acyclovir and 5-vinyl-1-arabinofuranosyluracil

The sensitivity of different herpes simplex virus type 2 (HSV-2) strains to inhibition by 5-vinyl-1-beta-D-arabinofuranosyluracil (VaraU) was evaluated in comparison to 9-(2-hydroxyethoxymethyl)guanine (ACV; acyclovir) and trisodiumphosphonoformate (Na3PFA; foscarnet), using a plaque inhibition assay in primary rabbit testes (PRT) cells as well as in human embryonic lung fibroblast (HELF) cell cultures. The order of decreasing activity found was ACV much greater than VaraU greater than Na3PFA in PRT cells and ACV greater than VaraU much greater than Na3PFA in HELF cells, with 50% inhibition doses (ID50) of 1.8, 8.8, and greater than 110 microM for the three drugs in HELF cells, respectively. After 72hr of drug treatment, inhibition of HELF cell proliferation by VaraU (ID50, greater than 1000 microM) was less than that by ACV and Na3PFA, resulting in high selectivity indexes of greater than 100 against HSV-2 for VaraU and ACV. Their in vivo efficacy was assessed in a mouse encephalitis model. Using a treatment schedule of three daily intraperitoneal (ip) doses over a period of 5 days, only the survival times of mice were considerably prolonged by VaraU (150 or 300 mg/kg per day; P less than 0.05 or P less than 0.001, respectively). In contrast, ACV treatment (150 mg/kg per day) led to a nearly complete prevention of encephalitis and death (P less than 0.001). Similar therapy results with VaraU application through the drinking water were obtained using only one-sixth of the high ip dose (approximately 50 mg/kg per day) but over a prolonged period of treatment. Under similar conditions no therapeutic effect of oral Na3PFA was observed.

Topics: Acyclovir; Animals; Antiviral Agents; Arabinofuranosyluracil; Cells, Cultured; Encephalitis; Female; Foscarnet; Herpes Simplex; Mice; Organophosphorus Compounds; Phosphonoacetic Acid; Simplexvirus; Uridine; Virus Replication

The effect of (E)-5-(2-bromovinyl)- and 5-vinyl-1-beta-D-arabinofuranosyluracil (BrVaraU, VaraU) in comparison to 9-(2-hydroxyethoxymethyl)guanine (ACV) on the proliferation of human lymphoblastoid P3HR-1 cells in culture and on the expression of Epstein-Barr virus capsid antigen (VCA) in the same cells was evaluated. After 7 days of cell growth, at 100 mumol/l the total number of new generations in drug-treated cultures was similar or 5 and 10% below that in drug-free control cultures, for VaraU, ACV, and BrVaraU, respectively. During the same time the percentage of VCA-expressing cells decreased from 6.3% in drug-free cultures to 1.3, 1.5, and 2.0% in cultures treated with VaraU, ACV and BrVaraU, respectively. In VaraU-treated cultures a further decrease in the percentage of VCA-positive cells down to 0.5% was revealed 7 days after drug removal. VaraU was also effective in reducing the proportion of VCA-expressing cells at 10 and 1 mumol/l. At 14 days after drug removal, the inhibitory effect of ACV was nearly reversed, whereas BrVaraU showed a prolonged VCA- suppressing effect.

Topics: Acyclovir; Antigens, Viral; Antiviral Agents; Arabinofuranosyluracil; Capsid Proteins; Cell Line; Herpesvirus 4, Human; Humans; Uridine

Four nucleoside analogues--acyclovir [9-(2-hydroxyethoxymethyl)guanine], bromovinyldeoxyuridine [(E)-5-(2-bromovinyl)-2-deoxyuridine], vinylarauracil 5-vinyl-1-beta-D-arabinofuranosyluracil and bromovinylarauracil [(E)-5-(2-bromovinyl)-1-beta-D-arabinofuranosyluracil]--were compared in the therapy of acute keratitis induced in the rabbit cornea by inoculation of the KUPKA strain of herpes simplex virus type 1 (HSV-1). In comparison to placebo-treated animals, the drugs reduced the mean plaque counts in conjunctival swabs as follows: acyclovir to 0.16-1.73%, bromovinyldeoxyuridine to 0.02-0.25%, vinylarauracil to 0.55-5.96% and bromovinylarauracil to 0.12-3.39% of control values. Latency was established to a most limited extent in 1 or 2 out of 5 rabbits treated with vinylarauracil or bromovinylarauracil, respectively. One or 6 out of 84 or 98 explanted ganglion fragments (1.3 or 6%) were positive for HSV-1 as compared to 72 fragments out of 173 (43%) from placebo-treated rabbits. Acyclovir and bromovinyldeoxyuridine completely prevented latency.

Topics: Acute Disease; Acyclovir; Animals; Antiviral Agents; Arabinofuranosyluracil; Bromodeoxyuridine; Chemical Phenomena; Chemistry; Keratitis, Dendritic; Rabbits; Simplexvirus; 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