Philippine Science Letters
vol. 3 | no. 2 | 2010
published online November 12, 2010


Synergistic in vitro cytotoxicity of adociaquinone B and heptyl prodigiosin against MCF-7 breast cancer cell line

by Zenaida P. Bojo1*, Cyril D. Deaño1, Sonia D. Jacinto2, and Gisela P. Concepcion1

1The Marine Science Institute,
2 Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines



A major limitation of cancer chemotherapy is the inability to escalate doses of an anticancer drug due to intolerable cytotoxic side effects. This limitation can be overcome by using a combination of drugs administered at lower doses. In this study, we investigated the effects of combining two compounds isolated from marine organisms for in vitro cytotoxicity to the MCF-7 breast cancer cell line by the MTT assay. Adociaquinone B, from the marine sponge Xestospongia sp., and heptyl prodigiosin, from the marine bacterium Pseudovibrio denitrificans strain Z143-1, were combined in three molar proportions and the combinatorial effect was determined by isobologram analysis and the fractional inhibitory concentration (FIC) of each compound. To determine if these compounds individually caused apoptosis in MCF-7 cells, we performed brightfield microscopy to investigate cell morphology and Hoechst 33342 staining to check for chromatin condensation. Apoptosis is the preferred mode of cell death in cancer therapy because it causes minimal inflammation. Initial findings of this study suggest a synergistic cytotoxic effect of combinations of these two compounds against MCF-7 breast cancer cells, and their ability to induce apoptosis individually.

* Corresponding author
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Submitted: June 22, 2010
Revised: October 19, 2010
Accepted: October 20, 2010
Published: November 12, 2010
Editor-in-charge: Eduardo A. Padlan
Fancisco S. Chung, Jr.
Marina Gálvez-Peralta