Sea Cucumber Lipid-Soluble Extra Fraction Prevents Ovalbumin-Induced Allergic Airway Inflammation

Abstract

In a previous study, our research group demonstrated that sea cucumber (Apostichopus japonicus) extracts ameliorated allergic airway inflammation through CD4CD25Foxp3 T (regulatory T; Treg) cell activation and recruitment to the lung. In this study, we aimed to determine which components of sea cucumber contribute to the amelioration of airway inflammation. We used n-hexane fractionation to separate sea cucumber into three phases (n-hexane, alcohol, and solid) and evaluated the ability of each phase to elevate Il10 expression in splenocytes and ameliorate symptoms in mice with ovalbumin (OVA)/alum-induced asthma. Splenocytes treated with the n-hexane phase showed a significant increase in Il10 expression. In the n-hexane phase, 47 fatty acids were identified. Individual fatty acids that comprised at least 5% of the total fatty acids were 16:0, 16:1n-7, 18:0, 18:1n-7, 20:4n-6, and 20:5n-3 (eicosapentaenoic acid). After administering the n-hexane phase to mice with OVA/alum-induced asthma, their asthma symptoms were ameliorated. Several immunomodulatory effects were observed in the n-hexane phase-pretreated group, compared with a vehicle control group. First, eosinophil infiltration and goblet cell hyperplasia were significantly reduced around the airways. Second, the concentrations of Th2-related cytokines (IL-4, IL-5, and IL-13) and Th17-related cytokines (IL-17) were significantly decreased in the spleen and bronchoalveolar lavage fluid (BALF). Finally, the concentrations of TGF-β and IL-10, which are associated with Treg cells, were significantly increased in the BALF and splenocyte culture medium. In conclusion, a fatty acid-rich fraction (n-hexane phase) of sea cucumber extract ameliorated allergic airway inflammation in a mouse model.

Effects of Diets Containing Different Concentration of Saccharina japonica Algae on Growth and Interleukin (IL)-10 Gene Expression of Juvenile Sea Cucumber Apostichopus japonicus

“…Interleukin (IL)-10 gene expression level were significantly affected by different experimental diets fed sea cucumbers extract. IL-10 is an antiinflammatory cytokine, secreted by Treg cells, suppress immune responses and also can inhibit the synthesis of pro--inflammatory cytokines, protect against asthma disease [47]. In the present study, we found that (IL)-10 gene expression level significantly increased in the spleen of mice induced by 10 and 15% Saccharina japonica diets fed sea cucumbers extracts.…”

Marine-Derived Compounds for the Potential Treatment of Glucocorticoid Resistance in Severe Asthma

“…A component of this extract, n-hexane, a fatty-acid-rich fraction, ameliorated allergic airway inflammation in a mouse model of ovalbumin-induced asthma: eosinophil infiltration and goblet cell hyperplasia were significantly reduced around the airways, and the concentrations of Th2-related cytokines (IL-4, IL-5, and IL-13) and Th17-related cytokines (IL-17) were significantly decreased in the spleen and bronchoalveolar lavage fluid [88].…”

“…Experimental studies with marine compounds demonstrating their effectiveness in in vitro or in vivo models of bronchial asthma are scarce [84][85][86][87][88]. On the other hand, recent studies revealed the significant potential of marine compounds to interfere with molecular mechanisms similar to those involved in GC-resistant asthma.…”

Structures and Anti-Allergic Activities of Natural Products from Marine Organisms

“…Lee et al [ 59 ] investigated the anti-allergic activity of sea cucumber and demonstrated that the liquid salting-out extract of sea cucumber activated and recruited regulatory T and Treg cells that improved allergic airway inflammation. Moreover, sea cucumber extract rich in palmitoleic acid inhibited IgE better than extracts poor in palmitoleic acid, whereas palmitoleic acid lowers serum total immunoglobulin E (IgE) concentrations.…”