Objective
We investigated the effects of hydrolyzed rice bran (HRB), an arabinoxylan extracted from rice bran, on mast cell degranulation and cytokine production.
Materials and methods
HRB was obtained by treating rice bran with an extract obtained from shiitake mushrooms. Bone marrow-derived mast cells (BMMCs) were prepared by culturing bone marrow cells from BALB/c mice in the presence of interleukin-3 and stem cell factor for 4 weeks. BMMCs were pretreated with HRB (0–3 mg/ml) for 30 min and were then antigen activated.
Results
Pretreatment of BMMCs with HRB significantly inhibited antigen-induced degranulation and cytokine production (tumor necrosis factor-α and interleukin-4) in a dose-dependent manner. HRB also diminished membrane fusion between liposomes in which soluble N-ethyl maleimide-sensitive factor attachment protein receptors were reconstituted. Phosphorylation of RelA and mitogen-activated kinases after antigen stimulation was suppressed by pretreatment of BMMCs with HRB.
Conclusions
These findings suggest that HRB may have an anti-inflammatory effect by inhibiting mast cell degranulation and cytokine production.