Photodynamic Therapy in Dermatology

Fritsch, Clemens; Goerz, G.; Ruzicka, Thomas

doi:10.1001/archderm.134.2.207

Cited by 252 publications

(194 citation statements)

References 39 publications

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“…The correlation of fluorescence intensity under Wood's light with the porphyrin levels suggests that the clinical evaluation of the fluorescence gives an orientation on superficial intralesional porphyrin levels. This method is already used in photodynamic diagnosis (PDD), a novel, effective diagnostic modality in tumour detection and demarcation (Figure 1) (Fritsch et al, 1996a(Fritsch et al, , 1997b(Fritsch et al, , 1997dKriegmair et al, 1996).…”

Section: Discussionmentioning

confidence: 99%

Optimum porphyrin accumulation in epithelial skin tumours and psoriatic lesions after topical application of δ-aminolaevulinic acid

et al. 1999

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Photodynamic therapy with topically applied δ-aminolaevulinic acid is used to treat skin tumours by employing endogenously formed porphyrins as photosensitizers. This study examines the time course of porphyrin metabolite formation after topical application of δ-aminolaevulinic acid. Porphyrin biosynthesis in human skin tumours (basal cell carcinoma, squamous cell carcinoma), in psoriatic lesions, and in normal skin was investigated. Skin areas were treated with δ-aminolaevulinic acid, and levels of total porphyrins, porphyrin metabolites and proteins were measured in samples excised after 1, 2, 4, 6, 9, 12 and 24 h. There was an increase in porphyrin biosynthesis in all tissues with maximum porphyrin levels in tumours between 2 and 6 h and in psoriatic lesions 6 h after treatment. The pattern of porphyrins showed no significant difference between normal and neoplastic skin, protoporphyrin being the predominant metabolite. The results suggest that optimum irradiation time for superficial epithelial skin tumours may be as soon as 2 h after application of δ-aminolaevulinic acid, whereas for treatment of psoriatic lesions an application time of 6 h is more suitable. © 1999 Cancer Research Campaign

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Section: Discussionmentioning

confidence: 99%

Optimum porphyrin accumulation in epithelial skin tumours and psoriatic lesions after topical application of δ-aminolaevulinic acid

et al. 1999

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“…This form of oxygen is also a harmful species to biological systems and its production under controlled conditions has been extensively studied in the last two decades as the basis of an alternative approach to the treatment of neoplastic diseases known as photodynamic therapy (36).…”

Section: Ohmentioning

confidence: 99%

The antioxidant action of Polypodium leucotomos extract and kojic acid: reactions with reactive oxygen species

Gomes

Lunardi

González

et al. 2001

Braz J Med Biol Res

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Two natural products Polypodium leucotomos extract (PL) and kojic acid (KA) were tested for their ability to scavenge reactive oxygen species (in phosphate buffer. Hydroxyl radicals were generated by the Fenton reaction, and the rate constants of scavenging were 1.6 x 10 9 M -1 s -1 for KA and 1.0 x 10 9 M -1 s -1 for PL, similar to that of ethanol (1.4 x 10 9 M -1 s -1 ). With superoxide anions generated by the xanthine/hypoxanthine system, KA and PL (0.2-1.0 mg/ml) inhibited · O 2 -dependent reduction of nitroblue tetrazolium by up to 30 and 31%, respectively. In the detection of 1 O 2 by rose bengal irradiation, PL at 1.0 mg/ml quenched singlet oxygen by 43% relative to azide and KA by 36%. The present study demonstrates that PL showed an antioxidant effect, scavenging three of four reactive oxygen species tested here. Unlike KA, PL did not significantly scavenge hydrogen peroxide. Correspondence

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“…Photodynamic therapy (PDT) is an effective treatment method for several kinds of neoplasms and is based on the use of different photosensitizers (3)(4)(5)(6). In general, the effectiveness of a photosensitizer depends on two important properties, namely the production of cytotoxic oxygen and fluorescence excited by laser irradiation, which are important for PDT and fluorescence-guided resection in neurosurgery (7)(8)(9).…”

Section: Introductionmentioning

confidence: 99%

Radiosensitizing effect of 5-aminolevulinic acid-induced protoporphyrin IX in glioma cells inï¿½vitro

et al. 2012

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Abstract. 5-Aminolevulinic acid (ALA) is a prodrug used in photodynamic therapy and fluorescence-guided resection of malignant gliomas due to its high cellular uptake in tumours. Porphyrin compounds act not only as photosensitizers but also as radiosensitizers. In the present study, the possible use of 5-ALA as a radiosensitizer for malignant gliomas was examined in vitro. Rat glioma cell lines (9L, C6) were pre-treated with 5-ALA and exposed to ionizing irradiation. The radiosensitizing effect of 5-ALA was evaluated by colony-forming assay. Intracellular reactive oxygen species (ROS) produced by 5-ALA and irradiation were evaluated by confocal laser scanning microscopy. Pre-treatment with 5-ALA enhanced the radiosensitivity of 9L cells to single-dose ionizing irradiation compared with controls (D 0 value, 4.35±0.20 and 4.84±0.23 Gy, respectively, P≤0.05). Exposure to multi-dose ionizing irradiation revealed high radiosensitivity in both 9L and C6 cells pre-treated with 5-ALA compared to controls. Production of intracellular ROS increased in 9L cells pretreated with 5-ALA after ionizing irradiation compared to control cells. Thus, 5-ALA functions as a specific radiosensitizer for malignant gliomas. Intracellular 5-ALA-induced PpIX plays an important role in the production of ROS and the radiosensitizing effect under ionizing irradiation conditions.

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Photodynamic Therapy in Dermatology

Cited by 252 publications

References 39 publications

Optimum porphyrin accumulation in epithelial skin tumours and psoriatic lesions after topical application of δ-aminolaevulinic acid

Optimum porphyrin accumulation in epithelial skin tumours and psoriatic lesions after topical application of δ-aminolaevulinic acid

The antioxidant action of Polypodium leucotomos extract and kojic acid: reactions with reactive oxygen species

Radiosensitizing effect of 5-aminolevulinic acid-induced protoporphyrin IX in glioma cells inï¿½vitro

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