Protective effects of genistein on proinflammatory pathways in human brain microvascular endothelial cells

Much More than Nutrients: The Protective Effects of Nutraceuticals on the Blood-Brain Barrier in Diseases

The dysfunction of the blood-brain barrier (BBB) is well described in several diseases, and is considered a pathological factor in many neurological disorders. This review summarizes the most important groups of natural compounds, including alkaloids, flavonoids, anthocyanidines, carotenoids, lipids, and vitamins that were investigated for their potential protective effects on brain endothelium. The brain penetration of these compounds and their interaction with BBB efflux transporters and solute carriers are discussed. The cerebrovascular endothelium is considered a therapeutic target for natural compounds in diseases. In preclinical studies modeling systemic and central nervous system diseases, nutraceuticals exerted beneficial effects on the BBB. In vivo, they decreased BBB permeability, brain edema, astrocyte swelling, and morphological changes in the vessel structure and basal lamina. At the level of brain endothelial cells, nutraceuticals increased cell survival and decreased apoptosis. From the general endothelial functions, decreased angiogenesis and increased levels of vasodilating agents were demonstrated. From the BBB functions, elevated barrier integrity by tightened intercellular junctions, and increased expression and activity of BBB transporters, such as efflux pumps, solute carriers, and metabolic enzymes, were shown. Nutraceuticals enhanced the antioxidative defense and exerted anti-inflammatory effects at the BBB. The most important signaling changes mediating the increased cell survival and BBB stability were the activation of the WNT, PI3K-AKT, and NRF2 pathways, and inhibition of the MAPK, JNK, ERK, and NF-κB pathways. Nutraceuticals represent a valuable source of new potentially therapeutic molecules to treat brain diseases by protecting the BBB.

Biomacromolecules as Immunomodulators: Utilizing Nature’s Tools for Immune Regulation

Although there are numerous available immunomodulators, those of natural origin would be preferable based on their safety profile and effectiveness. The research and clinical interest in immunomodulators have increased in the last decades, especially in the immunomodulatory properties of plant-based therapies. Innovative technologies and extensive study on immunomodulatory natural products, botanicals, extracts, and active moieties with immunomodulatory potential could provide us with valuable entities to develop as novel immunomodulatory medicines to enhance current chemotherapies. This review focuses on plant-based immunomodulatory drugs that are currently in clinical studies. However, further studies in this area are of utmost importance to obtain complete information about the positive effects of medicinal plants and their chemical components and molecules as an alternative to combatting various diseases and/or prevention.

Main Colonic Metabolites from Coffee Chlorogenic Acid May Counteract Tumor Necrosis Factor-α-Induced Inflammation and Oxidative Stress in 3T3-L1 Cells

Obesity is coupled with an altered redox state and low-level inflammation. Oxidative stress may increase pre-adipocyte proliferation, adipocyte differentiation and mature adipocyte size. Regarding inflammation, the dysregulation of cytokine production by adipose tissue takes place in obesity, which is promoted by oxidative stress. Polyphenols may exert a positive effect on obesity, not only by modulating the redox state, but also due to their anti-inflammatory activity. Coffee, which is one of the most consumed beverages, is very rich in phenolic compounds. Bioavailability studies on coffee phenols have shown that the most abundant group of metabolites in plasma and urine are dihydrocaffeic (DHCA), dihydroferulic (DHFA), and hydroxyhippuric (HHA) acids, the three acids of colonic origin. To better understand the antioxidant and anti-inflammatory properties of DHCA, DHFA, and HHA, an inflammation/oxidation model was set up in the pre-adipocyte 3T3-L1 cell line using tumor necrosis factor-α (TNF-α). After the exposure of 3T3-L1 cells to 0.5, 1, 5, and 10 µM of TNF-α at different times, the cell viability, interleukin (IL)-6 secretion, and the production of reactive oxygen species (ROS) and glutathione (GSH) were determined. Using the TNF-α prooxidant and proinflammatory conditions established (10 µM, 24 h), it was observed that the physiological concentrations (0.5, 1, 5, and 10 µM) of DHCA, DHFA, and HHA induced dose-dependent antioxidant effects according to the ROS, GSH, and antioxidant enzyme (glutathione peroxidase) results. In addition, reductions in the IL-1β, IL-6, and monocyte chemoattractant protein-1 (MCP-1) concentrations were observed to different extents depending on the metabolite (DHFA, HHA, or DHCA) and the concentration used. In conclusion, the main colonic metabolites from coffee chlorogenic acids may counteract TNF-α-induced inflammation and oxidative stress in the 3T3-L1 cell line, and thus, they present antiobesity potential.

Colonic Coffee Phenols Metabolites, Dihydrocaffeic, Dihydroferulic, and Hydroxyhippuric Acids Protect Hepatic Cells from TNF-α-Induced Inflammation and Oxidative Stress

Coffee presents beneficial health properties, including antiobesity effects. However, its effects on inflammation are controversial. Hydroxycinnamic acids are the main coffee phenolic bioactive compounds. In human bioavailability studies carried out with coffee, among the most abundant compounds found in urine and plasma were the colonic metabolites, dihydrocaffeic (DHCA), dihydroferulic (DHFA), and hydroxyhippuric (HHA) acids. To understand the hepato-protective potential of these three compounds, we tested whether treatment with realistic concentrations (0.5-10 µM) were effective to counteract inflammatory process and oxidative status induced by tumor necrosis factor α (TNF-α). First, we established a novel model of inflammation/oxidation using TNF-α and HepG2 cells. Afterwards, we evaluated the activity of DHCA, DHFA, and HHA against the inflammatory/oxidative challenge through the determination of the inflammatory mediators, interleukins (IL)-6, and IL-8 and chemokines, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1, as well as the levels of biomarkers of oxidative stress, such as reactive oxygen species, reduced glutathione, and the antioxidant enzymes glutathione peroxidase and reductase. Results showed that all three compounds have a potential hepato-protective effect against the induced inflammatory/oxidative insult.

Genistein attenuates neuroinflammation and oxidative stress and improves cognitive impairment in a rat model of sepsis-associated encephalopathy: potential role of the Nrf2 signaling pathway

Oxidative stress and inflammation seem to be the main factors responsible for cognitive impairment in sepsis. Genistein (GEN) is claimed to exert many beneficial effects on health, however, its possible effects on brain sepsis remains unclear. Here, we assess the influence and underling mechanisms of GEN on cognitive impairments in cecal ligation and puncture (CLP)-induced septic model. Rats were randomly divided into Sham, Sham + GEN, CLP, CLP + GEN gropus. Rats were treated with GEN (15 mg/kg at 0 and 12 h after CLP, i.p). Twenty-four hours after CLP, protein levels of cytokines, NF-kB and Nrf2, myeloperoxidase (MPO) activity, oxidative damage to lipids and proteins, the activities of antioxidant enzymes and the expression of Nrf2-target genes were evaluated in the hippocampus. At 10 days after sepsis induction, behavioral tests were conducted to evaluate cognitive impairment. The results indicate that GEN can enhance survival percentage and improve cognitive function. Genistein administration significantly reduced TNF-α and IL-1β levels, MPO activity and protein level of NF-kB in the hippocampus of septic rats. Genistein also decreased the levels of oxidative stress parameters (MDA and protein carbonyls) and elevated the activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in septic rats. Furthermore, nuclear Nrf2 and the expression of HO-1 and NQO-1 were also elevated by GEN treatment. These findings suggest that GEN improves cognition impairment in septic rats via decreasing inflammatory responses and oxidative stress, and activation of the Nrf2 pathway.

The multimodal action of genistein in Alzheimer's and other age-related diseases

Genistein is a phytoestrogen that, due to its structural similarity with estrogen, can both mimic and antagonize estrogen effects. Early analysis proved that at high concentrations, genistein inhibits breast cancer cell proliferation, thereby suggesting an anticancer activity. Since then, many discoveries have identified the genistein mechanism of action, including cell cycle arrest, apoptosis induction, as well as angiogenesis, and metastasis inhibition. In this review, we aim to discuss the multimodal action of genistein as an antioxidant, anti-inflammatory, anti-amyloid β, and autophagy promoter, which could be responsible for the genistein beneficial effect on Alzheimer's. Furthermore, we pinpoint the main signal transduction pathways that are known to be modulated by genistein. Genistein has thus several beneficial effects in several diseases, many of them associated with age, such as the above mentioned Alzheimer disease. Indeed, the beneficial effects of genistein for health promotion depend on each multimodality. In the context of geroscience, genistein has promising beneficial effects due to its multimodal action to treat age associated-diseases.

Polyphenols: Potential anti-inflammatory agents for treatment of metabolic disorders

Ample evidence highlights the potential benefits of polyphenols in health status especially in obesity-related metabolic disorders such as insulin resistance, type 2 diabetes, and cardiovascular diseases. Mechanistically, due to the key role of "Metainflammation" in the pathomechanism of metabolic disorders, recently much focus has been placed on the properties of polyphenols in obesity-related morbidities. This narrative review summarizes the current knowledge on the role of polyphenols, including genistein, chlorogenic acid, ellagic acid, caffeic acid, and silymarin in inflammatory responses pertinent to metabolic disorders and discusses the implications of this evidence for future directions. This review provides evidence that the aforementioned polyphenols benefit health status in metabolic disorders via direct and indirect regulation of a variety of target proteins involved in inflammatory signaling pathways. However, due to limitations of the in vitro and in vivo studies and also the lack of long-term human clinical trials studies, further high-quality investigations are required to firmly establish the clinical efficacy of the polyphenols for the prevention and management of metabolic disorders.

Molecular Changes Underlying Genistein Treatment of Wound Healing: A Review

Estrogen deprivation is one of the major factors responsible for many age-related processes including poor wound healing in postmenopausal women. However, the reported side-effects of estrogen replacement therapy (ERT) have precluded broad clinical administration. Therefore, selective estrogen receptor modulators (SERMs) have been developed to overcome the detrimental side effects of ERT on breast and/or uterine tissues. The use of natural products isolated from plants (e.g., soy) may represent a promising source of biologically active compounds (e.g., genistein) as efficient alternatives to conventional treatment. Genistein as natural SERM has the unique ability to selectively act as agonist or antagonist in a tissue-specific manner, i.e., it improves skin repair and simultaneously exerts anti-cancer and chemopreventive properties. Hence, we present here a wound healing phases-based review of the most studied naturally occurring SERM.

Potential therapeutic applications of phytoconstituents as immunomodulators: Pre-clinical and clinical evidences

Autoimmune and infectious diseases are the major public health issues and have gained great attention in the last few years for the search of new agents with therapeutic benefits on the host immune functions. In recent years, natural products (NPs) have been studied broadly for their multi-targeted activities under pathological conditions. Interestingly, several attempts have been made to outline the immunomodulatory properties of NPs. Research on in-vitro and in-vivo models have shown the immunomodulatory activity of NPs, is due to their antiinflammatory property, induction of phagocytosis and immune cells stimulation activity. Moreover, studies on humans have suggested that phytomedicines reduce inflammation and could provide appropriate benefits either in single form or complex combinations with other agents preventing disease progression, subsequently enhancing the efficacy of treatment to combat multiple malignancies. However, the exact mechanism of immunomodulation is far from clear, warranting more detailed investigations on their effectiveness. Nevertheless, the reduction of inflammatory cascades is considered as a prime protective mechanism in a number of inflammation regulated autoimmune diseases. Altogether, this review will discuss the biological activities of plant-derived secondary metabolites, such as polyphenols, alkaloids, saponins, polysaccharides and so forth, against various diseases and their potential use as an immunomodulatory agent under pathological conditions.

Meningitic Escherichia coli-induced upregulation of PDGF-B and ICAM-1 aggravates blood-brain barrier disruption and neuroinflammatory response

Background

Blood-brain barrier (BBB) disruption and neuroinflammation are considered key mechanisms of pathogenic Escherichia coli invasion of the brain. However, the specific molecules involved in meningitic E. coli-induced BBB breakdown and neuroinflammatory response remain unclear. Our previous RNA-sequencing data from human brain microvascular endothelial cells (hBMECs) revealed two important host factors: platelet-derived growth factor-B (PDGF-B) and intercellular adhesion molecule-1 (ICAM-1), which were significantly upregulated in hBMECs after meningitic E. coli infection. Whether and how PDGF-B and ICAM-1 contribute to the development of E. coli meningitis are still unclear.

Methods

The western blot, real-time PCR, enzyme-linked immunosorbent assay, immunohistochemistry, and immunofluorescence were applied to verify the significant induction of PDGF-B and ICAM-1 by meningitic E. coli in vivo and in vitro. Evan’s blue assay and electric cell-substrate impedance sensing assay were combined to identify the effects of PDGF-B on BBB permeability. The CRISPR/Cas9 technology, cell-cell adhesion assay, and electrochemiluminescence assay were used to investigate the role of ICAM-1 in neuroinflammation subversion.

Results

We verified the significant induction of PDGF-B and ICAM-1 by meningitic E. coli in mouse as well as monolayer hBMECs models. Functionally, we showed that the increase of PDGF-B may directly enhance the BBB permeability by decreasing the expression of tight junction proteins, and the upregulation of ICAM-1 contributed to neutrophils or monocytes recruitment as well as neuroinflammation subversion in response to meningitic E. coli infection.

Conclusions

Our findings demonstrated the roles of PDGF-B and ICAM-1 in mediating bacterial-induced BBB damage as well as neuroinflammation, providing new concepts and potential targets for future prevention and treatment of bacterial meningitis.

TNF-α-induced oxidative stress and endothelial dysfunction in EA.hy926 cells is prevented by mate and green coffee extracts, 5-caffeoylquinic acid and its microbial metabolite, dihydrocaffeic acid

The main phenol in mate and coffee, 5-caffeoylquinic-acid (5-CQA), and its relevant microbial metabolites, dihydrocaffeic (DHCA) and dihydroferulic (DHFA) acids, have shown oxidative-stress protective effects in HepG2 cells. To evaluate possible endothelial-protective effects of the extracts and compounds, endothelial EA.hy926 cells were pre-treated with yerba mate (YME) and green coffee bean (GCBE) phenolic extracts, 5-CQA, DHCA and DHFA and afterwards stressed with tumour-necrosis-factor-alpha (TNF-α). Then oxidative-stress markers and endothelial-nitric-oxide-synthase levels were studied. TNF-α (10 ng/mL, 24 h) depleted reduced glutathione (GSH) and eNOS levels, increased reactive oxygen species (ROS) production, glutathione peroxidase (GPx) and reductase (GR) activities, and protein oxidation (carbonyl groups, CG) in EA.hy926 cells. Pre-treatment with YME, GCBE, 5-CQA, DHCA at certain physiological concentrations, lowered ROS production, recovered depleted GSH, reduced GR and GPx activities, and CG levels, and enhanced eNOS concentration.. YME, GCBE and 5-CQA show antioxidant effects in endothelial cells playing DHCA an important role in such protection; moreover, the extracts, 5-CQA, DHCA and DHFA increased eNOS levels.

Genistein and Myd88 Activate Autophagy in High Glucose-Induced Renal Podocytes In Vitro

BACKGROUND Renal podocyte damage plays a crucial role in the development of diabetic nephropathy. Genistein is derived from a leguminous plant, and MyD88 and TRIF are adaptor molecules in the Toll-like receptor (TLR) signaling pathway, which may play a role in autophagy. In this study, we utilized an in vitro high glucose (HG)-treated podocyte model to investigate the effects and underlying mechanisms of Genistein and MyD88 or TRIF siRNA induced autophagy and renal protection. MATERIAL AND METHODS An immortalized mouse podocyte cell line was treated with HG, Genistein, chloroquine, and/or transfected with specific Myd88 and TRIF siRNAs. The formation of autophagosomes and related autophagic vacuoles were monitored by transmission electron microscopy. The expression of autophagy-related factors and podocyte structure and functional markers, including LC3, p62, p-mTOR, synaptopodin, and nephrin, were measured by Western blot, and LC3 and p-mTOR expression were also assessed by immunofluorescence. RESULTS We showed that HG transiently (after 6-h exposure) induced expression of the autophagy activation marker LC3-II in podocytes. Genistein treatment induced autophagy in both normal and HG-treated podocytes through inactivating mTOR signaling. Moreover, Genistein protected podocytes against chloroquine in HG-cultured conditions in vitro by maintaining the level of autophagy-related proteins. In addition, MyD88 siRNA downregulated expression of autophagy-related proteins, whereas Genistein treatment reversed these effects. CONCLUSIONS This study demonstrated that Genistein-induced autophagy could be a potential treatment strategy for glomerular diseases.

Anti-inflammatory Activity of 8-Hydroxydaidzein in LPS-Stimulated BV2 Microglial Cells via Activation of Nrf2-Antioxidant and Attenuation of Akt/NF-κB-Inflammatory Signaling Pathways, as Well As Inhibition of COX-2 Activity

It was demonstrated that isoflavones can cross the blood-brain barrier, making them desirable candidate agents for the prevention of neurological symptoms. 8-Hydroxydaidzein (8-OHD, 4',7,8-trihydoxyisoflavone) is an isoflavone found only in fermented soy food. Current results showed that 8-OHD inhibited LPS-stimulated production of nitric oxide (NO) and proinflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-6, by inhibiting gene expression in BV2 microglial cells. Moreover, 8-OHD markedly quenched reactive oxygen species (ROS) and activated NF-E2-related factor 2 (Nrf2) so as to upregulate expression of Phase II enzymes, including heme oxygenase (HO)-1, NAD(P)H quinone dehydrogenase 1 (NQO1), and the modifier subunit of glutamate cysteine ligase (GCLM). 8-OHD also suppressed LPS-stimulated phosphorylation of Akt and NF-κB-p65. The anti-inflammatory activity of 8-OHD was attenuated by the HO-1 inhibitor zinc protoporphyrin (Znpp) but augmented by the PI3K/Akt inhibitor LY294002. 8-OHD also diminished LPS-induced prostaglandin E₂ (PGE₂) production without affecting cyclooxygenase (COX)-2 expression. In vitro assay shows that 8-OHD displayed mixed-type inhibition of COX-2 with an IC₅₀ of 8.9 ± 1.2 μM. These data suggest that the anti-inflammatory activity of 8-OHD may be associated with the activation of Nrf2/HO-1 and attenuation of Akt/NF-κB signaling pathways as well as inhibition of COX-2 enzyme activity. In conclusion, 8-OHD, a potent Nrf2 activator, Akt/NF-κB activation suppressor, and COX-2 enzyme inhibitor, may have health-promoting effects for mitigating microglia activation and preventing neuroinflammation.

Genistein: mechanisms of action for a pleiotropic neuroprotective agent in stroke

Genistein is a plant estrogen promoted as an alternative to post-menopausal hormone therapy because of a good safety profile and its promotion as a natural product. Several preclinical studies of cerebral ischemia and other models of brain injury support a beneficial role for genistein in protecting the brain from injury whether administered chronically or acutely. Like estrogen, genistein is a pleiotropic molecule that engages several different mechanisms to enhance brain health, including reduction of oxidative stress, promotion of growth factor signaling, and immune suppression. These actions occur in endothelial, glial, and neuronal cells to provide a coordinated beneficial action to ischemic challenge. Though many of these protective actions are associated with estrogen-like actions of genistein, additional activities on other receptors and intracellular targets suggest that genistein is more than a mere estrogen-mimic. Importantly, genistein lacks some of the detrimental effects associated with post-menopausal estrogen treatment and may provide an alternative to hormone therapy in those patients at risk for ischemic events.

Differential Effects of High-Protein Diets Derived from Soy and Casein on Blood-Brain Barrier Integrity in Wild-type Mice

A number of studies report that a diet high in protein influences cognitive performance, but the results are inconsistent. Studies demonstrated that protein from different food sources has differential effects on cognition. It is increasingly recognized that the integrity of cerebrovascular blood–brain barrier (BBB) is pivotal for central nervous system function. However, to date, no studies have reported the effects of high-protein diets on BBB integrity. Therefore, in this study, the effects of diets enriched in casein or soy protein on BBB permeability were investigated. Immunomicroscopy analyses of cerebral parenchymal immunoglobulin G extravasation indicated significant BBB disruption in the cortex of young adult mice maintained on high-casein diet for 12 weeks, while no signs of BBB dysfunction were observed in mice fed with control or high-soy protein diet. Moreover, cortical expression of glial fibrillary acidic protein (GFAP) was significantly greater in mice fed the high-casein diet compared to control mice, indicating heightened astrocyte activation, whereas mice maintained on a soy-enriched diet showed no increase of GFAP abundance. Plasma concentrations of homocysteine were markedly greater in mice maintained on a high-casein diet in comparison to control mice. Collectively, these findings suggest that a diet enriched in casein but not soy protein may induce astrocyte activation through exaggerated BBB permeability by increased plasma homocysteine. The outcomes indicate the differential effects of protein sources on BBB and neuroinflammation, which may provide an important implication for dietary guidelines for protein supplementation.

Soy Isoflavones Promote Radioprotection of Normal Lung Tissue by Inhibition of Radiation-Induced Activation of Macrophages and Neutrophils

INTRODUCTION

Radiation therapy for lung cancer is limited by toxicity to normal lung tissue that results from an inflammatory process, leading to pneumonitis and fibrosis. Soy isoflavones mitigate inflammatory infiltrates and radiation-induced lung injury, but the cellular immune mediators involved in the radioprotective effect are unknown.

METHODS

Mice received a single dose of 10 Gy radiation delivered to the lungs and daily oral treatment of soy isoflavones. At different time points, mice were either processed to harvest bronchoalveolar lavage fluid for differential cell counting and lungs for flow cytometry or immunohistochemistry studies.

RESULTS

Combined soy and radiation led to a reduction in infiltration and activation of alveolar macrophages and neutrophils in both the bronchoalveolar and lung parenchyma compartments. Soy treatment protected F4/80CD11c interstitial macrophages, which are known to play an immunoregulatory role and are decreased by radiation. Furthermore, soy isoflavones reduced the levels of nitric oxide synthase 2 expression while increasing arginase-1 expression after radiation, suggesting a switch from proinflammatory M1 macrophage to an anti-inflammatory M2 macrophage phenotype. Soy also prevented the influx of activated neutrophils in lung caused by radiation.

CONCLUSIONS

Soy isoflavones inhibit the infiltration and activation of macrophages and neutrophils induced by radiation in lungs. Soy isoflavones-mediated modulation of macrophage and neutrophil responses to radiation may contribute to a mechanism of resolution of radiation-induced chronic inflammation leading to radioprotection of lung tissue.

Genistein alleviates β-amyloid-induced inflammatory damage through regulating Toll-like receptor 4/nuclear factor κB

Genistein (GEN), a major soybean isoflavone (SIF), might possess neuroprotective properties through its anti-inflammatory activity. We hypothesized that GEN could prevent the inflammatory damage detected in C6 cells induced by β-amyloid peptides 25-35 (Aβ25-35). Accordingly, we evaluated the inflammatory damage induced by Aβ25-35 and the protective effect of GEN against Aβ25-35 in C6 cells. In our study, the C6 glial cells (rats glioma cell lines) were preincubated with or without GEN for 2 h following incubation with Aβ25-35 for another 24 h. Then, methylthiazolyl tetrazolium (MTT) assay was used to assess the cell viability. Immunofluorescence staining was used to identify the C6 cells. Inflammatory factors tumor necrosis factor (TNF)-α and interleukin (IL)-1β were analyzed by using enzyme-linked immunosorbent assay (ELISA). Western blot analysis and reverse transcription-polymerase chain reaction analysis were performed to assess the expression of Toll-like receptors 4 (TLR4), inhibitor of kappaB-alpha (IκB-α). The current results showed that GEN could alleviate Aβ25-35-induced cell apoptosis and prevent Aβ25-35-induced TNF-α and IL-1β release from C6 cells. In addition, GEN prevented Aβ25-35-induced upregulation of the gene and protein expression of TLR4, and GEN significantly upregulated the expression of IκB-α in C6 cells damaged by Aβ25-35. These results suggest that GEN can alleviate the inflammatory stress caused by Aβ25-35 treatment, which might be associated with the neuroprotective effect of GEN regulating the TLR4/NFκB signaling pathway.

Plant-derived immunomodulators: an insight on their preclinical evaluation and clinical trials

The phagocyte-microbe interactions in the immune system is a defense mechanism but when excessively or inappropriately deployed can harm host tissues and participate in the development of different non-immune and immune chronic inflammatory diseases such as autoimmune problems, allergies, some rheumatoid disorders, cancers and others. Immunodrugs include organic synthetics, biological agents such as cytokines and antibodies acting on single targets or pathways have been used to treat immune-related diseases but with limited success. Most of immunostimulants and immunosuppressants in clinical use are the cytotoxic drugs which possess serious side effects. There is a growing interest to use herbal medicines as multi-component agents to modulate the complex immune system in the prevention of infections rather than treating the immune-related diseases. Many therapeutic effects of plant extracts have been suggested to be due to their wide array of immunomodulatory effects and influence on the immune system of the human body. Phytochemicals such as flavonoids, polysaccharides, lactones, alkaloids, diterpenoids and glycosides, present in several plants, have been reported to be responsible for the plants immunomodulating properties. Thus the search for natural products of plant origin as new leads for development of potent and safe immunosuppressant and immunostimulant agents is gaining much major research interest. The present review will give an overview of widely investigated plant-derived compounds (curcumin, resveratrol, epigallocatechol-3-gallate, quercetin, colchicine, capsaicin, andrographolide, and genistein) which have exhibited potent effects on cellular and humoral immune functions in pre-clinical investigations and will highlight their clinical potential.

Central inflammatory response to experimental stroke is inhibited by a neuroprotective dose of dietary soy

Dietary soy and soy isoflavones are neuroprotective in experimental cerebral ischemia. Because the isoflavones in soy that are responsible for this neuroprotective effect act as phytoestrogens, we hypothesized that they would mimic the beneficial effects of estrogens on the innate inflammatory response to cerebral ischemia. Ovariectomized Sprague-Dawley rats were fed a soy free diet or a diet containing high dietary levels of soy for 5 weeks, after which they were subjected to transient middle cerebral artery occlusion (tMCAO) for 90min. Dietary soy was associated with a reduced inflammatory response in the cerebral cortex during the acute innate period 4 and 24h after tMCAO, including significant (>2-fold) reductions in interleukins 1 beta, 2, and 13, and the chemokine CXCL1. However, there was no effect of soy on tumor necrosis factor-alpha or interferon-gamma. Dietary soy was also associated with a 40 percent reduction in the nuclear translocation of p65 nuclear factor kappa B despite an increase in the expression of p65 RELA mRNA. In support of an early effect on the innate immune response to stroke, soy-fed rats had 44 percent fewer activated microglia in the infarct core than soy free rats. Interestingly, despite increased expression following injury, the steady state mRNA levels of inflammatory factors were not altered in soy-fed rats even though inflammatory proteins were. These data suggest that dietary soy isoflavones, like estrogens, inhibit of the innate immune response to injury. However, post-transcriptional mechanisms may play an important role in the mechanism of this action. Coupled with previously published data, these results support an early and rapid effect of dietary soy on the evolution of brain injury following stroke.

Inhibitory effects of a major soy isoflavone, genistein, on human DNA topoisomerase II activity and cancer cell proliferation

The inhibitory activity of 3 soy isoflavones (daidzein, genistein and glycitein) and their glycosides (daidzin, genistin and glycitin) on mammalian DNA polymerases (pols) and topoisomerases (topos) was investigated. Of the compounds tested, only genistein selectively inhibited human topo II activity and had an IC50 value of 37.5 µM. These isoflavones had no effect on the activity of human topo I; mammalian pols α, β, γ and κ; or on any other DNA metabolic enzyme tested. Thermal transition analysis indicated that genistein did not influence the direct binding to double-stranded DNA. Genistein prevented the proliferation of HCT116 human colon carcinoma cells with an LD50 of 94.0 µM and it halted the cell cycle in G2/M phase. These results suggest that decreases in cell proliferation due to genistein may result from the inhibition of cellular topo II and that genistein, a major soy isoflavone, may be an anticancer food component. The relationship between the structures and these bioactivities of soy isoflavones is discussed.

Hypoxia-inducible factor and vascular endothelial growth factor are targets of dietary soy during acute stroke in female rats

Dietary soy and soy isoflavones are neuroprotective in experimental cerebral ischemia. Because these isoflavones have estrogenic properties, we hypothesized that, like estrogens, they would inhibit acute vascular injury and the detrimental acute increase in hypoxia-induced vascular endothelial growth factor (VEGF) that leads to cerebral edema after stroke. Mature ovariectomized female Sprague Dawley rats were fed soy-free or soy-containing diets for 4 weeks followed by 90 minutes of transient middle cerebral artery occlusion. Similar to estrogens, dietary soy significantly reduced cerebral edema and vascular apoptosis 24 hours after stroke. Soy also inhibited the ischemia-induced increase in cortical VEGF and VEGF receptor (VEGFR)-2 protein expression observed 4 and 24 hours after stroke, although mRNA levels increased. The reduction in VEGF/VEGFR-2 was associated both with decreases in receptor phosphorylation and signaling to AKT and endothelial nitric oxide synthase. Furthermore degradation of the VEGFR-2 was increased with dietary soy. The primary ischemic stimulus for VEGF, hypoxia-inducible factor 1α (HIF1α), was similarly reduced by dietary soy 4 hours after transient middle cerebral artery occlusion in both the cortex and striatum. The inhibition of HIF1α activity was further confirmed by a significant decrease in the HIF1α-activated apoptotic mediator BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (Nip3-like protein X). These data suggest that soy isoflavones target events early in the ischemic cascade as part of their neuroprotective actions and counterbalance some of the detrimental effects of the endogenous response to cerebral injury.

CYTOTOXICITY AND CELLULAR UPTAKE OF CELLULOSE NANOCRYSTALS

There is growing evidence that filamentous nanoparticles offer advantages over spherical ones in drug delivery applications. The purpose of this study was to assess the potential of rod-like, plant-derived cellulose nanocrystals (CNCs) for nanomedical uses. Besides a nonspherical morphology, their facile bioconjugation, surface hydrophilicity and small size render CNCs promising drug carriers. The cytotoxicity of CNCs against nine different cell lines (HBMEC, bEnd.3, RAW 264.7, MCF-10A, MDA-MB-231, MDA-MB-468, KB, PC-3 and C6) was determined by MTT and LDH assay. CNCs showed no cytotoxic effects against any of these cell lines in the concentration range and exposure time studied (0–50 μg/mL and 48 h, respectively). Cellular uptake of fluorescein-5′-isothiocyanate-labeled CNCs by these cell lines, quantified with a fluorescence microplate reader, was minimal. The lack of cytotoxicity and the low nonspecific cellular uptake support our hypothesis that CNCs are good candidates for nanomedical applications.

Vascular effects of phytoestrogens and alternative menopausal hormone therapy in cardiovascular disease

Phytoestrogens are estrogenic compounds of plant origin classified into different groups including isoflavones, lignans, coumestans and stilbenes. Isoflavones such as genistein and daidzein are the most studied and most potent phytoestrogens, and are found mainly in soy based foods. The effects of phytoestrogens are partly mediated via estrogen receptors (ERs): ERα, ERβ and possibly GPER. The interaction of phytoestrogens with ERs is thought to induce both genomic and non-genomic effects in many tissues including the vasculature. Some phytoestrogens such as genistein have additional non-ER-mediated effects involving signaling pathways such as tyrosine kinase. Experimental studies have shown beneficial effects of phytoestrogens on endothelial cells, vascular smooth muscle, and extracellular matrix. Phytoestrogens may also affect other pathophysiologic vascular processes such as lipid profile, angiogenesis, inflammation, tissue damage by reactive oxygen species, and these effects could delay the progression of atherosclerosis. As recent clinical trials showed no vascular benefits or even increased risk of cardiovascular disease (CVD) and CV events with conventional menopausal hormone therapy (MHT), phytoestrogens are being considered as alternatives to pharmacologic MHT. Epidemiological studies in the Far East population suggest that dietary intake of phytoestrogens may contribute to the decreased incidence of postmenopausal CVD and thromboembolic events. Also, the WHO-CARDIAC study supported that consumption of high soybean diet is associated with lower mortalities from coronary artery disease. However, as with estrogen, there has been some discrepancy between the experimental studies demonstrating the vascular benefits of phytoestrogens and the data from clinical trials. This is likely because the phytoestrogens clinical trials have been limited in many aspects including the number of participants enrolled, the clinical end points investigated, and the lack of long-term follow-up. Further investigation of the cellular mechanisms underlying the vascular effects of phytoestrogens and careful evaluation of the epidemiological evidence and clinical trials of their potential vascular benefits would put forward the use of phytoestrogens as an alternative MHT for the relief of menopausal symptoms and amelioration of postmenopausal CVD.

Phytoestrogen calycosin-7-O-β-D-glucopyranoside ameliorates advanced glycation end products-induced HUVEC damage

Vasculopathy including endothelial cell (EC) apoptosis and inflammation contributes to the high incidence of stroke and myocardial infarction in diabetic patients. The aim of the present study was to investigate the effect of calycosin-7-O-β-D-glucopyranoside (CG), a phytoestrogen, on advanced glycation end products (AGEs)-induced HUVEC damage. We observed that CG can significantly ameliorate AGEs-induced HUVEC oxidative stress and apoptosis. The ratio of SOD/MDA was significantly increased to the normal level by CG pretreatment. CG preincubation dramatically increased anti-apoptotic Bcl-2 while decreased pro-apoptotic Bax and Bad expressions as detected by immunocytochemistry. Moreover, CG ameliorated macrophage migration and adhesion to HUVEC; the monocyte chemotactic protein-1 and interleukin-6 levels in the culture supernatant were dramatically reduced by CG as determined by ELISA; the expressions of inflammatory proteins including ICAM-1, TGF-β1, and RAGE in both protein and mRNA levels were significantly reduced to the normal level by CG pretreatment as determined by immunocytochemistry and real-time RT-PCR. The intracellular investigation suggests that CG can reverse AGEs-activated ERK1/2 and NF-κB phosphorylation, in which estrogen receptors were involved in. Our results strongly indicate that CG can modulate EC dysfunction by ameliorating AGEs-induced cell apoptosis and inflammation.

Protective effects of 7-difluoromethyl-5,4'-dimethoxygenistein against human aorta endothelial injury caused by lysophosphatidyl choline

7-Difluoromethyl-5,4'-dimethoxygenistein (DFMG) is an active new derivative of genistein (GEN). It has shown effective protection in vascular endothelial injury. To further investigate its potential protective effects and its mechanism probably related to atherosclerosis, in present study, human aorta endothelial cells (HAECs) were chosen and treated with various concentrations of lysophosphatidyl choline (LPC) to establish an experimental model. Results showed that 10.0 μmol/l of LPC was optimal for inducing HAEC injury. DFMG pretreatment was able to prevent HAEC injury induced by LPC and restore cell viability in a concentration-dependent manner. The protective efficacy of DFMG (10.0 μmol/l) was significantly greater than that of GEN (10.0 μmol/l) and vitamin E (50.0 μmol/l). The mechanisms underlying the protective effects of DFMG are related to the activation of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase and to the clearance of intracellular reactive oxygen species. DFMG inhibits the apoptosis of HAECs mediated by LPC involving the blockage of the mitochondrial apoptotic pathway.

Soy protein based supplementation supports metabolic effects of resistance training in previously untrained middle aged males

OBJECTIVE

To determine changes in body composition, physical performance, metabolic and hormonal parameters induced by lifestyle counselling, resistance training and resistance training with soy protein based supplemention in middle aged males.

DESIGN

Randomised controlled study consisting of resistance training without (RT-G) or with (RTS-G) a soy protein based supplement and a control group with lifestyle education only (LE-G).

SUBJECTS

Forty healthy middle aged men (50-65 years, BMI 25-29.9 kg/m2).

MEASUREMENTS

Changes in body weight (BW) and waist circumference (WC) were measured and body composition (BC), fat mass (FM), lean body mass (LBM) were measured by skin fold anthropometry at baseline and after 12 weeks of intervention. In addition, changes in physical fitness, metabolic and hormonal parameters (lipids, glucose, fructosamines, insulin, insulin-like growth factor-1, Leptin, human growth hormone, dehydroepiandrosterone, testosterone, hs-CRP, Il-6) were evaluated.

RESULTS

Thirty-five participants completed the 12 week study. No significant changes in BW were noted although RM and WC dropped and LBM increased after training, particularly in the RTS group (FM 22.6 ± 5.5 kg to 21.2 ± 4.7 kg; LBM 68.5 ± 7.2 kg to 70.1 ± 7.4; p < 0.01). Subjects in the RTS group experienced more pronounced improvements in the strength measurements than the RT group. After the training intervention there were significant changes in hormonal and metabolic parameters as well as in glycemic control, particularly in the RTS group.

CONCLUSIONS

Our data suggest that resistance training, particularly in combination with a soy protein based supplement improves body composition and metabolic function in middle aged untrained and moderately overweight males.

Caveolae: a regulatory platform for nutritional modulation of inflammatory diseases

Dietary intervention strategies have proven to be an effective means of decreasing several risk factors associated with the development of atherosclerosis. Endothelial cell dysfunction influences vascular inflammation and is involved in promoting the earliest stages of lesion formation. Caveolae are lipid raft microdomains abundant within the plasma membrane of endothelial cells and are responsible for modulating receptor-mediated signal transduction, thus influencing endothelial activation. Caveolae have been implicated in the regulation of enzymes associated with several key signaling pathways capable of determining intracellular redox status. Diet and plasma-derived nutrients may modulate an inflammatory outcome by interacting with and altering caveolae-associated cellular signaling. For example, omega-3 fatty acids and several polyphenolics have been shown to improve endothelial cell function by decreasing the formation of ROS and increasing NO bioavailability, events associated with altered caveolae composition. Thus, nutritional modulation of caveolae-mediated signaling events may provide an opportunity to ameliorate inflammatory signaling pathways capable of promoting the formation of vascular diseases, including atherosclerosis.

Effects of flavonoids and other polyphenols on inflammation

Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and are consumed as part of the human diet in significant amounts. There are other types of polyphenols, including, for example, tannins and resveratrol. Flavonoids and related polyphenolic compounds have significant antiinflammatory activity, among others. This short review summarizes the current knowledge on the effects of flavonoids and related polyphenolic compounds on inflammation, with a focus on structural requirements, the mechanisms involved, and pharmacokinetic considerations. Different molecular (cyclooxygenase, lipoxygenase) and cellular targets (macrophages, lymphocytes, epithelial cells, endothelium) have been identified. In addition, many flavonoids display significant antioxidant/radical scavenging properties. There is substantial structural variation in these compounds, which is bound to have an impact on their biological profile, and specifically on their effects on inflammatory conditions. However, in general terms there is substantial consistency in the effects of these compounds despite considerable structural variations. The mechanisms have been studied mainly in myeloid cells, where the predominant effect is an inhibition of NF-κB signaling and the downregulation of the expression of proinflammatory markers. At present there is a gap in knowledge of in vitro and in vivo effects, although the pharmacokinetics of flavonoids has advanced considerably in the last decade. Many flavonoids have been studied for their intestinal antiinflammatory activity which is only logical, since the gastrointestinal tract is naturally exposed to them. However, their potential therapeutic application in inflammation is not restricted to this organ and extends to other sites and conditions, including arthritis, asthma, encephalomyelitis, and atherosclerosis, among others.

Genistein modulates NF-κB-associated renal inflammation, fibrosis and podocyte abnormalities in fructose-fed rats

The study determines the effect of genistein on inflammatory status and expression of nuclear factor-kappa B (NF-κB p65), transforming growth factor-β1 (TGF-β1) and receptor for advanced glycation end products (RAGE) in kidney of fructose-fed rats. Adult male Wistar rats were fed a diet containing either starch or fructose as the source of carbohydrate. Fifteen days later, after confirming the development of insulin resistance in fructose-fed rats, the rats in each dietary group were divided into two and treated with either genistein (1 mg/kg/day) in 30% dimethylsulfoxide (DMSO) or 30% DMSO alone for the next 45 days. The expression of NF-κB P(65), TGF-β1 and RAGE, histochemical localization of α-smooth muscle actin (α-SMA), levels of tumour necrosis factor-α (TNF-α) and interleukin-6(IL-6) and ultrastructural analysis were performed at the end of the experimental period. Fructose-fed rats displayed inflammatory changes in kidney. Increased expression of TGF-β1 and RAGE in cytosol and NF-κB p65 in nuclear fraction were observed. α-SMA expression was higher in fructose-fed rat kidney. Proliferation of connective tissue was evident from increased collagen deposition in perivascular and intraglomerular regions. Administration of genistein to fructose-fed rats reduced inflammation, fibrogenesis and NF-κB activation. Genistein also mitigated the structural changes such as basement membrane thickening, reduction in podocyte number and loss of glomerular filtration barrier integrity. These findings suggest that genistein prevents inflammation, fibrosis and early nephropathic changes in fructose-fed insulin resistant rats secondary to the attenuation of NF-κB activation.

Anti-inflammatory activity of natural dietary flavonoids

Over the past few decades, inflammation has been recognized as a major risk factor for various human diseases. Acute inflammation is short-term, self-limiting and it's easy for host defenses to return the body to homeostasis. Chronic inflammatory responses are predispose to a pathological progression of chronic illnesses characterized by infiltration of inflammatory cells, excessive production of cytokines, dysregulation of cellular signaling and loss of barrier function. Targeting reduction of chronic inflammation is a beneficial strategy to combat several human diseases. Flavonoids are widely present in the average diet in such foods as fruits and vegetables, and have been demonstrated to exhibit a broad spectrum of biological activities for human health including an anti-inflammatory property. Numerous studies have proposed that flavonoids act through a variety mechanisms to prevent and attenuate inflammatory responses and serve as possible cardioprotective, neuroprotective and chemopreventive agents. In this review, we summarize current knowledge and underlying mechanisms on anti-inflammatory activities of flavonoids and their implicated effects in the development of various chronic inflammatory diseases.

Dietary genistein and equol (4′, 7 isoflavandiol) reduce oxidative stress and protect rats against focal cerebral ischemia

High soy diets reduce injury in rat models of focal cerebral ischemia and are proposed as alternatives to hormone replacement therapy for postmenopausal women. The present study tests the hypothesis that the major soy isoflavone genistein and the daidzein metabolite equol are neuroprotective in transient focal cerebral ischemia in male and ovariectomized (OVX) female rats by inhibiting oxidative stress. Genistein is the primary circulating soy isoflavone in humans, whereas equol is the primary circulating isoflavone in rats. Male and OVX female Sprague-Dawley rats were fed an isoflavone-reduced diet alone or supplemented with genistein (500 ppm) or equol (250 ppm) for 2 wk prior to 90-min transient middle cerebral artery occlusion followed by reperfusion under isoflurane anesthesia. Indices of oxidative stress were determined 24 h after reperfusion, and cerebral injury was evaluated 3 days after reperfusion. Genistein and equol significantly reduced infarct size in both sexes. Further studies in OVX female rats revealed that this neuroprotection was accompanied by a decrease in NAD(P)H oxidase activity and superoxide levels in the brain. In addition, equol reduced plasma thiobarbituric acid reactive substances, and neurological deficits up to 7 days after injury. There were no significant differences in cerebral blood flow among treatment groups. In conclusion, dietary soy isoflavones are neuroprotective in transient focal cerebral ischemia in male and OVX female rats. These isoflavones may protect the brain via increases in endogenous antioxidant mechanisms and reduced oxidative stress.

Role of NADPH oxidase in interleukin-4-induced monocyte chemoattractant protein-1 expression in vascular endothelium

OBJECTIVE AND DESIGN

The pro-oxidative and pro-inflammatory pathways in vascular endothelium have been implicated in the development of atherosclerosis. In the present study, we investigated effect of interleukin-4 (IL-4) on monocyte chemoattractant protein-1 (MCP-1) expression in vascular endothelium and examined the role of distinct sources of reactive oxygen species (ROS) in this process.

METHODS AND RESULTS

Real-time reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay showed that IL-4 significantly up-regulated mRNA and protein expression of MCP-1 in human aortic endothelial cells (HAEC) and C57BL/6 mice. A significant and dose-dependent inhibition of IL-4-induced MCP-1 expression was observed in HAEC pre-treated with antioxidants, such as pyrrolidine dithiocarbamate and epigallocatechin gallate, indicating that IL-4-induced MCP-1 expression is mediated via a ROS-dependent mechanism. Additionally, pharmacological inhibitors of NADPH oxidase (NOX) significantly attenuated IL-4-induced MCP-1 expression in HAEC. Furthermore, the disruption of the NOX gene dramatically reduced IL-4-induced MCP-1 expression in NOX knockout mice (B6.129S6-Cybb(tm1Din)/J). In contrast, overexpression of MCP-1 in IL-4-stimulated HAEC was not affected by inhibiting other ROS generating pathways, such as xanthine oxidase and the mitochondrial electron transport chain.

CONCLUSIONS

These results demonstrate that IL-4 up-regulates MCP-1 expression in vascular endothelium through NOX-mediated ROS generation.

Chrysin suppresses IL-6-induced angiogenesis via down-regulation of JAK1/STAT3 and VEGF: an in vitro and in ovo approach

Chrysin, 5,7-dihydroxyflavone, possesses many biologic properties. This study aimed to investigate the effects and molecular mechanisms of chrysin on IL-6-induced angiogenesis in vitro and in ovo. Chicken chorioallantoic membrane assay, an in ovo angiogenesis assay, showed chrysin significantly suppressed IL-6-induced neovascularization. Furthermore, chrysin significantly suppressed human umbilical vein endothelial cell (HUVECs) migration and tube formation. The signaling pathway involved in chrysin-related antiangiogenesis was also investigated. The data indicated that chrysin is able to down-regulate the expression of glycoprotein 130 (gp130), soluble IL-6 receptor (IL-6R), phosphorylated JAK1 and STAT3, and VEGF in HUVECs. The IL-6-induced binding of STAT3 was significantly suppressed by chrysin. Moreover, chrysin did not further suppress VEGF expression with STAT3 knocked down. Taken together, the results show that chrysin suppresses IL-6-induced angiogenesis through modulation of the sIL-6R/gp130/JAK1/STAT3/VEGF signaling pathway. Chrysin may provide new therapeutic potential for IL-6-induced pathological angiogenesis.

Mechanisms of anti-atherosclerotic functions of soy-based diets

Soy-based diets have been reported to protect against the development of atherosclerosis. However, the underlying mechanism(s) for this protection remains unknown. Although atherosclerosis was traditionally considered a disease associated with impaired lipid metabolism, in recent years the inflammatory components of atherosclerosis have been explored. Recent studies have convincingly delineated that uncontrolled chronic inflammation is the principal contributing factor for the initiation and progression of atherosclerosis. Interaction between activated monocytes and vascular endothelial cells is an early event in atherogenesis. The adhesion of leukocytes, including monocytes, to the inflamed-vascular endothelium and their transmigration into intima initiate the inflammatory processes. Following transmigration, monocytes in the intima are transformed to macrophages, which take up oxidized-LDL (oxLDL) to generate lipid-laden macrophages, also known as foam cells. Hence, in this review article the inflammatory processes associated with atherosclerosis and possible anti-inflammatory functions of soy-based diets contributing to the prevention of atherosclerosis are presented.

Potential health-modulating effects of isoflavones and metabolites via activation of PPAR and AhR

Isoflavones have multiple actions on cell functions. The most prominent one is the activation of estrogen receptors. Other functions are often overlooked, but are equally important and explain the beneficial health effects of isoflavones. Isoflavones are potent dual PPARα/γ agonists and exert anti-inflammatory activity, which may contribute to the prevention of metabolic syndrome, atherosclerosis and various other inflammatory diseases. Some isoflavones are potent aryl hydrocarbon receptor (AhR) agonists and induce cell cycle arrest, chemoprevention and modulate xenobiotic metabolism. This review discusses effects mediated by the activation of AhR and PPARs and casts a light on the concerted action of isoflavones.

Oxidative mechanisms of IL-4-induced IL-6 expression in vascular endothelium

The present study is designed to investigate the effects of interleukin-4 (IL-4) on expression of interleukin-6 (IL-6), as well as to examine the role of distinct sources of reactive oxygen species (ROS) in this process. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) showed that IL-4 significantly up-regulated the mRNA and protein expression of IL-6 in human aortic endothelial cells (HAEC) and C57BL/6 mice. Dihydroethidium (DHE) and dichlorofluorescein (DCF) fluorescence staining demonstrated that IL-4 significantly increased ROS generation in HAEC. A significant and dose-dependent inhibition of IL-4-induced IL-6 expression was observed in HAEC pre-treated with antioxidants, such as pyrrolidine dithiocarbamate (PDTC) and epigallocatechin gallate (EGCG), indicating that IL-4-induced IL-6 expression is mediated via an ROS-dependent mechanism. Additionally, pharmacological inhibitor of NADPH oxidase (NOX) significantly attenuated IL-4-induced ROS generation and IL-6 expression in HAEC. Furthermore, the disruption of NOX gene dramatically and significantly reduced IL-4-induced IL-6 expression in NOX knockout mice (B6.129S6-Cybb(tm1Din)/J). In contrast, overexpression of IL-6 in IL-4-activated HAEC was not affected by inhibiting other ROS generating pathways, such as xanthine oxidase, arachidonic acid metabolism, and the mitochondrial electron transport chain. These results demonstrate that IL-4 up-regulates IL-6 expression in vascular endothelium through NOX-mediated ROS generation.

Genistein inhibition of topoisomerase IIalpha expression participated by Sp1 and Sp3 in HeLa cell

Genistein (4′, 5, 7-trihydroxyisoflavone) is an isoflavone compound obtained from plants that has potential applications in cancer therapy. However, the molecular mechanism of the action of genistein on cancer cell apoptosis is not well known. In this study, we investigated the effect of genistein on topoisomerase II-α (Topo IIα), an important protein involved in the processes of DNA replication and cell proliferation. The results revealed that inhibition of Topo IIα expression through the regulation of Specificity protein 1 and Specificity protein 3 may be one of the reasons for genistein’s induction of HeLa cell apoptosis.