GIARDICIDAL ACTIVITY OF LACTOFERRIN AND N-TERMINAL PEPTIDES

Human and bovine lactoferrins and their derived N-terminal peptides we re giardicidal in vitro. Fe3+, but not Fe2+, protected trophozoites fr om both native lactoferrin and peptides, although the latter lack iron -binding sites. Other divalent metal ions protected only against nativ e lactoferrin. Log-phase cells were more resistant to killing than sta tionary-phase cells. These studies suggest that lactoferrin, especiall y in the form of the N-terminal peptides, may be an important nonimmun e component of host mucosal defenses against Giardia lamblia.