Photodecomposition, photomutagenicity and photocytotoxicity of @entity6247 under He- XXXX laser photoirradiation and its effects on photodynamic therapy of cancer cells in vitro.

@entity6247 @entity1 @entity2491 @entity137 @entity33548 @entity904 @entity3838 @entity98
OBJECTIVE: Our aim was to study photodecomposition, photomutagenicity and @entity137 of @entity6247 (RP), a principal storage form of @entity904 in @entity1 and animals, under He- @entity33548 laser photoirradiation. Moreover, the effect of different concentrations and timing protocol of antioxidants on photodynamic therapy (PDT) is contradictory, so the effect of RP (as antioxidant) on the PDT @entity137 was studied. METHODS: Photomutagenicity was tested by Ames test. Photodecomposition was studied by UV-vis spectroscopy. @entity137 was measured with @entity98 -assay. Moreover, the effect of PDT, using @entity3838 derivatives (HpD) as photosensitizer under He- @entity33548 laser irradiation (10 J/cm(2)), was studied on HeLa cells either with or without RP (1-100  M) which incubated with the cells for short or long incubation period (1h or 24 h) prior to PDT. RESULTS: No photodecomposition of RP alone was obseved whereas there is a little photodecomposition of RP only in presence of HpD under irradiation with He- @entity33548 laser. Moreover, no photomutagenicity was observed in @entity2491 strains under laser irradiation in presence or absence of HpD. RP alone (1-100 M) significantly decrease the viability of HeLa cells. Laser irradiation of HeLa cells pre-incubated with RP alone for 24h showed further significant decrease in viability of the cells. While RP incubations for 1h before PDT had slight effect on the cells, 24 h incubation before PDT enhanced the @entity137 of PDT on HeLa cells. CONCLUSIONS: RP can be used 24 h before PDT to enhance its effects. RP is not mutagenic under irradiation with He- @entity33548 laser.
