Rice Bran Oligosaccharide Shows Immunomodulating Action

MIAMI Rice Bran Arabinoxylan Compound (RBAC), a supplement produced by enzymatic hydrolysis of hemicellulose B derived from rice bran, helps modulate the immune system, according to a recent University of Miami study, which found effects on cytokines, growth factors and natural killer (NK) cell cytotoxicity. The results of the study, sponsored by Daiwa Health Development, were published in the July issue of Functional Foods in Health and Disease.

The study specifically showed two months of either 1 g/d (n=10) and 3 g/d (n=10) doses of RBAC (as PeakImmune4®, by Daiwa) in healthy adults correlated to a short-term rise in NK cell cytotoxicity, which peaked at one week. There was also an associated rise in 9 of 12 cytokinesincluding interferon-, tumor necrosis factor- (TNFa), interleukins-1, -1, -8 and -10and epidermal growth factors, all which peaked at 30 days. Total bilirubin, total protein, creatinine and liver function tests to assess safety and tolerability found no safety or tolerability problems.

Researchers concluded the study results demonstrated true, multifactorial immunomodulation, not just simple immunostimulation or immunosuppression. "RBAC may help to destroy tumor cells and viruses directly, and increase the activity of immune cells, thereby optimizing the immune system, especially NKCC, which can increase the chance and speed of host recovery," they wrote. Based on these findings, they suggested RBAC should be further studied in immune-compromised populations, such as HIV/AIDS, cancer patients or otherwise-healthy smokers.

John Lewis, Ph.D. associate professor, department of psychiatry and behavioral sciences at the University of Miami Miller School of Medicine and corresponding research author, emphasized the study is the first step in testing RBAC in healthy adults.  In other words, the immune factors that we analyzed showed bi-directional, transient responses in people who were healthy without chronic disease.," he said. Our results are valid based on the statistical analysis that we performed in the study and appear to be consistent with the findings of other investigators as well.

Co-author Aaron H. Wolfson, M.D., professor and vice chairman of the department of radiation oncology at the University of Miami Miller School of Medicine, added, We are eagerly looking to expand the use of RBAC in patients with end stage solid tumors (cancers) in the near future in a phase one trial as a preliminary study to evaluate PeakImunne4 as a potential therapeutic agent in treating these terminal patients.