IJPPP Copyright © 2009-All rights reserved. Published by e-Century Publishing Corporation, Madison, WI 53711
Int J Physiol Pathophysiol Pharmacol 2012;4(2):99-107.

Original Article
Selective toxicity of rose bengal to ovarian cancer cells in vitro

Steven B Koevary

Department of Biomedical Sciences and Disease, New England College of Optometry, 424 Beacon Street, Boston, MA 02115;
Department of Cell Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA

Received June 12, 2012; accepted June 23, 2012; Epub June 25, 2012; Published June 30, 2012

Abstract: Rose bengal (RB) has been utilized as a photodynamic agent for the targeted killing of cancer cells. Recent data suggest that
intralesional RB alone may be effective in chemoablating locoregional and metastatic melanomas. The ability of RB to induce direct
and bystander melanoma cell death lead to the speculation that it may be similarly effective in the treatment of other neoplasms. The
objective of this study was to determine whether RB can limit the growth, or kill, ovarian cancer cells in vitro. Ovarian carcinoma cells
with or without a germline BRCA1 mutation were cultured with up to 800 µM RB for one hour or four days, after which their ability to
proliferate was assessed using the MTT assay. Control cells included an embryonic kidney cell line transformed with adenovirus, and
normal human fibroblasts. Ovarian cancer cells exhibited significant dose-dependent suppression of growth in response to RB; this
suppression was similar to that seen in response to treatment with carboplatin. RB treated ovarian cancer cells appeared rounded,
shrunken, and damaged. RB also inhibited the growth of kidney tumor cells but was much less effective in slowing the growth of
normal human fibroblasts suggesting that RB-mediated growth suppression might be tumor cell specific. Ovarian cancer cells treated
with RB displayed a significant increase in apoptosis that peaked at approximately four times the levels seen in untreated control cells.
Furthermore, RB exposure resulted in the intracellular generation of reactive oxygen species (ROS) at levels that were significantly
greater than in  untreated cells and similar to levels seen in cells treated short term with H2O2. These data suggest that RB may not
only suppress ovarian cancer cell growth but also induce their apoptotic cell death, justifying the further investigation of the effects of RB
in an animal model of ovarian cancer. (IJPPP1206002)

Keywords: Rose bengal, ovarian cancer, BRCA1, MTT assay, apoptosis, reactive oxygen species

Address all correspondence to:
Dr. Steven B Koevary
Department of Biomedical Sciences and Disease
New England College of Optometry, 424 Beacon Street
Boston, MA 02115, USA.
Tel: 617-587-5629; Fax: 617-587-5563
E-mail: koevarys@neco.edu