofuranosyluracil; Disease Models, Animal; Drug Administration Schedule; Drug Evaluation, Preclinical; Female; Herpes Simplex; Immune Tolerance; Male; Mice; Mice, Inbred BALB C

Topics: Animals; Antiviral Agents; Arabinofuranosyluracil; DNA, Viral; Herpes Simplex; Herpesviridae Infections; Herpesvirus 3, Human; Immunosuppression Therapy; Mice; Mice, Inbred BALB C; Phosphorylation; Simplexvirus; Thymidine Kinase

1-beta-D-Arabinofuranosyl-E-5-(2-bromovinyl)uracil (BV-araU) reduced the mortality rates of (i) 7-week-old, cyclophosphamide-treated, immunosuppressed mice (CYP mice) intraperitoneally infected with a moderately virulent strain of herpes simplex virus type 1 and (ii) 4-week-old CYP mice infected with a less virulent strain at doses of 20 and 50 mg/kg of body weight twice daily and 5 mg/kg, respectively. The degree of efficacy of BV-araU was equivalent to that of acyclovir in 4-week-old CYP mice infected with the less virulent strain. BV-araU (20 mg/kg) suppressed viral growth in various organs of CYP mice.

Topics: Acyclovir; Animals; Antiviral Agents; Arabinofuranosyluracil; Cyclophosphamide; Herpes Simplex; Immunosuppression Therapy; Male; Mice; Mice, Inbred ICR; Simplexvirus; Virus Replication

In vivo antiherpesvirus effects of 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil (brovavir) were tested in two mouse model infections with herpes simplex virus type 1 (HSV-1) strains which showed different degrees of virulence in mice. Successful efficacies of oral and intraperitoneal (i.p.) treatments with brovavir were demonstrated in both intracerebral and i.p. infections with the HSV-1 WT-51 strain of moderate virulence. However, only weak or modest effects of brovavir were observed against the two model infections with a highly virulent strain, HSV-1 VR-3. Brovavir was not effective in reducing mortality of mice infected i.p. with HSV-1 KOS, which exhibited the highest virulence in mice among HSV-1 strains used when inoculated i.p. However, the drug had a significant effect on intracerebral infection with the KOS strain. Efficacies of oral treatment with brovavir were almost equal to those of i.p. administration in the model infections. After intracerebral inoculation, the VR-3 strain grew in brains of mice at a higher rate than the WT-51 strain. By oral treatment with 50 mg of brovavir per kg twice daily, replication of the WT-51 strain in the brains was markedly suppressed and was eliminated after transient elevation of the titer. Growth of the VR-3 strain in the brains was simply delayed by the drug treatment. Thus, the antiviral efficacy of brovavir in mice was affected by the degree of virulence of the challenge virus strain used for infection.

Topics: Animals; Antiviral Agents; Arabinofuranosyluracil; Brain; Encephalitis; Herpes Simplex; Male; Mice; Mice, Inbred ICR; Simplexvirus; Uridine; Virus Replication

1-beta-D-Arabinofuranosyl-E-5-(2-bromovinyl)uracil (brovavir) and acyclovir were compared for their antiviral effects against herpes simplex virus type 1 (HSV-1) model infections in mice. Both drugs were not toxic to mice when they were administered orally by the same schedule used for therapeutic experiments. Brovavir was less toxic than acyclovir when injected by the intraperitoneal (i.p.) route. Marked efficacies of brovavir by either oral or i.p. administration were demonstrated in both experimental encephalitis and i.p. infection with HSV-1 WT-51 strain. Treatment with brovavir at a dose of 15 or 25 mg/kg twice daily resulted in increasing both survival rate and mean survival time of the infected mice. On the contrary, acyclovir showed only marginal effect against the experimental encephalitis. Survival rates of mice treated with brovavir were higher than those treated with acyclovir at corresponding doses with statistical significance. The superiority of brovavir was also found in the intracerebral infection with strain VR-3, a highly virulent strain for mice. Brovavir, but not acyclovir, at a dose of 200 mg/kg reduced the mortality. Acyclovir, however, were significantly effective in reducing mortality of systemically infected mice by both oral and i.p. administrations. The effective dose of acyclovir was lower than that of brovavir against i.p. infection with strain WT-51. Differences in mortality of strain VR-3-infected mice were statistically significant between acyclovir- and brovavir-treated groups.

Topics: Acyclovir; Animals; Antiviral Agents; Arabinofuranosyluracil; Disease Models, Animal; Drug Administration Routes; Encephalitis; Herpes Simplex; Humans; Male; Mice; Simplexvirus; Survival Rate

The antiviral activities and metabolic fates of E-5-(2-bromovinyl)-2'-deoxyuridine (BrVdUrd) and 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil (BrVaraUra) were compared in a dThd kinase-deficient human fibroblast cell line, infected with parental strains of herpes simplex virus, and other strains expressing no viral dThd kinase activity. Metabolic experiments were performed at concentrations well above the ID50 for each compound because radiolabeled agents were not available. BrVaraUra and its nucleotides qualitatively displayed chromatographic and anabolic characteristics which closely paralleled those of BrVdUrd and its nucleotides. Monophosphorylation of both drugs was dependent upon the presence of viral dThd kinase activity except in the case of one dThd kinase-negative type 1 mutant (SC16R5C1) which retained BrVdUrd/BrVaraUra kinase activity. Intracellular uptake of either parent compound was absent during mock-infection and minimal in the cases of infection with mutants unable to phosphorylate the parent compound. Parental type 1 strains were able to induce diphosphorylation and triphosphorylation of both compounds to a similar, dose-dependent degree. Extracts of type 2-infected cells contained greater quantities of BrVdUrd and its monophosphate compared with BrVaraUra and its monophosphate, after identical drug exposure and infection conditions. As previously observed for BrVdUrd, diphosphorylated and triphosphorylated nucleotides of BrVaraUra were not detected after type 2 infection. BrVdUrd and BrVaraUra metabolic breakdown pathways differed, however, as evidenced by the formation of E-5-(2-bromovinyl)uracil (BrVUra). Unlike BrVdUrd, BrVaraUra formed no BrVUra in infected cells, suggesting that replacement of 2'-deoxyribose with arabinose makes the compound biologically more stable, presumably because of resistance to enzymatic breakdown by pyrimidine nucleoside phosphorylases. In this dThd kinase-negative cell line, BrVdUrd and BrVaraUra displayed qualitatively similar susceptibility profiles in that activities were type 1 selective and dThd kinase dependent. Antiviral activities against dThd kinase-positive type 1 strains were similar with both compounds. These data would suggest that BrVdUrd and BrVaraUra have identical type-specific dThd-dTMP kinase-dependent mechanisms of cellular uptake and phosphorylation, but that the latter is not subjected to phosphorolysis and resultant formation of an inactive metabolite. Furthermore, the absenc

Topics: Arabinofuranosyluracil; Bromodeoxyuridine; Cell Line; Chromatography, High Pressure Liquid; Fibroblasts; Herpes Simplex; Humans; Osteosarcoma; Uridine

The efficiency of (E)-5-(2-bromovinyl)- and 5-vinyl-1-beta-D-arabinofuranosyluracil (BrVaraU, VaraU) as inhibitors of three herpes simplex virus type 1 (HSV-1) strains was assessed in comparison to (E)-5-(2-bromovinyl)-2'-deoxyuridine (BrVUdR), 9-(2-hydroxyethoxymethyl)guanine (ACV), and trisodium phosphonoformate (Na3PFA) using a plaque assay in human embryonic lung fibroblast (HELF) cell cultures. The following order of decreasing activity was found: BrVaraU greater than VaraU greater than BrVU-dR greater than ACV much greater than Na3PFA. In HELF cell cultures, the selectivity indexes of VaraU and BrVaraU were 10 times higher than those of BrVUdR and ACV. Protection of mice from encephalitis and death due to intracerebral (i.c.) infection with a clinical HSV-1 isolate was nearly complete if mice were treated intraperitoneally (i.p.) with two daily doses of VaraU and BrVaraU (100 or 200 mg/kg per day) over a period of 5 or 10 days. The efficacy was similar to ACV, but, using a treatment schedule of three daily i.p. doses over 10 days, with equimolar amounts of the nucleoside analogs, VaraU and BrVaraU (140 and 180 mg/kg per day) were superior to ACV (130 mg/kg per day) (P less than 0.05).

Topics: Acyclovir; Animals; Arabinofuranosyluracil; Bromodeoxyuridine; Cells, Cultured; Encephalitis; Female; Foscarnet; Herpes Simplex; Humans; Mice; Phosphonoacetic Acid; Simplexvirus; Uridine; Viral Plaque Assay

BV-araU and related compounds such as CV-araU, IV-araU and BV-araUMP showed marked activity against herpes simplex virus type 1 (HSV-1) in human embryonic lung fibroblast cells. BV-araU, CV-araU and BV-araUMP were also effective in mice infected intracerebrally with HSV-1. Especially, when mice were infected with a low dose of virus, both intravenous and oral treatment with BV-araU proved capable of increasing the mean survival time and decreasing the final mortality of the infected mice. The in vivo anti-HSV-1 activity of BV-araU was comparable to that of BVDU. BV-araU exhibited little toxicity for mice.

Topics: Animals; Antiviral Agents; Arabinofuranosyluracil; Encephalitis; Herpes Simplex; Male; Mice; Simplexvirus; Uridine