title: Improvement of aminolevulinic acid (ALA)-mediated photodynamic diagnosis using n-propyl gallate.
abstract: BACKGROUND
  Photodynamic diagnosis (PDD) using aminolevulinic acid (ALA) is widely used in clinical fields. In PDD, protoporphyrin IX (PpIX) is generated from ALA in tumors, allowing the detection of the tumors by PpIX fluorescence. However, it is well known that PpIX is bleached by light irradiation (photobleaching) resulting in reduced PDD efficiency. In this study, n-propyl gallate (NPG) was investigated as an enhancer of PDD efficiency.
  
  
  METHODS
  Tumor cells were incubated with NPG after treatment with ALA, and reactive oxygen species and PpIX fluorescence were measured.
  
  
  RESULTS
  The antioxidant NPG suppressed the production of reactive oxygen species from light-irradiated porphyrins and ameliorated photobleaching of PpIX generated from ALA in vitro and in vivo.
  
  
  CONCLUSIONS
  Incubation with NPG decreased the production of reactive oxygen species from PpIX and suppressed PpIX photobleaching. These results indicate that the antioxidant NPG may significantly improve PDD efficiency.
authors: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B102 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
authors: Tomohisa
authors: T
authors: Hirano
authors: Yuichiro
authors: Y
authors: Hagiya
authors: Hideo
authors: H
authors: Fukuhara
authors: Keiji
authors: K
authors: Inoue
authors: Taro
authors: T
authors: Shuin
authors: Kentaro
authors: K
authors: Matsumoto
authors: Katsushi
authors: K
authors: Inoue
authors: Tohru
authors: T
authors: Tanaka
authors: Ichiro
authors: I
authors: Okura
authors: Shun-Ichiro
authors: S
authors: Ogura
mesh_terms: D000622:Aminolevulinic Acid; D045744:Cell Line, Tumor; D004338:Drug Combinations; D004357:Drug Synergism; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods*; D009374:Neoplasms, Experimental / Q000473:pathology*; D017319:Photosensitizing Agents; D011435:Propyl Gallate; D011524:Protoporphyrins; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004338:Drug Combinations; D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; D011435:Propyl Gallate; C028025:protoporphyrin IX