Modified arabinoxylan rice bran (MGN3/Biobran) enhances intracellular killing of microbes by human phagocytic cells in vitro.
Phagocytic cells, comprised of neutrophils and monocytes/macrophages, play a key role in the innate immune response to infection. Our earlier study demonstrated that arabinoxylan rice bran (MGN-3/Biobran) activates murine peritoneal macrophage and macrophage cell lines. In this study, we investigated whether MGN-3 can upregulate the phagocytic activity of human phagocytes in peripheral blood to phagocytize Escherichia coli (E. coli), trigger the oxidative burst and produce cytokines. Phagocytic cells were pre-labeled with dichlorofluorescin diacetate dye and were incubated with phycoerythrin-labeled E. coli in the presence or absence of MGN-3. Phagocytosis and oxidative burst were assessed by flow cytometry. Results showed that treatment with MGN-3 enhanced the phagocytosis of E. coli by neutrophils and monocytes. This was associated with an increased oxidative burst. In addition, it caused a significant induction of cytokines (TNF-alpha, IL-6, IL-8 and IL-10); the effect was detected at 1 microg/ml and increased in a dose-dependent manner (P <or= 0.01). Notably, MGN-3 alone had no effect on the growth of 31 strains of bacteria suggesting that MGN-3 modulates phagocytic cellular function. These findings may have applications in the treatment of infections in the elderly and in immunocompromised patients.
Ghoneum
M
M
Department of Otolaryngology, Drew University of Medicine and Science, Los Angeles, CA 90059, USA. mghoneum@ucla.edu
Matsuura
M
M
Gollapudi
S
S
D001419:Bacteria / Q000187:drug effects; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis; D006801:Humans; D010586:Phagocytes / Q000187:drug effects* / Q000276:immunology; D010587:Phagocytosis / Q000187:drug effects*; D016897:Respiratory Burst / Q000187:drug effects; D014990:Xylans / Q000494:pharmacology*
D016207:Cytokines; D014990:Xylans; C419427:polysaccharide MGN3