Antimicrobial host defence peptide, LL-37, as a potential vaginal contraceptive.

Study Question: Does antimicrobial peptide, LL-37, inhibit sperm fertilizing ability?

Summary Answer: Our results indicate that LL-37 inhibits mouse and human sperm fertilizing ability.

What Is Known Already: LL-37, a cationic antimicrobial peptide, exerts its microbicidal effects through the disruption of microbial cytoplasmic membranes following its interaction with microbial surface anionic phospholipids. ALL-38 (an LL-37 close analogue: LL-37 + Ala at the N-terminus) is produced in the vagina 2-6 h post-intercourse from its precursor hCAP-18, a seminal plasma component.