The use of ALA derivates in photodynamic therapy

CASAS A, FUKUDA H, DI VENOSA G, BATLLE A

París, Francia

Congreso; Millenium meeting on porphyrins and porphyrias 2000; 2000

ALA-based Photodynamic Therapy is a cancer treatment based on the accumulation of porphyrins from 5-aminolevulinic acid (ALA), and their subsecuent destruction upon exposure to visible  light. We employed an adenocarcinoma cell line to test the efficacy of some ALA-derivatives as pro-photosensitisers. We found that the derivative Hexyl-ALA was the best compound at inducing porphyrin synthesis. Methyl-ALA employed in euimolar concentration, was less efficient than ALA. Cell survival was determined after incubation with ALA compounds producing similar porphyrin accumulation. Employing a 0.65 J/cm2 light dose, survival was 50% with ALA, 65% with Methyl-ALA and 90% with Hexyl-ALA, cell viability decreases to 50 % and to obtain a similar cell death employing ALA, the concentration must be ten times higher. This results are keeping in with those of porphyrin synthesis. Both ALA and ALA-derivatives induce a percentage of apoptotic cells in this cell line. The use of ALA derivatives can be exploited for improving the efficacy of ALA-photodynamic therapy.