Photodynamic lipid peroxidation in biological systems.

Oxidative degradation of cell membrane lipids in the presence of molecular oxygen, a sensitizing agent and exciting light is termed photodynamic lipid peroxidation (photoperoxidation). Like other types of lipid peroxidation, photoperoxidation is detrimental to membrane structure and function, and could play a role in many of the toxic as well as therapeutic effects of photodynamic action. Recent advances in our understanding of photoperoxidation and its biomedical implications are reviewed in this article. Specific areas of interest include (a) reaction mechanisms; (b) methods of detection and quantitation; and (c) cellular defenses (enzymatic and non-enzymatic).