Mode of action
The active substance in Gliolan®, 5-aminolevulinic acid (5-ALA) is absorbed by cells in the body where it is changed by enzymes into fluorescent molecules protoporphyrin IX (PPIX). Due to their different enzymes, malignant glioma cells seem to absorb and accumulate higher levels of 5-ALA than normal tissue and change it more rapidly into PPIX. When illuminated under a blue light of specific wavelength, the PPIX in the malignant tissue glows an intense red, while the normal brain tissue appears blue, enabling surgeons to distinguish between malignant and normal tissue.