title: Soyasaponin Ab ameliorates colitis by inhibiting the binding of lipopolysaccharide (LPS) to Toll-like receptor (TLR)4 on macrophages.
abstract: Many clinical studies have shown that daily intake of soybean [ Glycine max  (L.) Merr., Fabacease] or its foods may reduce the risk of osteoporosis, heart attack, hyperlipidemia, coronary heart disease, cardiovascular and chronic renal diseases, and cancers, including prostate, colon, and breast cancers. Of the soy constituents, soyasaponins exhibit anti-aging, antioxidant, apoptotic, and anti-inflammatory effects. However, the anti-inflammatory effect of soyasaponin Ab has not been thoroughly studied. Therefore, we investigated its anti-inflammatory effects in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitic mice and lipopolysaccharide (LPS)-stimulated peritoneal macrophages. Soyasaponin Ab inhibited colon shortening, myeloperoxidase activity, the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), and activation of the transcription factor nuclear factor-κB (NF-κB). Soyasaponin Ab (1, 2, 5, and 10 μM) inhibited the production of NO (IC(50) = 1.6 ± 0.1 μM) and prostaglandin E(2) (IC(50) = 2.0 ± 0.1 ng/mL), the expression of tumor necrosis factor (TNF)-α (IC(50) = 1.3 ± 0.1 ng/mL), interleukin (IL)-1β (IC(50) = 1.5 ± 0.1 pg/mL), and toll-like receptor (TLR)4, and the phosphorylation of interleukin-1 receptor-associated kinase (IRAK)-1 in LPS-stimulated peritoneal macrophages. Soyasaponin Ab weakly inhibited the phosphorylation of ERK, JNK, and p38. Soyasaponin Ab significantly reduced the binding of Alexa-Fluor-594-conjugated LPS to peritoneal macrophages. Soyasaponin Ab did not affect TLR4 expression or LPS-induced NF-κB activation in TLR4 siRNA-treated peritoneal macrophages (knockdown efficiency of TLR4 > 94%). On the basis of these findings, soyasaponin Ab may ameliorate colitis by inhibiting the binding of LPS to TLR4 on macrophages.
authors: Department of Life and Nanopharmaceutical Sciences, College of Pharmacy, Kyung Hee University, 1 Hoegi, Dongdaemun-gu, Seoul 130-701, Republic of Korea.
authors: In-Ah
authors: IA
authors: Lee
authors: Young-Jun
authors: YJ
authors: Park
authors: Eun-Ha
authors: EH
authors: Joh
authors: Dong-Hyun
authors: DH
authors: Kim
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D003092:Colitis / Q000139:chemically induced / Q000188:drug therapy*; D008070:Lipopolysaccharides / Q000378:metabolism* / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000737:chemistry* / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D012503:Saponins / Q000008:administration & dosage*; D051197:Toll-Like Receptor 4 / Q000187:drug effects / Q000378:metabolism*; D014302:Trinitrobenzenesulfonic Acid
chemical_list: D000893:Anti-Inflammatory Agents; D008070:Lipopolysaccharides; D012503:Saponins; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; C551307:soyasaponin Ab; D014302:Trinitrobenzenesulfonic Acid