Unveiling immunomodulatory effects of Euglena gracilis in immunosuppressed mice: Transcriptome and pathway analysis

The immunomodulatory effects of Euglena gracilis (Euglena) and its bioactive component, β-1,3-glucan (paramylon), have been clarified through various studies. However, the detailed mechanisms of the immune regulation remain to be elucidated. This study was designed not only to investigate the immunomodulatory effects but also to determine the genetic mechanisms of Euglena and β-glucan in cyclophosphamide (CCP)-induced immunosuppressed mice. The animals were orally administered saline, Euglena (800 mg/kg B.W.) or β-glucan (400 mg/kg B.W.) for 19 days, and CCP (80 mg/kg B.W.) was subsequently administered to induce immunosuppression in the mice. The mice exhibited significant decreases in body weight, organ weight, and the spleen index. However, there were significant improvements in the spleen weight and the spleen index in CCP-induced mice after the oral administration of Euglena and β-glucan. Transcriptome analysis of the splenocytes revealed immune-related differentially expressed genes (DEGs) regulated in the Euglena - and β-glucan-treated groups. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that pathways related with interleukin (IL)-17 and cAMP play significant roles in regulating T cells, B cells, and inflammatory cytokines. Additionally, Ptgs2, a major inflammatory factor, was exclusively expressed in the Euglena-treated group, suggesting that Euglena's beneficial components, such as carotenoids, could regulate these genes by influencing immune lymphocytes and inflammatory cytokines in CCP-induced mice. This study validated the immunomodulatory effects of Euglena and highlighted its underlying mechanisms, suggesting a positive contribution to the determination of phenotypes associated with immune-related diseases and the research and development of immunotherapies.

Combination of UHPLC-MS/MS with context-specific network and cheminformatic approaches for identifying bioactivities and active components of propolis

Discovering new bioactivities and identifying active compounds of food materials are major fields of study in food science. However, the process commonly requires extensive experiments and can be technically challenging. In the current study, we employed network biology and cheminformatic approaches to predict new target diseases, active components, and related molecular mechanisms of propolis. Applying UHPLC-MS/MS analysis results of propolis to Context-Oriented Directed Associations (CODA) and Combination-Oriented Natural Product Database with Unified Terminology (COCONUT) systems indicated atopic dermatitis as a novel target disease. Experimental validation using cell- and human tissue-based models confirmed the therapeutic potential of propolis against atopic dermatitis. Moreover, we were able to find the major contributing compounds as well as their combinatorial effects responsible for the bioactivity of propolis. The CODA/COCONUT system also provided compound-associated genes explaining the underlying molecular mechanism of propolis. These results highlight the potential use of big data-driven network biological approaches to aid in analyzing the impact of food constituents at a systematic level.

Evaluation of the Effects of Euglena gracilis on Enhancing Immune Responses in RAW264.7 Cells and a Cyclophosphamide-Induced Mouse Model

In this study we evaluated the immune-enhancing effects of β-glucan, the main component of Euglena gracilis (Euglena), and Euglena on inflammatory factor expression in RAW264.7 macrophages and ICR mice with cyclophosphamide-induced immunosuppression. Macrophages were treated with β-glucan or Euglena for 48 h. The β-glucan and Euglena groups exhibited higher levels of inducible nitric oxide synthase, nitric oxide, and tumor necrosis factor (TNF)-α than the control (vehicle alone) group. Animals were fed saline and β-glucan (400 mg/kg body weight (B.W.)) or Euglena (400 or 800 mg/kg B.W.) for 19 days, and on days 17-19, cyclophosphamide (CCP, 80 mg/ kg B.W.) was administered to induce immunosuppression in the ICR mouse model. CCP reduced the body weight, spleen index, and cytokine expression of the mice. To measure cytokine and receptor expression, splenocytes were treated with concanavalin A (ConA) or lipopolysaccharide (LPS) as a mitogen for 24 h. In vivo, ConA stimulation significantly upregulated the expression of interferon (IFN)-γ, interleukin (IL)-10, IL-12 receptor β1, IL-1β, and IL-2 in splenocytes from the β-glucan- or Euglena-treated groups compared with those in the splenocytes from the CCP-treated group; LPS stimulation increased the levels of the cytokines TNF-α, IL-1β, and IL-6 in splenocytes from the β-glucan- or Euglena- treated groups compared with those from the CCP-treated group, but most of these differences were not significant. These results demonstrate the effect of Euglena in ameliorating macrophages and immunosuppression in CCP-treated mice. Thus, Euglena has the potential to enhance macrophage- and splenocyte- mediated immune-stimulating responses.