Preclinical evaluation of magainin-A as a contraceptive antimicrobial agent

Objective: To evaluate the safety and contraceptive efficacy of magainin-A in monkeys. Design: Controlled laboratory study. Setting: Department of Immunology, National Institute for Research in Reproductive Health, Parel, Mumbai, India. Animal(s): Male and female bonnet monkeys (Macaca radiata). Intervention(s): Animals were treated intravaginally with 1 mg of magainin-A before attempted conception, as well as daily for 14 days to assess local and systemic toxicity. Main Outcome Measure(s): Suitability of magainin-A for the control of pregnancy and sexually transmitted infections. Result(s): Complete sperm immobilization was observed within 20 seconds after the exposure to magainin-A (800-1,000 mug) in vitro. Intravaginal administration of 1 mg of magainin-A blocked conception in monkeys. When magainin-A was administered intravaginally for 14 consecutive days, no treatment-related abnormalities were observed in menstrual cycle length, vaginal epithelial cell morphology, and hematologic/serum biochemical profiles. The peptide inhibited the growth of sexually transmitted infection-causing pathogens but not HIV-1 and HIV-2. Conclusion(s): Magainin-A can be used as an effective and safe intravaginal contraceptive compound with additional protection against sexually transmitted infection-causing pathogens.