Mode of hemolytic action of the antifungal polyene antibiotic filipin

Abstract
Filipin at low concentrations rapidly hemolyzes bovine erythrocytes. Of the known constituents of cell membranes tested, only cholesterol and phosphatidyl-choline prevented hemolysis. A specific complex was formed only with cholesterol. Filipin treatment caused a release of cholesterol from erythrocytes. Since all sterol is located in the cell membrane, the hemolytic action of filipin may be due to a displacement of cholesterol from the cell membrane thus weakening its stability. The internal pressure of the cell then could force the hemoglobin through the defective membrane.