Three phlorotannins from Sargassum carpophyllum are effective against the secretion of allergic mediators from antigen-stimulated rat basophilic leukemia cells

• Published in: Food chemistry Vol. 377; p. 131992
• Main Authors: Matsui, Takuya, Ito, Chihiro, Itoigawa, Masataka, Shibata, Toshiyuki
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 30.05.2022
• Subjects: Animals; Fuhalol-type phlorotannin; Hypersensitivity; Immunoglobulin E; Leukemia; Mast Cells; Proteasome; Rat basophilic leukemia (RBL-2H3) cells; Rats; Sargassum; Sargassum carpophyllum; PGD2; Sargassum carpophyllum; COX-2; Fuhalol-type phlorotannin; IgE; LC/MS; DCFH-DA; DNP-HSA; Ca2; FDR; IC50; ROS; Rat basophilic leukemia (RBL-2H3) cells; HPLC; Proteasome
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2021.131992

•Three known phlorotannins were isolated from Sargassum carpophyllum.•The phlorotannins suppressed the secretion of allergic mediators in RBL-2H3 cells.•The phlorotannins have anti-allergic effects involving the IκB-proteosome pathway. Sargassum carpophyllum (Sargassaceae) is a brown seaweed that contains phlorotannins, which are phloroglucinol polymers with reported anti-inflammatory activities. The phlorotannins 2-[2-(3,5-dihydroxyphenoxy)-3,5-dihydroxyphenoxy]-1,3,5-benzenetriol (1), 2,2′-[[2-(3,5-dihydroxyphenoxy)-5-hydroxy-1,3-phenylene]bis(oxy)]bis(1,3,5-benzenetriol) (2), and 2-[2-[4-[2-(3,5-dihydroxyphenoxy)-3,5-dihydroxyphenoxy]-3,5-dihydroxyphenoxy]-3,5-dihydroxyphenoxy]-1,3,5-benzenetriol (3) were isolated from S. carpophyllum. Here, we evaluated the anti-allergic activities of these compounds and comprehensively explored their effects on intracellular protein levels. Immunoglobulin E-sensitized rat basophilic leukemia cells pretreated with any of these three compounds exhibited reduced β-hexosaminidase, prostaglandin D2, and tumor necrosis factor-α secretion compared with dinitrophenyl-human serum albumin (DNP-HSA)-stimulated cells. Reduction of β-hexosaminidase release was dose-dependent but the half-maximal inhibitory concentrations of the compounds were similar (36–51 μM). Proteomics analysis revealed that the three compounds up-regulated 25 proteins and down-regulated 33 proteins compared with DNP-HSA stimulation alone, and slightly suppressed proteasome 5 expression linked to the regulation of IκB. These results demonstrate that these phlorotannins are potentially useful for preventing immediate hypersensitivity. S. carpophyllum may be a functional food.