ANTIVIRAL ACTIVITY OF VIRACEA((R)) AGAINST ACYCLOVIR SUSCEPTIBLE AND ACYCLOVIR-RESISTANT STRAINS OF HERPES-SIMPLEX VIRUS

Viracea, a topical microbicide, is a blend of benzalkonium chloride an d phytochemicals derived from Echinacea purpurea and is a proprietary formula from Destiny BioMediX Corp. Viracea was tested against 40 stra ins of herpes simplex virus (HSV): 15 strains (five HSV-1 and ten HSV- 2) were resistant to acyclovir (ACV-R) and 25 strains (13 HSV-I and 12 HSV-2) were susceptible to ACV (ACV-S). The median ED,, of Viracea fo r the five ACV-R strains of HSV-1 was a 1:100 dilution of the drug wit h a range of 1:50-1:400. The median ED,, of Viracea for the ten ACV-R strains of HSV-2 was 1:200 with a range of 1:50-1:3200. For the ACV-S strains of HSV-I and HSV-2, the median ED,, of Viracea was 1:100 and 1 :200, respectively. The cytotoxicity of Viracea was evaluated in a sta ndard neutral red dye uptake assay in human foreskin fibroblasts. The cytotoxicity of Viracea approached only 50% at the highest concentrati on of the drug tested, a 1:2 dilution, indicating that Viracea is non- toxic in this cell cytotoxicity assay. Although the active component(s ) in Viracea that has anti-HSV activity is not known, it appears that this extract has good antiviral activity against both ACV resistant an d ACV susceptible strains of HSV-1 and HSV-2. (C) 1998 Elsevier Scienc e B.V. All rights reserved.