title: Glycyrrhetinic acid extracted from Glycyrrhiza uralensis Fisch. induces the expression of Toll-like receptor 4 in Ana-1 murine macrophages.
abstract: Glycyrrhetinic acid (GA) is an active component of licorice root that has long been used as a herbal medicine for the treatment of peptic ulcer, hepatitis, and pulmonary and skin diseases in Asia and Europe. In this study, we analyzed the effect of GA extracted from Glycyrrhiza uralensis Fisch. on the expression of Toll-like receptors (TLRs) that play key roles in regulating the innate immune response against invading pathogens. Stimulation of Ana-1 murine macrophages with GA induced a significant dose-dependent expression of TLR-4, and its mRNA expression that increased from 3-h post-treatment was approximately fivefold over the level in the mock-treated cells. No endotoxin contamination contributed to the GA-induced TLR-4 expression, because polymyxin B treatment did not alter the upregulated expression of TLR-4 in GA-treated cells. Several molecules, such as myeloid differentiation factor 88, interferon-β, and interleukin-6, which are involved in the TLR-4 downstream signaling pathway, were upregulated significantly in response to GA stimulation. Our findings demonstrate that GA is able to induce the expression of TLR-4 and activate its downstream signaling pathway.
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China.
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Peng
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Ya-Feng
authors.initials: YF
authors.lastname: Qiu
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Miao
authors.forename: Xiao-Qi
authors.initials: XQ
authors.lastname: Gao
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhou
authors.forename: Zi-Xue
authors.initials: ZX
authors.lastname: Shi
authors.forename: Yong-Li
authors.initials: YL
authors.lastname: Xu
authors.forename: Dong-Hua
authors.initials: DH
authors.lastname: Shao
authors.forename: Jian-Chao
authors.initials: JC
authors.lastname: Wei
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Ma
mesh_terms: D000818:Animals; D006034:Glycyrrhetinic Acid / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D029882:Glycyrrhiza uralensis / Q000737:chemistry*; D006801:Humans; D008264:Macrophages / Q000187:drug effects*; D051379:Mice; D015394:Molecular Structure; D015398:Signal Transduction / Q000187:drug effects; D051197:Toll-Like Receptor 4 / Q000187:drug effects* / Q000235:genetics
chemical_list: D051197:Toll-Like Receptor 4; D006034:Glycyrrhetinic Acid