Different Concentrations Of Emodin Research Articles

Trichoderma-derived emodin competes with ExpR and ExpI of Pectobacterium carotovorum subsp. carotovorum to biocontrol bacterial soft rot.

Quorum sensing inhibitors (QSIs) are an emerging control tool that inhibits the quorum sensing (QS) system of pathogenic bacteria. We aimed to screen for potential QSIs in the metabolites of Trichoderma and to explore their inhibitory mechanisms. We screened a strain of Trichoderma asperellum LN004, which demonstrated the ability to inhibit the color development of Chromobacterium subtsugae CV026, primarily attributed to the presence of emodin as its key QSI component. The quantitative polymerase chain reaction with reverse transcription results showed that after emodin treatment of Pectobacterium carotovorum subsp. carotovorum (Pcc), plant cell wall degrading enzyme-related synthetic genes were significantly downregulated, and the exogenous enzyme synthesis gene negative regulator (rsmA) was upregulated 3.5-fold. Docking simulations indicated that emodin could be a potential ligand for ExpI and ExpR proteins because it exhibited stronger competition than the natural ligands in Pcc. In addition, western blotting showed that emodin attenuated the degradation of n-acylhomoserine lactone on the ExpR protein and protected it. Different concentrations of emodin reduced the activity of pectinase, cellulase, and protease in Pcc by 20.81%-72.21%, 8.38%-52.73%, and 3.57%-47.50%. Lesion size in Chinese cabbages, carrots and cherry tomatoes following Pcc infestation was reduced by 10.02%-68.57%, 40.17%-88.56% and 11.36%-86.17%. Emodin from T. asperellum LN004 as a QSI can compete to bind both ExpI and ExpR proteins, interfering with the QS of Pcc and reducing the production of virulence factors. The first molecular mechanism reveals the ability of emodin as a QSI to competitively inhibit two QS proteins simultaneously. © 2023 Society of Chemical Industry.

Emodin, a Natural Anthraquinone, Increases Uric Acid Excretion in Rats with Potassium Oxonate-Induced Hyperuricemia.

The treatment of hyperuricemia and gout is mostly based on lowering serum uric acid levels using drugs, such as allopurinol, or increasing urinary excretion of uric acid. However, some patients still experience adverse reactions to allopurinol and turn to Chinese medicine as an alternative. Therefore, it is crucial to design a preclinical study to obtain more convincing data on the treatment of hyperuricemia and gout with Chinese medicine. This study aimed to explore the therapeutic effect of emodin, a Chinese herbal extract, in a rat model of hyperuricemia and gout. In this study, we used 36 Sprague-Dawley rats, which were randomly divided into six groups for experimentation. Hyperuricemia was induced in rats by intraperitoneal injections of potassium oxonate. The efficacy of emodin in reducing serum uric acid levels was demonstrated by comparing the positive control group with groups treated with three different concentrations of emodin. The inflammatory profiles, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α levels, were unaffected by emodin treatment. In the experimental results, it was observed that the serum uric acid concentration in the vehicle control group was 1.80 ± 1.14, while the concentrations in the moderate and high concentration emodin groups were 1.18 ± 0.23 and 1.12 ± 0.57, resulting in no significant difference in uric acid concentration between these treatment groups and the control group, indicating that emodin has a therapeutic effect on hyperuricemia. The increase in the fractional excretion of uric acid (FEUA) demonstrated that emodin promoted urinary uric acid excretion without significantly affecting the inflammatory profile. Thus, emodin reduced the serum uric acid concentration to achieve effective treatment of hyperuricemia and gout by increasing urinary excretion. These results were supported by the measured serum uric acid and FEUA levels. Our data have potential implications for the treatment of gout and other types of hyperuricemia in clinical practice.

Emodin protects lipopolysaccharide-induced myocardial injury and mitochondrial dysfunction via PI3K/AKT signaling pathway based on Network Pharmacology

Sepsis combined with myocardial injury is an important cause of septic shock and multiple organ failure. Cardiac dysfunction is a significant manifestation of sepsis and it is associated with the prognosis of the disease. It is assumed that damage to myocardial mitochondrial function is one of the main causes of cardiac dysfunction in septic patients, and the repair of myocardial mitochondrial function may alleviate cardiac dysfunction in septic patients. Emodin has been discovered to serve a variety of pharmacological effects, including anti-tumor, anti-inflammatory, antioxidant, and anti-apoptotic properties. In this study, we investigated the potential protective effect of Emodin on sepsis and revealed the underlying mechanisms using a network pharmacology approach coupled with experimental validation. The model of myocardial injury induced by LPS was established and divided into three groups: the control group, the lipopolysaccharide (LPS) group, and the LPS+Emodin group. The apoptosis rate, reactive oxygen species (ROS), mitochondrial permeability transition pore(MPTP), and mitochondrial membrane potential (MMP) were determined in LPS-induced sepsis Cardiacmyocytes treated with different concentrations of Emodin. In addition, the degree of myocardial mitochondrial damage was evaluated by electron microscopy. Signal pathway-related proteins were determined by Western blotting in vitro. And then, network pharmacology screening revealed TP53, CASP3, ILB, MYC, TNF, PTGS2, and PPARG as the critical overlapping targets in a PPI network, and GO and KEGG analyses revealed the top 10 enriched biological processes and signaling pathways associated with the therapeutic effects of emodin on sepsis. The results show the PI3K-AKT pathway is mainly involved in the emodin-sepsis myocardial injury network. Meanwhile, Emodin has been demonstrated to protect the myocardium from LPS-induced myocardial injury in vitro, and moderate doses of Emodin showed the most prominent effect. Emodin alleviates mitochondrial damage by reducing apoptosis and inhibiting oxidative stress and ameliorates protecting LPS-induced myocardial injury and mitochondrial dysfunction through the PI3K-AKT pathway. This provides a feasible strategy for preventing and treating myocardial injury and mitochondrial dysfunction in sepsis. This study was supported by the Science and Technology Bureau of Zhengjiang (Grant No.SH2022068 and SH2022042). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Therapeutic mechanism of emodin for treatment of rheumatoid arthritis: a network pharmacology-based analysis

To investigate the therapeutic mechanism of emodin in the treatment of rheumatoid arthritis (RA) using a network pharmacology-based method and validate this mechanism in a fibroblast-like synovial cell line. The PubChem, Targetnet, SwissTargetPrediction, Genecards, OMIM, and DisGeNET databases were searched to obtain emodin targets and RA-related genes. A protein-protein interaction (PPI) network was constructed, and GO and KEGG pathway enrichment analyses were carried out to analyze the intersection genes. AutoDock4.2.6 software was used to simulate molecular docking between emodin and its candidate targets. In a cultured fibroblast-like synovial cell line (MH7A), the effects of different concentrations of emodin on proliferation of tumor necrosis factor-α (TNF-α)-induced cells were investigated using CCK-8 assay, cell scratch experiment and flow cytometry; the changes in the expressions of nuclear factor-κB (NF-κB) pathway proteins were detected using Western blotting, and the mRNA expressions of the hub genes were examined with RT-qPCR. We identified 32 intersection genes of emodin and RA, and the key targets including CAPS3, ESR1, and MAPK14 involved mainly the NF-κB signaling pathway. Cell scratch experiment and flow cytometry demonstrated a strong inhibitory effect of emodin on MH7A cell proliferation. Treatment with TNF-α significantly increased the cellular expressions of the NF-κB pathway proteins, which were obviously lowered by treatment with 80 μmol/L emodin. The results of RT-qPCR showed that TNF-α treatment obviously up-regulated the expressions of the hub genes COX2 and P38MAPK, and emodin treatment significantly down-regulated the expressions of MAPK and PTGS2 and up-regulated the expression of CASP3. The therapeutic effect of emodin on RA is mediated mainly through regulation of cell proliferation, apoptosis, and the NF-κB pathway.

Emodin Protects SH-SY5Y Cells Against Zinc-Induced Synaptic Impairment and Oxidative Stress Through the ERK1/2 Pathway.

Zinc is an essential trace element important for the physiological function of the central nervous system. The abnormal accumulation of zinc inside neurons may induce mitochondrial dysfunction and oxidative stress, which contribute to many brain diseases. We hypothesized that natural anthraquinone derivative emodin can protect against neurotoxicity induced by pathological concentrations of zinc via the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway and alleviate oxidative stress and mitochondrial dysfunction. Human neuroblastoma (SH-SY5Y 26 cells) was treated with zinc sulfate and different concentrations of emodin, and changes in the levels of ETK1/2 expression, oxidative stress (DCFH-DA staining), mitochondrial function (JC-1 staining), lipid peroxidation (4-hydroxynonenal staining), and DNA oxidation (8-hydroxy-2-deoxyguanosine staining) were examined. Emodin ameliorated zinc-induced altered expression of levels of phosphorylated ERK1/2 (not total ETK1/2) and synaptic proteins (presynaptic SNAP 25, synaptophysin and postsynaptic PSD95) in SH-SY5Y cells. Moreover, emodin inhibited the generation of reactive oxygen species and oxidative stress and facilitated the collapse of mitochondrial membrane potential (ΔΨm) in SH-SY5Y cells. In conclusion, our results indicated that emodin exerts neuroprotective effects against zinc by normalizing synaptic impairment by decreasing the phosphorylation of ERK1/2, reducing reactive oxygen species and protecting mitochondrial function.

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 Rescues Intrahepatic Cholestasis via Stimulating FXR/BSEP Pathway in Promoting the Canalicular Export of Accumulated Bile.

AimBile salt export pump (BSEP) have been confirmed to play an important role for bile acid canalicular export in the treatment of cholestasis. In this study, we investigated the stimulatory effect of emodin on BSEP signaling pathway in cholestasis.MethodsCell and animal experiments were given different concentrations of emodin. The BSEP upstream molecule farnesoid X receptor was down-regulated by small interfering RNA (siRNA) technology or guggulsterones and up-regulated by lentivirus or GW4064. Real-time PCR and Western blotting was employed to detect the mRNA and protein levels of BSEP in LO2 cell, rat primary hepatocytes and liver tissue. Immunohistochemistry (IHC) was used to examine the expression of BSEP in liver tissues. Rat liver function and pathological changes of liver tissue were performed by biochemical test and hematoxylin and eosin (HE) staining.ResultsEmodin could increase the mRNA and protein expression of BSEP and FXR. When down-regulating farnesoid X receptor expression with the siRNA or inhibitor guggulsterones, and up-regulating farnesoid X receptor expression with the lentivirus or agonist GW4064, emodin could increase the mRNA level of BSEP and FXR and the protein level of BSEP, FXR1, and FXR2. Emodin also had a notable effect on rat primary hepatocytes experiment, rat pathological manifestation, BSEP, FXR1, and FXR2 positive staining in liver tissues and the test of liver function.ConclusionEmodin has a protective effect and a rescue activity on cholestasis via stimulating FXR/BSEP pathways in promoting the canalicular export of accumulated bile.

Emodin Successfully Inhibited Invasion of Brucella abortus Via Modulting Adherence, Microtubule Dynamics and ERK Signaling Pathway in RAW 264.7 Cells.

The aim of this work is to investigate the protective efficacy of emodin, an active, naturally-occurring anthraquinone derivative of several traditional Chinese herbs, against Brucella abortus infection in macrophages. Brucella were incubated with different concentrations of emodin and showed that bacterial survival rates were markedly reduced in a dose-dependent manner at increasing incubation time points. Through bacterial infection assay, the highest non-cytotoxic concentration of emodin demonstrated attenuated invasion of Brucella into macrophages, however it did not inhibit the growth of these pathogens within the host cells. On the other hand, emodin effectively decreased the number of bacteria that adhered to host cells, which indicated its potential as an anti-adhesin agent. Furthermore, using immunoblotting and FACS assay for detecting MAPK signaling proteins and F-actin polymerization, respectively, the results showed that the emodin-incubated cells displayed modest reduction in the phosphorylation levels of ERK1/2 and inhibition of F-actin polymerization as compared to control cells. These findings indicate the potential use of emodin as a naturally-occurring alternative method for the prevention of animal brucellosis although this requires confirmation of safe clinical doses.

The regulation effect of emodin on human embryonic hepatocyte L02 cell strain Farnesoid X receptor

Objective To investigate the regulation effect of emodin on human embryonic liver L02 cells strain farnesoid X receptor(FXR) pathways. Methods By using Guggulsterones, FXR genes were intervened with in L02 cells as model group, in three different concentrations of emodin (50.0 μmol/L, 25.0 μmol/L, 12.5 μmol/L) of emodin in the model group cells, FXR, small heterodimer parter(SHP), UDP-glucuronosyltransferase 2B4(UGT2B4), bile salt export pump(BSEP) mRNA and protein expressions were detected by real-time fluorescent quantitative PCR and Western blot test. Results (1)The relative expressions of FXR mRNA and protein in the model group (0.240±0.021, 0.385±0.119) decreased significantly than those of control group (1.000±0.088, 1.000±0.223), the differences were statistically significant (t=14.62, 4.21, all P<0.01). Compared with the model group, the relative expressions of FXR mRNA in the high, the middle and the low-dose emodin groups (0.755±0.083, 0.817±0.097, 0.547±0.080) were significantly higher (t=10.42, 10.03, 6.39, all P<0.01). The relative expressions of FXR protein in the medium-dose group (0.865±0.203) increased significantly (t=3.53, P<0.01). The relative expressions of FXR mRNA in the high and the medium-dose groups (0.755±0.083, 0.817±0.097) were higher than those in the low-dose group (0.547±0.080), the differences were statistically significant (t=3.11, 3.70, all P<0.01). (2)The relative expressions of SHP, UGT2B4, BSEP mRNA and protein in the model group (0.148±0.025, 0.205±0.039, 0.184±0.020; 0.458±0.130, 0.255±0.170, 0.303±0.100) were significantly lower than those in the control group (1.000±0.099, 1.000±0.104, 1.000±0.125; 1.000±0.129, 1.000±0.157, 1.000±0.162), the differences were statistically significant (t=14.50, 12.44, 11.19, 5.13, 5.57, 6.33, all P<0.01). The relative expressions of SHP, UGT2B4 and BSEP mRNA in the high, the middle and the low-dose groups (0.610±0.058, 0.514±0.041, 0.707±0.062; 0.755±0.108, 0.800±0.086, 0.727±0.076; 0.470±0.070, 0.582±0.050, 0.500±0.108) were significantly lower than those in the model group (0.148±0.025, 0.205±0.039, 0.184±0.020), the differences were statistically significant (t=12.75, 9.38, 13.94, 9.46, 10.90, 11.96, 7.53, 10.31, 5.00, all P<0.01). The relative expressions of SHP, UGT2B4 and BSEP mRNA in the high and the middle-dose emodin group (0.658±0.091, 0.624±0.113, 0.607±0.097; 0.868±0.194, 0.883±0.099, 0.913±0.131) were significantly higher than those in the low-dose group (0.458±0.130, 0.255±0.170, 0.303±0.100), the differences were statistically significant (t=2.18, 3.13, 3.78, 3.05, 5.53, 6.41, all P<0.01). The relative expression of SHP and BSEP protein in the low-dose group (0.645±0.135, 0.572±0.076) increased, the differences were statistically significant (t=1.73, P<0.05, t=3.72, P<0.01). The relative expression of BSEP protein in the high and the medium-dose groups (0.607±0.097, 0.913±0.131) was significantly higher than those in the low-dose group (0.572±0.076), the differences were statistically significant (t=1.99, 3.90, all P<0.01). The relative expressions of SHP and UGT2B4 mRNA in the high and the low-dose group (0.610±0.058, 0.470±0.070; 0.514±0.041, 0.582±0.050) were significantly lower than those in the medium-dose group (0.800±0.086), the differences were statistically significant (t=3.75, 6.47, 3.83, 3.42, all P<0.01). The expression levels of UGT2B4 and BSEP in the high and the low-dose groups(0.624±0.113, 0.644±0.097; 0.607±0.097, 0.572±0.076) were significantly lower than those in the medium-dose group(0.883±0.099, 0.913±0.131), the differences were statistically significant (t=4.27, 2.98, 6.30, 3.90, all P<0.01). Conclusions Guggulsterones can inhibit FXR and downstream genes SHP, UGT2B4, BSEP expressions in L02, and emodin can enhance FXR gene expression, promote SHP, UGT2B4, BSEP gene expression, inhibit cholestasis pathway, protection of liver cell, which shows a dosage discreapancy. Key words: Youth Fund of Emodin; Human embryonic liver cells L02; Farnesoid X receptor

Effect of Emodin on Expression of VEGF-A and VEGFR_2 Genes in Human Breast Carcinoma MCF-7 Cell

Background: Tumor angiogenesis is an important procedure for the tumor development as it confirms oxygen and nutrients source to increase cells through the expansion of new blood vessels, potentially causing cancer development and metastasis. Emodin, a tyrosine kinase inhibitor, is an innate anthraquinone derivative found in the roots and rhizomes of several plants. Pharmacological studies have revealed that emodin displays various biological roles, such as anti-inflammatory, antibacterial and anticancer action. Studies have confirmed that emodin prevents cell growth in some types of cancer cells. Therefore, inhibition of angiogenesis is a new strategy for cancer treatment. Objectives: In this study, we aimed to determine the effect of emodin on expression of VEGF-A and VEGFR-2 genes in MCF-7 cell line. Methods: Comparative cell viability was measured by MTT assay after treatment with different concentrations of emodin (0, 10, 20, 30, 40 and 50μM) for 24, 48, 72 hours. To investigate apoptosis in cells treated with emodin (0, 10, 20, 30, 40 and 50 µM), flow cytometry was used. Finally, alterations in expression of VEGF-A and VEGFR-2genes were analyzed by real time PCR. Results: Emodin showed an anti-cancer effect with concentration of 20 μM as IC50 in MCF-7 cells. Emodin induced apoptosis and significantly reduced mRNA level of VEGF-A and VEGFR-2 gene in MCF-7 cell line in a dose dependent manner. Conclusions: Based on results obtained, emodin significantly reduced mRNA level of VEGF-A and VEGFR-2 gene in MCF-7 cell line in a dose dependent manner.

Cytotoxic Effect of Emodin on Growth of SKBR3 Breast Cancer Cells

Background: The poor prognosis of breast cancer is due to its resistance to the conventional treatments. Therefore, researchers are studying about herbs which have anticancer effects. Emodin is a hydroxy-anthraquinone that is found in many medicinal plants and has biological and anticancer effects. According to previous studies, it inhibited the growth of cancer cells by apoptosis. Objectives: In this study, we aimed to determine the effect(s) of emodin on growth and proliferation of SKBR3 cancer cells. Methods: SKBR3 cells were cultivated for 24 hours. Then different concentrations of emodin (0, 10, 25 and 50 µM) were added to the test wells and incubated for 24, 48 and 72 hours. Cell viability was examined by MTT assay after 24, 48 and 72 hours. Apoptosis was determined in cells treated with emodin (0, 10, 25 and 50 µM) using flow cytometric assay. Alterations in expression of apoptotic-related genes (Caspase 3, 8, 9, Bcl2 and Bax) were determined by real time PCR. Caspase 3 activity was measured using a colorimetric assay. Results: Emodin had inhibitory effects on the proliferation of SKBR3 cells with IC50 value of 25 µM. Emodin induced apoptosis and increased the mRNA expression of Caspase 3, 8, 9 and Bax and decreased the mRNA expression of Bcl2 in SKBR3 cells. It also increased the activity of Caspase 3. Conclusions: Emodin had an inhibitory effect on the growth of SKBR3 cell line in a dose and time dependent manner. This study indicated that emodin induces apoptosis in SKBR3 cells through the alterations of the expression of apoptosis-related genes and increases the activity of Caspase 3.

Emodin Combined with Nanosilver Inhibited Sepsis by Anti-inflammatory Protection.

Background: Emodin is the main active component of rhubarb, which has demonstrated many beneficial effects against inflammation. Nanosilver is an effective antimicrobial agent. The present study was designed to observe the effects of Emodin combined with silver nanoparticles (E/S) on sepsis protection and related mechanism.Methods: E/S was prepared by loading different concentrations of Emodin on nanosilver and cytotoxicity of E/S were determined by suphorhodamine B assays. Anti-microbial activities of E/S were assayed by direct interaction with various common pathogens and anti-adhesive activites of E/S on leukocytes with endothelial cells were assayed by biochemical analysis. Next, inflammatory cell enumeration, inflammatory mediators in bronchoalveolar lavage fluid (BALF) and endothelial cell function were analyzed on a clinically relevant model of sepsis induced by cecal ligation and puncture (CLP) after E/S administration. The effects of E/S on NF-κB and p38 were also examined by western blot.Results: E/S exhibited little cytotoxicity action on endothelial cells and significant inhibitory activities against all tested common microorganisms and adherence between leukocyte and endothelial cells. E/S induced anti-sepsis protection mainly mediated by inhibition of inflammatory cells infiltration, down-regulation of TNF-alpha, IL-8 and lactic dehydrogenase (LDH), and inhibition of NF-κB and p38 pathways in mice 24 h post-CLP.Conclusion: Our data suggest that E/S has strong anti-sepsis effects, which was related with anti-inflammatory protection and thereby promote survival following sepsis challenge.

The effects of emodin on cell viability, respiratory burst and gene expression of Nrf2-Keap1 signaling molecules in the peripheral blood leukocytes of blunt snout bream (Megalobrama amblycephala)

We determined the effects of emodin on the cell viability, respiratory burst activity, mRNA levels of antioxidative enzymes (Cu-Zn SOD, CAT and NOX2), and gene expressions of the Nrf2-Keap1 signaling molecules in the peripheral blood leukocytes of blunt snout bream. Triplicate groups of cultured cells were treated with different concentrations of emodin (0.04–25 μg/ml) for 24 h. Results showed that the emodin caused a dramatic loss in cell viability, and occurred in a dose-dependent manner. Emodin exposure (1–25 μg/ml) were significantly induced the ROS generation compared to the control. The respiratory burst and NADPH oxidase activities were significantly induced at a concentration of 0.20 μg/ml, and inhibited at 25 μg/ml. Besides, mRNA levels of antioxidant enzyme genes were dramatically regulated by emodin exposure for 24 h. During low concentrations of exposure, mRNA levels of Cu-Zn SOD in the cells treated with 0.04, 0.20 μg/ml, CAT, NOX2 and Nrf2 in the cells treated with 1 μg/ml were sharply increased, respectively. Whereas, high concentrations were dramatically down-regulated the gene expressions of CAT in the cells treated with 5, 25 μg/ml and NOX2 in the cells treated with 25 μg/ml. Furthermore, sharp increase in Keap1and Bach1 expression levels were observed a dose-dependent manner. In conclusion, this study demonstrated that emodin could induce antioxidant defenses which were involved in cytotoxic activities, respiratory burst and the transcriptional regulation levels of antioxidant enzymes and Nrf2-Keap1 signaling molecules.

Emodin: One Main Ingredient of Shufeng Jiedu Capsule Reverses Chemoresistance of Lung Cancer Cells Through Inhibition of EMT

Background: Chemoresistance has become a an important worldwide problem to cancer treatment. Understanding the mechanism of drug resistance is the key to solve this problem and improve the survival of the patient. Doxorubicin and its analogues are widely used as antitumor drugs but many doxorubicin resistant cases have been identified in recent years. Doxorubicin (Dox) resistance is a very serious phenomenon in lung cancer treatment. As we could show previously, Shufeng Jiedu Capsule (SFJDC) can effectively reverse H69AR cells resistance to Dox, thus, the present study was designed to explore the mechanism underlying the effects of the main ingredient Emodin on chemosensitivity of H69AR cells to Dox. Methods: First, the growth inhibition rate of lung cancer cells and normal bronchial epithelial cells (BECs) was determined by MTT. Then, the resistance-induced epithelial-mesenchymal transition (EMT) of H69AR cells was examined by western blot and the effect of Emodin on Twist, Snail or Slug was assayed by Real-time PCR and Western blot. The activation of NF-kappa B was assayed by Western blot. Proliferation, apoptosis, migration and invasion of H69AR cells induced by Twist, Snail and Slug were also assayed by flow cytometry and transwell chamber. Results: The results showed that after administration of Dox (10µM) with different concentrations of Emodin, the cells exhibited a dose-dependent inhibition action to H69AR cells at 48 hours. H69AR induced the expression of Twist, Snail, and Slug when compared with Dox-sensitive H69 cells. The expression of Twist, Snail, and Slug can be effectively inhibited by combination of Dox and Emodin. The reversal of resistance was associated with the inhibition of NF-kappa B. Twist, Snail and Slug promoted proliferation, migration and invasion and inhibited apoptosis. Conclusion: Our data suggest that Emodin can effectively reverse the resistance of H69AR to Dox, an effect paralleled by inhibition of EMT, cell proliferation, apoptosis, migration and invasion.

Effects of emodin on the demethylation of tumor-suppressor genes in pancreatic cancer PANC-1 cells.

Emodin, a natural anthraquinone derivative isolated from Rheum palmatum, has been reported to inhibit the growth of pancreatic cancer cells through different modes of action; yet, the detailed mechanism remains unclear. In the present study, we hypothesized that emodin exerts its antitumor effect by participating in the regulation of the DNA methylation level. Our research showed that emodin inhibited the growth of pancreatic cancer PANC-1 cells in a dose- and time-dependent manner. Dot-blot results showed that 40 µM emodin significantly inhibited genomic 5 mC expression in the PANC-1 cells, and mRNA-Seq showed that different concentrations of emodin could alter the gene expression profile in the PANC-1 cells. BSP confirmed that the methylation levels of P16, RASSF1A and ppENK were decreased, while concomitantly the unmethylated status was increased. RT-PCR and western blotting results confirmed that the low expression or absence of expression of mRNA and protein in the PANC-1 cells was re-expressed following treatment with emodin. In conclusion, our study for the first time suggests that emodin inhibits pancreatic cancer cell growth, which may be related to the demethylation of tumor-suppressor genes. The related mechanism may be through the inhibition of methyltransferase expression.

Inhibitory effect of emodin on human hepatoma cell line SMMC-7721 and its mechanism.

Da Huang (Radix et Rhizoma Rhei) is the dried root or rhizome of Rheum palmatum L., Rheum tanguticum Maxim ex Balf. or Rheum officinale Braill of family Polygonaceae. It has heat clearing, damp drying, fire purging and toxin removing effects. Because of its definite curative efficacy, it has been widely applied in clinical settings. To study the inhibitory effect of emodin on human hepatoma cell line SMMC-7721 and its mechanism. MTT assay, flow cytometry and electron microscopy were used to investigate the inhibitory effect of different concentrations of emodin on human hepatoma cell line SMMC-7721. 12 h, 24 h and 48 h after the action of 20, 40 and 80 umol/L emodin on SMMC-7721 cells, the proliferation of human hepatoma SMMC-7721 cells was inhibited; the inhibitory effects showed time-and concentration-dependence. 48 h after the action of different concentrations of emodin on SMMC-7721 cells, cells in G2/M phase increased significantly, while the proportion of S phase cells gradually declined. Emodin can inhibit human hepatoma cell line SMMC-7721.

Effect of emodin in attenuating endoplasmic reticulum stress of pancreatic acinar AR42J cells

To explore the effect of emodin on endoplasmic reticulum (ER) stress of pancreatic acinar AR42J cells. Rat pancreatic acinar AR42J cells were cultured in 6-well plates, and divided into the normal control group, the model group (with the final concentration at 1 x 10(-7) mol · L(-1) for cerulean and lipopolysaccharide at 10 mg · L(-1)) and the emodin group (10, 20, 40 μmol · L(-1)). Cells in each group were cultured in three multiple pores for 24 h, and their supernate was removed after cell attachment. The normal control group was added with haploids, the model group was added with the modeling liquid for haploids, and the treatment groups were added with different concentrations of emodin at 15-20 min before the modeling liquid. The cells were continuously cultured for 3 h under 37 °C and 5% CO2. Their intracellular protease and lipase expressions were detected with kits. The cellular morphology was observed under optical microscope. The level of calcium in endoplasmic reticulum was measured under laser confocal microscopy. Western blot assay were used to determine the protein expression of ER-related signaling molecules. Emodin could significantly inhibit levels of amylase, lipase and intracellular calcium and ER. Emodin could reduce pancreatic acinar cell injury induced by the combination of cerulean and lipopolysaccharide. Its action mechanism is correlated with the inhibition of intracellular calcium overload and ER stress.

Emodin up-regulates glucose metabolism, decreases lipolysis, and attenuates inflammation in vitro.

Emodin, the major bioactive component of Rheum palmatum, has many different activities, including antitumor, anti-inflammatory, and antidiabetes effects. Recently, emodin was reported to regulate energy metabolism. In the present study, we further explored the effects of emodin on glucose and lipid metabolism. Differentiated C2C12 myotubes and 3T3-L1 adipocytes were treated with or without different concentrations of emodin (6.25, 12.5, 25 or 50 μmol/L) for different time (1 h, 3 h, 12 h, 24 h or 48 h). Glucose metabolism, oxygen consumption, lactic acid levels, glycerol levels, and inflammation pathways were then evaluated. Cells were collected for quantitative polymerase chain reaction (PCR) and western blot analysis. Emodin upregulated glucose uptake and consumption in both C2C12 myotubes and 3T3-L1 adipocytes, with glycolysis increased. Furthermore, emodin inhibited lipolysis under basal conditions (as well as in the presence of 10 ng/ml tumor necrosis factor (TNF-)-α in 3T3-L1 adipocytes) and significantly decreased phosphorylated perilipin. Moreover, emodin inhibited the nuclear factor-κB and extracellular signal-regulated kinase pathways in C2C12 myotubes and 3T3-L1 adipocytes. Emodin upregulates glucose metabolism, decreases lipolysis, and inhibits inflammation in C2C12 myotubes and 3T3-L1 adipocytes.

Emodin enhances cholesterol efflux by activating peroxisome proliferator‐activated receptor‐γ in oxidized low density lipoprotein‐loaded THP1 macrophages

Peroxisome proliferator-activated receptor (PPAR) γ is a nuclear receptor involved in the regulation of lipid metabolism. In the present study, we sought to investigate the effects of emodin, an anthraquinone derivative isolated from the roots of Rheum palmatum, on PPARγ signalling and cholesterol efflux in macrophage foam cells. Oxidized low-density lipoprotein (oxLDL)-stimulated THP1 macrophages were incubated with different concentrations of emodin (0-10μmol/L) for 18h. Western blot analysis and semiquantitative reverse transcription-polymerase chain reaction were used to assess the expression of key genes involved in cholesterol efflux, namely PPARγ, liver X receptor (LXR) α, ATP-binding cassette transporter (ABC) A1 and ABCG1. In addition, apolipoprotein (apo) A-I-mediated cholesterol efflux in emodin-treated cells was measured. Expresssion of PPARγ mRNA and protein was increased in emodin-treated cells in a time- and dose-dependent manner. Emodin treatment also concentration-dependently induced LXRα, ABCA1 and ABCG1 expression. Moreover, emodin promoted apoA-I-mediated cholesterol efflux from oxLDL-loaded THP1 macrophages, which was significantly abolished by pretreatment with the PPARγ-selective antagonist GW9662 or the specific small interfering RNA for PPARγ. Together, the results demonstrate that emodin promotes cholesterol efflux from THP1 macrophages via activation of the PPARγ signalling pathway and may represent a potential anti-atherosclerotic drug.

The effect of emodin on cytotoxicity, apoptosis and antioxidant capacity in the hepatic cells of grass carp (Ctenopharyngodon idellus)

We determined the effect of emodin on the lactate dehydrogenase (LDH) release, superoxide dismutase (SOD), glutathione (GSH), total antioxidant capacity (T-AOC), reactive oxygen species (ROS), mitochondria membrane potential (ΔΨm), and apoptosis in the hepatic cells of grass carp (Ctenopharyngodon idellus). Cultured cells were treated with different concentrations of emodin (0.04–25 μg/ml) for 24 h. We found that the cytotoxic effect of emodin was mediated by apoptosis, and that this apoptosis occurred in a dose-dependent manner. Emodin (1–25 μg/ml) significantly induced apoptosis accompanying by ΔΨm disruption and ROS generation and significantly reduced the SOD activities and T-AOC compared to the control. Thus, the oxidative effect of emodin may be attributed to the loss of the cell's ability to maintain the activity of its radical-scavenging enzymes. GSH was also significantly higher after 0.2–1 μg/ml emodin exposure, indicating that cells failed to maintain their redox balance when compensating for the increased oxidative stress. Our results suggest that emodin (1–25 μg/ml) exerts its cytotoxic effects via apoptosis by directly affecting the mitochondria.