Praeruptorin a inhibits lipopolysaccharide‐induced inflammatory response in murine macrophages through inhibition of NF‐κB pathway activation

Praeruptorin A (PA) is a pyranocoumarin compound isolated from the dried root of Peucedanum praeruptorum Dunn (Umbelliferae). However, the antiinflammatory effect of PA has not been reported. The present study investigated the antiinflammatory effect of PA in lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophage cells. PA significantly inhibited the LPS‐induced production of nitric oxide (NO), interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α). The mRNA and protein expressions of inducible nitric oxide synthase (iNOS), IL‐1β and TNF‐α were also suppressed by this compound. Further study showed that PA decreased the cytoplasmic loss of inhibitor κB‐α (IκB‐α) protein and inhibited the translocation of NF‐κB from cytoplasm to nucleus. Taken together, the results suggest that PA may exert antiinflammatory effects in vitro in LPS‐stimulated RAW 264.7 macrophages through inhibition of NF‐κB signal pathway activation. Copyright © 2010 John Wiley & Sons, Ltd.     

Myrislignan Attenuates Lipopolysaccharide‐induced Inflammation Reaction in Murine Macrophage Cells Through Inhibition of NF‐κB Signalling Pathway Activation

Myrislignan is a new kind of lignan isolated from Myristica fragrans Houtt. Its antiinflammatory effects have not yet been reported. In the present study, the antiinflammatory effects and the underlying mechanisms of myrislignan in lipopolysaccharide (LPS)‐induced inflammation in murine RAW 264.7 macrophage cells were investigated. Myrislignan significantly inhibited LPS‐induced production of nitric oxide (NO) in a dose‐dependent manner. It inhibited mRNA expression and release of interleukin‐6 (IL‐6) and tumour necrosis factor‐α (TNF‐α). This compound significantly inhibited mRNA and protein expressions of inducible NO synthase (iNOS) and cyclooxygenase‐2 (COX‐2) dose‐dependently in LPS‐stimulated macrophage cells. Further study showed that myrislignan decreased the cytoplasmic loss of inhibitor κB‐α (IκB‐α) protein and the translocation of NF‐κB from cytoplasm to the nucleus. Our results suggest that myrislignan may exert its antiinflammatory effects in LPS‐stimulated macrophages cells by inhibiting the NF‐κB signalling pathway activation. Copyright © 2012 John Wiley & Sons, Ltd.     

Toll‐like receptor 4‐mediated immunoregulation by the aqueous extract of Mori Fructus

The aqueous extract of Mori Fructus (MF) exerts a change of phenotype and a cytoprotective effect in macrophages. The present study was carried out to investigate the immunomodulating activity of MF on the expression of nitric oxide (NO), tumor necrosis factor alpha (TNF‐α), co‐stimulatory molecules and also interferon‐gamma (IFN‐γ) in macrophages and splenocytes. Toll‐like receptor 4 (TLR4) is a promising molecular target for immune‐modulating drugs. It was hypothesized that one possible upstream signaling pathway leading to immunoregulation of MF may be mediated by TLRs. Multiple signaling molecules (NF‐κB, ERK1/2, p38 and JNK) of the TLR4 signaling pathway were also detected. It was found that MF increased NO production and TNF‐α secretion in RAW 264.7 and peritoneal macrophages, co‐stimulatory molecules expression in peritoneal macrophages and IFN‐γ expression in splenocytes. Further studies indicated that MF could significantly induce the phosphorylation of signal molecules of MAPKs and the degradation of IκBα which finally led to the activation and nuclear translocation of nuclear factor‐κB (NF‐κB) for the target gene expression. All those notions disclosed that the aqueous extract MF is a new TLR4 activator, which induces a Th1 immune response as a consequence of induction of cytokines secretion, especially TNF‐α and IFN‐γ. Copyright © 2009 John Wiley & Sons, Ltd.     

1,2,3,6‐tetra‐O‐galloyl‐β‐D‐allopyranose gallotannin isolated,from Euphorbia jolkini,attenuates LPS‐induced nitric oxide production in macrophages

Nitric oxide (NO) is a pleiotropic regulator, critical to numerous biological processes, including vasodilatation and macrophage‐mediated immunity. Macrophages express inducible NO synthase (iNOS) and produce NO after lipopolysaccharide (LPS) stimulation. Gallotannins are water‐soluble polyphenols with wide‐ranging biological activities. Various chemical structures of gallotannins occurring in medicinal and food plants that are used worldwide showed several remarkable biological and pharmacological activities. In the present study, we examined the inhibitory effects of gallotannin 1,2,3,6‐tetra‐O‐galloyl‐β‐D‐allopyranose (GT24) isolated from Euphorbia jolkini on the LPS‐induced NO production and underlying mechanisms of action. GT24 dose‐dependently decreased LPS‐induced NO production and iNOS expression in J774A.1 macrophages. In addition, GT24 inhibited LPS‐induced activation of nuclear factor (NF)‐κB as indicated by inhibition of degradation of I‐κBα, nuclear translocation of NF‐κB, and NF‐κB dependent gene reporter assay. Our results suggest that GT24 possesses an inhibitory effect on the LPS‐induced inflammatory reaction. Copyright © 2010 John Wiley & Sons, Ltd.     

Houttuynia cordata Thunb. Volatile Oil Exhibited Anti‐inflammatory Effects In Vivo and Inhibited Nitric Oxide and Tumor Necrosis Factor‐α Production in LPS‐stimulated Mouse Peritoneal Macrophages In Vitro

Houttuynia cordata Thunb. (HC) is a medicinal herb that generally used in traditional Chinese medicine for treating allergic inflammation. The present study investigated the inhibitory effect of the volatile oil from HC Thunb. on animal models of inflammation and the production of inflammatory mediators in vivo and in vitro. In vivo, xylene‐induced mouse ear edema, formaldehyde‐induced paw edema and carrageenan‐induced mice paw edema were significantly decreased by HC volatile oil. HC volatile oil showed pronounced inhibition of prostaglandin (PG) E₂ and malondialdehyde production in the edematous exudates. In vitro exposure of mouse resident peritoneal macrophages to 1, 10, 100 and 1000 µg/mL of HC volatile oil significantly suppressed lipopolysaccharide (LPS)‐stimulated production of NO and tumor necrosis factor‐α (TNF‐α) in a dose‐dependent manner. Exposure to HC volatile oil had no effect on cell viability and systemic toxicity. Furthermore, HC volatile oil inhibited the production of NO and TNF‐α by down‐regulating LPS‐stimulated iNOS and TNF‐α mRNA expression. Western blot analysis showed that HC volatile oil attenuated LPS‐stimulated synthesis of iNOS and TNF‐α protein in the macrophages, in parallel. These findings add a novel aspect to the biological profile of HC and clarify its anti‐inflammatory mechanism. Copyright © 2012 John Wiley & Sons, Ltd.     

Antiinflammatory effects of Epimedium brevicornum water extract on lipopolysaccharide‐activated RAW264.7 macrophages

Epimedium brevicornum Maxim (Berberidaceae) possesses estrogenic properties. It is one of the most widespread herbal remedies used in Oriental medicine. The present study investigated the effects of Epimedium brevicornum water extract (EB) on proinflammatory mediators secreted from lipopolysaccharide (LPS)‐induced RAW264.7 macrophages. EB significantly inhibited the production of nitric oxide (NO), interleukin (IL)‐3, IL‐10, IL‐12p40, interferon‐inducible protein‐10, keratinocyte‐derived chemokine, vascular endothelial growth factor, monocyte chemotactic protein‐1 and granulocyte macrophage‐colony stimulating factor in LPS‐induced RAW264.7 cells at concentrations of 25, 50, 100 and 200 μg/mL (p < 0.05). These results suggest that EB has antiinflammatory activity related to its inhibition of NO, cytokine, chemokine and growth factor production in macrophages. Copyright © 2010 John Wiley & Sons, Ltd.     

Nimbolide Inhibits Nuclear Factor‐КB Pathway in Intestinal Epithelial Cells and Macrophages and Alleviates Experimental Colitis in Mice

Nimbolide is a limonoid extracted from neem tree (Azadirachta indica) that has antiinflammatory properties. The effect of nimbolide on the nuclear factor‐kappa B (NF‐κB) pathway in intestinal epithelial cells (IECs), macrophages and in murine colitis models was investigated. The IEC COLO 205, the murine macrophage cell line RAW 264.7, and peritoneal macrophages from interleukin‐10‐deficient (IL‐10^?/?) mice were preconditioned with nimbolide and then stimulated with tumor necrosis factor‐α (TNF‐α) or lipopolysaccharide. Dextran sulfate sodium‐induced acute colitis model and chronic colitis model in IL‐10^?/? mice were used for in vivo experiments. Nimbolide significantly suppressed the expression of inflammatory cytokines (IL‐6, IL‐8, IL‐12, and TNF‐α) and inhibited the phosphorylation of IκBα and the DNA‐binding affinity of NF‐κB in IECs and macrophages. Nimbolide ameliorated weight loss, colon shortening, disease activity index score, and histologic scores in dextran sulfate sodium colitis. It also improved histopathologic scores in the chronic colitis of IL‐10^?/? mice. Staining for phosphorylated IκBα was significantly decreased in the colon tissue after treatment with nimbolide in both models. Nimbolide inhibits NF‐κB signaling in IECs and macrophages and ameliorates experimental colitis in mice. These results suggest nimbolide could be a potentially new treatment for inflammatory bowel disease. Copyright © 2016 John Wiley & Sons, Ltd.     

Anti‐inflammatory Activities of Gouania leptostachya Methanol Extract and its Constituent Resveratrol

Gouania leptostachya DC. var. tonkinensis Pitard. Rhamnaceae is a traditional medicinal plant used in Thailand for treating various inflammatory symptoms. However, no systematic studies have been performed concerning the anti‐inflammatory effects or molecular mechanisms of this plant. The immunopharmacological activities of a methanol extract from the leaves and twigs of G. leptostachya (Gl‐ME) were elucidated based on the gastritis symptoms of mice treated with HCl/EtOH and the inflammatory responses, such as nitric oxide (NO) release and prostaglandin E₂ (PGE₂) production, from RAW264.7 cells and peritoneal macrophages. Moreover, inhibitory target molecules were also assessed. Gl‐ME dose‐dependently diminished the secretion of NO and PGE₂ from LPS‐stimulated RAW264.7 cells and peritoneal macrophages. The gastritis lesions of HCl/EtOH‐treated mice were also attenuated after Gl‐ME treatment. The extract (50 and 300 µg/mL) clearly reduced mRNA expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)‐2, nuclear translocation of p65/nuclear factor (NF)‐κB, phosphorylation of p65‐activating upstream enzymes, such as protein kinase B (AKT), inhibitor of κBα kinase (IKK), and inhibitor of κB (IκBα), and the enzymatic activity of Src. By HPLC analysis, one of the major components in the extract was revealed as resveratrol with NO and Src inhibitory activities. Moreover, this compound suppressed NO production and HCl/EtOH‐induced gastric symptoms. Therefore, these results suggest that Gl‐ME might be useful as an herbal anti‐inflammatory medicine through the inhibition of Src and NF‐κB activation pathways. The efficacy data of G. leptostachya also implies that this plant could be further tested to see whether it can be developed as potential anti‐inflammatory preparation. Copyright © 2014 John Wiley & Sons, Ltd.     

Anti‐inflammatory effect of isopimarane diterpenoids from Kaempferia galanga

Two new isopimarane diterpenes, 1α‐hydroxy‐14α‐methoxyisopimara‐8(9),15‐diene ( 7 ) and 1α,14α‐dihydroxyisopimara‐8(9),15‐diene ( 9 ) and eight known isopimarane diterpenes including (‐)‐sandaracopimaradiene ( 1 ), 6β‐acetoxysandaracopimaradiene‐9α‐ol ( 2 ), sandaracopimaradiene‐7β,9α‐diol ( 3 ), sandaracopimaradiene‐1α,9α‐diol ( 4 ), 6β‐acetoxysandaracopimaradiene‐9α‐ol‐1‐one ( 5 ), 6β‐acetoxysandaracopimaradiene‐1α,9α‐diol ( 6 ), 6β,14α‐dihydroxyisopimara‐8(9),15‐diene ( 8 ), and 6β,14β‐dihydroxyisopimara‐8(9),15‐diene ( 10 ) were isolated from hexane fraction of Kaempferia galanga ethanol extract. Compounds 5 , 6 , 8 , and 9 exerted the good anti‐inflammatory effect on lipopolysaccharide‐stimulated nitric oxide production from RAW264.7 cells with IC₅₀ of 11.2, 7.7, 14.3, and 12.1 μM, respectively. These four compounds inhibited nitric oxide synthase (iNOS) mRNA expression. Compounds 5 and 6 also suppressed cyclooxygenase 2 (COX‐2) mRNA expression; in addition, compound 6 had mild inhibitory effect on TNF‐α mRNA. Among these compounds, 5 dramatically inhibited iNOS and COX‐2 mRNA expression. The influential structures were proposed to be oxygen substitute at C‐1, C‐6, and α‐OH at C‐14.     

Withanolide sulfoxide from Aswagandha roots inhibits nuclear transcription factor‐kappa‐B,cyclooxygenase and tumor cell proliferation

Investigation of the methanol extract of Aswagandha (Withania somnifera) roots for bioactive constituents yielded a novel withanolide sulfoxide compound (1) along with a known withanolide dimer ashwagandhanolide (2) with an S‐linkage. The structure of compound 1 was established by extensive NMR and MS experiments. Compound 1 was highly selective in inhibiting cyclooxygenase‐2 (COX‐2) enzyme by 60% at 100 µm with no activity against COX‐1 enzyme. The IC₅₀ values of compound 1 against human gastric (AGS), breast (MCF‐7), central nervous system (SF‐268) and colon (HCT‐116) cancer cell lines were in the range 0.74–3.63 µm. Both S‐containing dimeric withanolides, 1 and 2, completely suppressed TNF‐induced NF‐κB activation when tested at 100 µm. The isolation of a withanolide sulfoxide from W. somnifera roots and its ability to inhibit COX‐2 enzyme and to suppress human tumor cell proliferation are reported here for the first time. In addition, this is the first report on the abrogation of TNF‐induced NF‐κB activation for compounds 1 and 2. Copyright © 2009 John Wiley & Sons, Ltd.     

Tectorigenin protects against experimental fulminant hepatic failure by regulating the TLR4/mitogen‐activated protein kinase and TLR4/nuclear factor‐κB pathways and autophagy

Tectorigenin has received attention due to its antiproliferation, anti‐inflammatory, and antioxidant activities. In this study, we investigated the effects of tectorigenin on lipopolysaccharide (LPS)/D‐galactosamine(D‐GalN)‐induced fulminant hepatic failure (FHF) in mice and LPS‐stimulated macrophages (RAW 264.7 cells). Pretreatment with tectorigenin significantly reduced the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), histological injury, apoptosis, and the mortality of FHF mice, by suppressing the production of inflammatory cytokines such as TNF‐α and IL‐6. Tectorigenin also suppressed the activation of the inflammatory response in LPS‐stimulated RAW 264.7 cells. Tectorigenin‐induced protection is mediated through its mitigation of TLR4 expression, inhibition of mitogen‐activated protein kinase (MAPK) and nuclear factor‐κB (NF‐κB) pathway activation, and promotion of autophagy in FHF mice and LPS‐stimulated RAW 264.7 cells. Therefore, tectorigenin has therapeutic potential for FHF in mice via the regulation of TLR4/MAPK and TLR4/NF‐κB pathways and autophagy.     

Hydroxy‐Safflower Yellow A inhibits the TNFR1‐Mediated Classical NF‐κB Pathway by Inducing Shedding of TNFR1

Hydroxy‐safflower yellow A (HSYA) is the major active component of safflower, a traditional Asia herbal medicine well known for its cardiovascular protective activities. The purpose of this study was to investigate the effect of HSYA on TNF‐α‐induced inflammatory responses in arterial endothelial cells (AECs) and to explore the mechanisms involved. The results showed that HSYA suppressed the up‐regulation of ICAM‐1 expression in TNF‐α‐stimulated AECs in a dose‐dependent manner. High concentration (120 μM) HSYA significantly inhibited the TNF‐α‐induced adhesion of RAW264.7 cells to AECs. HSYA blocked the TNFR1‐mediated phosphorylation and degradation of IκBα and also prevented the nuclear translocation of NF‐κB p65. Moreover, HSYA reduced the cell surface level of TNFR1 and increased the content of sTNFR1 in the culture media. TNF‐α processing inhibitor‐0 (TAPI‐0) prevented the HSYA inhibition of TNFR1‐induced IκBα degradation, implying the occurrence of TNFR1 shedding. Furthermore, HSYA induced phosphorylation of TNF‐α converting enzyme (TACE) at threonine 735, which is thought to be required for its activation. Conclusively, HSYA suppressed TNF‐α‐induced inflammatory responses in AECs, at least in part by inhibiting the TNFR1‐mediated classical NF‐κB pathway. TACE‐mediated TNFR1 shedding can be involved in this effect. Our study provides new evidence for the antiinflammatory and anti‐atherosclerotic effects of HSYA. Copyright © 2016 John Wiley & Sons, Ltd.