A novel porphyrin photosensitizer from bamboo leaves that induces apoptosis in cancer cell lines.
Anticancer Res. 2003 May-Jun;23(3B):2355-61. PMID: 12894515
Biotechnology Department, Miryang National University, 1025-1 Naei-dong, Miryang, Kyungnam, 627-702, Korea.
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. MATERIALS AND 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. CONCLUSION: The 201-hydroxypurpurin-7 delta-lactone esters are promising lead compounds as photosensitizers for photodynamic therapy of cancer.