Dieckol isolated from a brown alga, Eisenia nipponica, suppresses ear swelling from allergic inflammation in mouse

Se-rich tea polysaccharide extracted by high hydrostatic pressure attenuated anaphylaxis by improving gut microbiota and metabolic regulation

Selenium-rich tea polysaccharides (Se-TPS) were extracted via high hydrostatic pressure technology with a pressure of 400 MPa (200-500 MPa) for 10 min (3-20 min) at a material-to-solvent ratio of 1:40 (1:20-1:50). Subsequently, Se-TPS1-4 were isolated and purified, with Se-TPS3-4 as the main components. A spectral analysis proved that Se, which has antioxidant activity, existed. An in vitro study found that among Se-TPS, Se-TPS3-4 attenuated the release of β-hexosaminidase, histamine, and interleukin (IL)-4. Furthermore, in vivo experiments revealed that treatment with Se-TPS downregulated IL-4 levels and upregulated TGF-β and interferon-γ levels to improve imbalanced Th1/Th2 immunity in tropomyosin-sensitized mice. Moreover, Se-TPS promoted Lactobacillus and norank_f_Muribaculaceaek growth and upregulated metabolites such as genipin and coniferyl alcohol. Overall, these results showed the strong anti-allergy potential of Se-TPS by regulating mast cell-mediated allergic inflammatory responses and microbiota regulation, highlighting the potential of Se-TPS as a novel therapeutic agent to regulate allergy-associated metabolic disorders.

Preventive Effect of Ecklonia cava Extract on DSS-Induced Colitis by Elevating Intestinal Barrier Function and Improving Pathogenic Inflammation

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a complex gastrointestinal disorder with a multifactorial etiology, including environmental triggers, autoimmune mechanisms, and genetic predisposition. Despite advancements in therapeutic strategies for IBD, its associated mortality rate continues to rise, which is often attributed to unforeseen side effects of conventional treatments. In this context, we explored the potential of Ecklonia cava extract (ECE), derived from an edible marine alga known for its anti-inflammatory and antioxidant properties, in mitigating IBD. This study investigated the effectiveness of ECE as a preventive agent in a murine model of dextran sulfate sodium (DSS)-induced colitis. Our findings revealed that pretreatment with ECE significantly ameliorated colitis severity, as evidenced by increased colon length, reduced spleen weight, and histological improvements demonstrated by immunohistochemical analysis. Furthermore, ECE significantly attenuated the upregulation of inflammatory cytokines and mediators and the infiltration of immune cells known to be prominent features of colitis in mice. Notably, ECE alleviated dysbiosis of intestinal microflora and aided in the recovery of damaged intestinal mucosa. Mechanistically, ECE exhibited protective effects against pathogenic colitis by inhibiting the NLRP3/NF-κB pathways known to be pivotal regulators in the inflammatory signaling cascade. These compelling results suggest that ECE holds promise as a potential candidate for IBD prevention. It might be developed into a functional food for promoting gastrointestinal health. This research sheds light on the preventive potential of natural compounds like ECE in the management of IBD, offering a safer and more effective approach to combating this challenging disease.

Expression of interleukin-1β, interleukin-4, interferon-γ and tumour necrosis factor α in different tissue in a dinitrochlorobenzene-induced ear swelling test in mice

OBJECTIVE

To study the expression of interleukin-1β (IL-1β), interleukin-4 (IL-4), interferon-γ (IFN-γ) and tumour necrosis factor α (TNF-α) in different tissue in a dinitrochlorobenzene (DNCB)-induced ear swelling test in mice and further evaluate the correlation between the cytokine expression in different tissues and the degree of ear swelling.

METHODS

The mice were sensitised with a 0.50% DNCB solution on their back for 3 days. After 7 days, the thickness of their ears was measured and grouped. Different concentrations of the DNCB solution were challenged in the left ear of each group of mice, and the right ear was used as the control. The thickness of both ears was measured every 24 h, and the mice were sacrificed 72 h after the challenge. The expressions of IL-1β, IL-4, IFN-γ and TNF-α in the mouse serum, lymph node and ear tissue were quantified by enzyme-linked immunosorbent assay, respectively.

RESULTS

There was a linear positive correlation between the swelling index of the mouse lateral ear and the challenge concentration of DNCB (r = 0.96, p < 0.01). The high expression of IL-1β and IL-4 in the lateral ear tissue of the mice was positively correlated with the ear swelling index 48 h after the challenge. The correlation coefficient was 0.78 (p < 0.01). Furthermore, IFN-γ and TNF-α had no significant correlation with the ear swelling index 48 h after the challenge.

CONCLUSION

There is a correlation between the degree of ear swelling in mice and the concentration of DNCB and the expression of IL-1β and IL-4 in the lateral ear tissue. There is a sub-clinical skin sensitivity state in contact allergy.

The Anti-Allergic and Anti-Inflammatory Effects of Phlorotannins from the Edible Brown Algae, Ecklonia sp. and Eisenia sp

Because the number of people suffering from allergies has significantly increased, improved ways of treating these conditions by medical, pharmaceutical, and dietary means are required. Large numbers of studies on allergy have been conducted, and many anti-allergic compounds have been found. Phenolic compounds from terrestrial plants, including catechins and flavonoids, possess anti-allergic properties. Although polyphenols are present in some brown algae, their anti-allergic activities were not studied in detail before the 1990s. The focus was on the algal polyphenols, collectively called phlorotannins (eg., eckol, 6,6′-bieckol, 8,8′-bieckol, dieckol, and phlorofucofuroeckol-A), and research was conducted to clarify their anti-allergic activities. This review summarizes the anti-allergic effects of phlorotannins isolated from the brown alga, Eisenia nipponica, and related reports by other research groups.