The effect of nonoxynol-9 and chlorhexidine on HIV and sperm in vitro

Abstract

Summary: The effect of chlorhexidine and nonoxynol-9, either singly or in combination, on the replication and infectivity of HIV and the survival of both lymphocytes (MT2 cells) and human spermatozoa, was studied in vitro . Exposure of MT2 cells to 200 mug/ml nonoxynol-9 or 1 mg/ml chlorhexidine for one minute destroyed their viability. A combination of 60 mug/ml of nonoxynol-9 and chlorhexidine, however, killed MT2 cells under the same conditions. Nonoxynol-9 and chlorhexidine were both spermicidal, 268 mug/ml nonoxynol-9, or 2.063 mg/ml chlorhexidine caused complete immobilization of sperm after one minute. The same effect was achieved by a combination of 200 mug/ml nonoxynol-9 and 1.0 mg/ml chlorhexidine. The effect of chlorhexidine and nonoxynol-9 on the replication of HIV was estimated by the output of p24 (the HIV core protein) and the concentration of virus was determined by titration with MT2 cells. Separately, 300 mug/ml nonoxynol-9 alone completely inactivated HIV, while 1 mg/ml chlorhexidine was 80%-100% effective. Certain combinations of nonoxynol-9 and chlorhexidine were antagonistic in their inactivation of HIV, up to 400 mug/ml chlorhexidine partly neutralized the action of 200-500 mug/ml nonoxynol-9.