Emodin Group Research Articles

Emodin attenuates CY-induced oxidative injury in PBLs of the blunt snout bream (Megalobrama amblycephala) though the Nrf2-Keap1 signaling pathway

The present study aimed to evaluate the protective effects of emodin on cyclophosphamide (CY)-induced oxidative injury in peripheral blood leukocytes (PBLs) of blunt snout bream and the potential mechanisms. We examined the cell viability, lactate dehydrogenase (LDH) release, apoptosis, mitochondrial membrane potential (Δѱm), reactive oxygen species (ROS) generation and correlative gene expression of nuclear factor-erythroid 2 related factor-2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) signaling molecules. For the control group, PBLs were maintained in normal cell culture medium for 12 h. For the CY group, cells were exposed to 0.32 mg/mL CY for 6 h, followed by maintaining in RPMI-1640 complete medium for an additional 6 h. Cells in the CY + Emodin group were exposed to 0.32 mg/mL CY for 6 h, and then exposed to 0.20 μg/mL emodin for 6 h. We observed that emodin significantly inhibited CY-induced apoptosis in PBLs through increasing cell viability and decreasing LDH release. Emodin also inhibited Δѱm disruption and respiratory burst in CY-induced PBLs. In consistent with these results, emodin attenuated oxidative stress in CY-induced PBLs by significantly upregulating Nrf2, BTB and CNC homolog 1 (Bach1), superoxide dismutase (SOD) and catalase (CAT) genes while significantly downregulates Keap1 in Nrf2-Keap1 signaling pathway. These results collectively demonstrate that emodin can alleviate CY-induced oxidative stress in the PBLs of blunt snout bream, possibly through activating Nrf2-Keap1 signaling pathway. Our findings also suggest that emodin might be developed as a promising therapeutic agent for treating oxidative injury in blunt snout bream.

Emodin ameliorates acute pancreatitis-induced lung injury by suppressing NLRP3 inflammasome-mediated neutrophil recruitment.

Severe acute pancreatitis (SAP) activates the systemic inflammatory response and is potentially lethal. The aim of the present study was to determine the effects of emodin on acute lung injury (ALI) in rats with SAP and investigate the role of the Nod-like receptor protein 3 (NLRP3) inflammasome and its association with neutrophil recruitment. Sodium taurocholate (5.0%) was used to establish the SAP model. All animals were randomly assigned into four groups: Sham, SAP, emodin and dexamethasone (positive control drug) groups (n=10 mice per group). Histopathology observation of pancreatic and lung tissues was detected by hematoxylin and eosin staining. The levels of serum amylase, IL-1β and IL-18 were measured by ELISA. Single-cell suspensions were obtained from enzymatically digested lung tissues, followed by flow cytometric analysis for apoptosis. In addition, the expression levels of NLRP3 inflammasome-associated and apoptosis-associated proteins in lung tissues were measured by western blotting. Moreover, lymphocyte antigen 6 complex locus G6D+ (Ly6G+) cell recruitment was detected using immunohistochemical analysis. The results revealed that emodin markedly improved pancreatic histological injury and decreased the levels of serum amylase, IL-1β and IL-18. Pulmonary edema and apoptosis were significantly alleviated by emodin. Additionally, the protein expression levels of intercellular adhesion molecule 1, NLRP3, apoptosis-associated speck-like protein containing a CARD and cleaved caspase-1 were downregulated following emodin treatment. Moreover, emodin inhibited Ly6G+ cell recruitment in lung tissues. The present study demonstrated that emodin may offer protection against ALI induced by SAP via inhibiting and suppressing NLRP3 inflammasome-mediated neutrophil recruitment and may be a novel therapeutic strategy for the clinical treatment of ALI.

Proteomic Analysis of Emodin Treatment in Neuropathic Pain Reveals Dysfunction of the Calcium Signaling Pathway.

BackgroundNeuropathic pain (NP) is a syndrome of pain mediated by distinct pathophysiological processes, and current treatments are not fully satisfactory. Emodin is an effective component of Chinese traditional medicine and has an alleviating effect on NP, but the pharmacological mechanism is not clear.MethodsWe used isobaric tags for relative and absolute quantitation (iTRAQ) technique integrated with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to identify potential targets of emodin in a rat peripheral nerve chronic constriction injury (CCI) model.ResultsA total of 177 differentially expressed proteins were identified among the sham group, CCI group, and emodin group, with a threshold of 1.2-fold change and a P value ≤ 0.05. Among them, 100 differentially expressed proteins (51 up-regulated and 49 down-regulated) were identified in the CCI group compared with sham group. Moreover, 108 differentially expressed proteins (65 up-regulated and 43 down-regulated) were identified in the emodin group with the CCI group as reference. The enrichment analysis of Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed an important role of calcium signaling pathway, neurotransmitter regulation, and long-term potentiation (LTP) in emodin-treated CCI model. Real-time quantitative fluorescence PCR (qRT-PCR) and Western blot analysis revealed that emodin decreased expression of calcium signaling related proteins, including calmodulin (CaM) dependent protein kinase II (CaMK II), phospholipase Cβ1 (PLCβ1), protein kinase C (PKC), protein kinase C (PKA), and tropomyosin-related kinase B (TrkB), compared with the CCI group.ConclusionOverall, these findings indicated that emodin might alleviate NP by regulating the calcium signaling pathway.

Emodin Ameliorates Renal Damage and Podocyte Injury in a Rat Model of Diabetic Nephropathy via Regulating AMPK/mTOR-Mediated Autophagy Signaling Pathway.

PurposeThe activation of autophagy has potential protective effect on diabetic nephropathy (DN) podocyte injury, and the AMPK/mTOR signaling pathway is an important regulatory pathway of autophagy. Emodin has been reported to effectively delay DN progression; however, the therapeutic mechanisms involved in vivo remain ambiguous. The present study aimed to elucidate the mechanism of emodin in improving renal tissue and podocyte injury in DN by regulating the AMPK/mTOR-autophagy signaling pathway.MethodsAll rats were divided into 4 groups: a Sham group, a Vehicle group, a low-dose emodin (LD-Emo) group (20 mg/kg/day) and a high-dose emodin (HD-Emo) group (40 mg/kg/day). The different doses of Emo and distilled water were daily administrated for 8 weeks after the induction of DN by the unilateral nephrectomy combined with intraperitoneal injections of streptozotocin (STZ). The rats' general status, blood glucose, biochemical parameters, urinary protein excretion, renal histological changes and cell apoptosis in renal tissue, as well as the key protein expressions in the AMPK/mTOR signaling pathway and apoptosis-related proteins were examined, respectively.ResultsEmodin ameliorated the general condition, kidney weight and urinary protein excretion of the rats, but has little influence on serum biochemical parameters and did not lower blood glucose; emodin attenuated renal fibrosis including the cell numbers, extracellular matrix rate and collagen area in glomerulus, simultaneously relieved podocyte foot process fusion, up-regulated the expression of nephrin protein and suppressed glomerular and tubular epithelial cell apoptosis. In addition, emodin can induce and enhance autophagy in podocytes including increased expression of LC3-II/I, Beclin-1, p-AMPK protein and decreased expression of p62, p-mTOR protein, as well as increased autophagosomes in podocytes.ConclusionWe have demonstrated that emodin, as a natural regulator in vivo, reduced proteinuria and alleviated renal fibrosis without affecting hyperglycemia in DN rats. The potential mechanisms by which emodin exerts its renoprotective effects in vivo are through suppressing cell apoptosis and enhancing autophagy of podocytes via the AMPK/mTOR signaling pathway in the kidney.

Effect the Mechanism of Emodin Combined with Cp-1 on Proliferation and Apoptosis of Bladder Cancer Cell Line BIU-87

To investigate the effect of emodin combined with Cp-1 on the proliferation and apoptosis of bladder cancer cell line BIU-87. BIU-87 cells were randomly divided into control group, Cp-1 group, emodin group, Cp-1 combined with emodin group. Flow cytometry was used to detect the apoptosis of BIU-87 cells. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to detect the proliferation of BIU-87 cells. Western blot and reverse transcription–polymerase chain reaction were used to detect the recepteur d’origine nantais, Caspase-3 and B-cell lymphoma 2 expressions. Compared with control group, the cell survival rate of Cp-1 group, emodin group and Cp-1 combined with emodin groupwas significantly decreased, especially in Cp-1 combined with emodin group, which was significantly lower than that of Cp-1 group and emodin group (p<0.05), while the cell apoptosis rate of Cp-1 group, emodin group and Cp-1 combined with emodin group was significantly increased, especially in Cp-1 combined with emodin group, which was significantly higher than that of Cp-1 group and emodin group (p<0.05) and the expression of recepteur d’origine nantais decreased significantly (p<0.05). Inhibition of recepteur d’origine nantais expression suppressed B-cell lymphoma 2 and increased Caspase-3 significantly (p<0.05). Our results indicated that emodin combined with Cp-1 could enhance the apoptosis and inhibit proliferation of bladder cancer cells. The mechanism may be that emodin can inhibit the expression of recepteur d’origine nantais, down regulated the expression of B-cell lymphoma 2, which increased the expression of caspase-3 in bladder cancer cells and promoted the apoptosis of bladder cancer cells.

The intervention mechanism of emodin on TLR3 pathway in the process of central nervous system injury caused by herpes virus infection

ABSTRACT Background and purpose: To investigate the effect of Emodin on the inflammatory response of brain tissue and the expression of the TLR3 pathway in mice with herpes virus encephalitis. Method: Twenty male BALB/c mice were randomly divided into the NS group, HSV-1 group, HSV-1 + Emodin group and HSV-1 + ACV group. The histopathological features and the effect of TLR3 expression were observed by staining and immunohistochemistry (IHC) respectively. The gene expression of TLR3, trif, TRADD, TRAF6, traf3, p38, Nemo and IRF3 was detected by polymerase chain reaction (PCR). The protein production of TLR3 and its downstream molecules was detected by Western blot. The expression of IL-6, TNF-α and IFN-β in the brain tissues was detected by ELISA. Result: Compared to the HSV-1 group, the pathological changes (inflammatory cell infiltration, necrotic temporal lobe and massive hemorrhage) were not as obvious as those in the HSV-1+emodin and HSV-1+ACV groups. The TLR3 staining increased significantly in the HSV-1 groups and decreased in the HSV-1 + emodin group. Compared with the NS group, the mRNA expression of TLR3, TRIF, TRADD, TRAF6, traf3, p38, NEMO and IRF3 decreased by 20%–60% in the HSV-1 + emodin group and 30% in the HSV-1 + ACV group, respectively. The expression of IL-6, TNF-α and IFN-β decreased by 30%-50% in the HSV-1 + emodin group and showed no significant change in the HSV-1 + ACV group, respectively. Conclusion: Emodin could inhibit the inflammatory response in the brain of mice with herpes virus encephalitis. The inhibition of TLR3 expression may play an important role in this process.

Emodin protects against intestinal and lung injury induced by acute intestinal injury by modulating SP-A and TLR4/NF-κB pathway.

Objective: Our aim was to investigate the effect of emodin on intestinal and lung injury induced by acute intestinal injury in rats and explore potential molecular mechanisms.Methods: Healthy male Sprague–Dawley (SD) rats were randomly divided into five groups (n=10, each group): normal group; saline group; acute intestinal injury model group; model + emodin group; model+NF-κB inhibitor pynolidine dithiocarbamate (PDTC) group. Histopathological changes in intestine/lung tissues were observed by Hematoxylin and Eosin (H&E) and terminal deoxynucleotidyl transferase biotin-dUTP nick-end labeling (TUNEL) staining. Serum IKBα, p-IKBα, surfactant protein-A (SP-A) and toll-like receptor 4 (TLR4) levels were examined using enzyme-linked immunosorbent assay (ELISA). RT-qPCR was performed to detect the mRNA expression levels of IKBα, SP-A and TLR4 in intestine/lung tissues. Furthermore, the protein expression levels of IKBα, p-IKBα, SP-A and TLR4 were detected by Western blot.Results: The pathological injury of intestinal/lung tissues was remarkedly ameliorated in models treated with emodin and PDTC. Furthermore, the intestinal/lung injury scores were significantly decreased after emodin or PDTC treatment. TUNEL results showed that both emodin and PDTC treatment distinctly attenuated the apoptosis of intestine/lung tissues induced by acute intestinal injury. At the mRNA level, emodin significantly increased the expression levels of SP-A and decreased the expression levels of IKBα and TLR4 in intestine/lung tissues. According to ELISA and Western blot, emodin remarkedly inhibited the expression of p-IKBα protein and elevated the expression of SP-A and TLR4 in serum and intestine/lung tissues induced by acute intestinal injury.Conclusion: Our findings suggested that emodin could protect against intestinal and lung injury induced by acute intestinal injury by modulating SP-A and TLR4/NF-κB pathway.

Emodin ameliorates renal injury in BXSB mice by modulating TNF-α/ICAM-1

The purpose of the present study was to explore the effects of emodin on renal injury in a BXSB mouse model of lupus and its mechanisms. BXSB mice were fed different concentrations of emodin (0, 5, 10 and 20 mg/kg.d), and the levels of intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α) and fibronectin (FN) levels in the glomeruli and serum levels of the anti-dsDNA antibody were determined. Mesangial cells (MCs) were cultured in vitro, and IgG-type anti-dsDNA antibody and/or emodin were added to the MC culture supernatant. In addition, TNF-α small interfering RNA (siRNA) was transfected into MCs to explore the mechanism of action of emodin. The results showed that the mice fed emodin presented decreases in the urinary protein content and glomerular TNF-α, ICAM-1 and FN levels (P<0.05). Moreover, the urine protein, TNF-α, ICAM-1 and FN levels were decreased in a dose-dependent manner (P<0.05). In vitro, the anti-dsDNA antibody group exhibited increased levels of ICAM-1 and TNF-α (P<0.05), and the anti-dsDNA antibody group showed myofibroblast-like structural changes. The aforementioned indexes were decreased in the emodin group (P<0.05), and the extent of transdifferentiation was significantly reduced. Moreover, the level of ICAM-1 decreased with the down-regulation of TNF-α (P<0.05). Emodin reduced the urine protein levels and serum levels of the anti-dsDNA antibody in a mouse model of lupus nephritis (LN). The underlying mechanism may be related to decreased levels of TNF-α, ICAM-1 and FN and the inhibition of dsDNA antibody-induced MC damage.

Emodin alleviates gemcitabine resistance in pancreatic cancer by inhibiting MDR1/P-glycoprotein and MRPs expression.

Gemcitabine is a gold standard chemotherapeutic agent for pancreatic cancer. However, gemcitabine has limited effectiveness due to the short-term development of chemoresistance. Emodin, a natural anthraquinone derivative isolated from the roots of rheumatic palm leaves prevents immunosuppression and exerts anticancer effects. The present study aimed to evaluate the effect of emodin on gemcitabine resistance. Gemcitabine-resistant PANC-1 pancreatic cancer cell xenografts were established in athymic mice, which were randomly assigned into four treatments groups as follows: Gemcitabine group, Emodin group, Gemcitabine+Emodin group and Negative control group. Body weight, tumor volume and tumor weight were measured over the course of treatment. The effect of each treatment on tumor tissue proliferation and apoptosis from nude mice was evaluated by using immunohistochemistry. The effect of each treatment on the proliferation of gemcitabine-resistant PANC-1 cells was also determined by using the Cell Counting Kit-8. Then, reverse transcription-quantitative (RT-q) PCR and western blotting were used to detect the mRNA and protein expression, respectively, of multidrug resistance gene 1 (MDR1) and the drug resistance-related proteins MRP1 and MRP5. The function and expression level of DR1 gene product, p-glycoprotein, was also analysed by flow cytometry and RT-qPCR, respectively. The results demonstrated that the combination of gemcitabine and emodin significantly reduced xenograft volume and reduced tumor growth in mice compared with treatment with gemcitabine or emodin only. In addition, emodin treatment reduced resistance to gemcitabine, which was characterized by the downregulation of P-glycoprotein, MRP1 and MRP5 expression in the group receiving combination treatment. The level of P-glycoprotein was also decreased in the group treated with gemcitabine+emodin compared with the single treatment groups. Taken together, these results demonstrated that emodin enhanced gemcitabine efficacy in tumor treatment and alleviated gemcitabine resistance in PANC-1 cell xenografts in mice via suppressing MDR1/P-glycoprotein and MRP expression.

Proteomics Unravels Emodin Causes Liver Oxidative Damage Elicited by Mitochondrial Dysfunction.

Emodin is one of the main active compounds in many Chinese traditional herbs. Due to its potential toxic effect on the liver, the possible injury mechanism needs to be explored. In the present study, we investigated liver injury mechanisms of emodin on rats by the technology of proteomics. Firstly, 4530 proteins were identified from the liver of rats treated with emodin by label free proteomics. Inside, 892 differential proteins were selected, presenting a downward trend. Bioinformatics analysis showed that proteins interfered with by emodin were mainly involved in oxidation-reduction biological processes and mitochondrial metabolic pathways, such as mitochondrial fatty acid β-oxidation, citric acid cycle, and oxidative phosphorylation, which were further confirmed by western blot. The decrease in maximal respiration, ATP production, spare respiratory capacity, and coupling efficiency and increase in proton leakage were detected by seahorse XFe 24 analyzer, which confirmed the damage of mitochondrial function. The down-regulated expressions in antioxidant proteins were verified by western blot and a significant increase of ROS levels were detected in emodin group, which showed that emodin disrupted redox homeostasis in livers. Molecular docking revealed that the main targets of emodin might be acadvl and complex IV. Generally, emodin could induce oxidative stress in livers by directly targeting acadvl/complex IV and inhibiting fatty acid β-oxidation, citric acid cycle, and oxidative phosphorylation taken place in mitochondria.

Radix Polygoni Multiflori and Its Main Component Emodin Attenuate Non-Alcoholic Fatty Liver Disease in Zebrafish by Regulation of AMPK Signaling Pathway.

PurposeNonalcoholic fatty liver disease (NAFLD) has become a predictor of death in many diseases. This study was carried out to investigate the therapeutic effect of Radix Polygoni Multiflori Preparata (RPMP) and its main component emodin on egg yolk powder-induced NAFLD in zebrafish. Further investigation was performed to explore whether emodin was the main component of RPMP for the treatment of NAFLD as well as the underlying therapeutic mechanism of RPMP and emodin.MethodsZebrafish were divided into control group, egg yolk powder group, RPMP group and emodin group. The obesity of zebrafish was evaluated by body weight, body length and BMI. The content of lipid was detected by triglyceride (TG), total cholesterol (TC) reagent kit and the fatty acid was detected by nonesterified free fatty acids (NEFA) reagent kit. HE staining was used to detect the histological structure of liver. Whole-mount Oil red O staining and Frozen oil red O staining were carried out to investigate the lipid accumulation in liver. KEGG and STRING databases were performed to analyze the potential role of AMPK between insulin resistance (IR) and fatty acid oxidation. Western blot and RT-qPCR were carried out for mechanism research.ResultsRPMP and emodin significantly reduced zebrafish weight, body length and BMI. Both RPMP and emodin treatment could reduce the lipid deposition in zebrafish liver. RPMP significantly reduced the content of TG. However, emodin significantly reduced the contents of TG, TC and NEFA in zebrafish with NAFLD. The protein interaction network indicated that AMPK participated in both IR and fatty acid oxidation. Further investigation indicated that RPMP and emodin reduced hepatic lipogenesis via up-regulating the expressions of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT2), amp-activated protein kinase alpha (AMPKα), proliferator-activated receptor alpha (PPARα), carnitine palmitoyl transferase 1a (CPT-1a) and acyl-coenzyme A oxidase 1 (ACOX1).ConclusionThese findings suggest that emodin is the main component of RPMP for the treatment of NAFLD, which is closely related to the regulation of AMPK signaling pathway which increases IR and fatty acid oxidation.

Protective effect of emodin on intestinal epithelial tight junction barrier integrity in rats with sepsis induced by cecal ligation and puncture.

The present study investigated the protective effects of emodin on intestinal epithelial tight junction (TJ) barrier integrity in cecal ligation and puncture (CLP)-induced septic rats and its possible mechanisms of action. Healthy male Sprague-Dawley rats were randomly divided into three groups (n=20 per group): Sham group, CLP group and CLP + emodin group. Animals were sacrificed at 12 and 24 h after the model was established. Abdominal aortic blood and specimens of the ileum were harvested for analysis. The histopathological changes in intestinal mucosa and the ultrastructures of intestinal epithelial cells were investigated using light microscopy and transmission electron microscopy. The integrity of the intestinal barrier was assessed by examining plasma diamine oxidase (DAO) levels and the ratio of urine lactulose to mannitol (L/M). The levels of the intestinal TJ proteins claudin-3, zonula occludens (ZO)-1 and occludin were detected using immunohistochemistry, western blotting and reverse transcription-quantitative PCR. The results showed that the pathological damage to intestinal mucosa and the intestinal tissue injury score in the CLP + emodin group were significantly reduced compared to those of the CLP group, and the differences were more obvious at 24 h compared with 12 h. DAO activity and the L/M ratio in the emodin pre-treatment group decreased significantly at 24 h compared with the CLP groups. The protein and mRNA levels of the TJ proteins claudin-3, ZO-1 and occludin in the emodin pre-treatment groups at 12 and 24 h were increased, while occludin mRNA level was found to be decreased compared with the CLP groups. The present study suggested that emodin may significantly reduce the damage to the intestinal epithelial barrier in sepsis, inhibit intestinal barrier permeability and protect intestinal barrier integrity. Emodin may protect intestinal barrier integrity by elevating expression levels of the TJ proteins claudin-3, ZO-1 and occludin in CLP rats.

Emodin regulates microRNA expressions of ileum in sepsis mice model

Objective To investigate the regulation of emodin on microRNA expressions in mouse model with sepsis by GeneChip microRNA array. Methods Forty two c57 mice were randomly (random number) divided into 3 groups: sham operation group (sham group, n=14),sepsis group(n=14) and emodin group (n=14). The sepsis model of the mouse was subjected to cecal ligation and puncture (CLP). Mice in emodin group received intraperitoneal injection of emodin (40 mg/kg) half an hour before operation and every 12 hours after CLP. All mice were sacrificed 48 h after surgery and part of the ileum were removed for intestine tissue stained with hematoxylin eosin. The levels of tumor necrosis factor-α(TNF-α), interleukin-6 (IL-6) and intestinal fatty acid binding protein (I-FABP) in peripheral blood were measured by enzyme-linked immunosorbent assay (ELISA). Total RNA of ileum tissues was extracted from the sepsis group and emodin group, and then subjected to miRNA microarray. The results of microarray were further verified by quantitative real-time PCR (qRT-PCR). Target genes of differentially expressed miRNAs were predicted and subjected to gene ontology (GO) and KEGG pathway enrichment analysis. Data of multi-groups were analyzed by one way variance (ANOVA) and inter-group comparisons were made by SNK-q tests. Mann-Whitney U test was used when homogeneity of variance were not met. The value of P<0.05 was considered statistically significant. Results Compared to the sepsis group, the levels of serum TNF-α, IL-6 and I-FABP in the emodin group were decreased significantly. MiRNA microarray showed that 23 miRNAs were differentially expressed in the emodin group as compared to the sepsis group, among which 17 miRNAs were up-regulated and 6 miRNAs were down-regulated. qRT-PCR results were consistent with miRNA array data. Target genes of 10 selected miRNAs were predicted and subjected to bioinformatic analysis. A total of 3 410 target genes were significantly enriched in 2 072 GO biological process terms, 246 GO cellular component items and 277 GO molecular function terms. Moreover, KEGG pathway analysis showed that these differential miRNAs were involved in the regulation of PI3K-Akt signaling pathway, MAPK signaling pathway, and TNF signaling pathway. Conclusions Emodin can regulate the expression of multiple microRNAs, and play an important role in protecting the intestinal mucosal barrier via a variety of targets and pathways. Key words: Emodin; Sepsis; Intestinal mucosa; MicroRNA; Expression profiles; Bioinformatics

Emodin Alleviates the Airway Inflammation of Cough Variant Asthma in Mice by Regulating the Notch Pathway.

BackgroundThis study investigated the effects and underlying mechanisms of emodin on cough variant asthma (CVA) in mice.Material/MethodsThe bronchial asthma mouse model was successfully established by use of ovalbumin (OVA) sensitization and challenge. The BALB/c mice were divided into 6 groups: a control group, an OVA model without or with emodin (15, 30, 60 mg/kg) group, and a dexamethasone (0.5 mg/g) group. The effect of the treatment was determined by measuring airway responsiveness. The levels of immunoglobulin molecules, as well as inflammatory cytokines in bronchoalveolar lavage fluid (BALF) and serum, were determined by ELISA. The lung tissues were stained by hematoxylin-eosin (HE). The expressions of Notch receptors (Notch 1–3) and Delta-like (DLL) 4 in the lung tissues were detected by RT-PCR and Western blot analysis.ResultsCompared with the model group, emodin treatment significantly increased the levels of immunoglobulin E (IgE) and IgG1/IgG2a in BALF and serum (p<0.05). HE results indicated that emodin inhibited the infiltration of inflammatory cells and that emodin reduced the levels of inflammatory cytokines, interleukin (IL)-5, IL-17, and interferon (IFN)-γ in BALF and serum (p<0.05). Furthermore, the expressions of Notch 1, 2, 3, and DLL4 in lung tissue were inhibited by emodin treatment.ConclusionsThe results demonstrated that emodin alleviated inflammation in CVA mice, which might be associated with suppression of the Notch pathway. Emodin might be a promising therapeutic agent for allergic asthma.

Emodin regulates neutrophil phenotypes to prevent hypercoagulation and lung carcinogenesis

BackgroundHypercoagulation and neutrophilia are described in several cancers, however, whether they are involved in lung carcinogenesis is currently unknown. Emodin is the main bioactive component from Rheum palmatum and has many medicinal values, such as anti-inflammation and anticancer. This study is to investigate the contributions of neutrophils to the effects of emodin on hypercoagulation and carcinogenesis.MethodsThe effects of emodin on neutrophil phenotypes were assessed by cell proliferation, morphological changes, phagocytosis and autophagy in vitro. The anti-coagulation and cancer-preventing actions of emodin were evaluated in the urethane-induced lung carcinogenic model. The expressions of Cit-H3 and PAD4 in lung sections were assessed by immunohistochemistry, CD66b+ neutrophils were distinguished by immunofluorescence, and cytokines and ROS were examined with ELISA. The neutrophils-regulating and hypercoagulation-improving efficacies of emodin were confirmed in a Lewis lung cancer allograft model. The related targets and pathways of emodin were predicted by network pharmacology.ResultsIn vitro, emodin at the dose of 20 µM had no effect on cell viability in HL-60N1 but increased ROS and decreased autophagy and thus induced apoptosis in HL-60N2 with the morphological changes. In the urethane-induced lung carcinogenic model, before lung carcinogenesis, urethane induced obvious hypercoagulation which was positively correlated with lung N2 neutrophils. There were the aggravated hypercoagulation and lung N2 neutrophils after lung carcinoma lesions. Emodin treatment resulted in the ameliorated hypercoagulation and lung carcinogenesis accompanied by the decreased N2 neutrophils (CD66b+) in the alveolar cavity. ELISA showed that there were more IFN-γ, IL-12 and ROS and less IL-6, TNF-α and TGF-β1 in the alveolar cavity in the emodin group than those in the control group. Immunohistochemical analysis showed that emodin treatment decreased Cit-H3 and PAD4 in lung sections. In the Lewis lung cancer allograft model, emodin inhibits tumor growth accompanied by the attenuated coagulation and intratumor N2 neutrophils. Network pharmacology indicated the multi-target roles of emodin in N2 neutrophil activation.ConclusionsThis study suggests a novel function of emodin, whereby it selectively suppresses N2 neutrophils to prevent hypercoagulation and lung carcinogenesis.

Emodin alleviates myocardial ischemia/reperfusion injury by inhibiting gasdermin D-mediated pyroptosis in cardiomyocytes.

BackgroundEmodin has recently been reported to have a powerful antiinflammatory effect, protecting the myocardium against ischemia/reperfusion (I/R) injury. Pyroptosis is a proinflammatory programmed cell death that is related to many diseases. The present study investigated the effect of emodin on pyroptosis in cardiomyocytes.Materials and methodsSprague Dawley rats were randomly divided into sham, I/R, and I/R+Emodin groups. I/R model was subjected to 30 minutes’ ligation of left anterior descending coronary artery, followed by 2 hours of reperfusion. Cardiomyocytes were exposed to hypoxic conditions for 1 hour and normoxic conditions for 2 hours. The level of the pyroptosis was detected by Western blot, real-time PCR analysis, and ELISA.ResultsThe level of gasdermin D-N domains was upregulated in cardiomyocytes during I/R or hypoxia/reoxygenation (H/R) treatment. Moreover, emodin increased the rate of cell survival in vitro and decreased the myocardial infarct size in vivo via suppressing the levels of I/R-induced pyroptosis. Additionally, the expression of TLR4, MyD88, phospho-IκBα, phospho-NF-κB, and the NLRP3 inflammasome was significantly upregulated in cardiomyocytes subjected to H/R treatment, while emodin suppressed the expression of these proteins.ConclusionThis study confirms that emodin treatment was able to alleviate myocardial I/R injury and inhibit pyroptosis in vivo and in vitro. The inhibitory effect of emodin on pyroptosis was mediated by suppressing the TLR4/MyD88/NF-κB/NLRP3 inflammasome pathway. Therefore, emodin may provide an alternative treatment for myocardial I/R injury.

Effect of emodin on gut microbiota of rats with acute kidney failure

The aim of this paper was to investigate the effect of emodin on gut microbiota in acute kidney injury rats( AKI). Rats were randomly divided into several groups: normal group,model group,low-dose of emodin group( 10 mg·kg~(-1)),medium-dose of emodin group( 25 mg·kg~(-1)),high-dose of emodin group( 50 mg·kg~(-1)) and control group( 5 mg·kg~(-1) of benazepril hydrochloride).The AKI model rats were established by intraperitoneal injection of small dose of gentamicin sulfate for 7 days. Two hours after intraperitoneal injection,except for the normal group and the model group,the other groups were given corresponding doses of drugs for 15 days. The serum levels of serum creatinine( SCr),urea nitrogen( BUN),plasma endotoxin level,24 h urinary protein and D-lactate in the plasma were determined by sarcosine oxidase,urease method,tal reagent method,bromo cresol chloroform method and double antibody sandwich enzyme-linked immunoadsorbent assay,respectively. Gut microbial communities were assayed by fluorescent quantitative PCR methods. HE staining was used to detect the pathological changes of the kidneys. Compared with the normal group,there were significant differences in body weight,urinary protein( UTP),bacterial endotoxin,urea nitrogen,creatinine,D-lactate in the plasma and four bacterial contents in the model group( P<0. 05). The urinary protein,urea nitrogen,D-lactate,creatinine and plasma bacterial endotoxin in control group and each emodin group were lower than those in model group,especially for high-dose of emodin( P<0. 01). Moreover,pathology resolution in high-dose emodin was better than other groups. Except for low-dose of emodin group,qRT-PCR data suggested that the amounts of Escherichia coli and Enterococcus in medication administration group were increased,while the amounts of Lactobacilli and Bifidobacterium were reduced compared with model group( P<0. 05),especially for high-dose of emodin( P<0. 01). There is a clear imbalance of gut microbiota in rats with AKI. Emodin could regulate the imbalance of gut microbiota,which might be one of the mechanisms of its effects on AKI rats.

Therapeutic effects of emodin on acute choiestatic hepatitis and mechanism in rats

Objective To investigate the therapeutic effects of emodin on acute cholestatic hepatitis and mec-hanism thereof. Methods Fifty Sprague-Dawley (SD) rats were randomly divided into 5 groups and were treated with emodin, ursodeoxycholic acid, dexamethasone, or normal saline respectively for 4 days.On the fifth day gastric perfusion of alpha-naphthylisothiocyanate(ANIT) was performed to establish models of choiestatic hepatitis.Four to six hours after the establishment of model the above mentioned agents were given continuously.Forty-eight hours after the model establishment blood samples were collected from abdominal aorta to examine the total bilirubin(TB), direct bilirubin(DB), alanine aminotransferase(ALT), total bile acid(TBA), aspartate aminotransferase(AST), alkaline phosphatase(ALP), gamma glutamine transferase(GGT). Specimen of liver was collected to undergo pathological examination.Real-time PCR was used to detect the mRNA expression of farnesoid X receptor(FXR), small heterodimer partner(SHP), bile salt export pump(BSEP), uridine diphosphate glucuronosyltransferase 2 family polypeptide B4(UGT2B4). Results The serum levels of total bilirubin (TB), direct bilirubin (DB), alanine aminotransferase (ALT), total bile acids (TBA), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) of the model group were respectively (68.1±26.1) μmol/L, (46.3±20.1) μmol/L, (483±228) U/L, (159.1±57.9) μmol/L, (2.0±0.5) U/L, (996±382) U/L, (324±120) U/L.The levels of TB, DB, ALT, TBA, AST, ALP of the emodin group were respectively (15.0±8.7) μmol/L, (10.8±3.9) μmol/L, (147±71) U/L, (60.1±22.7) μmol/L, (295±104) U/L, (222±59) U/L, and were all significantly lower than those of the model group (all P<0.05). The levels of TB, DB, ALT, TBA, AST, GGT, ALP of the emodin group were all significantly lower than those of the ursodeoxycholic acid group (all P<0.05). The levels of TB, DB, ALT, TBA, GGT, AST were all significantly lower than those of the dexamethasone group (all P<0.01). The expression levels of FXR, SHP, BSEP, UGT2B4 mRNA in the emodin group (1.087±0.285, 0.892±0.390, 0.902±0.149, 1.785±0.403) were all significantly higher than those of the model group (0.152±0.088, 0.559±0.194, 0.561±0.123, 0.177±0.039, all P<0.05). Conclusions By decreasing the levels of TB, DB, ALT, TBA, AST, ALP and reducing pathological changes, emodin has a protective effect on cholestatic hepatitis.It has better effects than ursodeoxycholic acid and dexamethasone.These effects may be due to promoting FXR, SHP, BSEP and UGT2B4 expression. Key words: Emodin; Cholestasis; Hepatitis; Farnesoid X receptor; Small heterodimer partner; Uridine diphosphate glucuronosyltransferase 2 family polypeptide B4; Bile salt export pump

Combined Use of Emodin and Ginsenoside Rb1 Exerts Synergistic Neuroprotection in Cerebral Ischemia/Reperfusion Rats.

Acute ischemic stroke (AIS) generally causes neurological dysfunction and poses a serious threat to public health. Here, we aimed to assess the independent and combined effects of ginsenoside Rb1 (GRb1) and Emodin on neuroprotection through regulating Connexin 43 (Cx43) and Aquaporin 4 (AQP4) expression in cerebral ischemia/reperfusion (I/R) model rats. Adult male Sprague-Dawley (SD) rats were randomly divided into five groups: sham group, I/R group, Emodin group, GRb1 group and Emodin+GRb1 group. They were further allocated to four subgroups according to the 6h, 1d, 3d, and 7d time points except the sham group. Based on the modified Longa suture method, the focal cerebral I/R model was established by middle cerebral artery occlusion (MCAO). The neurological deficit scores (NDS), blood brain barrier (BBB) permeability and cerebral infarction area were assessed at each corresponding time point. Cx43 and AQP4 levels were assessed by Real-time PCR and Immunofluorescence. Compared with I/R group, both the independent and combined use of GRb1 and Emodin could alleviate NDS, reduce the BBB permeability, reduce the infarction area and down-regulate Cx43 and AQP4 expression at 6h, 1d, 3d, and 7d after I/R (P < 0.05). The Emodin+GRb1 group had more significant effects than Emodin group and GRb1 group (P < 0.05). In conclusion, the combination of Emodin and GRb1 exerts synergistically neuroprotective functions through regulating AQP4 and Cx43 after I/R.

Emodin Attenuates Lipopolysaccharide-Induced Acute Liver Injury via Inhibiting the TLR4 Signaling Pathway in vitro and in vivo

Aims: Emodin is an anthraquinone with potential anti-inflammatory properties. However, the possible molecular mechanisms and protective effects of emodin are not clear. The objective of this study was to investigate the possible molecular mechanisms and protective effects of emodin on lipopolysaccharide (LPS)-induced acute liver injury (ALI) via the Toll-like receptor 4 (TLR4) signaling pathway in the Raw264.7 cell line and in Balb/c mice.Methods: This study established an inflammatory cellular model and induced an ALI animal model. TLR4 was overexpressed by lentivirus and downregulated by small interfering RNA (siRNA) technology. The mRNA and protein levels of TLR4 and downstream molecules were detected in cells and liver tissue. The tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 levels in supernatant and serum were determined by ELISA. The distribution and expression of mannose receptor C type 1 (CD206) and arginase 1 (ARG1) in the liver were tested by immunofluorescence. Mouse liver function and histopathological observations were assessed.Results: Administration of emodin reduced the protein and/or mRNA levels of TLR4 and its downstream molecules following LPS challenge in Raw264.7 cells and in an animal model. Additionally, emodin suppressed the expression of TNF-α and IL-6 in cell culture supernatant and serum. The inhibitory effect of emodin was also confirmed in RAW264.7 cells, in which TLR4 was overexpressed or knocked down. Additionally, ARG1 and CD206 were elevated in the emodin groups. Emodin also decreased serum ALT and AST levels and alleviated the liver histopathological damage induced by LPS.Conclusion: Emodin showed excellent hepatoprotective effects against LPS-induced ALI, possibly by inhibiting TLR4 signaling pathways.