Share Email Print
cover

Proceedings Paper

Effect of antiooxidants on phthalocyanine photosensitization of human erythrocytes
Author(s): Ehud Ben-Hur; Ionel Rosenthal
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Photohemolysis of human erythrocytes sensitized by sulfonated aluminum phthalocyanine was used as an endpoint to study possible chemical modifications of photodynamic therapy. Ascorbate, in concentrations up to 0.1 mM, had a small protective effect. In larger amounts it stimulated the rate of photohemolysis in a concentration dependent manner up to 1mM, by a factor of 2. Azide and D20 tests indicated some participation of singlet oxygen, although to a lesser extent than in the absence of ascorbate. Kinetic considerations augur for a reaction path initiated by an interaction of excited sensitizer-ascorbate, parallel to the singlet oxygen-mediated process. Because of the ubiquitous presence of ascorbate in human tissues in concentrations comparable to those of dissolved oxygen, it is a reasonable estimation that in photodynamic therapy, a fraction of the photodynamic damage proceeds via a Type I, ascorbate-assisted, mechanism. Tocopherol had an effect opposite to that of ascorbate, namely it inhibited the photohemolysis. Likewise, quercetin, a plant flavonoid, was protective against phthalocyanine-induced photohemolysis.

Paper Details

Date Published: 18 June 1993
PDF: 9 pages
Proc. SPIE 1881, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy II, (18 June 1993); doi: 10.1117/12.146324
Show Author Affiliations
Ehud Ben-Hur, New York Blood Ctr. (United States)
Ionel Rosenthal, Volcani Ctr. (Israel)


Published in SPIE Proceedings Vol. 1881:
Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy II
Thomas J. Dougherty, Editor(s)

© SPIE. Terms of Use
Back to Top