2-acetylpyridine-thiosemicarbazone and Herpes-Simplex

2-Acetylpyridine semicarbazone (APSC), 2-acetylpyridine thiosemicarbazone (APTSC) and 2-acetylpyridine-4-methyl-3-thiosemicarbazonoe (APMTSC) were evaluated against type-2 herpes simplex virus (HSV-2)-induced genitalis and encephalitis in mice and guinea pigs. The antiviral activity of these compounds was compared with that of acyclovir. With 1,3-butanediol as a topical treatment vehicle, 1% APSC and APTSC showed significant activity against the genital infection in mice, as evidenced by increased survivors and decreased severity of vaginal lesions. Reduced titers of virus recovered from the lesions were also observed with APTSC treatments. Eight different commercially available vehicles were compared to determine in which topically administered 1% APTSC would be most efficacious against the vaginal disease induced in mice. Significant results were observed with Squibb cream base, Eucerin base, and K-Y jelly; these effects were essentially equivalent to using 1,3-butanediol Unibase, Aquaphor, polyethylene glycol, polyvinyl alcohol and petrolatum were less effective as carrier vehicles. The herpesvirus genital infection in guinea pigs was treated with 1% APMTSC and APTSC comparing Squibb cream, Eucerin and K-Y jelly bases; while neither compound exerted striking effects against this infection in any vehicle, 1% APMTSC in Squibb cream was effective in increasing mean survival time and reducing lesion score and titers of recoverable virus. In this experiment, treatments with 1 and 5% acyclovir in polyethylene glycol base were effective in reducing titers of virus from the vaginal area. Orally administered APTSC (12.5, 25, 50 mg/kg/day given twice daily for 7 days) caused moderate prevention of death of mice infected intraperitoneally with HSV-2; subcutaneous injection of the compound was markedly effective with efficacy comparable to that of acyclovir at 120 mg/kg/day.

Topics: Administration, Intravaginal; Administration, Topical; Animals; Butylene Glycols; Female; Genital Diseases, Female; Guinea Pigs; Herpes Simplex; Mice; Pharmaceutical Vehicles; Semicarbazones; Simplexvirus; Thiosemicarbazones

A series of 111 thiosemicarbazones of 2-acetylpyridine, 2-acetylquinoline, 1-acetylisoquinoline, and related compounds were evaluated as inhibitors of herpes simplex virus in vitro and in a cutaneous herpes guinea pig model. All derivatives tested were potent inhibitors of virus replication with mean 50% inhibitory concentrations of 1.1 micrograms/ml for both type 1 and 2 herpes simplex virus. Inhibitory concentrations for cellular protein and DNA synthesis were considerably higher for many compounds resulting in in vitro therapeutic indices ranging from greater than 100 (highly selective) to less than 1 (negatively selective). All compounds were tested for dermal toxicity following topical administration of saturated solutions in 1,3-butanediol to the shaved, depilated skin of guinea pigs. Approximately 50% of the compounds produced slight to no dermal toxicity whereas the remaining compounds produced moderate to severe dermal toxicity. 28 compounds were evaluated in the cutaneous herpes guinea pig model against herpes simplex virus type 1. A number of N4-monosubstituted 2-acetylpyridine thiosemicarbazones produced highly significant reductions in days to healing and lesion score without producing untoward dermal toxicity. Structure-activity relationships revealed that a reduction of the azomethine bond in the molecule (i.e., conversion of a thiosemicarbazone to a thiosemicarbazide) greatly diminished dermal toxicity apparently without producing a proportional decrease in antiviral activity.

Topics: Animals; Antiviral Agents; Cell Line; Dose-Response Relationship, Drug; Female; Guinea Pigs; Herpes Simplex; Isoquinolines; Microbial Sensitivity Tests; Pyridines; Quinolines; Simplexvirus; Skin; Structure-Activity Relationship; Thiosemicarbazones