Efficacy and toxicity of zinc salts as candidate topical microbicides against vaginal herpes simplex virus type 2 infection

Abstract

Zinc salt solutions administered as topical microbicides provided significant protection against herpes simplex virus type 2 infection in a mouse vaginal challenge model. However, at the therapeutic concentration, the salt solutions caused sloughing of sheets of vaginal epithelial cells. These observations limit the utility of zinc salts as microbicides and suggest that the application of zinc solutions to mucosal surfaces has the potential to cause damage that might increase susceptibility to secondary infections at a later time.

FIG. 1.

Photomicrographs (×400) of cytospin preparations of vaginal lavage cells collected from mice 6 h after intravaginal administration of saline (upper panel) or a 200 mM zinc sulfate solution (lower panel). Samples from saline-treated animals show isolated cells, predominantly leukocytes. In contrast, samples from zinc sulfate-treated and zinc acetate-treated (data not shown) animals show rafts of sloughed vaginal epithelial cells.