Tilorone acts as a lysosomotropic agent in fibroblasts.

Tilorone, an amphiphilic cationic compound with antiviral activity perturbed the lysosomal system. In cultured fibroblasts tilorone induced storage of sulfated glycosaminoglycans, enhanced secretion of precursor forms of lysosomal enzymes, inhibited intracellular proteolytic maturation of lysosomal enzymes, and inhibited receptor-mediated endocytosis of lysosomal enzymes. In isolated lysosomes tilorone was found to increase pH and to abolish the ATP-dependent acidification. These effects suggest that tilorone acts like a weak base that accumulates in acid compartments of the cells, raises the pH therein and interferes with lysosomal catabolic activity and with receptor-mediated transport of lysosomal enzymes.