Emodin suppresses lipopolysaccharide-induced pro-inflammatory responses and NF-κB activation by disrupting lipid rafts in CD14-negative endothelial cells

The study on the material basis and the mechanism for anti-renal interstitial fibrosis efficacy of rhubarb through integration of metabonomics and network pharmacology

The cooperative material basis of the multi-component and multi-target mechanism of action of Traditional Chinese Medicine (TCM) is difficult to elucidate because of the current lack of appropriate techniques and strategies.

Emodin inhibits human sperm functions by reducing sperm [Ca(2+)]i and tyrosine phosphorylation

Emodin, a bioactive anthraquinone widely used in Chinese traditional medicine, disrupts mouse testicular gene expression in vivo. In this study, we investigated the toxicity of emodin to human sperm in vitro. Different doses of emodin (25, 50, 100, 200 and 400μM) were applied to ejaculated human sperm. The results indicated that 100, 200 and 400μM emodin significantly inhibited the total motility, progressive motility and linear velocity of human sperm. In addition, sperm's ability to penetrate viscous medium together with progesterone induced capacitation and acrosome reaction was also adversely affected by emodin. In contrast, emodin did not affect sperm viability. Furthermore, intracellular Ca(2+) concentration ([Ca(2+)]i) and tyrosine phosphorylation, which serve as key regulators of sperm function, were dose-dependently reduced by emodin (50-400μM). These results suggest that emodin inhibits human sperm functions by reducing sperm [Ca(2+)]i and suppressing tyrosine phosphorylation in vitro.

Multifunctional core/shell nanoparticles cross-linked polyetherimide-folic acid as efficient Notch-1 siRNA carrier for targeted killing of breast cancer

In gene therapy, how genetic therapeutics can be efficiently and safely delivered into target tissues/cells remains a major obstacle to overcome. To address this issue, nanoparticles consisting of non-covalently coupled polyethyleneimine (PEI) and folic acid (FA) to the magnetic and fluorescent core/shell of Fe3O4@SiO2(FITC) was tested for their ability to deliver Notch-1 shRNA. Our results showed that Fe3O4@SiO2(FITC)/PEI-FA/Notch-1 shRNA nanoparticles are 64 nm in diameter with well dispersed and superparamagnetic. These nanoparticles with on significant cytotoxicity are capable of delivering Notch-1 shRNA into human breast cancer MDA-MB-231 cells with high efficiency while effectively protected shRNA from degradation by exogenous DNaseI and nucleases. Magnetic resonance (MR) imaging and fluorescence microscopy showed significant preferential uptake of Fe3O4@SiO2(FITC)/PEI-FA/Notch-1 shRNA nanocomplex by MDA-MB-231 cells. Transfected MDA-MB-231 cells exhibited significantly decreased expression of Notch-1, inhibited cell proliferation, and increased cell apoptosis, leading to the killing of MDA-MB-231 cells. In light of the magnetic targeting capabilities of Fe3O4@SiO2(FITC)/PEI-FA, our results show that by complexing with a second molecular targeting therapeutic, such as Notch-1 shRNA in this report, Fe3O4@SiO2(FITC)/PEI-FA can be exploited as a novel, non-viral, and concurrent targeting delivery system for targeted gene therapy as well as for MR imaging in cancer diagnosis.

Shufeng Jiedu Capsule protect against acute lung injury by suppressing the MAPK/NF-κB pathway

This study sought to investigate the protective effect of an alternative medicine, Shufeng Jiedu Capsule, in acute lung injury and inflammation signaling pathways related to that action. Hematoxylin and eosin (HE) staining was used to observe pathological changes in rat lung tissue, arterial blood was subjected to blood gas analysis and lactic acid levels were determined, immunofluorescent staining for interleukin-1β (IL-1β) was performed, enzyme linked immunosorbent assay (ELISA) was used to detect biomarkers of the nuclear factor-κB (NF-κB) inflammation pathway including IL-1β and tumor necrosis factor α (TNF-α), biomarkers of the mitogen-activated protein kinase (MAPK) signal pathway including P-selectin, transforming growth factor β (TGF-β), keratinocyte-derived chemokine (KC), and C-Jun/AP-1 were measured, and real-time PCR was used to detect NF-κB mRNA. Results in rats with lipopolysaccharide-induced acute lung injury suggested that Shufeng Jiedu Capsule may increase the partial pressure of oxygen in lung tissue, decrease lactic acid levels, inhibit inflammatory factors such as IL-1β and TNF-α, and suppress the levels of P-selectin, TGF-β, KC, C-Jun/AP-1, and NF-κB mRNA. Thus, Shufeng Jiedu Capsule is a traditional medicine that may alleviate acute lung injury by suppressing the MAPK/NF-κB signaling pathway.

Emodin ameliorated lipopolysaccharide-induced fulminant hepatic failure by blockade of TLR4/MD2 complex expression in D-galactosamine-sensitized mice

Emodin has been reported to possess anti-inflammatory and anti-oxidant activities. The aim of this study was to explore the effect and mechanism of emodin on lipopolysaccharide (LPS)-induced fulminant hepatic failure (FHF) in D-galactosamine (D-GalN)-sensitized mice. Our results showed that pretreatment with emodin inhibited the elevation of plasma aminotransferases, alleviated the hepatic histopathological abnormalities and improved the survival rate of LPS/D-GalN-primed mice. Moreover, emodin markedly attenuated the increased serum and hepatic tumor necrosis factor-α (TNF-α) production, and activated hepatic p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signal pathways in LPS/D-GalN-challenged mice. Furthermore, using an in vitro experiment, we found that emodin dose-dependently suppressed TNF-α production, dampened AP-1 and NF-κB activation, and blocked toll-like receptor (TLR) 4/myeloid differentiation factor (MD) 2 complex expression in LPS-elicited RAW264.7 mouse macrophage cells. Taken together, these data suggested that emodin could effectively prevent LPS-induced FHF, which might be mediated by inhibition of TNF-α production, deactivation of MAPKs and NF-κB, and blockade of TLR4/MD2 complex expression.

Emodin inhibits growth and induces apoptosis in an orthotopic hepatocellular carcinoma model by blocking activation of STAT3

BACKGROUND AND PURPOSE

Aberrant activation of STAT3 is frequently encountered and promotes proliferation, survival, metastasis and angiogenesis in hepatocellular carcinoma (HCC). Here, we have investigated whether emodin mediates its effect through interference with the STAT3 activation pathway in HCC.

EXPERIMENTAL APPROACH

The effect of emodin on STAT3 activation, associated protein kinases and apoptosis was investigated using various HCC cell lines. Additionally, we also used a predictive tumour technology to analyse the effects of emodin . The in vivo effects of emodin were assessed in an orthotopic mouse model of HCC.

KEY RESULTS

Emodin suppressed STAT3 activation in a dose- and time-dependent manner in HCC cells, mediated by the modulation of activation of upstream kinases c-Src, JAK1 and JAK2. Vanadate treatment reversed emodin-induced down-regulation of STAT3, suggesting the involvement of a tyrosine phosphatase and emodin induced the expression of the tyrosine phosphatase SHP-1 that correlated with the down-regulation of constitutive STAT3 activation. Interestingly, silencing of the SHP-1 gene by siRNA abolished the ability of emodin to inhibit STAT3 activation. Finally, when administered i.p., emodin inhibited the growth of human HCC orthotopic tumours in male athymic nu/nu mice and STAT3 activation in tumour tissues.

CONCLUSIONS AND IMPLICATIONS

Emodin mediated its effects predominantly through inhibition of the STAT3 signalling cascade and thus has a particular potential for the treatment of cancers expressing constitutively activated STAT3.

Therapeutic effect of emodin on collagen-induced arthritis in mice

Emodin, an anthraquinone isolated from the Chinese herb Radix et Rhizoma Rhei, has been reported to have anti-inflammatory, antibacterial, and antitumor activities. However, the effect of emodin on collagen-induced arthritis (CIA) has not yet been investigated. The purpose of this study was to investigate whether emodin has a protective effect against collagen-induced arthritis in mice and its possible mechanisms. CIA was induced in mice by immunization with bovine type II collagen. The mice were treated with emodin (5, 10, and 20 mg/kg/day, i.g.) from days 21 to 42 after immunization. The clinical scores and hind paw swelling were evaluated. The expression of prostaglandin E2 (PGE2) and cyclooxygenase-2 (COX-2) in synovial tissues was determined. The levels of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in the plasma were measured by enzyme-linked immunosorbent assay. The results showed that emodin treatment significantly alleviated the severity of the disease, based on the reduced hind paw swelling and clinical scores, compared with untreated CIA mice. Comparing with untreated CIA mice, emodin treatment inhibited the levels of TNF-α and IL-6 in the plasma, PGE2 production, and COX-2 protein expression in synovial tissues in a dose manner. In conclusion, our results suggest that anti-inflammatory effects of emodin against collagen-induced arthritis in mice may be due to its ability to inhibit pro-inflammatory mediators. Emodin may be a promising potential therapeutic reagent for arthritis treatment.

Emodin inhibits LPS-induced inflammatory response by activating PPAR-γ in mouse mammary epithelial cells

Emodin, an anthraquinone derivative isolated from the rhizomes of Rheum palmatum, has been reported to have a protective effect against lipopolysaccharide (LPS)-induced mastitis. However, the underlying molecular mechanisms are not well understood. The aim of this study was to investigate the molecular mechanisms of emodin in modifying lipopolysaccharide (LPS)-induced signaling pathways in mouse mammary epithelial cells (MEC). The pro-inflammatory cytokines were determined by ELISA. Nuclear factor-κB (NF-κB), inhibitory kappa B (IκBα) protein, p38, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and PPAR-γ were determined by Western blotting. The results showed that emodin suppressed tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), iNOS and COX-2 expression. We also found that emodin inhibited LPS-induced NF-κB activation, IκBα degradation, phosphorylation of ERK, JNK and P38. Furthermore, emodin could activate PPAR-γ and the anti-inflammatory effects of emodin can be reversed by GW9662, a specific antagonist for PPAR-γ. In conclusion, our results demonstrate that emodin activates PPAR-γ, thereby attenuating LPS-induced inflammatory response.

Emodin improves lipopolysaccharide-induced microcirculatory disturbance in rat mesentery

OBJECTIVE

Sepsis is a systemic inflammatory response syndrome. Emodin is a major ingredient of Rheum Palmatum, a Chinese herb that is widely used in China for treatment of endotoxemia-related diseases. This study intended to examine the effect of Emodin on LPS-induced rat mesenteric microcirculatory disturbance and the underlying mechanisms.

METHODS

The male Wistar rats received LPS (5 mg/kg/hr) for 90 min, with or without administration of Emodin (10 mg/kg/hr) by enema 30 min before (pre-treatment) or after (post-treatment) LPS infusion, and the dynamics of mesenteric microcirculation were determined by inverted intravital microscopy. Expression of adhesion molecules and TLR4, NF-κB p65, ICAM-1, MPO, and AP-1 in mesentery tissue was evaluated by flow cytometry and Western-blot, respectively.

RESULTS

Pre or post-treatment with Emodin significantly ameliorated LPS-induced leukocyte emigration, reactive oxygen species production and albumin leakage, and the expression of TLR4, NF-κB p65, ICAM-1, MPO and AP-1 in mesentery.

CONCLUSIONS

These results demonstrate the beneficial role of Emodin in attenuating the LPS-induced microcirculatory disturbance, and support the use of Emodin for patients with endotoxemia.

Cyanidin-3-O-β-glucoside inhibits lipopolysaccharide-induced inflammatory response in mouse mastitis model

Cyanidin-3-O-β-glucoside (C3G) (CAS number 7084-24-4), a typical anthocyanin pigment that exists in the human diet, has been reported to have anti-inflammatory properties. However, the effect of C3G on lipopolysaccharide (LPS)-induced mastitis and the molecular mechanisms have not been investigated. In this study, we detected the protective effects of C3G on a LPS-induced mouse mastitis model and investigated the molecular mechanisms in LPS-stimulated mouse mammary epithelial cells (MMECs). Our results showed that C3G could attenuate mammary histopathologic changes and myeloperoxidase activity, and inhibit TNF-α, interleukin (IL)-1β, and IL-6 production caused by LPS. Meanwhile, C3G dose-dependently inhibited TNF-α and IL-6 in LPS-stimulated MMECs. C3G suppressed LPS-induced nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3) activation. Furthermore, C3G disrupted the formation of lipid rafts by depleting cholesterol. Moreover, C3G activated liver X receptor (LXR)-ABCG1-dependent cholesterol efflux. Knockdown of LXRα abrogated the anti-inflammatory effects of C3G. In conclusion, C3G has a protective effect on LPS-induced mastitis. The promising anti-inflammatory mechanisms of C3G are associated with upregulation of the LXRα-ABCG1 pathway which result in disrupting lipid rafts by depleting cholesterol, thereby suppressing toll-like receptor 4-mediated NF-κB and IRF3 signaling pathways induced by LPS.

Emodin attenuates systemic and liver inflammation in hyperlipidemic mice administrated with lipopolysaccharides

Non-alcoholic fatty liver disease (NAFLD) is a major epidemics of the modern societies and has an inflammatory component in the pathogenesis. However, approved anti-inflammatory therapies are not currently available for the prevention of the transition from simple steatosis to non-alcoholic steatohepatitis (NASH). We aimed to test if a Chinese herb-derived compound, emodin could halt the simple steatosis to NASH transition. LDLR^-/- mice were fed a western-type diet for 10 weeks; and during the last four weeks, the mice were intra-peritoneally injected daily with LPS with or without emodin. Systemic inflammation was evaluated by measurement of serum levels of cytokines and chemokines and flow cytometric analysis of spleen leukocytes. Liver inflammation was determined by histology, immunocytochemistry and flow cytometry. Quantitative real-time PCR and Western blot were performed to examine the effects of emodin on LPS-induced inflammatory responses in macrophages. Our data showed that emodin ameliorated systemic inflammation, reduced inflammatory cell infiltration in the liver, and attenuated liver function impairment. In vitro experiments showed emodin inhibited LPS-induced expression of proinflammatory cytokines in macrophages through suppressing Erk1/2 and p38 signaling. In conclusion, emodin inhibited the transition from simple steatosis to NASH in hyperlipidemic mice challenged with LPS through suppressing systemic and macrophage inflammation. Emodin may be developed as a therapy for NAFLD by the virtue of its anti-inflammatory effects.

Emodin Isolated from Polygoni cuspidati Radix Inhibits TNF-α and IL-6 Release by Blockading NF-κB and MAP Kinase Pathways in Mast Cells Stimulated with PMA Plus A23187

Emodin, a naturally occurring anthraquinone derivative isolated from Polygoni cuspidati radix, has several beneficial pharmacologic effects, which include anti-cancer, anti-diabetic, and anti-inflammatory activities. In this study, the authors examined the effect of emodin on the production of proinflammatory cytokines, such as, tumor necrosis factor (TNF)-α and interleukin (IL)-6, in mouse bone marrow-derived mast cells (BMMCs) stimulated with phorbol 12-myristate 13-acetate (PMA) plus the calcium ionophore A23187. To investigate the mechanism responsible for the regulation of pro-inflammatory cytokine production by emodin, the authors assessed its effects on the activations of transcriptional factor nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs). Emodin attenuated the nuclear translocation of (NF)-κB p65 and its DNA-binding activity by reducing the phosphorylation and degradation of IκBα and the phosphorylation of IκB kinase B (IKK). Furthermore, emodin dose-dependently attenuated the phosphorylations of MAPKs, such as, extracellular signal-regulated kinase 1/2 (ERK1/2), p38 MAP kinase, and the stress-activated protein kinases (SAPK)/c-Jun-N-terminal kinase (JNK). Taken together, the findings of this study suggest that the anti-inflammatory effects of emodin on PMA plus A23187-stimulated BMMCs are mediated via the inhibition of NF-κB activation and of the MAPK pathway.

Medicinal plants, human health and biodiversity: a broad review

Biodiversity contributes significantly towards human livelihood and development and thus plays a predominant role in the well being of the global population. According to WHO reports, around 80 % of the global population still relies on botanical drugs; today several medicines owe their origin to medicinal plants. Natural substances have long served as sources of therapeutic drugs, where drugs including digitalis (from foxglove), ergotamine (from contaminated rye), quinine (from cinchona), and salicylates (willow bark) can be cited as some classical examples.Drug discovery from natural sources involve a multifaceted approach combining botanical, phytochemical, biological, and molecular techniques. Accordingly, medicinal-plant-based drug discovery still remains an important area, hitherto unexplored, where a systematic search may definitely provide important leads against various pharmacological targets.Ironically, the potential benefits of plant-based medicines have led to unscientific exploitation of the natural resources, a phenomenon that is being observed globally. This decline in biodiversity is largely the result of the rise in the global population, rapid and sometimes unplanned industrialization, indiscriminate deforestation, overexploitation of natural resources, pollution, and finally global climate change.Therefore, it is of utmost importance that plant biodiversity be preserved, to provide future structural diversity and lead compounds for the sustainable development of human civilization at large. This becomes even more important for developing nations, where well-planned bioprospecting coupled with nondestructive commercialization could help in the conservation of biodiversity, ultimately benefiting mankind in the long run.Based on these findings, the present review is an attempt to update our knowledge about the diverse therapeutic application of different plant products against various pharmacological targets including cancer, human brain, cardiovascular function, microbial infection, inflammation, pain, and many more.

Targeted abrogation of diverse signal transduction cascades by emodin for the treatment of inflammatory disorders and cancer

Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is a natural occurring anthraquinone derivative isolated from roots and barks of numerous plants, molds, and lichens. It is found as an active ingredient in different Chinese herbs including Rheum palmatum and Polygonam multiflorum, and has diuretic, vasorelaxant, anti-bacterial, anti-viral, anti-ulcerogenic, anti-inflammatory, and anti-cancer effects. The anti-inflammatory effects of emodin have been exhibited in various in vitro as well as in vivo models of inflammation including pancreatitis, arthritis, asthma, atherosclerosis and glomerulonephritis. As an anti-cancer agent, emodin has been shown to suppress the growth of various tumor cell lines including hepatocellular carcinoma, pancreatic, breast, colorectal, leukemia, and lung cancers. Emodin is a pleiotropic molecule capable of interacting with several major molecular targets including NF-κB, casein kinase II, HER2/neu, HIF-1α, AKT/mTOR, STAT3, CXCR4, topoisomerase II, p53, p21, and androgen receptors which are involved in inflammation and cancer. This review summarizes reported anti-inflammatory and anti-cancer effects of emodin, and re-emphasizes its potential therapeutic role in the treatment of inflammatory diseases and cancer.

Synergistic effects of curcumin with emodin against the proliferation and invasion of breast cancer cells through upregulation of miR-34a

Curcumin, a biphenyl compound derived from rhizome, is a powerful anti-cancer agent. Emodin is an active component isolated from the root and rhizome of Rheum palmatum that has been widely used in traditional Chinese medicine for the treatment of various diseases. Currently, there are no studies examining the effect of curcumin in combination with emodin on tumor cell growth. In this study, we report for the first time that combined curcumin and emodin administration synergistically inhibits proliferation (MTT assay), survival (flow cytometry), and invasion (transwell migration assay) of breast cancer cells. Synergism is determined by the Chou-Talalay method. Moreover, we demonstrate that miR-34a is upregulated by curcumin and emodin. This microRNA helps mediate the anti-tumor effects of curcumin and emodin by downregulating Bcl-2 and Bmi-1. Our results not only provide insight into the mechanism of synergy between curcumin and emodin in breast cancer cells, but also suggest a new and potentially useful approach for breast cancer therapy.

VCAM-1-targeted core/shell nanoparticles for selective adhesion and delivery to endothelial cells with lipopolysaccharide-induced inflammation under shear flow and cellular magnetic resonance imaging in vitro

Multifunctional nanomaterials with unique magnetic and luminescent properties have broad potential in biological applications. Because of the overexpression of vascular cell adhesion molecule-1 (VCAM-1) receptors in inflammatory endothelial cells as compared with normal endothelial cells, an anti-VCAM-1 monoclonal antibody can be used as a targeting ligand. Herein we describe the development of multifunctional core-shell Fe(3)O(4)@SiO2 nanoparticles with the ability to target inflammatory endothelial cells via VCAM-1, magnetism, and fluorescence imaging, with efficient magnetic resonance imaging contrast characteristics. Superparamagnetic iron oxide and fluorescein isothiocyanate (FITC) were loaded successfully inside the nanoparticle core and the silica shell, respectively, creating VCAM-1-targeted Fe(3)O(4)@SiO2(FITC) nanoparticles that were characterized by scanning electron microscopy, transmission electron microscopy, fluorescence spectrometry, zeta potential assay, and fluorescence microscopy. The VCAM-1-targeted Fe(3)O(4)@SiO2(FITC) nanoparticles typically had a diameter of 355 ± 37 nm, showed superparamagnetic behavior at room temperature, and cumulative and targeted adhesion to an inflammatory subline of human umbilical vein endothelial cells (HUVEC-CS) activated by lipopolysaccharide. Further, our data show that adhesion of VCAM-1-targeted Fe(3)O(4)@SiO2(FITC) nanoparticles to inflammatory HUVEC-CS depended on both shear stress and duration of exposure to stress. Analysis of internalization into HUVEC-CS showed that the efficiency of delivery of VCAM-1-targeted Fe(3)O(4)@SiO2(FITC) nanoparticles was also significantly greater than that of nontargeted Fe(3)O(4)@SiO2(FITC)-NH2 nanoparticles. Magnetic resonance images showed that the superparamagnetic iron oxide cores of the VCAM-1-targeted Fe(3)O(4)@SiO2(FITC) nanoparticles could also act as a contrast agent for magnetic resonance imaging. Taken together, the cumulative adhesion and uptake potential of these VCAM-1-targeted Fe(3)O(4)@SiO2(FITC) nanoparticles targeted to inflammatory endothelial cells could be used in the transfer of therapeutic drugs/genes into these cells or for diagnosis of vascular disease at the molecular and cellular levels in the future.

Emodin regulating excision repair cross-complementation group 1 through fibroblast growth factor receptor 2 signaling

AIM: To investigate the molecular mechanisms underlying the reversal effect of emodin on platinum resistance in hepatocellular carcinoma.

METHODS: After the addition of 10 μmol/L emodin to HepG2/oxaliplatin (OXA) cells, the inhibition rate (IR), 50% inhibitory concentration (IC₅₀) and reversal index (IC₅₀ in experimental group/IC₅₀ in control group) were calculated. For HepG2, HepG2/OXA, HepG2/OXA/T, each cell line was divided into a control group, OXA group, OXA + fibroblast growth factor 7 (FGF7) group and OXA + emodin group, and the final concentrations of FGF7, emodin and OXA in each group were 5 ng/mL, 10 μg/mL and 10 μmol/L, respectively. Single-cell gel electrophoresis was conducted to detect DNA damage, and the fibroblast growth factor receptor 2 (FGFR2), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and excision repair cross-complementing gene 1 (ERCC1) protein expression levels in each group were examined by Western blotting.

RESULTS: Compared with the IC₅₀ of 120.78 μmol/L in HepG2/OXA cells, the IC₅₀ decreased to 39.65 μmol/L after treatment with 10 μmol/L emodin; thus, the reversal index was 3.05. Compared with the control group, the tail length and Olive tail length in the OXA group, OXA + FGF7 group and OXA + emodin group were significantly increased, and the differences were statistically significant (P < 0.01). The tail length and Olive tail length were lower in the OXA + FGF7 group than in the OXA group, and this difference was also statistically significant. Compared with the OXA + FGF7 group, the tail extent, the Olive tail moment and the percentage of tail DNA were significantly increased in the OXA + emodin group, and these differences were statistically significant (P < 0.01). In comparison with its parental cell line HepG2, the HepG2/OXA cells demonstrated significantly increased FGFR2, p-ERK1/2 and ERCC1 expression levels, whereas the expression of all three molecules was significantly inhibited in HepG2/OXA/T cells, in which FGFR2 was silenced by FGFR2 shRNA. In the examined HepG2 cells, the FGFR2, p-ERK1/2 and ERCC1 expression levels demonstrated increasing trends in the OXA group and OXA + FGF7 group. Compared with the OXA group and OXA + FGF7 group, the FGFR2, p-ERK1/2, and ERCC1 expression levels were significantly lower in the OXA + emodin group, and these differences were statistically significant. In the HepG2/OXA/T cell line that was transfected with FGFR2 shRNA, the FGFR2, p-ERK1/2 and ERCC1 expression levels were significantly inhibited, but there were no significant differences in these expression levels among the OXA, OXA + FGF7 and OXA + emodin groups.

CONCLUSION: Emodin markedly reversed OXA resistance by enhancing OXA DNA damage in HepG2/OXA cells, and the molecular mechanism was related to the inhibitory effect on ERCC1 expression being mediated by the FGFR2/ERK1/2 signaling pathway.

Emodin ameliorates lipopolysaccharide-induced mastitis in mice by inhibiting activation of NF-κB and MAPKs signal pathways

Emodin is an anthraquinone derivative from the Chinese herb Radix et Rhizoma Rhei. It has been reported that emodin possesses a number of biological properties, such as anti-inflammatory, anti-virus, anti-bacteria, anti-tumor, and immunosuppressive properties. However, the effect of emodin on mastitis is not yet known. The aim of this study was to investigate whether emodin has protective effect against lipopolysaccharide (LPS)-induced mastitis in a mouse model. The mouse model of mastitis was induced by injection of LPS through the duct of mammary gland. Emodin was administered intraperitoneally with the dose of 1, 2, and 4 mg/kg respectively 1h before and 12h after induction of LPS. Emodin significantly reduced infiltration of neutrophilic granulocyte, activation of myeloperoxidase (MPO), concentration of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6), mRNA expression levels of TNF-α, IL-1β and IL-6, which were increased in LPS-induced mouse mastitis. In addition, emodin influenced nuclear factor kappa-B signal transduction pathway by inhibiting activation of nuclear transcription factor-kappaB (NF-κB) p65 and degradation inhibitor of NF-κB α (IκBα), and emodin also influenced mitogen activated protein kinases signal transduction pathway by depression activation of p38, extracellular signal-regulated kinase (ERK), and c-jun NH2-terminal kinase (JNK). In conclusion, these results indicated that emodin could exert beneficial effects on experimental mastitis induced by LPS and may represent a novel treatment strategy for mastitis.

MYADM controls endothelial barrier function through ERM-dependent regulation of ICAM-1 expression

The endothelium maintains a barrier between blood and tissue that becomes more permeable during inflammation. Membrane rafts are ordered assemblies of cholesterol, glycolipids, and proteins that modulate proinflammatory cell signaling and barrier function. In epithelial cells, the MAL family members MAL, MAL2, and myeloid-associated differentiation marker (MYADM) regulate the function and dynamics of ordered membrane domains. We analyzed the expression of these three proteins in human endothelial cells and found that only MYADM is expressed. MYADM was confined in ordered domains at the plasma membrane, where it partially colocalized with filamentous actin and cell-cell junctions. Small interfering RNA (siRNA)-mediated MYADM knockdown increased permeability, ICAM-1 expression, and leukocyte adhesion, all of which are features of an inflammatory response. Barrier function decrease in MYADM-silenced cells was dependent on ICAM-1 expression. Membrane domains and the underlying actin cytoskeleton can regulate each other and are connected by ezrin, radixin, and moesin (ERM) proteins. In endothelial cells, MYADM knockdown induced ERM activation. Triple-ERM knockdown partially inhibited ICAM-1 increase induced by MYADM siRNA. Importantly, ERM knockdown also reduced ICAM-1 expression in response to the proinflammatory cytokine tumor necrosis factor-α. MYADM therefore regulates the connection between the plasma membrane and the cortical cytoskeleton and so can control the endothelial inflammatory response.

Downregulation of miR-138 sustains NF-κB activation and promotes lipid raft formation in esophageal squamous cell carcinoma

PURPOSE

Constitutive activation of NF-κB signaling plays vital roles in esophageal squamous cell carcinoma (ESCC) progression. The aim of this study was to evaluate the effect of miR-138 on NF-κB activation and ESCC progression.

EXPERIMENTAL DESIGN

Expression of miR-138 in ESCC cell lines, ESCC tissues, and 205 archived ESSC specimens was determined using real-time PCR analysis. Anchorage-independent growth, chicken chorioallantoic membrane, Transwell matrix invasion and Annexin V-binding assays, and a xenograft tumor model were used to determine the role of miR-138 in ESCC progression. The effect of miR-138 on NF-κB activation was investigated using IKK in vitro kinase, electrophoretic mobility shift, lipid raft isolation, and luciferase reporter assays.

RESULTS

miR-138 was downregulated and inversely correlated with tumor progression and patient survival in ESCCs. Downregulation of miR-138 enhanced, whereas upregulation of miR-138 reduced, the aggressive phenotype of ESCC cells both in vitro and in vivo. Silencing miR-138 promoted K63-linked polyubiquitination of the NF-κB signaling intermediaries TRAF2 and RIP1 and sustained NF-κB activation. Furthermore, downregulation of miR-138 induced lipid raft formation via upregulating multiple components of lipid rafts, including FLOT1, FLOT2, and caveolin-1. Importantly, the in vitro analysis was consistent with a significant inverse correlation between miR-138 expression and NF-κB hyperactivation in a cohort of human ESCC specimens.

CONCLUSION

Our results show that miR-138 functions as a tumor-suppressive miRNA and that downregulation of miR-138 contributes to constitutive NF-κB activation and ESCC progression.

Anticancer potential of emodin

Traditional Chinese Medicine (TCM) is widely used in clinical research due to its low toxicity, low number of side effects, and low cost. Many components of common fruits and vegetables play well-documented roles as chemopreventive or chemotherapeutic agents that suppress tumorigenesis. Anthraquinones are commonly extracted from the Polygonaceae family of plants, e.g., Rheum palmatum and Rheum officinale. Some of the major chemical components of anthraquinone and its derivatives, such as aloe-emodin, danthron, emodin, chrysophanol, physcion, and rhein, have demonstrated potential anticancer properties. This review evaluates the pharmacological effects of emodin, a major component of Aloe vera. In particular, emodin demonstrates anti-neoplastic, anti-inflammatory, anti-angiogenesis, and toxicological potential for use in pharmacology, both in vitro and in vivo. Emodin demonstrates cytotoxic effects (e.g., cell death) through the arrest of the cell cycle and the induction of apoptosis in cancer cells. The overall molecular mechanisms of emodin include cell cycle arrest, apoptosis, and the promotion of the expression of hypoxia-inducible factor 1α, glutathione S-transferase P, N-acetyltransferase, and glutathione phase I and II detoxification enzymes while inhibiting angiogenesis, invasion, migration, chemical-induced carcinogen-DNA adduct formation, HER2/neu, CKII kinase, and p34cdc2 kinase in human cancer cells. Hopefully, this summary will provide information regarding the actions of emodin in cancer cells and broaden the application potential of chemotherapy to additional cancer patients in the future.

Effects of an anthraquinone derivative from Rheum officinale Baill, emodin, on airway responses in a murine model of asthma

Emodin is a component from traditional Chinese herbal medicines. We focused on investigating whether emodin possesses distinct anti-inflammatory activity on a non-infectious mouse model of asthma, and we aimed to elucidate its involvement with the NF-κB pathway. BALB/c mice that were sensitized and challenged to ovalbumin were treated with emodin (40 mg/kg) 1h before they were challenged with OVA. Our study demonstrated that emodin inhibited OVA-induced increases in eosinophil count; interleukin (IL)-4, IL-5, and IL-13 levels were recovered in bronchoalveolar lavage fluid and reduced serum levels of OVA-specific IgE, IgG, and IgG1. Histological studies demonstrated that emodin substantially inhibited OVA-induced eosinophilia in lung tissue and mucus hyper-secretion by goblet cells in the airway. Furthermore, pretreatment with emodin resulted in a significant reduction in mRNA expression of acidic mammalian chitinase (AMCase), chitinase 3-like protein 4 (Ym2) and Muc5ac in lung tissues and airway hyperresponsiveness to methacholine. These findings suggest that emodin may effectively delay the progression of airway inflammation and could be used as a therapy for patients with allergic airway inflammation.

Downregulation of phosphatase of regenerating liver-3 is involved in the inhibition of proliferation and apoptosis induced by emodin in the SGC-7901 human gastric carcinoma cell line

Emodin, an anthraquinone derivative isolated mainly from the root and rhizome of the medicinal plant Rheum palmatum L., was found to exert anticancer effects on various cultured cancer cells. Phosphatase of regenerating liver-3 (PRL-3), a novel gene, has been known to play an important role in the promotion of cellular proliferation as well as inhibition of apoptosis in cancer cells. However, there is relatively little information in the published literature with regard to the anticancer mechanism of emodin, and whether emodin is involved in the regulation of PRL-3 in human gastric carcinoma cells is not known. In the present study, we investigated the effects of emodin on SGC-7901 cell proliferation, apoptosis and regulation of PRL-3. The results showed that the proliferation of SGC-7901 cells was inhibited by emodin in a time- and concentration-dependent manner. The results also showed that early apoptosis rates increased in a concentration-dependent manner after emodin treatment. Furthermore, real-time quantitative PCR analysis showed that PRL-3 mRNA was significantly decreased by treatment with emodin. Western blotting showed that PRL-3 protein expression was also downregulated significantly. Overall, the present study demonstrated that emodin inhibited cell growth and induced apoptotic cell death in the SGC-7901 human gastric carcinoma cell line. Downregulation of PRL-3 is involved in the inhibition of proliferation and apoptosis induced by emodin. PRL-3 may be a new potential therapeutic target for gastric cancer using emodin.

Chrysophanol-8-O-glucoside, an anthraquinone derivative in rhubarb, has antiplatelet and anticoagulant activities

Rhubarb is a widely used traditional medicine and has been reported to elicit a number of biological effects including anti-inflammatory and antiplatelet effects. In the present study, we investigated the effects of anthraquinone derivatives isolated from rhubarb on platelet activity. Of four anthraquinone derivatives isolated from rhubarb examined, chrysophanol-8-O-glucoside (CP-8-O-glc) was found to have the most potent inhibitory effect on collagen- and thrombin-induced platelet aggregation. CP-8-O-glc-treated mice showed significantly prolonged bleeding times. Furthermore, CP-8-O-glc was found to have a significant inhibitory effect on rat platelet aggregation ex vivo and on thromboxane A(2) formation in vitro. In coagulation tests, CP-8-O-glc did not alter prothrombin time, and it prolonged the activated partial thromboplastin time. However, CP-8-O-glc only inhibited platelet phosphatidylserine exposure, but not exert direct inhibition on intrinsic factors. This study demonstrates the antiplatelet and anticoagulant effects of CP-8-O-glc and suggests that this compound might be of therapeutic benefit for the prevention of platelet-related cardiovascular diseases.

Anti-inflammatory activities of Reynoutria elliptica through suppression of mitogen-activated protein kinases and nuclear factor-κB activation pathways

Reynoutria elliptica has been used in traditional Korean medicine to promote blood circulation, relieve pain, increase dieresis, and alleviate respiratory problems, through as yet undefined mechanisms. We set out to determine whether the anti-inflammatory effects of this plant are linked with its ability to suppress mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) activation in lipopolysaccharide (LPS)-activated RAW 264.7 cells. We found for the first time that the hexane fraction of Reynoutria elliptica (HRE) significantly inhibited LPS-stimulated NO and PGE2 synthesis. This is due to the diminishing of the mRNA and protein expression of iNOS and COX-2, respectively. HRE also suppressed LPS-stimulated TNF-α secretion in a dose-dependent manner, which might be due to the suppression of LPS-induced MAPKs and NF-κB activation. Moreover, our HPLC data demonstrated that the major components of the HRE were bioactive compounds such as emodin-6-Glc, emodin, and physcion. Overall, our results indicate that Reynoutria elliptica could be provided as a potential candidate for anti-inflammation treatment.

Emodin, a naturally occurring anthraquinone derivative, suppresses IgE-mediated anaphylactic reaction and mast cell activation

The high-affinity receptor for IgE (FcɛRI)-mediated activation of mast cells plays an important role in allergic diseases such as asthma, allergic rhinitis and atopic dermatitis. Emodin, a naturally occurring anthraquinone derivative in oriental herbal medicines, has several beneficial pharmacologic effects, such as anti-cancer and anti-diabetic activities. However, the anti-allergic effect of emodin has not yet been investigated. To assess the anti-allergic activity of emodin, in vivo passive anaphylaxis animal model and in vitro mouse bone marrow-derived mast cells were used to investigate the mechanism of its action on mast cells. Our results showed that emodin inhibited degranulation, generation of eicosanoids (prostaglandin D(2) and leukotriene C(4)), and secretion of cytokines (TNF-α and IL-6) in a dose-dependent manner in IgE/Ag-stimulated mast cells. Biochemical analysis of the FcɛRI-mediated signaling pathways demonstrated that emodin inhibited the phosphorylation of Syk and multiple downstream signaling processes including mobilization of intracellular Ca(2+) and activation of the mitogen-activated protein kinase, phosphatidylinositol 3-kinase, and NF-κB pathways. When administered orally, emodin attenuated the mast cell-dependent passive anaphylactic reaction in IgE-sensitized mice. Thus, emodin inhibits mast cell activation and thereby the anaphylactic reaction through suppression of the receptor-proximal Syk-dependent signaling pathways. Therefore, emodin might provide a basis for development of a novel anti-allergic drug.

Adhesion of bio-functionalized ultrasound microbubbles to endothelial cells by targeting to vascular cell adhesion molecule-1 under shear flow

The expression of certain endothelial cell adhesion molecules is increased during endothelial dysfunction or inflammatory activation. This has led to the concept of using microbubbles for targeted molecular imaging or drug delivery. In this approach, microbubbles with a specific ligand to receptors expressed at the site of specific diseases are constructed. The present study aimed to engineer a novel type of bio-functionalized microbubbles (vascular cell adhesion molecule 1 [VCAM-1]-targeted microbubbles), and determine whether VCAM-1-targeted microbubbles exhibit specific adhesion to lipopolysaccharide (LPS)-activated endothelial cells. Our data showed that VCAM-1 expression was significantly upregulated in both LPS-activated endothelial cells in vitro and endothelium in a rat atherosclerosis model in vivo. Targeted microbubbles were designed by conjugating anti-VCAM-1 monoclonal antibodies to the shell of microbubbles using biotin-avidin bridging chemistry methods. Microbubble adhesion to endothelial cells was assessed in a flow chamber at two shear stress conditions (6.3 and 10.4 dynes/cm²). Our data showed that microbubble adhesion depends on both the surface anti-VCAM-1 antibody densities and the exposed shear stresses. Adhesion of VCAM-1-targeted microbubbles onto LPS-activated endothelial cells increased with the surface antibody densities, and decreased with the exposed shear stresses. These findings showed that the specific ligand-carrying microbubbles have considerable potential in targeted ultrasound molecular imaging or ultrasound-assisted drug/gene delivery applications.