Primaquine and lysosomotropic amines inhibit malaria sporozoite entry into human liver cells

The binding and entry of Plasmodium berghei sporozoites to human hepatoma HepG2 cells is inhibited in a dose-dependent manner by primaquine, chloroquine and other lysosomotropic amines. The site of action of these agents appears to be the hepatoma cell itself, not the sporozoite. While this inhibitory effect of primaquine is rapidly reversible, the precise mechanism responsible for this effect is not presently known.