Spermicidal activity of dermaseptins

Objective: The present study was undertaken to elucidate the spermicidal efficacy of two synthetic antimicrobial peptides, dermaseptin (DS1 and DS4). Methods: Twenty samples of fresh semen were obtained from patients aged between 23 and 35 years. The ability of DS to kill sperm was evaluated by the Sander-Cramer test under in vitro conditions. Results: The data showed that sperm motility was inhibited with various concentrations of DS at different intervals ranging from 2 to 240 min. The effective 100% inhibitory concentration (EC100) of DS4 in 2 min during the sperm immobilization assay was 100 mu g/mL whereas the sperm immobilization of EC100 of DS1 was 200 mu g/mL. The presence of 0.1% chelating agent ethylenediaminetetraacetic acid (EDTA) reduced the EC100 of DS4 to 10 mu g/mL whereas less than a two-time enhancement in DS1 activity was observed upon combination with EDTA. The action of DSs on sperm motility was observed to be dose dependent. Supplementation with pentoxifylline and that with calcium are known to enhance the motility of sperm but they did not prevent the spermicidal action of DSs. Conclusion: This present study indicates that DS is an effective agent to kill sperm. In view of this fact, it is suggested that DS4 has antibacterial, antiviral, antifungal and potentially spermicidal activities and could be a potent vaginal contraceptive. (c) 2005 Elsevier Inc. All rights reserved.