From Bench to Bedside: The Growing use of Arabinoxylan Rice Bran (MGN-3 /Biobran) in Cancer Immunotherapy

MGN-3/Biobran is a denatured hemicellulose obtained by reacting rice bran hemicellulose with multiple carbohydrate hydrolyzing enzymes from Shiitake mushrooms. Over the last 24 years, our fundamental research objective has been to study the biotherpeutic activity of MGN-3 as a treatment for cancer based on its ability to activate the immune system. This objective has been pursued in vitro, and in animal and human studies. This review is focused on the immunomodulatory effects of MGN-3 and on its potential as an anticancer agent. In vitro studies showed that culturing different human and murine cancer cell lines with MGN-3 resulted in a reduction of the survival rate of cancer cells. In vivo studies have also shown that MGN-3 induces tumor regression in several models of animal bearing tumor, including gastric cancer, neuroblastoma, and Ehrlich carcinoma. In addition, the anti-cancer activity of MGN-3 has been shown in human clinical trials and in several case reports on patients with Hepatocellular Carcinoma (HCC) and progressive and partially metastasized cancer. Patients that were treated with MGN-3 in addition to Conventional Therapy (CT), as compared with CT alone, showed: 1) less recurrence of cancer, 2) higher survival rate and 3) improved Quality of Life (QOL) as characterized by improvements in physical activity, appetite, sleep, and digestion, and a decrease in pain and anxiety. This review summarizes the preclinical and clinical research on MGN-3/Biobran since it was frst patented in 1992. Various animal studies and human clinical trials including different types of malignancies have demonstrated that MGN-3 is a potent Biological Response Modifer (BRM). MGN-3 enhances the cytotoxic reactivity of immune cells with anti-cancer activity such as NK and CD8+ T cells via increasing cell granularity, stimulates the production of interferons, IL-2 and IL-12, and functions as a natural adjuvant for Dendritic Cells (DC). Therefore, MGN-3 may be used in DC-based vaccine strategies against infections and cancer. Importantly, MGN-3 is a unique BRM because it is a safe non-toxic agent and does not exhibit hyporesponsiveness. MGN-3 has the potential to be a novel and promising immune modulatory adjuvant that could complement the existing immunotherapeutic modalities for cancer patients.