A novel porphyrin photosensitizer from bamboo leaves that induces apoptosis in cancer cell lines.
BACKGROUND
In the screening of new anticancer agents, we found that a methanol extract of bamboo leaves induced rapid apoptosis in the human leukemia CMK-7 cell line.


METHODS
The active compounds in the extract were isolated by chromatographic methods and their structures were determined by NMR and mass spectroscopy. Apoptosis by the compounds were evaluated in CMK-7 and human colon adenocarcinoma Colo320 DM cells by monitoring the caspase-3 activation and DNA cleavage.


RESULTS
The active compounds are 201-hydroxypurpurin-7 delta-lactone ethyl methyl diester (1) and the corresponding methyl phytyl diester (2). The apoptosis by compound 1 (0.3 to 0.1 microM for CMK-7 cells) was enhanced when the culture was briefly irradiated with a fluorescent lamp. This photodynamic induction of apoptosis by compound 1 was much stronger than that by a known photosensitizer, pyropheophorbidemethyl. Compound 2 was a weaker inducer of apoptosis than compound 1, but the apoptosis occurred after light irradiation.


CONCLUSIONS
The 201-hydroxypurpurin-7 delta-lactone esters are promising lead compounds as photosensitizers for photodynamic therapy of cancer.
Kim
Keun Ki
KK
Biotechnology Department, Miryang National University, 1025-1 Naei-dong, Miryang, Kyungnam, 627-702, Korea.
Kawano
Yasuhiro
Y
Yamazaki
Yoshimitsu
Y
D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology; D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000473:pathology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007947:Leukemia, Megakaryoblastic, Acute / Q000188:drug therapy / Q000473:pathology; D009682:Magnetic Resonance Spectroscopy; D017319:Photosensitizing Agents / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D011166:Porphyrins / Q000302:isolation & purification / Q000494:pharmacology*; D031787:Sasa / Q000737:chemistry*; D014407:Tumor Cells, Cultured; D020298:U937 Cells
D000972:Antineoplastic Agents, Phytogenic; D017319:Photosensitizing Agents; D010936:Plant Extracts; D011166:Porphyrins