Comparison of the immunological activities of arabinoxylans from wheat bran with alkali and xylanase-aided extraction

Differences in immunoregulatory activities of arabinoxylans (AXs) from wheat bran extracted by alkaline- and enzyme-based methods are unknown. We extracted AX from wheat bran by the 2 procedures. Chemical analysis revealed that alkaline-extracted AX (AXA) contained a lower amount of protein (4.10%) than enzyme-extracted AX (AXE, 9.85%) and no ferulic acid (as compared with 43.5 mg/100 g in AXE). AXA consisted of a highly substituted population with a ratio of arabinose to xylose of 0.83 (AXE: 0.56), meanwhile the weight-average molecular weight of AXA (3.517 × 105 Da) was about 10 times that of AXE (3.252 × 104 Da). Both AXA and AXE had potent stimulating effects on innate and acquired immune responses on oral administration in female BALB/c mice. AXE showed higher macrophage phagocytosis and delayed hypersensitivity reaction than did AXA, with no significant differences in enhancing lymphocyte proliferation. Whether extracted by alkaline- or enzyme-aided methods, the obtained AXs could be explored as potent natural immunomodulators.