Activation of macrophages stimulated by the bengkoang fiber extract through toll-like receptor 4.
Bengkoang (Pachyrhizus erosus (L.) Urban) is an edible root tuber containing fairly large amounts of carbohydrates and crude fibers. Our previous studies showed that the bengkoang fiber extract (BFE) stimulates activation of macrophages, leading to induction of phagocytotic activity and cytokine production. In the present study we investigated the mechanism underlying activation of murine macrophages by BFE. BFE increased production of TNF-α, IL-6, and nitric oxide by J774.1 cells. In addition BFE also facilitated the gene expression levels of inducible nitric oxide synthase. We examined the effect of a TLR4 inhibitor on cytokine production to investigate the membrane receptor of macrophage activation by BFE. Treatment of J774.1 cells with the TLR4 inhibitor significantly inhibited production of IL-6 and TNF-α, suggesting that TLR4 is the target membrane receptor for BFE. The main signal molecules located downstream of TLR4 such as JNK, p38, ERK, and NF-κB were activated by BFE treatment. The immunostimulatory effect of BFE was cancelled by the pectinase treatment, suggesting that the active ingredient in BFE is pectin-like molecules. Overall results suggested that BFE activates J774.1 cells via the MAPK and NF-κB signaling pathways.
Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan. mars95@agr.ehime-u.ac.jp.
Ika Dyah
ID
Kumalasari
Kosuke
K
Nishi
Agus Budiawan Naro
AB
Putra
Takuya
T
Sugahara
D000818:Animals; D002460:Cell Line; D004043:Dietary Fiber / Q000494:pharmacology*; D056747:Immunomodulation; D015850:Interleukin-6 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000009:adverse effects; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects*; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D011096:Polygalacturonase / Q000378:metabolism; D015398:Signal Transduction; D051197:Toll-Like Receptor 4 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D004043:Dietary Fiber; D015850:Interleukin-6; D008070:Lipopolysaccharides; D016328:NF-kappa B; D010936:Plant Extracts; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D011096:Polygalacturonase