Mechanistic insight of the photodynamic effect induced by tri- and tetra-cationic porphyrins on Candida albicans cells.

摘要: The photodynamic mechanism of action induced by 5-(4-trifluorophenyl)-10,15,20-tris(4-N,N,N-trimethylammoniumphenyl)porphyrin (TFAP3+), 5,10,15,20-tetrakis(4-N,N,N-trimethylammoniumphenyl)porphyrin (TMAP4+) and 5,10,15,20-tetrakis(4-N-methylpyridyl)porphyrin (TMPyP4+) was investigated on Candida albicanscells. These cationic porphyrins are effective photosensitizers, producing a ∼5 log decrease cell survival when the cultures incubated with 5 μM photosensitizer irradiated for 30 min visible light. Studies under anoxic conditions indicated that oxygen is necessary inactivation this yeast. Furthermore, photoinactivation C. albicanscells negligible in presence 100 mM azide ion, whereas photocytotoxicity these increased D2O. In contrast, addition mannitol produced effect cellular phototoxicity. On other hand, vitro direct observation singlet molecular oxygen, O2(1Δg) phosphorescence at 1270 nm analyzed using albicans A shorter lifetime found yeast suspensions. bind strongly to generated inside cells rapidly quenched biomolecules microenvironment. Therefore, results indicate appear act as photosensitizers mainly via intermediacy O2(1Δg).