DNA Damage Induced by Hypocrellin-A Photosensitization

Abstract

Hypocrellin-A (HC-A) isolated from Hypocrellia bambusae Sacc., is a new and effective photosensitizer. Illumination of sarcoma 180 cells with visible light in the presence of HC-A leads to a decrease in cell viability and ³H-TdR incorporation, causes DNA strand breakage, and results in the selective destruction of guanine moieties in DNA. HC-A photosensitization causes an increase in the θ₂₆₀/θ₂₈₀ ratio in the circular dichroism spectra of DNA in vitro. Of the four usual 2′-deoxynucleotides illuminated in the presence of HC-A only 2′-deoxyguanylic acid was destroyed.