RBAC exhibits chemo-sensitizing activity against human breast cancer cells in vitro.
(Los Angeles, CA) June 27, 2008 – A major breakthrough in this area of cancer therapeutics has recently been reported in the Journal of Cancer Detection and Prevention, Volume 32: 1-6 (2008). The study concluded that treatment of human breast cancer cells with Rice Bran Arabinoxylan Compound (RBAC), produced by Daiwa Pharmaceuticals Co., Ltd., of Tokyo, Japan significantly sensitizes the cancer to the chemotherapeutic agent daunorubicin. This suggested that the RBAC, a food supplement, in conjunction with chemotherapy may be useful for the treatment of breast cancer.
The ability of RBAC to sensitize breast cancer cells was studied under the direction of Sastry Gollapudi, Ph.D., at University of California, Irvine. In these studies, breast cancer cells (BCCs) (MCF-7 and HCC70 cells) were cultured with different concentrations of RBAC (100-1000 μg/ml) in the presence or absence of chemotherapeutic agent, daunorubicin (DNR) (from 1x10-9 - 1x10 -6 M) for three days. Cancer cell survival was determined by a colorimetric MTT assay.
To gain insights into the mechanism(s) by which RBAC sensitizes cancer cells, the authors examined DNR accumulation in breast cancer cells by flow cytometry. The results showed that treatment with RBAC increased susceptibility of BCCs to DNR (5.5-fold for MCF-7 and 2.5-fold for HCC70 cells) as compared to BCCs treated with DNR alone. The sensitizing effect of RBAC was associated with increased accumulation of DNR in cancer cells. The study data demonstrated that RBAC is an effective chemo-sensitizer and may represent a potential novel adjuvant for the treatment of breast cancer. The promise of anti-cancer activity by rice and rice bran derivatives has recently been the focus of much research.
“One of the major problems associated with cancer chemotherapy is the unwanted toxicity of anti-cancer drugs,” said Noriano Shirai, vice president with the U.S. division of Daiwa Health Development.
“Identification of natural compounds that enhance the activity of anti-cancer drugs may lead to new approaches to reduce the side effects of these drugs and increase their efficacy in the treatment of cancers,” added Shirai.
RBAC is an arabinoxylan extracted from rice bran that has proven to be a potent biological response modifier with the ability to boost the function of different arms of the immune system, such as Natural Killer (NK) cells, T and B cells, macrophages, and the production of TNF-α and IFN-γ. In addition, RBAC has demonstrated an additional characteristic as a novel anti-tumor agent able to sensitize: 1) human leukemia cells to death receptor [CD95]-induced apoptosis; 2) cancer cells to yeast-induced apoptosis; 3) human adriamycin-resistant (AR) myeloid leukemia cells to adriamycin (ADR) treatment and; 4) human breast cancer cells to DNR treatment, as shown in the study.
Daiwa Pharmaceuticals is the parent company of Daiwa Health Development based in Los Angeles, CA. For more information, contact Norinao Shirai at 310.329.2362 or NShirai@DHDUSA.net.
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Gollapudi S. and Ghoneum M. MGN-3/Biobran, modified arabinoxylan from rice bran, sensitizes human breast cancer cells to chemotherapeutic agent, daunorubicin. Cancer Detect Prev. Volume 32: 1-6 (2008).