Disruption of lipid rafts by lidocaine inhibits erythrocyte invasion by Plasmodium falciparum

Membrane lipid rafts have been implicated in erythrocyte invasion process by Plasmodium falciparum. In this study, we examined the effect of lidocaine, a local anesthetic, which disrupts lipid rafts reversibly without affecting membrane cholesterol content on parasite invasion. In the presence of increasing concentrations of lidocaine in the culture medium, parasite invasion was progressively decreased with complete inhibition at 2 mM. Decreased invasion was also seen in erythrocytes pre-treated with lidocaine and cultured in the absence of lidocaine. This inhibitory effect on parasite invasion was reversed following removal of lidocaine from erythrocyte membranes. Our findings show that disruption of lipid rafts in the context of normal cholesterol content markedly inhibits parasite invasion and confirm an important role for lipid rafts in invasion of erythrocytes by P. falciparum.