Effect of disodiumN,N-dialanyl protoporphyrinate, diarginine protoporphyrinate and diarginineN,N-dialanyl protoporphyrinate on respiratory burst of human neutrophilsin vitro

Abstract

The effect of three amino acid protoporphyrin IX (PPIX) derivatives evaluated as sensitizers in photodynamic therapy — disodium N,N -dialanyl protoporphyrinate ( PP(Ala)2Na2), diarginine protoporphyrinate (PPArg2) and diarginine N,N -dialanyl protoporphyrinate (PP(Ala)2Arg2) – non-irradiated and pre-irradiated with UV-A, on respiratory burst of non-stimulated and opsonized zymosan stimulated neutrophils was studied. A potential synergistic effect of diazepam (7-chloro-1-methyl-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one) was also examined. PP(Ala)2Na2showed strong pro-oxidant effect towards non-stimulated neutrophils, while PPArg2and PP(Ala)2Arg2revealed no significant effect. In the case of stimulated neutrophils all studied porphyrins showed antioxidant effect, although for PP(Ala)2Na2this effect was significantly weaker than that of PPArg2and PP(Ala)2Arg2. After pre-irradiation with UV-A (λ = 365 nm, fluence 2.0 J.cm-2, fluence rate 6.7 mW.cm-2) the antioxidant activity of all studied sensitizers towards non-stimulated granulocytes did not change significantly when compared to effects of non-irradiated porphyrins, while in the case of stimulated cells, only PPArg2caused significant decrease of respiratory burst. Non-irradiated diazepam showed significant antioxidant effect and enhanced antioxidant effect of all studied porphyrins towards stimulated neutrophils, while after UV-A pre-irradiation it revealed no significant antioxidant effect on non-stimulated and stimulated neutrophils, both alone and in combination with porphyrin sensitizers.