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-alpha 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.
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-alpha 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.