Cam RESEaRCH ExtRa The effects of arabinoxylan on dendritic cells New research suggests that arabinoxylan has beneficial effects on dendritic cells, the antigen presenting cells which play a key role in anti-tumour immunity. Nutritional Therapist Juliet Hayward, Ba (Hons), ma, DNN, reports on the studies involving BioBran. B iobran is rice bran that has been modified by hydrolysing enzymes from the shiitake mushroom. The main active component is of fluorescence intensity" ­ a measurement of antigen expression ­ of these two co-stimulatory molecules. The researchers deduced further evidence of dendritic maturation by the reduction in endocytic activity; the process by which the cell membrane is broken down to form organelles. Dendritic cells treated with Biobran and the cytokine mixes, out performed dendritic cells treated with cytokine mixes alone. The arabinoxylan also increased CD123 antigen fivefold on the DC surface. CD123 that suppress DC maturation, such as interleukin 10, prostaglandin 2, vascular endothelial growth factor and transforming growth factor beta. (6) antigen is also known as an interleukin 3 receptor. It transmits the interleukin 3 signal and is considered an important cytokine. (7) The hope is that by improving dendritic maturation, the supplement will create a hostile environment for tumours, improve immunological suppression and prove to be an invaluable tool for people trying to regain their health. References 1. ghoneum m and Jewett a. Production of tumour necrosis factor-alpha and interferon-gamma from human peripheral blood lymphocytes by mgN-3, a modified arabinoxylan from rice bran, and its synergy with interleukin-2 in vitro. Cancer Detect Prev 2000; 24: 314-324. 2. ghoneum m and abedi S. Enhancement of natural killer cell activity of aged mice by modified arabinoxylan rice bran (mgN -3/Biobran). J Pharm Pharmacol 2004; 56: 1581-1588. 3. Kim Hy et al. a polysaccharide extracted from rice bran fermented with Lentinus edodes enhances natural killer cell activity and exhibits anticancer effects. J med Food 2007; 10: 25-31. 4. Perrot I et al. Dendritic cells infiltrating human non-small cell lung cancer are blocked at immature stage. J Immunol 2007; 178: 2763-2769. 5. Lutz mB and Schuler g. Immature, semi-mature and fully mature dendritic cells: which signals induce tolerance or immunity? trends Immunol 2002; 23: 445-449. 6. Rabinovich ga et al. Immunosuppressive strategies that are mediated by tumour cells. annu Rev immunol 2007; 25: 267-296. 7. Cholujova D, Jakubikova J, Sedlak J. Biobran ­ augmented maturation of human monocyte-derived dendritic cells. Neoplasma: 2009; 56 (2): 89-95. arabinoxylan, a type of hemicellulose. In earlier research the supplement was found to have immunomodulatory effects on NK cells, macrophages, T and B lymphocytes. (1,2,3). Scientists found that it enhanced NK activity, and increased the production of tumour necrosis factor and interferon. There is now new research on its effects on dendritic cells. Dendritic cells are antigen presenting cells, which play a key role in anti-tumour immunity. Dendritic cells should not be confused with neurons; they have no relationship with them. There are different subsets of dendritic cells. There are myeloid dendritic cells that stimulate T cells and secrete interleukin 2 and plasmacytoid dendritic cells that resemble plasma cells and produce interferon-alpha. They are found in the tissues that are in contact with the external environment, such as lungs, nose, skin, stomach and intestines. When in their immature state they are also found in the blood. Once they have matured they grow branch-like projections called dendrites, from which they receive their name. Once activated and loaded with antigens, they migrate to the lymphoid tissue and interact with T cells and B cells, to initiate and shape an immune response towards invading antigens. However, if a non-activated immature dendritic cell (iDC) presents antigens to T cells without the co-stimulation of key molecules, the antigens are tolerated rather than acted upon. Activation and maturation of the DC should be initiated when they encounter pathogens, lymphocytes, cytokines and the products of damaged tissues. The maturation process involves the transportation of molecules ­ entrusted with lymphocyte recognition and antigen presentation ­ to the cell surface. There are changes to the structure and shape of the cell, greater motility and an increased output of cytokines. Both the myeloid dendritic cell (mDC) and the plasmacytoid dendritic cell (pDC) were found to infiltrate many types of human tumours, but the majority of DC penetrating the tumour were immature; unable to mount an attack on the neoplasm. (4,5) Tumours also produce factors In vitro research Encouraging the maturation of dendritic cells through a dietary supplement is an attempt to fundamentally improve this situation and the in vitro research has shown great promise. Dana Cholujova, Jana Jakubikova and Jan Sedlak from the Laboratory of Tumour Immunology at the Cancer Research Institute in Bratislava, undertook the research. They treated peripheral monocytes with interleukin 4 and granulocyte macrophage colony stimulating factor (GM-CSF) to produce immature dendritic cells. The dendritic cells were further treated with a cytokine maturation mix, which either contained TNF-a and interleukin 1 and 6 or a mix of interferon and lipopolysaccharide (an endotoxin that induces the secretion of pro-inflammatory cytokines). Different concentrations of Biobran were then added to the DC (10, 100, 400 and 1000 ug/ml) either with the cytokine maturation mix or without it. The dendritic cells that were matured with Biobran, GM-CSF and IL-4 were found to have increased levels of CD83. CD83 is both an immunoglobulin and marker of dendritic maturation. CD80 is a molecule found on activated B cells and monocytes, which primes T cells against antigens presented by the antigen presenting c ells. When they treated the iDC with the supplement, there found a greater abundance of CD80 on the cell surface. There was also more CD86, a protein that sends stimulatory signals aimed at T cells activation. The supplement considerably increased the "mean about the author Juliet Hayward, BA (Hons), MA, DNN, is a Nutritional Therapist and member of the British Association for Applied Nutrition and Nutritional Therapy (BANT). She works at the Harley Street Therapy Centre. She has worked with Biobran for 9 years and currently does consultancy work for the Really Healthy Company. 26 cam may 2009 www.Cam-mag.Com research.indd 26 23/4/09 10:13:20