Glossogyne tenuifolia acts to inhibit inflammatory mediator production in a macrophage cell line by downregulating LPS-induced NF-κB

Abstract

Glossogyne tenuifolia (hsiang-ju) (GT) is a traditional antipyretic herb used in Chinese medicine; however, no information is available to explain its action. The objective of this research was to elucidate the molecular pharmacological activity and the effective components in the ethanol extract of GT. We found that GT had potent anti-inflammatory effects on the lipopolysaccharide (LPS)-activated murine macrophages, RAW264.7. GT downregulated LPS-induced expression of inducible nitric oxide synthase (iNOS) by blocking its transcription. GT also caused a dose-dependent inhibition of the release of prostaglandin E(2) by repressing the promoter activity of the inducible cyclooxygenase (COX-2) gene. Moreover, GT exerted a dose-dependent inhibition of the LPS-stimulated release of the proinflammatory cytokines, TNF-alpha, IL-1 beta, IL-6, and IL-12. To determine the mechanism by which GT inhibits LPS signaling, we focused on nuclear factor-kappa B (NF-kappa B) activation. Western blot analysis revealed that GT abolished LPS-induced inhibitor-kappa B phosphorylation. The electrophoretic mobility shift assay demonstrated that GT abolished LPS-mediated kappa B DNA binding activity. Moreover, macrophages were transfected with a vector coding for the luciferase reporter gene under the control of NF-kappa B cis-acting elements, and the transfected macrophages showed that the LPS-stimulated luciferase activity was GT-sensitive. These results suggest that GT attenuates inflammatory mediator synthesis of activated macrophages through an NF-kappa B-dependent pathway. The active components of GT were identified as oleanolic acid and luteolin-7-glucoside. Both of these compounds inhibited LPS-stimulated inflammatory mediator production and NF-kappa B activation. We conclude that GT inhibits NF-kappa B-mediated gene expression and downregulates inflammatory mediator production in murine macrophages.

Medicinal chemistry and pharmacology of genus Tripterygium (Celastraceae)

“…At low concentrations (up to 3 μM), oleanolic acid (83) inhibited release of TNF-α, IL-1β, and IL-6 (Wu et al, 2004). 3-Epikatonic acid (86) inhibited production of IL-2, IL-8, and TNF-α; triptotriterpenonic acid A (89) and 2α,3β-dihydroxy-olean-12-ene-22,29-lactone (95) inhibited IL-2 production (Duan et al, 2000(Duan et al, , 2001a.…”

“…Oleanolic acid (83) is a good inhibitor of adenosine deaminase (EC 3.5.4.4) (Koch et al, 1994), one isoform of which is increased in many cancers and immune diseases. This compound also inhibited production of NO and PGE 2 (Wu et al, 2004). Wilforol C (91) has been patented as a leukotriene antagonist .…”

“…Oleanolic acid (83) blocked NF-κB-mediated gene activation (Wu et al, 2004). At higher concentrations, however, it activated NF-κB, increased binding of NF-κB to DNA, and stimulated expression of iNOS and TNF-α by increasing levels of the mRNAs for these proteins (Choi et al, 2001); these are proinflammatory effects.…”

Immunomodulatory mechanism of the aqueous extract of sword brake fern (Pteris ensiformis Burm.)

“…The murine COX-2 promoter plasmid (pCOX2/GL3) containing a 731-bp promoter fragment, −724 to +7 relative to the transcription start, was constructed as described previously (Wu et al, 2004). A luciferase reporter plasmid, pNF-B-Luc, which contains six B cis-acting elements was purchased from Stratagene (La Jolla, CA).…”

Biomedical Vignette

“…Wu et al [37] report that the ethanol extract of G. tenuifolia exhibits potent anti-inflammatory efficacy on an LPS-activated murine macrophage cell line. It also exerts dose-dependent inhibition of the LPS-stimulated release of the proinflammatory cytokines TNF-␣, IL-1␤, IL-6 and IL-12 through inhibition of NF-B gene expression.…”