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Penta‐ O ‐galloyl‐ β ‐ D ‐glucose ameliorates inflammation by inhibiting MyD 88/ NF ‐ κB and MyD 88/ MAPK signalling pathways
Author(s) -
Jang SeEun,
Hyam Supriya R,
Jeong JinJu,
Han Myung Joo,
Kim DongHyun
Publication year - 2013
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/bph.12333
Subject(s) - chemistry , lipopolysaccharide , inflammation , mapk/erk pathway , receptor , flow cytometry , tumor necrosis factor alpha , microbiology and biotechnology , nf κb , pharmacology , signal transduction , biochemistry , biology , immunology
Background and Purpose The gallnut of R hus chinensis MILL and its main constituent penta‐ O ‐galloyl‐ β ‐ D ‐glucose ( PGG ) inhibited NF ‐ κB activation in LPS ‐stimulated peritoneal and colonic macrophages. Here we have investigated PGG mechanisms underlying anti‐inflammatory effects of PGG in vitro and in vivo . Experimental Approach Male C57BL /6 mice (18–22 g, 6 weeks old) were used to prepare peritoneal and colonic macrophages and for the induction of colitis by intrarectal administration of 2,3,4‐trinitrobenzene sulphonic acid ( TNBS ). A range of inflammatory markers and transcription factors were evaluated by elisa , immunoblotting, flow cytometry and confocal microscopy. Key Results Expression of Toll‐like receptor ( TLR )‐4 or Lipopolysaccharide ( LPS ) binding to TLR ‐4 in LPS ‐stimulated peritoneal macrophages was not affected by PGG. However PGG inhibited binding of an anti‐ MyD 88 antibody to peritoneal macrophages, but did not reduce binding of anti– IL ‐1 receptor‐associated kinase ( IRAK1 ) and IRAK4 antibodies to the macrophages with or without transfection with MyD 88 siRNA . PGG potently reduced the activation of IRAK1 , NF ‐ κB , and MAPKs in LPS ‐ or pepetidoglycan‐stimulated peritoneal and colonic macrophages. PGG suppressed IL ‐1 β , TNF ‐ α and IL ‐6 in LPS ‐stimulated peritoneal macrophages, while increasing expression of the anti‐inflammatorycytokine IL ‐10. Oral administration of PGG inhibited colon shortening and myeloperoxidase activity in mice with TNBS ‐induced colitis, along with reducing NF ‐ κB activation and IL ‐1 β , TNF ‐ α , and IL ‐6 levels, whereas it increased IL ‐10. Conclusions and Implications PGG reduced activation of NF ‐ κB and MAPK signalling pathways by directly interacting with the MyD 88 adaptor protein. PGG may ameliorate inflammatory diseases such as colitis.