Edible algae (Ecklonia cava) bioprocessed with mycelia of shiitake (Lentinula edodes) mushrooms in liquid culture and its isolated fractions protect mice against allergic asthma.

BACKGROUND: Ecklonia cava is an edible marine brown alga harvested from the ocean that is widely consumed in Asian countries as a health-promoting medicinal food The objective of the present study is to evaluate the anti-asthma mechanism of a new functional food produced by bioprocessing edible algae Ecklonia cava and shiitake Lentinula edodes mushroom mycelia and isolated fractions. METHODS: We used as series of methods, including high performance liquid chromatography, gas chromatography, cell assays, and an in vivo mouse assay to evaluate the asthma-inhibitory effect of Ecklonia cava bioprocessed (fermented) with Lentinula edodes shiitake mushroom mycelium and its isolated fractions in mast cells and in orally fed mice. RESULTS: The treatments inhibited the degranulation of RBL-2H3 cells and immunoglobulin E (IgE) production, suggesting anti-asthma effects in vitro. The in vitro anti-asthma effects in cells were confirmed in mice following the induction of asthma by alumina and chicken egg ovalbumin (OVA). Oral administration of the bioprocessed Ecklonia cava and purified fractions suppressed the induction of asthma and was accompanied by the inhibition of inflammation- and immune-related substances, including eotaxin; thymic stromal lymphopoietin (TSLP); OVA-specific IgE; leukotriene C4 (LTC4); prostaglandin D2 (PGD2); and vascular cell adhesion molecule-1 (VCAM-1) in bronchoalveolar lavage fluid (BALF) and other fluids and organs. Th2 cytokines were reduced and Th1 cytokines were restored in serum, suggesting the asthma-induced inhibitory effect is regulated by the balance of the Th1/Th2 immune response. Serum levels of IL-10, a regulatory T cell (Treg) cytokine, were increased, further favoring reduced inflammation. Histology of lung tissues revealed that the treatment also reversed the thickening of the airway wall and the contraction and infiltration of bronchial and blood vessels and perialveolar inflammatory cells. The bioprocessed Ecklonia cava/mushroom mycelia new functional food showed the highest inhibition as compared with commercial algae and the fractions isolated from the bioprocessed product. CONCLUSIONS: The in vitro cell and in vivo mouse assays demonstrate the potential value of the new bioprocessed formulation as an anti-inflammatory and anti-allergic combination of natural compounds against allergic asthma and might also ameliorate allergic manifestations of foods, drugs, and viral infections.

Effects of a thromboxane-receptor antagonist, BAY u 3405, on prostaglandin D2- and exercise-induced bronchoconstriction.

In the pathogenesis of exercise-induced bronchoconstriction (EIB), prostaglandin D2 (PGD2) may play a role as a newly generated, mast cell-derived mediator. As the bronchoconstrictor effects of PGD2 are predominantly mediated via stimulation of thromboxane receptors in the lung, we studied a novel, orally effective, thromboxane-receptor antagonist, BAY u 3405, on EIB in 12 male subjects with mild asthma. On 4 study days, we determined, in a randomized, double-blind, placebo-controlled, crossover fashion, the effects of 20 mg of BAY u 3405 administered orally 1 hour before PGD2 and exercise challenges, respectively. Increasing dosages of PGD2 were inhaled to establish dose-response curves that allowed determination of the provocative concentration necessary to decrease FEV1 by at least 20% (PC20) and to increase specific airway resistance (SR(aw)) by 100% (PC100). EIB was measured as a maximal fall/increase in postexertional FEV1/SR(aw) after bicycle exercise and cold-air breathing. Prechallenge lung-function values were similar on all four occasions. BAY u 3405 did not elicit any effect on resting bronchial tone. After placebo, the geometric means (SD) of PC20 and PC100 were 0.0380 (2.6) and 0.0266 (2.4) mg/ml, increasing to 0.554 (5.9) and 0.143 (8.1) mg/ml after BAY u 3405 (p = 0.0002). Mean (SD) maximal postexertional decrease in FEV1 and increase in SR(aw) after placebo was 29.4% (16.4%) and 280% (135%), and after BAY u 3405, 31.4% (18.1%) and 379% (281%) (not significant). No clinically relevant BAY u 3405-related side effects were observed. From these results we conclude that BAY u 3405 is highly effective in attenuating PGD2-induced bronchoconstriction.(ABSTRACT TRUNCATED AT 250 WORDS)