In vitro lysis of the bloodstream forms of Trypanosoma brucei gambiense by stearylamine-bearing liposomes.
Cytolytic activity of liposomes consisting of stearylamine and phosphatidylcholine (SA/PC-liposomes) was examined in vitro against the bloodstream forms of Trypanosoma brucei gambiense. More than 99% of the cells (2 X 10(6)/ml) were killed within 30 min by treatment with 15 mol% SA/PC-liposomes (100 microM total lipids). As few as 1.2 X 10(12) liposomes per ml (equivalent to 2 nM liposome) showed trypanocidal activity. Fluorescence microscopy of cells treated with the dansylated SA/PC-liposomes suggested that the liposomes bound to and accumulated on the cell surface, eventually damaging the plasma membrane. SA/PC-liposomes showed no significant hemolysis when incubated with human and mouse erythrocytes under conditions that killed greater than 99.9% of the T. b. gambiense trypomastigotes. Human leukocytes were also shown to be less susceptible to SA/PC-liposomes than T. b. gambiense. These results may point to a new direction in strategy for therapy of African trypanosomiasis.
Tachibana
H
H
Department of Parasitology, School of Medicine, Tokai University, Kanagawa, Japan.
Yoshihara
E
E
Kaneda
Y
Y
Nakae
T
T
D000588:Amines / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001769:Blood / Q000469:parasitology; D002452:Cell Count / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D008081:Liposomes / Q000008:administration & dosage / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D010713:Phosphatidylcholines / Q000494:pharmacology; D014347:Trypanosoma brucei gambiense / Q000187:drug effects*
D000588:Amines; D008081:Liposomes; D010713:Phosphatidylcholines; C009317:stearylamine