title: Characterization of Nitric Oxide Modulatory Activities of Alkaline-Extracted and Enzymatic-Modified Arabinoxylans from Corn Bran in Cultured Human Monocytes.
abstract: The ingestion of foods and food-derived substances that may mediate the immune system is widely studied. Evidence suggests cereal arabinoxylans (AXs) have immunomodulatory activities that may impart health benefits in terms of immune enhancement. This study extracted AXs from corn bran using alkali and developed a modification process using three endoxylanases to obtain fractions of lower molecular weight ranges. In vitro studies showed extracted and modified AXs significantly (P < 0.05) elevated nitric oxide (NO) synthesis by the human U937 monocytic cell line (ranging from 53.7 ± 1.1 to 62.9 ± 1.2 μM per million viable cells) at all concentrations tested (5-1000 μg/mL), indicative of immune enhancement compared to an untreated control (43.7 ± 1.9 μM per million viable cells). The study suggested the dose range and Mw distribution of AXs are key determinants of immune-modulatory activity. AXs in the low Mw range (0.1-10 KDa) were the most effective at inducing NO secretion by U937 macrophages at low AX concentration ranges (5-50 μg/mL), with NO production peaking at 62.9 ± 1.2 μM per million viable cells with 5 μg/mL of AX (P = 0.0009). In contrast, AXs in the high Mw range (100-794 kDa) were most effective at inducing NO at high AX concentration ranges (500-1000 μg/mL) with NO production reaching a maximum of 62.7 ± 1.3 μM per million viable cells at 1000 μg/mL of AX (P = 0.0011). The findings suggest that dietary AXs from corn bran may heighten innate immune responses in the absence of infection or disease.
authors.affiliation: Department of Food and Tourism Management, Manchester Metropolitan University , Manchester M15 6BG, U.K.
authors.forename: Zhengxiao
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Institute of Food Science and Innovation, University of Chester , Chester CH1 4BJ, U.K.
authors.forename: Christopher
authors.initials: C
authors.lastname: Smith
authors.affiliation: Institute of Food Science and Innovation, University of Chester , Chester CH1 4BJ, U.K.
authors.forename: Weili
authors.initials: W
authors.lastname: Li
authors.affiliation: School of Healthcare Science, Manchester Metropolitan University , E203 John Dalton Building, Chester Street, Manchester M1 5GD, U.K.
authors.forename: Jason
authors.initials: J
authors.lastname: Ashworth
mesh_terms: D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D005591:Chemical Fractionation; D004798:Enzymes / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008970:Molecular Weight; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D014990:Xylans / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D004798:Enzymes; D014990:Xylans; D009569:Nitric Oxide; C085118:arabinoxylan
keywords: arabinoxylan; corn bran; immune-modulatory activity; in vitro; molecular weight