Consumption of diets fortified with edible mushrooms alters IL‐6 secretion in vivo and in vitro and spleen cell proliferation in dextran sodium sulfate (DSS)‐treated mice

Abstract

Exotic mushrooms (e.i. shiitake – SM) have long been used in ancient Chinese medicine for treatment and prevention of chronic inflammatory diseases. However, little scientific data exist on the health benefits of white button (WM) and portabello (PM) mushrooms commonly consumed in the US. We investigated the capacity of WB, PM, and SM to modulate IL‐6 secretion in vivo and in vitro and spleen cell proliferation in two‐month old C57BL/6 mice fed either the AIN76 diet, or the same diet fortified with 5% dry mushrooms (16/group). After 6 weeks, 8 mice in each group received 3% DSS in drinking water (an experimental model for colitis) or plain water. Upon euthanasia, spleen cells were activated with Con A and LPS (2.5 μg/ml). In control, but not DSS‐treated mice, spleen cell proliferation was higher in mice fed WM and PM fortified diets than in those fed SM‐diet. In control mice, consumption of mushroom‐ diets was associated with lower plasma IL‐6 levels, with the greatest benefit observed with SM. In DSS‐treated mice, all mushrooms significantly increased plasma IL‐6 levels (p<0.05). Mushrooms reduced baseline in vitro IL‐6 secretion but had no effect in Con A‐treated cells. Reduced plasma IL‐6 levels in control mice may modulate CRP level, a risk factor for cardiovascular disease. Increased plasma IL‐6 levels in DSS‐treated mice may be beneficial because they would down‐regulate blood levels of proinflammatory cytokines.