Dietary hematein ameliorates fatty streak lesions in the rabbit by the possible mechanism of reducing VCAM-1 and MCP-1 expression

Standardized microwave extract of Sappan Lignum exerts anti‑inflammatory effects through inhibition of NF‑κB activation via regulation of heme oxygenase‑1 expression

The extract of Sappan Lignum, the heartwood of Caesalpinia sappan L., has been used in medicine to improve blood circulation. Recently, the application of microwave extraction methods has been a major focus of research into the extraction of components from natural sources. In this experiment, we compared the anti‑inflammatory effects of Sappan Lignum prepared by heat‑70% EtOH extraction (CSE‑H‑70E) and microwave‑70% EtOH extraction (CSE‑MW‑70E). High‑performance liquid chromatography analysis was used to identify the compounds in these extracts. The heat‑70% EtOH and microwave‑70% EtOH extracts of Sappan Lignum had different chromatograms. CSE‑MW‑70E significantly inhibited the protein expression of iNOS and COX‑2, PGE2, TNF‑α, and reduced NO and IL‑1β production in macrophages exposed to LPS, whereas, only high concentrations of CSE‑H‑70E (20 µg/ml) resulted in any effects. Furthermore, CSE‑MW‑70E upregulated heme oxygenase‑1 (HO‑1) expression. In addition, the use of tin protoporphyrin, an inhibitor of HO‑1, confirmed the inhibitory effects of CSE‑MW‑70E on pro‑inflammatory mediators. These results suggested that the CSE‑MW‑70E‑mediated upregulation of HO‑1 played an important role in the anti‑inflammatory effects of macrophages. Therefore, these findings showed that microwave extraction can be utilized to improve the extraction efficiency and biological activity of Sappan Lignum.

Compounds from Caesalpinia sappan with anti-inflammatory properties in macrophages and chondrocytes

The heartwood of Caesalpinia sappan is a traditional ingredient of food and beverages in South East Asia and has been used in traditional medicine as an analgesic and anti-inflammatory drug or to promote blood circulation.

Chemometrics approach for the prediction of structure-activity relationship for membrane transporter bilitranslocase

Membrane transport proteins are essential for cellular uptake of numerous salts, nutrients and drugs. Bilitranslocase is a transporter, specific for water-soluble organic anions, and is the only known carrier of nucleotides and nucleotide-like compounds. Experimental data of bilitranslocase ligand specificity for 120 compounds were used to construct classification models using counter-propagation artificial neural networks (CP-ANNs) and support vector machines (SVMs). A subset of active compounds with experimentally determined transport rates was used to build predictive QSAR models for estimation of transport rates of unknown compounds. Several modelling methods and techniques were applied, i.e. CP-ANN, genetic algorithm, self-organizing mapping and multiple linear regression method. The best predictions were achieved using CP-ANN coupled with a genetic algorithm, with the external validation parameter QV(2) of 0.96. The applicability domains of the models were defined to determine the chemical space in which reliable predictions can be obtained. The models were applied for the estimation of bilitranslocase transport activity for two sets of pharmaceutically interesting compounds, antioxidants and antiprions. We found that the relative planarity and a high potential for hydrogen bond formation are the common structural features of anticipated substrates of bilitranslocase. These features may serve as guidelines in the design of new pharmaceuticals transported by bilitranslocase.

Citreoviridin enhances tumor necrosis factor-α-induced adhesion of human umbilical vein endothelial cells

Endothelial adhesion plays an important role in the process of atherosclerosis, which is regulated by endothelial adhesion molecules and chemoattractant molecules. In some areas of China, citreoviridin (CIT) is considered a risk factor for the development of atherosclerosis. Here, we investigated the role of CIT in adhesion of human umbilical vein endothelial cells (HUVECs) together with the stimulation of tumor necrosis factor-α (TNF-α). Adhesion of HUVECs to monocytes was analyzed by coculture experiments using U937 cells labeled with 2,7-bis(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethylester. The expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin was determined by Western blot and enzyme-linked immunosorbent assay (ELISA). The expression of monocyte chemoattractant protein-1 (MCP-1) was measured by reverse transcription polymerase chain reaction and ELISA. The activation of nuclear factor-κB (NF-κB) was assessed by Western blot and immunofluorescence staining. CIT markedly increased TNF-α-induced HUVECs adhesion to monocytes and the expression levels of ICAM-1, VCAM-1, E-selectin, and MCP-1. TNF-α-induced nuclear translocation of NF-κB in HUVECs was significantly elevated by CIT. Our study demonstrates that CIT upregulates TNF-α-induced endothelial adhesion via increasing activation of NF-κB, which results in the expression of ICAM-1, VCAM-1, E-selectin, and MCP-1. CIT plays a pivotal role in the process of endothelial cell adhesion and may thereby play an important role in the improvement of atherosclerosis in areas of China that have a high prevalence of CIT contamination and atherosclerosis.

The role of Rho/Rho-kinase pathway in the expression of ICAM-1 by linoleic acid in human aortic endothelial cells

Linoleic acid (LA), a dietary unsaturated fatty acid, has been known to increase the expression of adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) through the activation of nuclear factor-kappa B. Rho/Rho-kinase (ROCK) pathway mediates various cellular functions related to cardiovascular disease and affects the expression of ICAM-1. However, the exact mechanism underlying this action has not been fully elucidated. In this study, we aimed to find out the role of Rho/ROCK pathway in LA-induced ICAM-1 expression in human aortic endothelial cells (HAECs). We found that LA increased ICAM-1 expression and phosphorylation of ROCK and MYPT-1, a distal signal of ROCK. Y-27632, a ROCK inhibitor, suppressed ICAM-1 expression and phosphorylation of MYPT-1 induced by LA. The effect of LA on the increased phosphorylation of MYPT1 and expression of ICAM-1 was abolished by knocking down RhoA and ROCK2 protein level expression using small interfering RNA. LA increased NF-κB DNA-binding activity, which was inhibited with pretreatment with Y-27632. This study suggests that Rho/ROCK pathway plays a role in LA-induced ICAM-1 expression, which is possibly mediated by NF-κB in HAECs.

Caesalpinia sappan extract inhibits IL1β-mediated overexpression of matrix metalloproteinases in human chondrocytes

Exacerbated production of matrix metalloproteinases (MMPs) is a key event in the progression of osteoarthritis (OA) and represents a promising target for the management of OA with nutraceuticals. In this study, we sought to determine the MMP-inhibitory activity of an ethanolic Caesalpinia sappan extract (CSE) in human OA chondrocytes. Thus, human articular chondrocytes isolated from OA cartilage and SW1353 chondrocytes were stimulated with Interleukin-1beta (IL1β), without or with pretreatment with CSE. Following viability assays, the production of MMP-2 and MMP-13 was assessed using ELISA, whereas mRNA levels of MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-13 and TIMP-1, TIMP-2, TIMP-3 were quantified using RT-qPCR assays. Chondrocytes were co-transfected with a MMP-13 luciferase reporter construct and NF-kB p50 and p65 expression vectors in the presence or absence of CSE. In addition, the direct effect of CSE on the proteolytic activities of MMP-2 was evaluated using gelatin zymography. We found that CSE significantly suppressed IL1β-mediated upregulation of MMP-13 mRNA and protein levels via abrogation of the NF-kB(p65/p50)-driven MMP-13 promoter activation. We further observed that the levels of IL1β-induced MMP-1, MMP-3, MMP-7, and MMP-9 mRNA, but not TIMP mRNA levels, were down-regulated in chondrocytes in response to CSE. Zymographic results suggested that CSE did not directly interfere with the proteolytic activity of MMP-2. In summary, this study provides evidence for the MMP-inhibitory potential of CSE or CSE-derived compounds in human OA chondrocytes. The data indicate that the mechanism of this inhibition might, at least in part, involve targeting of NF-kB-mediated promoter activation.

Vascular protective potential of the total flavanol glycosides from Abacopteris penangiana via modulating nuclear transcription factor-κB signaling pathway and oxidative stress

ETHNOPHARMACOLOGICAL RELEVANCE

"Sanxuelian", the rhizome of Abacopteris penangiana (AP), is traditionally used in Chinese medicine for the treatment of blood circulation stasis, hemorheology barriers, edema and inflammation for patients of metabolic syndrome. This study was to investigate the protective effect of the total flavanol glycosides from AP (FAP) on diabetic vascular impairments by measuring the extents of oxidative stress and inflammatory response in mice.

MATERIALS AND METHODS

The experimental aortic pathology in diabetic mice was induced by fed on high-fat diet and injected with streptozotocin. The activities of FAP on attenuating aortas injuries, hypoglycemic, hypolipidemic, inhibiting oxidative stress and anti-inflammation were investigated. Additionally, the aortic expressions of nuclear transcription factor-κB (NFκB) were determined by western blot and immunohistochemistry analysis. Furthermore, the effects of FAP on human umbilical vein endothelia cells (HUVECs) were studied.

RESULTS

In animal study, the results showed that FAP enhanced the activities of antioxidant enzymes and attenuated the levels of proinflammatory cytokines. The plasma lipid profiles and glucose level in FAP treated groups were significantly decreased along with the vascular impairments were alleviated. Moreover, the aortic expression of NFκB was decreased. In cellular experiment, FAP could inhibit the apoptosis of HUVECs induced by H(2)O(2).

CONCLUSIONS

The results indicated that FAP had hypolipidemic, hypoglycemic and vascular protective activities and represented a potential herb for the treatment of aortic pathology involved with metabolic syndrome.

Extract of the dried heartwood of Caesalpinia sappan L. attenuates collagen-induced arthritis

AIM OF THIS STUDY

To confirm the anti-arthritic effect and explore the potential mechanism of the dried heartwood of Caesalpinia sappan L. (HCS) on collagen-induced arthritis (CIA) in rats, an animal model of rheumatoid arthritis.

MATERIALS AND METHODS

CIA was induced in male Wistar rats by intradermal injection of bovine collagen-II in Freund's incomplete adjuvant (IFA). The rats in the onset of arthritis were treated daily with oral administration of an ethanol extract from HCS (EHCS) at different doses (1.2, 2.4 and 3.6g/kg) or olive oil-vehicle for 10 days. Paw swelling, arthritis index, radiographic and histopathologic changes were evaluated to confirm the anti-arthritic effect of EHCS on CIA in rats. Levels of proinflammatory cytokines interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) as well as prostaglandin E2 (PGE2) in blood and expression of cyclooxygenase-2 (COX-2) and transcription factor NF-κB p65 in paw cartilage were detected to further study the molecular mechanism of the anti-arthritic effects of EHCS on CIA in rats. In addition, the adverse effects of EHCS on liver and kidney of rats were also evaluated.

RESULTS

The results showed that the EHCS markedly attenuated collagen-induced arthritis and reduced the levels of IL-1β, IL-6, TNF-α and PGE2 in serum and the expression of COX-2 and transcription factor NF-κB p65 in paw cartilage of CIA rats. EHCS (3.6g/kg) induced slight hepatotoxicity and body weight loss.

CONCLUSION

These results indicate that EHCS significantly attenuates CIA in rats by decreasing the levels of IL-1β, IL-6, TNF-α and PGE2 in serum and the expression of COX-2 and transcription factor NF-κB in paw cartilage.

Effect of caffeic acid on tumor necrosis factor-alpha-induced vascular inflammation in human umbilical vein endothelial cells

Recruitment of specific leukocyte subpopulations at the site of inflammation requires a series of cell adhesion molecules (CAMs)-mediated interactions. The major CAMs, viz., intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin are expressed on endothelium in response to various cytokines. Caffeic acid (CA), a natural phenolic compound from herbs and other sources, has been shown to prevent cardiovascular diseases. We investigated the effect of CA on the expression of CAMs by human umbilical vein endothelial cells (HUVECs) stimulated with tumor necrosis factor (TNF-alpha). Adhesion of monocytes to CA-treated HUVECs was evaluated by co-culture experiments using 2,7-bis(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethylester (BCECF-AM) labeling of U937 cells. The expression of adhesion and chemoattractant molecules was evaluated by Western blot and reverse transcription-polymerase chain reaction (RT-PCR), respectively. CA significantly inhibited the TNF-alpha-induced increase in U937 monocyte adhesion to HUVECs as well as decreased the protein and mRNA expression levels of CAMs on HUVECs. CA also inhibited the mRNA expression of monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8). The involvement of nuclear factor (NF)-kappaB in the transcriptional control of CAMs protein was assessed by degradation of inhibitory (I)kappaB and nuclear translocation of NF-kappaB using Western blotting and immunofluorescence staining. CA attenuated TNF-alpha-induced IkappaB degradation and NF-kappaB translocation from cytosol to the nucleus. In conclusion, TNF-alpha-induced NF-kappaB-DNA complex formation was inhibited by CA. CA reduced TNF-alpha-induced endothelial adhesiveness to HUVECs by inhibiting transcription factor activation, and CAMs expression suggesting its potential role in atherosclerosis diseases.

The inhibitory effect of simvastatin on the ADMA-induced inflammatory reaction is mediated by MAPK pathways in endothelial cells

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is emerging as a key contributor for endothelial dysfunction associated with inflammation. Statins can inhibit vascular inflammatory reaction and improve endothelial function. The aim of this study was to investigate in human endothelial cells the signaling pathways of ADMA-induced inflammatory reaction and potential inhibitory effects of simvastatin. Endothelial cells were cultured and used for all of the studies. Tumor necrosis factor-alpha(TNF-alpha) and soluble intercellular adhesion molecule-1 (sICAM-1) were determined by enzyme-linked immunosorbent assay. Nuclear factor-kappaB (NF-kappaB) was assayed by electrophoretic mobility shift assay. The activation of mitogen-activated protein kinases (MAPKs), including p38 MAPK and extracellular signal-related kinase (ERK(1/2)), were characterized by Western blot analysis. Treatment with ADMA (3-30 micromol/L) increased the concentration of sICAM-1 in a dose-dependent manner. ADMA (30 micromol/L) significantly enhanced the concentrations of TNF-alpha and sICAM-1, the activity of NF-kappaB and the phosphorylation of p38 MAPK and ERK(1/2). The increased secretion of TNF-alpha and sICAM-1 and the increased activity of NF-kappaB by ADMA were altered by SB203580 (5 micromol/L) or PD98059 (20 micromol/L), but not by LY294002 (20 micromol/L). Simvastatin (0.1, 0.5, or 2.5 micromol/L) markedly inhibited the elevated concentrations of TNF-alpha and sICAM-1, the activity of NF-kappaB, and the phosphorylation of p38 MAPK and ERK(1/2) induced by ADMA. Simvastatin inhibited ADMA-induced inflammatory reaction by p38 MAPK and ERK(1/2) pathways in cultured endothelial cells.

4-O-methylgallic acid down-regulates endothelial adhesion molecule expression by inhibiting NF-kappaB-DNA-binding activity

We here investigated the functional effect of 4-O-methylgallic acid (4-OMGA), a major metabolite of gallic acid abundant in red wine, on vascular inflammation and its action mechanism. 4-OMGA inhibited the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs) stimulated with tumor necrosis factor-alpha (TNF-alpha), resulting in the suppression of leukocyte adhesion to HUVECs. In addition, 4-OMGA inhibited the promoter activities of ICAM-1 and VCAM-1 and the activity of nuclear factor-kappaB (NF-kappaB) without affecting cytosolic IkappaB kinase (IKK) activation, inhibitor of kappaB (IkappaB) phosphorylation and degradation, and nuclear translocation of NF-kappaB. This compound did not alter nitric oxide (NO) generation, but inhibited reactive oxygen species (ROS) production in TNF-alpha-stimulated HUVECs, suggesting that NO and ROS are not involved in 4-OMGA-mediated inhibition of NF-kappaB activity. Moreover, 4-OMGA directly blocked the binding activity of NF-kappaB to its consensus DNA oligonucleotide, when pre-incubated with the nuclear extract from TNF-alpha-stimulated HUVECs, but not with the oligonucleotide alone. This inhibition was completely abolished by the addition of dithiothreitol. 4-OMGA exhibits an anti-inflammatory property by interfering with the formation of the NF-kappaB-DNA complex in the nuclei through direct and redox-sensitive interactions and may play an important role in the prevention of inflammatory responses such as the atherosclerotic process.

3-Hydroxyanthranilic acid, one of l-tryptophan metabolites, inhibits monocyte chemoattractant protein-1 secretion and vascular cell adhesion molecule-1 expression via heme oxygenase-1 induction in human umbilical vein endothelial cells

Heme oxygenase (HO)-1 is important in the vascular system, and its genetic or pharmacological induction in endothelium would be effective for the prevention and treatment of atherosclerosis. The naturally occurring antioxidant 3-hydroxyanthranilic acid (HA), one of l-tryptophan metabolites formed in vivo along the metabolic route known as the kynurenine pathway during inflammation or infection, was found to induce HO-1 expression and to stimulate nuclear translocation of NF-E2 related factor 2 (Nrf2) in human umbilical vein endothelial cells (HUVECs). Pre-treatment with HA inhibited the secretion of monocyte chemoattractant protein (MCP)-1, the expression of vascular cell adhesion molecule (VCAM)-1 and the activation of transcriptional nuclear factor (NF)-kappaB in HUVECs stimulated with tumor necrosis factor-alpha, the major pro-inflammatory cytokine causing endothelial inflammation. Interestingly, the observed anti-inflammatory effects of HA were mimicked by a HO-1 inducer, cobalt protoporphyrin, and bilirubin, one of HO-1 enzymatic products, but abolished in the presence of a HO-1 inhibitor, tin protoporphyrin. Based on our findings, we suggest that Nrf2-dependent HO-1 expression induced by HA inhibits MCP-1 secretion, VCAM-1 expression and NF-kappaB activation associated with vascular injury and inflammation in atherosclerosis.

Glabridin suppresses intercellular adhesion molecule-1 expression in tumor necrosis factor-alpha-stimulated human umbilical vein endothelial cells by blocking sphingosine kinase pathway: implications of Akt, extracellular signal-regulated kinase, and nuclear factor-kappaB/Rel signaling pathways

(R)-4-(3,4-Dihydro-8,8-dimethyl)-2H,8H-benzo[1,2-b:3,4-b'] dipyran-3yl)-1,3-benzenediol (glabridin) is known to have anti-inflammatory, antimicrobial, and cardiovascular protective activities. In the present study, we report the inhibitory effect of glabridin on intercellular adhesion molecule-1 (ICAM-1) expression in tumor necrosis factor-alpha (TNF-alpha)-stimulated human umbilical vein endothelial cells (HUVECs). Glabridin inhibited THP-1 cell adhesion to HUVECs stimulated by TNF-alpha and cell surface expression of ICAM-1 in TNF-alpha-stimulated HUVECs. The mRNA expression of adhesion molecules, including ICAM-1, vascular cell adhesion molecule-1, and E-selectin, was also suppressed by glabridin. Further study demonstrated the inhibitory effect of glabridin on nuclear factor (NF)-kappaB/Rel DNA binding, inhibitory factor-kappaB alpha (IkappaB alpha), and IkappaB beta degradation, IkappaB kinase activation, and p65 nuclear translocation in TNF-alpha-stimulated HUVECs. Treatment of a variety of cell lines with glabridin revealed that inhibitory effect of glabridin on NF-kappaB/Rel activation is not cell type-specific, and both inducible and constitutive NF-kappaB/Rel activation was suppressed by glabridin treatment. Moreover, TNF-alpha-induced phosphorylation of Akt and extracellular signal-regulated kinase (ERK) was blocked by glabridin treatment in HUVECs. Glabridin also suppressed sphingosine-1-phosphate (S1P)-induced cell surface expression and mRNA expression of ICAM-1. Further study demonstrated that TNF-alpha-induced sphingosine kinase activity was inhibited by glabridin, and the inhibitory effect of glabridin on TNF-alpha-induced ICAM-1 expression was reversed by addition of exogenous S1P. Together, our results indicate that the inhibitory effect of glabridin on ICAM-1 expression might be mediated, at least in part, by inhibiting sphingosine kinase pathway and subsequent inhibition of signaling pathways, including Akt, ERK, and NF-kappaB/Rel signaling pathway.

Use of an improved zirconyl hematoxylin stain in the diagnosis of Barrett's esophagus

Barrett's esophagus is a precancerous condition characterized by replacement of the normal stratified squamous epithelium by a simple columnar epithelium with goblet cells that secrete an acidic mucin. As originally formulated, fresh solutions of zirconyl hematoxylin stain goblet cells poorly. An improved formula, quintupling the amount of oxidant, yields zirconyl hematoxylin solutions that stain goblet cells darkly even when fresh. The improved zirconyl hematoxylin can be used in place of alcian blue in the diagnosis of Barrett's esophagus. The ingredients of zirconyl hematoxylin are always readily available and are generally recognized as safe.

Development and optimization of a method for the analysis of Brazilein by HPLC with electrochemical detection

The aim of this study was to establish an easy and accurate method for the determination of Brazilein in plant samples due to its potential pharmacological activities. High-performance liquid chromatography (HPLC) with electrochemical detection (ED) was used for the assay of Brazilein in this study for the first time. Crucial influence parameters including concentration of dodecane-1-sulfonic acid sodium salt (DSASS), inorganic modifier, tetrabutyl-ammonium hydroxide solution (TBAOH), and applied potential of proposed method were investigated. The proposed method is simple, rapid (analysis time: approximately 10 min), sensitive [(detection limit: 0.6 ng per injection (20 microl) at a signal-noise ratio 3:1)], highly selective and precise (intra- and inter-day precisions were within 5%, n = 7). The calibration graph of Brazilein was linear in the range 0.6-150 ng per injection 20 microl. Recovery of Brazilein was over 92% by standard addition method.

Application of stereological methods for the quantification of VCAM-1 and ICAM-1 expression in early stages of rabbit atherogenesis

Early stages of atherogenesis are characterized by the overexpression of cell adhesion molecules with the subsequent accumulation of macrophages, smooth muscle cells and proliferation of extracellular matrix in arterial intima. The quantification of atherogenic changes is necessary for the objective evaluation of the atherogenic process. The purpose of this study was to introduce stereological methods that may be used for the quantification of immunohistochemical staining, namely intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Twenty-four New Zealand White rabbits were subdivided into the three groups. Eighteen rabbits received a 0.4% cholesterol diet for 1, 2 and 3 months, respectively. Stereological principles of the systematic uniform random sampling and the point-counting method were applied for the quantification. Stereological analysis showed that VCAM-1 and ICAM-1 were upregulated during the consumption of high cholesterol diet and that VCAM-1, but not ICAM-1, has a considerable role in the formation of early atherosclerotic lesions. Stereological methods proved to be useful for the quantification of immunohistochemistry and can be used for an objective characterization of atherogenic changes in atherosclerosis.

Silymarin inhibits TNF-alpha-induced expression of adhesion molecules in human umbilical vein endothelial cells

Silymarin is known to have an anti-atherosclerotic activity, but the mechanism responsible for it remains unclear. Here, we demonstrate a possible mechanism involved in the anti-atherosclerotic activity of silymarin. Silymarin inhibited THP-1 cell adhesion to human umbilical vein endothelial cells (HUVECs). Silymarin also suppressed the TNF-alpha-induced protein and mRNA expression of adhesion molecules, such as VCAM-1, ICAM-1 and E-selectin, in HUVECs. Moreover, silymarin suppressed the TNF-alpha-induced DNA binding of NF-kappaB/Rel in HUVECs. Taken together, these results demonstrate that silymarin exerts an anti-atherosclerotic activity, at least in part, by inhibiting the expression of adhesion molecules.

Hematein inhibits atherosclerosis by inhibition of reactive oxygen generation and NF-kappaB-dependent inflammatory mediators in hyperlipidemic mice

Hematein, a natural compound, is a known anti-inflammatory and antiatherogenic agent in the rabbit model. The authors investigated the effects of this compound on atherogenesis and possible mechanisms of the actions in the hyperlipidemic mice. Low-density lipoprotein receptor-deficient (Ldlr-/-) mice fed a high-cholesterol diet alone for 8 weeks developed the fatty streak lesion in the aortic sinus, whereas this lesion was significantly reduced by hematein treatment without a change in plasma lipid levels compared with control mice. Hematein treatment reduced plasma levels of lipid peroxide and superoxide generation in LPS-stimulated peritoneal macrophage. Hematein treatment inhibited NF-kappaB-DNA binding activity in peritoneal macrophages from Ldlr-/- mice and the activation of NF-kappaB in RAW264.7 macrophages. This compound suppressed plasma nitrite/nitrate levels in Ldlr-/- mice and NO production and iNOS expression in LPS+IFNgamma-stimulated peritoneal macrophages. Hematein treatment also suppressed the activity of iNOS promoters in RAW264.7 macrophages, and reduced the plasma levels of TNF-alpha and IL-1beta and the production of these cytokines in LPS+IFNgamma-stimulated peritoneal macrophages. These results suggest that hematein inhibits atherosclerotic lesion formation, possibly by reducing proinflammatory mediators through a decrease in reactive oxygen species generation and NF-kappaB activation.