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

Abstract

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 (AX A) contained a lower amount of protein (4.10%) than enzyme-extracted AX (AX E, 9.85%) and no ferulic acid (as compared with 43.5 mg/100 g in AX E). AX A consisted of a highly substituted population with a ratio of arabinose to xylose of 0.83 (AX E: 0.56), meanwhile the weight-average molecular weight of AX A (3.517 × 10 5 Da) was about 10 times that of AX E (3.252 × 10 4 Da). Both AX A and AX E had potent stimulating effects on innate and acquired immune responses on oral administration in female BALB/c mice. AX E showed higher macrophage phagocytosis and delayed hypersensitivity reaction than did AX A, 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.