In Vivo Tumor Inhibitory Effects of Nutritional Rice Bran Supplement MGN-3/Biobran on Ehrlich Carcinoma-Bearing Mice*

*Data partially presented at AICR/WCRF International Research Conference on Food, Nutrition, and Cancer, Washington, July 2006.

Abstract

This study was undertaken to investigate the in vivo anti-tumor activity of MGN-3/Biobran, a modified arabinoxylan rice bran. Swiss albino mice were inoculated intramuscularly in the right thigh with Ehrlich ascites carcinoma (EAC) cells. On Day 8, mice bearing a solid Ehrlich carcinoma (SEC) tumor were treated with MGN-3 via intraperitoneal injection. Tumor growth, cytokine production, and apoptotic effect of MGN-3 were examined. MGN-3 caused a highly significant delay in both tumor volume (63.27%) and tumor weight (45.2%) as compared to controls (P < 0.01). The mechanisms by which MGN-3 exerts its antitumor effect seem to involve its ability to induce apoptosis and immune modulation. MGN-3 induced a 1.8-fold increase in the percentage of apoptotic SEC cells as determined by flow cytometry and the histopathological examination. In addition, MGN-3 influenced plasma cytokine production by increasing the levels of tumor necrosis factor-α and interferon-γ, while downregulating levels of the immune suppressing cytokine interleukin-10. Data also showed that non-tumor-bearing mice intramuscularly injected with MGN-3 resulted in a twofold increase in natural killer activity. No adverse side effects due to MGN-3 treatment were observed; all animals displayed normal feeding/drinking and life activity patterns. These data may have clinical implications for the treatment of solid cancers.

ACKNOWLEDGMENT

We thank Daiwa Pharmaceutical Co. LTD, Tokyo, Japan, for the financial support of this project.

Notes

^a Abbreviations are as follows: IP, intraperitoneal; PBS, phosphate-buffered solution. Each value represents the mean ± SE of the corresponding number of animals/group. Net final body weight = (Final body weight at Day 35 − Tumor weight at Day 35). Body weight gain (Net final body weight – Initial body weight).

^b Significant at P < 0.01 as compared to the PBS group.

^c Significant at P < 0.025 as compared to the initial body weight.

^a Abbreviations are as follows: IP, intraperitoneal; PBS, phosphate-buffered solution.

^a Abbreviations are as follows: IP, intraperitoneal; PBS, phosphate-buffered solution; TNF-α, tumor necrosis factor-alpha; IFN-γ, interferon-gamma; IL-10, interleukin-10. Each value represents the mean ± SE from the indicated number of mice.

^b Percent change as compared to control group.

^c Significantly different from the control group at 0.01 level.

^d Significantly different from the PBS tumor-bearing group at 0.01 level.

*Data partially presented at AICR/WCRF International Research Conference on Food, Nutrition, and Cancer, Washington, July 2006.