Down‐regulatory effect of usnic acid on nuclear factor‐κB‐dependent tumor necrosis factor‐α and inducible nitric oxide synthase expression in lipopolysaccharide‐stimulated macrophages RAW 264.7

The purpose of this study was to investigate the molecular mechanisms that are responsible for the antiinflammatory effect of usnic acid (UA). UA is one of the most common and abundant lichen metabolites. The present study examined the effects of UA on the tumor necrosis factor‐α (TNF‐α) and nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 macrophages and the underlying molecular mechanisms. UA decreased the TNF‐α level in LPS‐stimulated RAW264.7 macrophages in dose‐dependent manner, the IC₅₀ value was 12.8 µM. RT‐PCR analysis indicated that it inhibited TNF‐α mRNA expression. Furthermore, it inhibited NO production in LPS‐activated RAW264.7 macrophages, the IC₅₀ value was 4.7 µM. Western blot analysis showed that UA attenuated LPS‐induced synthesis of iNOS protein and nuclear translocation of NF‐κB p65 in the macrophages, in parallel. UA also inhibited LPS‐mediated I‐κBα degradation. Taken together, this suggests that UA has an antiinflammatory effect by inhibiting TNF‐α and iNOS expression, possibly through suppression of nuclear translocation of NF‐κB p65 and I‐κBα degradation. Copyright © 2008 John Wiley & Sons, Ltd.     

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.     

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.     

A Polyphenol‐rich Pomegranate Fruit Extract Suppresses NF‐κB and IL‐6 Expression by Blocking the Activation of IKKβ and NIK in Primary Human Chondrocytes

Pomegranate fruit extract (PE) rich in polyphenols has been shown to exert chondroprotective effects, but the mechanism is not established. Here, we used an in vitro model of inflammation in osteoarthritis (OA) to investigate the potential of PE to suppress interleukin 1 beta (IL‐1β)‐stimulated expression of inflammatory cytokine IL‐6, generation of reactive oxygen species (ROS) levels, and investigated the mechanism of NF‐κB inhibition by analyzing the activation of the kinases upstream of IκBα in primary human chondrocytes. Total and phosphorylated forms of kinases and expression of IL‐6 were determined at protein and mRNA levels by western immunoblotting and Taqman assay, respectively. Dihydrorhodamine 123 staining estimated ROS generation. Pomegranate fruit extract inhibited the mRNA and protein expression of IL‐6, generation of ROS, and inhibited the IL‐1β‐mediated phosphorylation of inhibitor of nuclear factor kappa‐B kinase subunit beta (IKKβ), expression of IKKβ mRNA, degradation of IκBα, and activation and nuclear translocation of NF‐κB/p65 in human chondrocytes. Importantly, phosphorylation of NF‐κB‐inducing kinase was blocked by PE in IL‐1β‐treated human OA chondrocytes. Taken together, these data suggest that PE exerts the chondroprotective effect(s) by suppressing the production of IL‐6 and ROS levels. Inhibition of NF‐κB activation by PE was blocked via modulation of activation of upstream kinases in human OA chondrocytes. Copyright © 2017 John Wiley & Sons, Ltd.     

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.     

Isoforskolin and forskolin attenuate lipopolysaccharide‐induced inflammation through TLR4/MyD88/NF‐κB cascades in human mononuclear leukocytes

The principal active component of isoforskolin (ISOF) is from the plant Coleus forskohlii, native to China, which has attracted much attention for its biological effects. We hypothesize that ISOF and forskolin (FSK) pretreatment attenuates inflammation induced by lipopolysaccharide (LPS) related to toll‐like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and nuclear factor kappa B (NF‐κB) signaling. Mononuclear leukocytes (MLs) from healthy donors' blood samples were separated by using density gradient centrifugation. Protein levels of TLR4, MyD88, and NF‐κB were detected using western blot and inflammatory cytokines interleukin (IL) 1β, IL‐2, IL‐6, IL‐21, IL‐23, tumor necrosis factor (TNF) α, and TNF‐β were tested by enzyme‐linked immunosorbent assay and Quantibody array in MLs. Our results showed that LPS augmented the protein levels of TLR4, MyD88, and NF‐κB in MLs and the production of IL‐1β, IL‐2, IL‐6, IL‐21, IL‐23, TNF‐α, and TNF‐β in supernatants of MLs. Despite treatment with ISOF and FSK prior to LPS, the protein levels of TLR4, MyD88, NF‐κB, IL‐1β, IL‐2, IL‐6, IL‐21, IL‐23, TNF‐α, and TNF‐β in MLs were apparently decreased. roflumilast (RF) and dexamethasone (DM) had a similar effect on MLs with ISOF and FSK. Our results, for the first time, have shown that ISOF and FSK attenuate inflammation in MLs induced by LPS through down‐regulating protein levels of IL‐1β and TNF‐α, in which TLR4/MyD88/NF‐κB signal pathway could be involved.     

Chelidonine inhibits TNF‐α‐induced inflammation by suppressing the NF‐κB pathways in HCT116 cells

Nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) is a complex that regulates several hundreds of genes, including those involved in immunity and inflammation, survival, proliferation, and the negative feedback of NF‐κB signaling. Chelidonine, a major bioactive, isoquinoline alkaloid ingredient in Chelidonium majus, exhibits antiinflammatory pharmacological properties. However, its antiinflammatory molecular mechanisms remain unclear. In this work, we explored the effect of chelidonine on TNF‐induced NF‐κB activation in HCT116 cells. We found chelidonine inhibited the phosphorylation and degradation of the inhibitor of NF‐κB alpha and nuclear translocation of RELA. Furthermore, by inhibiting the activation of NF‐κB, chelidonine downregulated target genes involved in inflammation, proliferation, and apoptosis. Chelidonine also inhibited mitogen‐activated protein kinase pathway activation by blocking c‐Jun N‐terminal kinase and p38 phosphorylation. These results suggest that chelidonine may be a potential therapeutic agent against inflammatory diseases in which inhibition of NF‐κB activity plays an important role.     

Nerolidol Protects Against LPS‐induced Acute Kidney Injury via Inhibiting TLR4/NF‐κB Signaling

Acute kidney injury (AKI) is a critical care syndrome, resulting in acute reduction of renal function and up to 22% mortality of hospitalized patients. Nerolidol is a major component in several essential oils that possesses various pharmacological properties. The present study aimed to investigate the potential effect of nerolidol on lipopolysaccharide (LPS)‐induced AKI. Nerolidol dose‐dependently reduced the pathological injuries of kidney induced by LPS in rats. Nerolidol significantly decreased the levels of blood urea nitrogen and creatinine in LPS‐treated rats in a dose‐dependent manner. In addition, nerolidol inhibited LPS‐induced decrease of cell viability in NRK‐52E rat proximal tubular cells, which effect was concentration dependent. Nerolidol notably inhibited the increase of TNFα and IL‐1β in LPS‐treated rats and the mRNA expression of TNFα and IL‐1β in LPS‐treated NRK‐52E cells. Nerolidol suppressed the increase of toll‐like receptor 4 (TLR4) expression, phosphorylation and nuclear translocation of p65 NF‐κB in kidneys of LPS‐treated rats and LPS‐treated NRK‐52E cells. Overexpression of TLR4 and p65 NF‐κB significantly suppressed nerolidol‐induced inhibition of TNFα and IL‐1β expression and increase of cell viability in LPS‐treated cells. In summary, we found that nerolidol played a critical anti‐inflammatory effects through inhibition of TLR4/NF‐κB signaling and protected against LPS‐induced AKI. Copyright © 2017 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.     

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.     

Protective effect of Astragalus polysaccharides on ATP binding cassette transporter A1 in THP‐1 derived foam cells exposed to tumor necrosis factor‐alpha

Astragalus polysaccharide (APS), the main extract from the traditional Chinese medicinal herb Astragalus membranaceus, has been reported to benefit the treatment of immune‐inflammatory diseases and metabolic disorders. In atherosclerotic plaques, proinflammatory cytokines exert adverse effects on lipids thereby aggravating atherosclerosis. Recent evidence shows that tumor necrosis factor‐alpha (TNF‐α) can down‐regulate the expression of ATP‐binding cassette transporter A1 (ABCA1), which plays a vital role in reverse cholesterol transport and determines the process of atherosclerosis. In the present study, the effects of APS on ABCA1 expression, cholesterol effluent rate and total cholesterol content of THP‐1 derived foam cells exposed to TNF‐α were investigated. Compared with the foam cells exposed to TNF‐α, ABCA1 expression was promoted in the presence of APS. Consequently the cholesterol effluent rate increased and the total cholesterol content decreased significantly. TNF‐α could enhance the activity of nuclear factor‐kappa B (NF‐κB) in the foam cells. This effect could be attenuated by APS. These findings suggest that APS could protect ABCA1 against the lesion of TNF‐α in THP‐1 derived foam cells, which may contribute to its antiatherosclerotic properties. Copyright © 2009 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.     

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.     

Inhibition of TNF‐α‐Induced MUC5AC Mucin Gene Expression and Production by Wogonin Through the Inactivation of NF‐κB Signaling in Airway Epithelial Cells

In this study, we investigated whether wogonin significantly affects MUC5AC mucin gene expression and production in human airway epithelial cells. Confluent NCI‐H292 cells were pretreated with wogonin for 30 min and then stimulated with tumor necrosis factor‐α (TNF‐α) for 24 h or the indicated periods. The MUC5AC mucin gene expression and mucin protein production were measured by RT‐PCR and ELISA, respectively. We found that incubation of NCI‐H292 cells with wogonin significantly inhibited mucin production and down‐regulated MUC5AC gene expression induced by TNF‐α in a dose‐dependent fashion. To elucidate the action mechanism of wogonin, effect of wogonin on TNF‐α‐induced NF‐κB signaling pathway was investigated by western blot analysis. Wogonin inhibited NF‐κB activation induced by TNF‐α. Inhibition of IKK by wogonin led to the suppression of IκB phosphorylation and degradation, p65 nuclear translocation and NF‐κB‐regulated gene expression. This, in turn, led to the down‐regulation of MUC5AC protein production in NCI‐H292 cells. Wogonin also inhibited the gene products involved in cell survival (Bcl‐2) and proliferation (cyclooxygenase‐2). These results suggest that wogonin inhibits the NF‐κB signaling pathway, which may explain its role in the inhibition of MUC5AC mucin gene expression and production. Copyright © 2013 John Wiley & Sons, Ltd.     

Regulation of adhesion molecules expression in TNF‐α‐stimulated brain microvascular endothelial cells by tanshinone IIA: involvement of NF‐κB and ROS generation

Pro‐inflammatory cytokine‐mediated expression of cell surface adhesion molecules plays a key role in endothelial cell injury, leading to vascular inflammation and the development of many cerebrovascular diseases. Thus, antiinflammatory agents targeting these adhesion molecules may represent potential drugs for the prevention and treatment of cerebrovascular diseases. The present study explored the effects of tanshinone IIA (Tan IIA), an active ingredient present in the Salvia miltiorrhiza root, on the expression of cellular adhesion molecules in TNF‐α‐stimulated brain microvascular endothelial cells (BMVECs). Treatment with Tan IIA was found to suppress the expression of vascular cell adhesion molecule‐1 (VCAM‐1) and intercellular adhesion molecule‐1 (ICAM‐1), resulting in inhibition of TNF‐α‐induced adhesion of neutrophils to BMVECs in a dose‐dependent manner. In addition, Tan IIA significantly inhibited TNF‐α‐induced production of reactive oxygen species (ROS), which was accompanied by decreased malondialdehyde (MDA) levels. Treatment with Tan IIA also inhibited nuclear factor‐kappa B (NF‐κB) activation. Together, these results suggest that Tan IIA regulates TNF‐α‐induced expression of VCAM‐1 and ICAM‐1 through inhibition of NF‐κB activation and ROS generation in BMVECs. Copyright © 2010 John Wiley & Sons, Ltd.     

Umbelliferone Improves an Impaired Glucose and Lipid Metabolism in High‐Fat Diet/Streptozotocin‐Induced Type 2 Diabetic Rats

Umbelliferone (UMB) is a natural product that has several pharmacological effects including antihyperglycemic activity in diabetic rats. Thus, the objective of this study was to investigate the effect of UMB on insulin resistance and on the regulation of glucose and lipid metabolism in type 2 diabetic rats. Type 2 diabetes was induced in rats by feeding a high‐fat diet (45 kcal% fat) and a single dose of streptozotocin injection. After 8 weeks of treatment, UMB significantly reduced the elevated blood glucose levels and insulin resistance and increased the liver glycogen and serum adiponectin. Moreover, the serum lipid and the storages of triglyceride and non‐esterified fatty acid in liver tissue were reduced. From histological examination, the lipid droplets in liver tissue were clearly decreased, and the fat cell size in the fat tissue was smaller in diabetic rats treated with UMB. Interestingly, UMB increased fat cell adiponectin, plasma membrane glucose transporter 4 (GLUT4) and peroxisome proliferator‐activated receptor gamma (PPARγ), and liver PPARα protein expressions. Our findings demonstrate that UMB improves glucose and lipid metabolism in type 2 diabetes by stimulating the insulin secretion and the related mechanisms via stimulating expression of adiponectin, GLUT4, PPARγ, and PPARα‐protein expressions. Copyright © 2015 John Wiley & Sons, Ltd.     

A New Phenolic Component from Triticum aestivum Sprouts and its Effects on LPS‐Stimulated Production of Nitric oxide and TNF‐α in RAW 264.7 Cells

An unusual new phenolic component, triticumoside (1), and eight known compounds, isoorientin (2), isoscoparin (3), (2R)‐2‐O‐β‐D‐glucopyranosyloxy‐4,7‐dimethoxy‐2H‐1,4‐benzoxazin‐3(4H)‐one (4), adenosine (5), β‐sitosterol (6), daucosterol (7), 6′‐O‐linolenoyl daucosterol (8), α‐tocopherol (9), were isolated from Triticum aestivum sprouts. The hybrid structure of 1, which is a hybrid between a flavone and a polyoxygenated benzene, is rarely found in natural sources. In addition, the effects of these compounds on LPS‐induced NO and TNF‐α production in RAW 264.7 cells were evaluated. At a concentration of 2.0 μM, compounds 2–4 significantly inhibited the production of both NO and TNF‐α. Compound 1 exhibited inhibitory activity on the secretion of TNF‐α at concentrations as low as 2.0 μM, but it did not reduce NO levels at any of the tested concentrations. Copyright © 2013 John Wiley & Sons, Ltd.