Anti-inflammatory effect of the six compounds isolated from Nauclea officinalis Pierrc ex Pitard, and molecular mechanism of strictosamide via suppressing the NF-κB and MAPK signaling pathway in LPS-induced RAW 264.7 macrophages.

Nauclea officinalis Pierrc ex Pitard. is a Chinese medicinal herb that contains high level of alkaloids which is the most abundant and active constituent. Strictosamide isolated from Nauclea officinalis Pierrc ex Pitard. showed significant effects on inflammatory response, compared with pumiloside, 3-epi-pumiloside, vincosamide, 3α,5α-tetrahydrodeoxycordifoline lactam and naucleamide A-10-O-β-D-glucopyranoside of this plant. we investigated the biological activities of the six compounds mentioned-above, and the underlying molecular mechanism exerted by the most potent one, strictosamide. The effects of strictosamide and other five compounds on the inhibitory activity of nitric oxide (NO) were screened by Griess test. The contents of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in media were detected by using Enzyme-linked immunosorbent (ELISA) kits. The effects on the mRNA expression of nitric oxide synthase (iNOS), TNF-α and IL-1β of strictosamide were further investigated by RT-qPCR. Western blot assay was conducted to illustrate the effects of strictosamide on iNOS and phosphorylation of p65, inhibitor of NF-κB (IκB)-α, IκB-kinase (IKK)-α as well as p-extracellular signal-regulated kinase (ERK), p-c-jun N-terminal kinase (JNK) and p-p38 in the protein levels. Strictosamide potently suppressed the productions of NO, TNF-α and IL-1β in LPS-induced RAW 264.7 macrophages, and it dose-dependently alleviated the LPS-simulated protein level of iNOS as well as the mRNA expressions of iNOS, TNF-α and IL-1β. In addition, molecular data revealed that strictosamide markedly decreased the expressions of p-p65, p-IκBα and p-IKKα. Furthermore, strictosamide significantly attenuated LPS-induced the phosphorylation of p38, ERK and JNK. At present study, the results indicated that the anti-inflammatory activity of strictosamide was associated with the restraint of NO, TNF-α and IL-1β via negative regulation of both NF-κB and mitogen-activated protein kinases (MAPKs) in LPS-induced RAW 264.7 cells.

Li D ，Chen J ，Ye J ，Zhai X ，Song J ，Jiang C ，Wang J ，Zhang H ，Jia X ，Zhu F ... -  《-》

Nauclea officinalis inhibits inflammation in LPS-mediated RAW 264.7 macrophages by suppressing the NF-κB signaling pathway.

Nauclea officinalis has been traditionally used in China for the treatment of fever, pneumonia and enteritidis etc. This study aims to investigate effects of N. officinalis on the inflammatory response as well as the possible molecular mechanism in LPS-stimulated RAW 264.7 murine macrophage cells. Anti-inflammatory activity of N. officinalis (10, 20, 50, and 100µg/mL) was investigated by using LPS-induced RAW 264.7 macrophages. The NO production was determined by assaying nitrite in culture supernatants with the Griess reagent. The levels of TNF-α, IL-6 and IL-1β in culture media were measured with ELISA kits. Real time fluorescence quantitative PCR was detected for mRNA expression of iNOS, TNF-α, IL-6 and IL-1β. Western blot assay was performed to illustrate the inhibitory effects of N. officinalis on phosphorylation of IκB-α and NF-κB p65. Treatment with N. officinalis (10-100µg/mL) dose-dependently inhibited the production as well as mRNA expression of NO, TNF-α, IL-6 and IL-1β in RAW 264.7 macrophages. Western blot assay suggested that the mechanism of the anti-inflammatory effect was associated with the inhibition of phosphorylation of IκB-α and NF-κB p65. The results indicated that N. officinalis potentially inhibited the activation of upstream mediator NF-κB signaling pathway via suppressing phosphorylation of IκB-α and NF-κB p65 to inhibit LPS-stimulated inflammation.

Zhai XT ，Zhang ZY ，Jiang CH ，Chen JQ ，Ye JQ ，Jia XB ，Yang Y ，Ni Q ，Wang SX ，Song J ，Zhu FX ... -  《-》

Cnidilide, an alkylphthalide isolated from the roots of Cnidium officinale, suppresses LPS-induced NO, PGE(2), IL-1β, IL-6 and TNF-α production by AP-1 and NF-κB inactivation in RAW 264.7 macrophages.

Cnidilide, an alkyl phthalide isolated from the rhizome of Cnidium officinale, has been reported to possess antispasmodic and sedative effects. However, the anti-inflammatory capacity and molecular mechanism of cnidilide have not been studied to date. In the present study, we investigated the inhibitory effects of cnidilide on LPS-induced pro-inflammatory mediators and the underlying molecular mechanisms in RAW 264.7 macrophages. Our results indicated that cnidilide potently inhibits inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression at the protein and mRNA levels and their promoter activities, causing attendant decreases in the production of nitric oxide (NO) and prostaglandin E2 (PGE2). In addition, cnidilide reduced LPS-induced production and mRNA expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in a dose-dependent manner. Molecular data revealed that cnidilide inhibited LPS-induced transcriptional activity of activator protein-1 (AP-1) by reducing the phosphorylation and nuclear translocation of c-Fos and c-Jun. In addition, cnidilide attenuated LPS-induced transcriptional activity of nuclear factor-κB (NF-κB), and this reduction was accompanied by parallel reduction in the phosphorylation, but not in the translocation of p65 NF-κB. In addition, cnidilide inhibited LPS-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and mitogen- and stress-activated protein kinase 1(MSK-1), a downstream kinase. Moreover, the phosphorylation of c-Jun N-terminal kinase (JNK) was suppressed by cnidilide in a concentration-dependent manner, whereas it did not inhibit the extracellular signal-regulated kinase (ERK) phosphorylation in LPS-stimulated RAW 264.7 macrophages. Taken together, our findings suggest that cnidilide has anti-inflammatory properties by inhibiting p38 MAPK, JNK, AP-1, and the NF-κB pathway in LPS-stimulated RAW 264.7 macrophages.

Lee WS ，Shin JS ，Jang DS ，Lee KT ... -  《-》

Aloe-emodin from rhubarb (Rheum rhabarbarum) inhibits lipopolysaccharide-induced inflammatory responses in RAW264.7 macrophages.

Rheum rhabarbarum (rhubarb) has long been used for the treatment of inflammation in China and other Asian countries. However, the mechanism underlying the anti-inflammatory activity of this medicinal plant is not fully understood. The present study was designed to investigate the anti-inflammatory effects of anthraquinones, the major constituents in rhubarb, and the molecular mechanism involved in their anti-inflammatory effects. RAW264.7 cells were stimulated by lipopolysaccharide (LPS) in the presence or absence of the compounds examined. The proliferation of RAW264.7 cells was assayed by the Alamar-Blue method. The quantity of nitric oxide (NO) was determined by Griess assay. The expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR. Inducible nitric oxide synthase (iNOS), inhibitor of nuclear factor κBα (IκBα), extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK), c-Jun NH2-terminal kinase (JNK), and Akt/phosphoinositide 3-kinase (PI3K) protein expression levels were determined by Western blotting. Aloe-emodin markedly suppressed the production of NO, interleukin-6 (IL-6), and interleukin-1β (IL-1β) in LPS-stimulated RAW264.7 cells with no apparent cytotoxicity. The mRNA expression levels of iNOS, IL-6, and IL-1β genes were also significantly inhibited by aloe-emodin. Western blot analysis showed that aloe-emodin suppressed LPS-induced iNOS protein expression, IκBα degradation, and the phosphorylation of ERK, p38, JNK, and Akt. These results demonstrate that aloe-emodin is the bioactive component of rhubarb that confers an anti-inflammatory effect through a likely mechanism involving a decrease in pro-inflammatory cytokine production in LPS-induced RAW264.7 macrophages via inhibition of NF-κB, MAPK, and PI3K pathways.

Hu B ，Zhang H ，Meng X ，Wang F ，Wang P ... -  《-》

Eugenolol and glyceryl-isoeugenol suppress LPS-induced iNOS expression by down-regulating NF-kappaB AND AP-1 through inhibition of MAPKS and AKT/IkappaBalpha signaling pathways in macrophages.

Yeh JL ，Hsu JH ，Hong YS ，Wu JR ，Liang JC ，Wu BN ，Chen IJ ，Liou SF ... -  《INTERNATIONAL JOURNAL OF IMMUNOPATHOLOGY AND PHARMACOLOGY》