Photoactivity of ultradeformable liposome of Aluminium phthalocyanine chloride on Leishmania chagasi and THP-1 macrophages

INDIRA HERNANDEZ, EDER ROMERO, WILFREDO VALDIVIESO, JORGE MONTANARI, MARIA JOSE MORILLA, FERNANDO MARTINEZ, EDGAR PáEZ, PATRICIA ESCOBAR

Lucknow, India

Congreso; Worldleish4-4th World Congress on Leishmaniasis; 2009

The ultradeformables liposomes (UDL) are vehicles used for drug transport on topical formulations. The use of UDL incorporated with phthalocyanine aluminium chloride (AlPc) could increase AlPc photoactivity and specificity against cutaneous leishmaniasis Materials and methods: Promastigotes and intracellular amastigotes of Leishmania chagasi infecting THP-1 cells were treated with UDL-AlPc, free AlPc and empty UDL. After 24 h, cells were irradiated at a fluence rate of 17 J/cm2 (597-752 nm). Control cells were kept in darkness. After 24 h, parasite inhibition was determined microscopically and the results were expressed as IC50 or CC50 values calculated by sigmoidal regression analysis. Compound localization was determined by confocal microscopy using JC-1 mitochondrial probe. Results: UDL-AlPc were phototoxic on L. chagasi promastigotes (IC50 of 3.77 E-05 ìM). They were 91 times more active than free AlPc (IC50 0.0034 ìM). UDL-AlPc were more active on L. chagasi intracellular amastigotes infecting THP-1 cells (0.00068 µM) than free AlPc (IC50 0.04 µM). In non infected THP-1 cells, UDL-PcAl were more phototoxic (CC50 0.00071 ìM) than free PcAl (CC50 0.0037 ìM). In darkness, UDL-PcAl and empty UDL were toxic on promastigotes but not on THP-1 cells. UDL-PcAl was co-localized partially at the cell mitochondria and free PcAl mainly at the mitochondrial level. Conclusions: The incorporation of PcAl on UDL increase the in vitro phototoxic effect against L. chagasi. In vivo studies are required to confirm the photoactivity of UDL-PcAl and its potential application in the topical treatment of cutaneous leishmaniasis.