The mechanism research on the anti-liver fibrosis of emodin based on network pharmacology

AIMS

This study was designated to illustrate the underlying mechanisms of emodin anti-liver fibrosis via network pharmacology and experiment.

METHODS

The TSMCP and Genecards database were applied to screen the relevant targets of emodin or liver fibrosis. The essential target was selected by using Cytoscape to analyze the topological network of potential targets. Furthermore, we constructed a preliminary molecule docking study to explore the binding site by Surflex-Dock suite SYBYL X 2.0. The DAVID database was selected for gene functional annotations and KEGG enrichment analysis. Moreover, we demonstrated the ameliorating effect of emodin on carbon tetrachloride (CCl4 )-induced liver injury in mice. We also verified the network predictions in vitro via various techniques.

RESULTS

The collected results showed that 35 targets were related to emodin, and 6,198 targets were associated with liver fibrosis. The Venn analysis revealed that 17 intersection targets were correlated with emodin anti-liver fibrosis. The topological network analysis suggested that the p53 was the remarkable crucial target. Besides, the molecule docking results showed that emodin could directly interact with p53 by binding the active site residues ASN345, GLN331, and TYR347. Finally, KEGG pathway enrichment results indicated that essential genes were mainly enriched in mitogen-activated protein kinase (MAPK) signaling pathways. Moreover, our study confirmed that emodin alleviated CCl4 -induced liver injury in mice, inducing hepatic stellate cells (HSCs) apoptosis via regulating the p53/ERK/p38 axis.

CONCLUSIONS

This study partially verified the network pharmacological prediction of emodin inducing HSCs cell apoptosis through the p53/ERK/p38 axis.

Anthraquinones from Aloe spp. inhibit Cryptococcus neoformans sensu stricto: effects against growing and mature biofilms

This study aimed to evaluate the in vitro effect of aloe emodin, barbaloin and chrysophanol on growing and mature biofilms of Cryptococcus neoformans sensu stricto. The compounds were added at the moment of inducing biofilm growth or after growth for 72 h to evaluate their effects on growing and mature biofilms, respectively. Then, biofilm biomass was evaluated by crystal violet staining and metabolic activity by the XTT reduction assay. Morphological alterations were also evaluated by laser scanning confocal microscopy. Aloe emodin and barbaloin affected growing biofilms and disrupted mature biofilms, reducing metabolic activity by > 60% and biomass by > 70%. Chrysophanol only inhibited mature biofilms, but to a lesser extent. In conclusion, anthraquinones, especially aloe emodin and barbaloin, show a relevant effect against growing and mature biofilms of C. neoformans sensu stricto.

Emodin Alleviates Intestinal Barrier Dysfunction by Inhibiting Apoptosis and Regulating the Immune Response in Severe Acute Pancreatitis

OBJECTIVE

The intestinal barrier injury caused by severe acute pancreatitis (SAP) can induce enterogenous infection, further aggravating the inflammatory reactions and immune responses. This study aimed to test the hypothesis that emodin protects the intestinal function and is involved in the immune response in SAP.

METHODS

The network pharmacology was established using the Swiss target prediction and pathway enrichment analysis. The SAP mice model was induced by cerulein (50 μg/kg) and lipopolysaccharide (10 mg/kg) hyperstimulation. The pharmacological effect of emodin in treating SAP was evaluated at mRNA and protein levels by various methods.

RESULTS

The network analysis provided the connectivity between the targets of emodin and the intestinal barrier-associated proteins and predicted the BAX/Bcl-2/caspase 3 signaling pathway. Emodin alleviated the pathological damages to the pancreas and intestine and reduced the high concentrations of serum amylase and cytokines in vivo. Emodin increased the expression of intestinal barrier-related proteins and reversed the changes in the apoptosis-related proteins in the intestine. Simultaneously, emodin regulated the ratio of T helper type 1 (TH1), TH2, TH17, γδ T cells, and interferon γ/interleukin 17 producing γδ T cells.

CONCLUSIONS

These findings partly verified the mechanism underlying the regulation of the intestinal barrier and immune response by emodin.

Protective effects of Da-cheng-qi decoction in rats with intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH), the most fatal subtype of stroke, has no disease-modifying treatment. Da-cheng-qi decoction (DCQ), composed of rhubarb, is one of the most commonly used Chinese traditional decoctions in ICH treatment. But the mechanism is not clear. Emodin is an active compound found in rhubarb.

PURPOSE

To study the protective effects of DCQ on ICH and its possible mechanisms of action.

METHODS

The ICH model was reproduced by injecting collagenase-VII into the left caudate putamen (CPu) of rats. DCQ and emodin were used to treat the ICH rats for 7 days. Behavior tests, proteomic analysis, morphological studies, and western blotting were performed.

RESULTS

The neurological deficits in the ICH rats recovered with DCQ and emodin on the 14^th day after ICH. The proteomics data revealed that DCQ significantly corrected the pathological signals in the CPu and hippocampus after ICH. The numbers of amoebic microglia in the CPu and M2 microglia in both CPu and hippocampus were significantly increased after DCQ and emodin treatment. The increase in GluN2B-containing NMDA receptor (NR2B) and postsynaptic density protein-95, activation of mitogen-activated protein kinase (MAPK) signals in the CPu, and secondary neurodegeneration (SND) in the hippocampus were significantly recovered in DCQ-treated rats. Inhibition of MAPK p38 (p38) in the hippocampus was observed after DCQ and emodin treatment.

CONCLUSION

The protective effects of DCQ on ICH were confirmed in this study, and its mechanism may be related to the inhibition of MAPK and activation of M2 microglia. These results are beneficial to the development of ICH therapeutic targets.

Emodin Attenuates Acetaminophen-Induced Hepatotoxicity via the cGAS-STING Pathway

Emodin is a natural bioactive compound from traditional Chinese herbs that exerts anti-inflammatory, antioxidant, anticancer, hepatoprotective, and neuroprotective effects. However, the protective effects of emodin in acetaminophen (APAP)-induced hepatotoxicity are not clear. The present study examined the effects of emodin on APAP-induced hepatotoxicity and investigated the potential molecular mechanisms. C57BL/6 mice were pretreated with emodin (15 and 30 mg/kg) for 5 consecutive days and then given APAP (300 mg/kg) to establish an APAP-induced liver injury model. Mice were sacrificed to detect the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and albumin (ALB) and the liver tissue levels of glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD). Histological assessment, Western blotting, and ELISA were performed. Emodin pretreatment significantly reduced the levels of ALT, AST, and ALP; increased the levels of ALB; alleviated hepatocellular damage and apoptosis; attenuated the exhaustion of GSH and SOD and the accumulation of MDA; and increased the expression of antioxidative enzymes, including nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and NAD(P)H quinone dehydrogenase 1 (NQO1). Emodin also inhibited the expression of NLRP3 and reduced the levels of pro-inflammatory factors, including interleukin-1 beta (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α). Emodin inhibited interferon (IFN)-α, cyclic GMP-AMP synthase (cGAS), and its downstream signaling effector stimulator of interferon genes (STING) expression to protect the liver against APAP-induced inflammatory responses and apoptosis. These results suggest that emodin protected hepatocytes from APAP-induced liver injury via the upregulation of the Nrf2-mediated antioxidative stress pathway, the inhibition of the NLRP3 inflammasome, and the downregulation of the cGAS-STING signaling pathway.

Physcion Induces Potential Anticancer Effects in Cervical Cancer Cells

BACKGROUND

The extent of morphological and ultrastructural changes in HeLa cells was assessed by optical, fluorescence and electron microscopy after exposure to various concentrations of physcion, taking into account the biological properties of the test compound.

METHODS

Cell viability was assessed by MTT assay, while the cell cycle, LC3 expression, apoptosis, change of mitochondrial potential, Bcl-2 protein expression level and the level of reactive oxygen species were analyzed by flow cytometry.

RESULTS

As a result of physcion encumbrance, concentration-dependent inhibition of HeLa cell viability and the G0/G1 phase of the cell cycle was observed. Activation of the lysosomal system was also revealed, which was expressed by an increased number of lysosomes, autophage vacuoles and increased expression of the LC3 protein, a marker of the autophagy process. Transmission electron microscopy and fluorescence microscopy showed that physcion induced clear changes in cervical cancer cells, especially in the structure of the nucleus and mitochondria, which correlated with the production of reactive oxygen species by the test compound and indicated the induction of the oxidative process. At the same time, the pro-apoptotic effect of physcion was demonstrated, and this mechanism was dependent on the activation of caspases 3/7 and the reduction in Bcl-2 protein expression.

CONCLUSION

The obtained results indicate an antitumor mechanism of action of physcion, based on the induction of oxidative stress, autophagy and apoptosis.

Emodin resists to Cyprinid herpesvirus 3 replication via the pathways of Nrf2/Keap1-ARE and NF-κB in the ornamental koi carp (Cyprinus carpio haematopterus)

Cyprinid herpesvirus 3 (CyHV-3) causes high mortality in carp. Emodin has been shown of the effects of antioxidant, anti-inflammatory and antiviral. In present study, we investigated the preventive effects and mechanism of emodin on CyHV-3 infection. The ornamental koi carp (Cyprinus carpio haematopterus) were intraperitoneally injected with emodin (10 mg/kg, 20 mg/kg, or 40 mg/kg). 72 h later, an intraperitoneal injection of CyHV-3 was administered, and collected the samples one week later to detect the antioxidant parameters, antioxidant genes, inflammatory genes and to perform histopathology assays. The results showed that emodin significantly suppressed CyHV-3 replication (P < 0.05), improved the koi survival rate and slowed the damage caused by CyHV-3. Emodin treatment increased the antioxidant activity and decreased the lipid peroxidation level of the koi. Compared to the CyHV-3 group, emodin treatment resulted in the same antioxidant parameters after CyHV-3 infection. Emodin treatment activated the Nuclear factorery throid 2-related factor 2/Kelch-like ECH-associated protein 1-antioxidatant response element (Nrf2/Keap1-ARE) pathway and upregulated the expression of heme oxygenase 1 (HO-1), superoxide dismutase (SOD), and catalase (CAT) in the hepatopancreas after CyHV-3 infection. Emodin activated the nuclear factor kappa-B (NF-κB) pathway and decreased the expression of interleukin-6 (IL-6), interleukin-8 (IL-8), and tumour necrosis factor-α (TNF-α) in the koi induced by CyHV-3. In conclusion, emodin treatment can suppress CyHV-3 replication and reduce the mortality of koi caused by CyHV-3. Emodin improves antioxidant function, relieves oxidative stress and inflammation cytokines via Nrf2/Keap1-ARE and NF-κB pathways, and protects against the adverse effects induced by CyHV-3.

Emodin inhibits viability, proliferation and promotes apoptosis of hypoxic human pulmonary artery smooth muscle cells via targeting miR-244-5p/DEGS1 axis

OBJECTIVE

This study aimed to determine the effects of emodin on the viability, proliferation and apoptosis of human pulmonary artery smooth muscle cells (PASMCs) under hypoxia and to explore the underling molecular mechanisms.

METHODS

PASMCs were cultured in a hypoxic environment (1% oxygen) and then treated with emodin. Cell viability, proliferation and apoptosis were evaluated using CCK-8 assay, EdU staining assay, western blot and Mito-tracker red CMXRos and Annexin V-FITC apoptosis detection assay. The microRNA (miRNA)/mRNA and protein expression levels were assessed by quantitative real-time PCR and western blotting, respectively. Based on transcriptomics and proteomics were used to identify potential signaling pathways. Luciferase reporter assay was utilized to examine the interaction between miR-244-5p and DEGS1.

RESULTS

Emodin at 40 and 160 µM concentration-dependently suppressed cell viability, proliferation and migration, but enhanced cell apoptosis of PASMCs under hypoxia. Transcriptomic and proteomic analysis revealed that emodin could attenuate the activity of PI3K/Akt signaling in PASMCs under hypoxia. In addition, delta 4-desaturase, sphingolipid 1 (DEGS1) was found to be a direct target of miR-244-5p. Emodin could significantly up-regulated miR-244-5p expression and down-regulated DEGS1 expression in PASMCs under hypoxia. Furthermore, emodin-mediated effects on cell viability, migration, apoptosis and PI3K/Akt signaling activity of PASMCs under hypoxia were significantly attenuated by miR-244-5p knockdown.

CONCLUSIONS

Our results indicated that emodin suppressed cell viability, proliferation and migration, promoted cell apoptosis of PASMCs under hypoxia via modulating miR-244-5p-mediated DEGS1/PI3K/Akt signaling pathway. MiR-244-5p/DEGS1 axis was initially investigated in this current study, which is expected to further the understanding of the etiology of pulmonary arterial hypertension.

CK2α/CSNK2A1 Induces Resistance to Doxorubicin through SIRT6-Mediated Activation of the DNA Damage Repair Pathway

CK2α/CSNK2A1 is involved in cancer progression by phosphorylating various signaling molecules. Considering the role of CSNK2A1 in cancer progression and the phosphorylation of SIRT6 and the role of SIRT6 in chemoresistance through the DNA damage repair pathway, CSNK2A1 and SIRT6 might be involved in resistance to conventional anti-cancer therapies. We evaluated the expression of CSNK2A1 and phosphorylated SIRT6 in the 37 osteosarcoma patients and investigated the effects of CSNK2A1 and the phosphorylation of SIRT6 on Ser338 on resistance to the anti-cancer effects of doxorubicin. Higher expression of CSNK2A1 and phosphorylated SIRT6 was associated with shorter survival in osteosarcoma patients. U2OS and KHOS/NP osteosarcoma cells with induced overexpression of CSNK2A1 were resistant to the cytotoxic effects of doxorubicin, and the knock-down of CSNK2A1 potentiated the cytotoxic effects of doxorubicin. CSNK2A1 overexpression-mediated resistance to doxorubicin was associated with SIRT6 phosphorylation and the induction of the DNA damage repair pathway molecules. CSNK2A1- and SIRT6-mediated resistance to doxorubicin in vivo was attenuated via mutation of SIRT6 at the Ser338 phosphorylation site. Emodin, a CSNK2A1 inhibitor, potentiated the cytotoxic effects of doxorubicin in osteosarcoma cells. This study suggests that blocking the CSNK2A1-SIRT6-DNA damage repair pathway might be a new therapeutic stratagem for osteosarcomas.

Natural-derived compounds and their mechanisms in potential autosomal dominant polycystic kidney disease (ADPKD) treatment

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is a monogenic kidney disorder that impairs renal functions progressively leading to kidney failure. The disease affects between 1:400 and 1:1000 ratio of the people worldwide. It is caused by the mutated PKD1 and PKD2 genes which encode for the defective polycystins. Polycystins mimic the receptor protein or protein channel and mediate aberrant cell signaling that causes cystic development in the renal parenchyma. The cystic development is driven by the increased cyclic AMP stimulating fluid secretion and infinite cell growth. In recent years, natural product-derived small molecules or drugs targeting specific signaling pathways have caught attention in the drug discovery discipline. The advantages of natural products over synthetic drugs enthusiast researchers to utilize the medicinal benefits in various diseases including ADPKD.

CONCLUSION

Overall, this review discusses some of the previously studied and reported natural products and their mechanisms of action which may potentially be redirected into ADPKD.

Chaiqin chengqi decoction ameliorates acute pancreatitis in mice via inhibition of neuron activation-mediated acinar cell SP/NK1R signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Chaiqin chengqi decoction (CQCQD) and its derivatives have been widely used in China for the early management of patients with acute pancreatitis (AP). Numerous studies demonstrate the anti-inflammatory and anti-oxidative effects of CQCQD and derivatives, but whether these effects can be attributed to suppressing neurogenic inflammation, has never been studied.

AIM OF THE STUDY

To investigate the effects of CQCQD on substance P (SP)-neurokinin 1 receptor (NK1R) based neurogenic inflammation in an experimental AP model.

MATERIAL AND METHODS

For AP patients on admission, pain score was accessed by visual analog scale (VAS); the levels of serum SP and expressions of pancreatic SP and NK1R were also determined. For in vivo study, mice received 7 intraperitoneal injections of cerulein (50 μg/kg) at hourly intervals to induce AP, whilst controls received normal saline injections. In the treatment groups, CQCQD (10 g/kg, 200 μl) was intragastrically given at the third, fifth, and seventh of the cerulein injection or the NK1R antagonist CP96345 (5 mg/kg) was intraperitoneally injected 30 min before the first cerulein administration. The von Frey test was performed to evaluate pain behavior. Animals were sacrificed at 12 h from the first cerulein/saline injection for severity assessment. Pharmacology network analysis was used to identify active ingredients of CQCQD for AP and pain. In vitro, freshly isolated pancreatic acinar cells were pre-treated with CQCQD (5 mg/ml), CP96345 (1 μM), or selected active compounds of CQCQD (12.5, 25, and 50 μM) for 30 min, followed by SP incubation for another 30 min.

RESULTS

The VAS score as well as the levels of serum SP and expressions of pancreatic SP-NK1R were up-regulated in moderately severe and severe patients compared with those with mild disease. CQCQD, but not CP96345, consistently and significantly ameliorated pain, pancreatic necrosis, and systemic inflammation in cerulein-induced AP as well as inhibited NK1R internalization of pancreatic acinar cells. These effects of CQCQD were associated with reduction of pancreatic SP-NK1R and neuron activity in pancreas, dorsal root ganglia, and spinal cord. Baicalin, emodin, and magnolol, the top 3 active components of CQCQD identified via pharmacology network analysis, suppressed NK1R internalization and NF-κB signal pathway activation in isolated pancreatic acinar cells.

CONCLUSIONS

CQCQD ameliorated cerulein-induced AP and its associated pain via inhibiting neuron activation-mediated pancreatic acinar cell SP-NK1R signaling pathways and its active compounds baicalin, emodin, and magnolol contributed to this effect.

Emodin from Aloe Inhibits Porcine Reproductive and Respiratory Syndrome Virus via Toll-Like Receptor 3 Activation

Porcine reproductive and respiratory syndrome virus (PRRSV) causes severe reproductive failure in sows and respiratory diseases in growing and finishing pigs and results in great economic losses to the swine industry. Although vaccines are available, PRRSV remains a major threat to the pig farms. Thus, there is an urgent need to develop antiviral drugs to compensate for vaccines. In this study, we report that Aloe extract (Ae) can strongly inhibit PRRSV in Marc-145 cells and porcine alveolar macrophages lines (iPAMs) in vitro. Furthermore, we identified a novel anti-PRRSV molecule, Emodin, from Ae by high-performance liquid chromatography (HPLC). Emodin exerted its inhibitory effect through targeting the whole stages of PRRSV infectious cycle. Moreover, we also found that Emodin can inactivate PRRSV particles directly. Notably, we confirmed that Emodin was able to significantly induce Toll-like receptor 3 (TLR3) (p < 0.01), IFN-α (p < 0.05) and IFN-β expression in iPAMs, indicating that induction of antiviral agents via TLR3 activation by Emodin might contribute to its anti-PRRSV effect. These findings imply that the Emodin from Aloe could hamper the proliferation of PRRSV in vitro and might constitute a new approach for treating PRRSV infection.

Emodin alleviates LPS-induced myocardial injury through inhibition of NLRP3 inflammasome activation

Myocardial injury and cardiovascular dysfunction are serious consequences of sepsis and contribute to high mortality. Currently, the pathogenesis of myocardial injury in sepsis is still unclear, and therapeutic approaches are limited. In this study, we investigated the protective effect of emodin on septic myocardial injury and the underlying mechanism. Lipopolysaccharide (LPS)-induced C57BL/6 mice and cardiomyocytes were used as models of sepsis in vivo and in vitro, respectively. The results showed that emodin alleviated cardiac dysfunction, myocardial injury and improved survival rate in LPS-induced septic mice. Emodin attenuated the levels of inflammatory cytokines and cardiac inflammation induced by LPS. Emodin reduced NOD-like receptor protein 3 (NLRP3) and Gasdermin D (GSDMD) expression in the heart tissue of LPS-induced septic mice. In vitro, emodin alleviated LPS-induced cell injury and inflammation in cardiomyocytes by inhibiting NLRP3 inflammasome activation. In addition, an NLRP3 inhibitor was used to further confirm the function of the NLRP3 inflammasome in LPS-induced myocardial injury. Taken together, our findings suggest that emodin improves LPS-induced myocardial injury and cardiac dysfunction by alleviating the inflammatory response and cardiomyocyte pyroptosis by inhibiting NLRP3 inflammasome activation, which provides a feasible strategy for preventing and treating myocardial injury in sepsis.

Assessment of the anti-inflammatory effects of three rhubarb anthraquinones in LPS-Stimulated RAW264.7 macrophages using a pharmacodynamic model and evaluation of the structure-activity relationships

ETHNOPHARMACOLOGICAL RELEVANCE

Rhubarb (Rhei Radix et Rhizoma) is a traditional Chinese medicine, has been used as a strong astringent in China to treat inflammation-related diseases, such as acute pancreatitis, acute cholecystitis, appendicitis and so on. Rhein, emodin and aloe-emodin are the important active anthraquinone in rhubarb, and are considered to be the main ingredients contributing to anti-inflammatory.

AIM OF THE STUDY

Rhein, emodin and aloe-emodin, anthraquinones with the same parent structure that are found in rhubarb, have beneficial anti-inflammatory effects in vitro and in vivo. Anthraquinone derivatives also have important clinical roles. However, their pharmacodynamic differences and the structure-activity relationships associated with their anti-inflammatory properties have not been systematically explored. The present study was designed to quantify the effects of three rhubarb anthraquinones on inflammation and to explore the structure-activity relationships of these compounds.

MATERIALS AND METHODS

In this study, we detected NF-κB phosphorylation, iNOS protein expression, and IL-6 and NO production in LPS-stimulated RAW264.7 cells and then calculated median effect equations and built a dynamic pharmacodynamic model to quantitatively evaluate the efficacy of these three anthraquinones. Additionally, to determine the structure-activity relationships, we investigated the physicochemical properties and molecular electrostatic potentials of the drug molecules.

RESULTS

We found that rhein, emodin, and aloe-emodin exerted at least dual-target (NF-κB, iNOS) inhibition of LPS-induced inflammatory responses. Compared with rhein and emodin, aloe-emodin had a stronger anti-inflammatory effect, and its inhibition of iNOS protein expression was approximately twice that of NF-κB phosphorylation. In addition, aloe-emodin had the strongest hydrophobic effect among the three anthraquinones.

CONCLUSIONS

Overall, we concluded that the receptor binding the rhubarb anthraquinones had a hydrophobic pocket. Anthraquinone molecules with stronger hydrophobic effects had higher affinity for the receptor, resulting in greater anti-inflammatory activity. These results suggest that the addition of a hydrophobic group is a potential method for structural modification to design anti-inflammatory anthraquinone derivatives with enhanced potency.

Revealing the therapeutic targets and molecular mechanisms of emodin-treated coronavirus disease 2019 via a systematic study of network pharmacology

Emodin has shown pharmacological effects in the treatment of infection with severe acute respiratory syndrome coronavirus-2, which leads to coronavirus disease 2019 (COVID-19). Thus, we speculated that emodin may possess anti-COVID-19 activity. In this study, using bioinformatics databases, we screened and harvested the candidate genes or targets of emodin and COVID-19 prior to the determination of pharmacological targets and molecular mechanisms of emodin against COVID-19. We discovered core targets for the treatment of COVID-19, including mitogen-activated protein kinase 1 (MAPK1), tumor protein (TP53), tumor necrosis factor (TNF), caspase-3 (CASP3), epidermal growth factor receptor (EGFR), vascular endothelial growth factor A (VEGFA), interleukin 1B (IL1B), mitogen-activated protein kinase 14 (MAPK14), prostaglandin-endoperoxide synthase 2 (PTGS2), B-cell lymphoma-2-like protein 1 (BCL2L1), interleukin-8 (CXCL8), myeloid cell leukemia-1 (MCL1), and colony stimulating factor 2 (CSF2). The GO analysis of emodin against COVID-19 mainly included cytokine-mediated signaling pathway, response to lipopolysaccharide, response to molecule of bacterial origin, developmental process involved in reproduction, and reproductive structure development. The KEGG results exhibited that the molecular pathways mainly included IL-17 signaling pathway, AGE-RAGE signaling pathway in diabetic complications, TNF signaling pathway, pertussis, proteoglycans in cancer, pathways in cancer, MAPK signaling pathway, NOD-like receptor signaling pathway, NF-kappa B signaling pathway, etc. Also, molecular docking results revealed the docking capability between emodin and COVID-19 and the potential pharmacological activity of emodin against COVID-19. Taken together, these findings uncovered the targets and pharmacological mechanisms of emodin for treating COVID-19 and suggested that the vital targets might be used as biomarkers against COVID-19.

Mechanistic insights into the anti-depressant effect of emodin: an integrated systems pharmacology study and experimental validation

Depression is a complex neuropsychiatric disease involved multiple targets and signaling pathways. Systems pharmacology studies could potentially present a comprehensive molecular mechanism to delineate the anti-depressant effect of emodin (EMO). In this study, we investigated the anti-depressant effects of EMO in the chronic unpredictable mild stress (CUMS) rat model of depression and gained insights into the underlying mechanisms using systems pharmacology and molecular simulation analysis. Forty-three potential targets of EMO for treatment of depression were obtained. GO biological process analysis suggested that the biological functions of these targets mainly involve the regulation of reactive oxygen species metabolic process, response to lipopolysaccharide, regulation of inflammatory response, etc. KEGG pathway enrichment analysis showed that the PI3K-Akt signaling pathway, insulin resistance, IL-17 signaling pathway were the most significantly enriched signaling pathways. The molecular docking analysis revealed that EMO might have a strong combination with ESR1, AKT1 and GSK3B. Immunohistochemical staining and Western blotting showed that 2 weeks' EMO treatment (80 mg/kg/day) reduced depression related microglial activation, neuroinflammation and altered PI3K-Akt signaling pathway. Our findings provide a systemic pharmacology basis for the anti-depressant effects of EMO.

Optimal combination of anti-inflammatory components from Chinese medicinal formula Liang-Ge-San

ETHNOPHARMACOLOGICAL RELEVANCE

Liang-Ge-San (LGS), a traditional Chinese medicine (TCM) formula, is usually used in acute inflammatory diseases in China.

AIM OF THE STUDY

This study aims to detect the optimal combination of anti-inflammatory components from LGS.

MATERIALS AND METHODS

Four mainly representative components (phillyrin, emodin, baicalin, and liquiritin) from LGS were chosen. The optimal combination was investigated by orthogonal design study. Zebrafish inflammation model was established by lipopolysaccharide (LPS)-yolk microinjection, and then the anti-inflammatory activities of different combinations were determined by survival analysis, changes on inflammatory cells infiltration, the MyD88/NF-κB and MAPK pathways and inflammatory cytokines production.

RESULTS

The different combinations of bioactive ingredients from LGS significantly protected zebrafish from LPS-induced inflammation, as evidenced by decreased recruitment of macrophages and neutrophils, inhibition of the MyD88/NF-κB and MAPK pathways and down-regulation of TNF-α and IL-6. Among them, the combination group 8 most significantly protected against LPS. The combination of group 8 is: 0.1 μM of emodin, 2 μM of baicalin, 20 μM of phillyrin and 12.5 μM of liquiritin.

CONCLUSION

The optimized combination group 8 exerts the most significant anti-inflammatory activity by inhibiting the recruitment of inflammatory cells, activation of the MyD88/NF-κB and MAPK pathways and the secretion of pro-inflammatory cytokines. This present study provides pharmacological evidences for the further development of new modern Chinese drug from LGS to treat acute inflammatory diseases, but indicated the use of zebrafish in the screening of components from formulas.

Emodin protects knee joint cartilage in rats through anti-matrix degradation pathway: An in vitro and in vivo study

AIMS

Osteoarthritis (OA) is a common joint disease and the main cause of disability. We sought to determine the effective concentration of emodin on chondrocytes and to identify the dosage of emodin that induces a comparable therapeutic effect with the COX-2 inhibitor drug, celecoxib that is currently used to treat OA.

MATERIAL AND METHODS

In vitro experiments induced inflammation of chondrocytes by IL-1β, and an osteoarthritis model was established in vivo by cutting rat anterior cruciate ligament. Western Blot, Real-time PCR, HE staining, Safranin O-green staining and immunohistochemistry were performed to detect MMP-3, MMP-13, ADAMTS-4, iNOS and COL2A1 on the chondrocytes or the tibial plateau. The cytokine activity and content in serum of six groups of rats were measured by kit.

RESULTS

It was found that the surface layer of the cartilage was thicker and smoother after the administration of emodin. Tissue expression of MMP-3, MMP-13, ADAMTS-4 and iNOS were significantly (p < 0.05) decreased in chondrocytes and cartilage treated with different doses of emodin, and the content of COL2A1 was reversed. Emodin also significantly decreased the blood levels of COX-2 and PGE2. The effective emodin in vitro was 5 μmol/L, whereas emodin at 80 mg/kg was equivalent to celecoxib in vivo.

CONCLUSION

Emodin reduces the expression of cartilage matrix degradation biomarkers, thereby reducing the degradation of cartilage matrix and protecting the knee joint cartilage. Emodin at 5 μmol/L shows the best concentration to treat chondrocytes, and the protective effect of emodin at 80 mg/kg is comparable to that of celecoxib.

Physcion, a novel inhibitor of 5α-reductase that promotes hair growth in vitro and in vivo

Androgenic alopecia (AGA) has a high incidence. Excess dihydrotestosterone in blood capillaries, which is converted from testosterone by 5α-reductase, is an AGA causative factor. We identified the inhibitory activity of four Polygonum multiflorum compounds against 5α-reductase via high-performance liquid chromatography, and the results showed that Physcion was a potent 5α-reductase inhibitor. Additionally, we found that through inhibiting 5α-reductase expression, Physcion could shorten the time of dorsal skin darkening and hair growth, improve hair follicle morphology, and significantly increase hair follicle count. Eventually, through molecular docking study, we found the binding energy and molecular interactions between Physcion and 5α-reductase type II. These results suggested that Physcion is a potent 5α-reductase inhibitor, as well as a new natural medicine for treating AGA.

Emodin attenuates silica-induced lung injury by inhibition of inflammation, apoptosis and epithelial-mesenchymal transition

Silicosis is a fatal pulmonary disease caused by the inhalation of silica dust, and characterized by inflammation and fibrosis of the lung, with no effective treatment to date. Here we investigate the effect of emodin, an anthraquinone derivative isolated from rhubarb using a mouse silicosis model and in vitro cultured human macrophages and alveolar epithelial cells. Results from histological examination indicated that emodin reduced the degree of alveolitis and fibrosis in the lungs of mice exposed to silica particles. We also demonstrated that emodin effectively inhibited the phosphorylation of Smad3 and NF-κB and reduced the levels of inflammatory factors in the lung tissue of mice treated with silica particles. In addition, we found that emodin inhibited apoptosis and demonstrated an anti-fibrotic effect by down-regulating the pro-apoptotic protein Bax and up-regulating the anti-apoptotic protein Bcl-2. Furthermore, emodin increased E-cadherin levels, reduced the expression of Vimentin, α-SMA and Col-I, as well as pro-inflammatory factors TGF-β1, TNF-α and IL-1β in vivo and in vitro. These results suggested that emodin can regulate epithelial-mesenchymal transition (EMT) through the inhibition of the TGF-β1/Smad3 signaling pathway and the NF-κB signaling pathway to prevent alveolar inflammation and apoptotic process. Overall, this study showed that emodin can alleviate pulmonary fibrosis in silicosis through regulating the inflammatory response and fibrotic process at multiple levels.

Antitumor Effects of Self-Assembling Peptide-Emodin in situ Hydrogels in vitro and in vivo

PURPOSE

To study the in vitro and in vivo antitumor effects of the colloidal suspension-in situ hydrogel of emodin (EM) constructed with the self-assembling peptide RADA16-I and systematically evaluate the feasibility of the delivery system.

METHODS

The MTT and colony-formation assays were used to determine the viability of normal cells NCTC 1469 and tumor cells Hepa1-6. The uptake of EM in the RADA16-I-EM in situ hydrogel by tumor cells was analyzed by laser confocal microscope and flow cytometry. Flow cytometry was used to detect the cell apoptosis and cell cycle distribution. Transwell assay was used to detect the migration and invasion of tumor cells. The antitumor efficacy of the RADA16-I-EM in situ hydrogel and its toxic effects was further assessed in vivo on Hepa1-6 tumor-bearing C57 mice.

RESULTS

The results showed that the RADA16-I-EM in situ hydrogels could obviously reduce the toxicity of EM to normal cells and the survival of tumor cells. The uptake of EM by the cells from the hydrogels was obviously increased and could significantly induce apoptosis and arrest cell cycle in the G2/M phase, and reduce the migration, invasion and clone-formation ability of the cells. The RADA16-I-EM in situ hydrogel could also effectively inhibit the tumor growth and obviously decrease the toxic effects of EM on normal tissues in vivo.

CONCLUSION

Our results demonstrated that RADA16-I has the potential to be a carrier for the hydrophobic drug EM and can effectively improve the delivery of hydrophobic antitumor drugs with enhanced antitumor effects and reduced toxic effects of the drugs on normal cells and tissues.

Physcion, a tetra-substituted 9,10-anthraquinone, prevents homocysteine-induced endothelial dysfunction by activating Ca2+- and Akt-eNOS-NO signaling pathways

BACKGROUND

Homocysteine (Hcy) induced vascular endothelial dysfunction is known to be closely associated with oxidative stress and impaired NO system. 1,8-Dihydroxy-3-methoxy-6-methylanthracene-9,10-dione (physcion) has been known to has antioxidative and anti-inflammatory properties.

PURPOSE

The purpose of the present study was to define the protective effect of physcion on Hcy-induced endothelial dysfunction and its mechanisms involved.

STUDY DESIGN AND METHODS

Hyperhomocysteinemia (HHcy) rat model was induced by feeding 3% methionine. A rat thoracic aortic ring model was used to investigate the effects of physcion on Hcy-induced impairment of endothelium-dependent relaxation. Two doses, low (L, 30 mg/kg/day) and high (H, 50 mg/kg/day) of physcion were used in the present study. To construct Hcy-injured human umbilical vein endothelial cells (HUVECs) model, the cells treated with 3 mM Hcy. The effects of physcion on Hcy-induced HUVECs cytotoxicity and apoptosis were studied using MTT and flow cytometry. Confocal analysis was used to determine the levels of intracellular Ca2+. The levels of protein expression of the apoptosis-related markers Bcl-2, Bax, caspase-9/3, and Akt and endothelial nitric oxide synthase (eNOS) were evaluated by western blot.

RESULTS

In the HHcy rat model, plasma levels of Hcy and malondialdehyde (MDA) were elevated (20.45 ± 2.42 vs. 4.67 ± 1.94 μM, 9.42 ± 0.48 vs. 3.47 ± 0.59 nM, p < 0.001 for both), whereas superoxide dismutase (SOD) and nitric oxide (NO) levels were decreased (77.11 ± 4.78 vs. 115.02 ± 5.63 U/ml, 44.51 ± 4.45 vs. 64.18 ± 5.34 μM, p < 0.001 and p < 0.01, respectively). However, treatment with physcion significantly reversed these changes (11.82 ± 2.02 vs. 20.45 ± 2.42 μM, 5.97 ± 0.72 vs. 9.42 ± 0.48 nM, 108.75 ± 5.65 vs. 77.11 ± 4.78 U/ml, 58.14 ± 6.02 vs. 44.51 ± 4.45 μM, p < 0.01 for all). Physcion also prevented Hcy-induced impairment of endothelium-dependent relaxation in HHcy rats (1.56 ± 0.06 vs. 15.44 ± 2.53 nM EC50 for ACh vasorelaxation, p < 0.05 vs. HHcy). In Hcy-injured HUVECs, physcion inhibited the impaired viability, apoptosis and reactive oxygen species. Hcy treatment significantly increased the protein phosphorylation levels of p38 (2.26 ± 0.20 vs. 1.00 ± 0.12, p <0.01), ERK (2.11 ± 0.21 vs. 1.00 ± 0.11, p <0.01) and JNK. Moreover, physcion reversed the Hcy-induced apoptosis related parameter changes such as decreased mitochondrial membrane potential (MMP) and Bcl-2/Bax protein ratio, and increased protein expression of caspase-9/3 in HUVECs. Furthermore, the downregulation of Ca2+, Akt, eNOS and NO caused by Hcy were recovered with physcion treatment in HUVECs.

CONCLUSION

Physcion prevents Hcy-induced endothelial dysfunction by activating Ca2+- and Akt-eNOS-NO signaling pathways. This study provides the first evidence that physcion might be a candidate agent for the prevention of cardiovascular disease induced by Hcy.

Physcion 8-O-β-glucopyranoside ameliorates liver fibrosis through inflammation inhibition by regulating SIRT3-mediated NF-κB P65 nuclear expression

Physcion 8-O-β-glucopyranoside (PSG), an anthraquinone extracted from Rumex japonicus Houtt, has various pharmacological effects, however, the effect of PSG on liver fibrosis and its related mechanism remain to be determined. We here showed that PSG ameliorated liver injury and liver fibrosis, decreased collagen deposition and inhibited inflammation in carbon tetrachloride (CCl4)-induced rats. Consistent with the in vivo results, PSG suppressed the transforming growth factor-β1 (TGF-β1)-induced cell viability, liver fibrosis and secretion of inflammatory factors in hepatic stellate cells (HSCs). Interestingly, PSG increased the enzyme activity and promoter activity of sirtuin 3 (SIRT3) in fibrotic liver and activated HSCs. In addition, PSG notably increased the mRNA and protein expression of SIRT3 both in vivo and in vitro. Depletion of SIRT3 either by using 3-TYP (SIRT3 selective inhibitor) or SIRT3 siRNA attenuated the anti-inflammatory effect of PSG in activated HSCs. Further study found that TGF-β1 increased the nuclear expression of NF-κB p65, but showed no obvious effect on the total NF-κB p65 expression. Compared to the control adenovirus (Ad.mk), overexpression of SIRT3 by infecting adenovirus encoding SIRT3 (Ad.SIRT3) notably decreased the nuclear expression of NF-κB p65 in activated HSCs. Our results demonstrated that PSG attenuated inflammation by regulating SIRT3-mediated NF-κB P65 nuclear expression in liver fibrosis, providing novel molecular insights into the anti-fibrotic effect of PSG.

Emodin Improves Glucose and Lipid Metabolism Disorders in Obese Mice via Activating Brown Adipose Tissue and Inducing Browning of White Adipose Tissue

BACKGROUND

Adipose tissue (e.g. white, brown and brite) plays a critical role in modulating energy metabolism. Activating brown adipose tissue (BAT) and inducing browning in white adipose tissue (WAT) has been proposed to be a potential molecular target for obesity treatment. Emodin is a natural anthraquinone derivative that exhibits variety of pharmacologic effects including lowering lipids and regulating glucose utilization. However, the underlying mechanism of action is still unclear. In the present study, we investigated whether emodin could alleviate obesity via promoting browning process in adipose tissue.

METHODS

C57BL/6J mice were fed with high fat diet to induce obesity. Emodin at the doses of 40 and 80 mg/kg were orally given to obesity mice for consecutive 6 weeks. Parameters including fasting blood glucose, oral glucose tolerance, blood lipids, and the ratios of subcutaneous white adipose tissue (scWAT) or BAT mass to body weight, and morphology of adipose tissue were observed. Besides, the protein expression of uncoupling protein 1 (UCP1) and prohibitin in BAT and scWAT was determined by immunohistochemistry method. Relative mRNA expression of Cd137, transmembrane protein 26 (Tmem26) and Tbx1 in scWAT was analyzed using qRT-PCR. And the protein expression of UCP1, CD36, fatty acid transporter 4 (FATP4), peroxisome proliferator-activated receptor alpha (PPARα) and prohibitin of scWAT and BAT were analyzed using western blotting. In addition, ultra-high-performance liquid chromatography with electrospray ionization tandem mass spectrometry was utilized to detect the small lipid metabolites of scWAT and BAT.

RESULTS

Emodin decreased the body weight and food intake in HFD-induced obesity mice, and it also improved the glucose tolerance and reduced the blood lipids. Emodin treatment induced beiging of WAT, and more multilocular lipid droplets were found in scWAT. Also, emodin significantly increased markers of beige adipocytes, e.g. Cd137, Tmem26 and Tbx1 mRNA in scWAT, and UCP1, CD36, FATP4, PPARα and prohibitin protein expression in scWAT and BAT. Furthermore, emodin perturbed the lipidomic profiles in scWAT and BAT of obese mice. Emodin increased total ceramides (Cers), lysophosphatidylcholines (LPCs), lyso-phosphatidylcholines oxygen (LPCs-O), and phosphatidylethanolamines oxygen (PEs-O) species concentration in scWAT. Specifically, emodin significantly up-regulated levels of Cer (34:1), LPC (18:2), LPC-(O-20:2), PC (O-40:7), PE (O-36:3), PE (O-38:6), PE (O-40:6), and sphingolipid (41:0) [SM (41:0)], and down-regulated PC (O-38:0), PE (O-40:4), PE (O-40:5) in scWAT of obesity mice. In terms of lipid matabolites of BAT, the emodin remarkably increased the total PCs levels, which was driven by significant increase of PC (30:0), PC (32:1), PC (32:2), PC (33:4) and PC (38:0) species. In addition, it also increased species of LPCs, e.g. LPC (20:0), LPC (20:1), LPC (22:0), LPC (22:1), LPC (24:0), and LPC (24:1). Especially, emodin treatment could reverse the ratio of PC/PE in HFD-induced obese mice.

CONCLUSIONS

These results indicated that emodin could ameliorate adiposity and improve metabolic disorders in obese mice. Also, emodin could promote browning in scWAT and activate the BAT activities. In addition, emodin treatment-induced changes to the scWAT and BAT lipidome were highly specific to certain molecular lipid species, indicating that changes in tissue lipid content reflects selective remodeling in scWAT and BAT of both glycerophospholipids and sphingolipids in response to emodin treatment.

Emodin-Conjugated PEGylation of Fe3O4 Nanoparticles for FI/MRI Dual-Modal Imaging and Therapy in Pancreatic Cancer

BACKGROUND

Pancreatic cancer (PC) remains a difficult tumor to diagnose and treat. It is often diagnosed as advanced by reason of the anatomical structure of the deep retroperitoneal layer of the pancreas, lack of typical symptoms and effective screening methods to detect this malignancy, resulting in a low survival rate. Emodin (EMO) is an economical natural product with effective treatment and few side effects of cancer treatment. Magnetic nanoparticles (MNPs) can achieve multiplexed imaging and targeted therapy by loading a wide range of functional materials such as fluorescent dyes and therapeutic agents.

PURPOSE

The purpose of this study was to design and evaluate a multifunctional theranostic nanoplatform for PC diagnosis and treatment.

METHODS

In this study, we successfully developed EMO-loaded, Cy7-functionalized, PEG-coated Fe₃O₄ (Fe₃O₄-PEG-Cy7-EMO). Characteristics including morphology, hydrodynamic size, zeta potentials, stability, and magnetic properties of Fe₃O₄-PEG-Cy7-EMO were evaluated. Fluorescence imaging (FI)/magnetic resonance imaging (MRI) and therapeutic treatment were examined in vitro and in vivo.

RESULTS

Fe₃O₄-PEG-Cy7-EMO nanoparticles had a core size of 9.9 ± 1.2 nm, which showed long-time stability and FI/MRI properties. Bio-transmission electron microscopy (bio-TEM) results showed that Fe₃O₄-PEG-Cy7-EMO nanoparticles were endocytosed into BxPC-3 cells, while few were observed in hTERT-HPNE cells. Prussian blue staining also confirmed that BxPC-3 cells have a stronger phagocytic ability as compared to hTERT-HPNE cells. Additionally, Fe₃O₄-PEG-Cy7-EMO had a stronger inhibition effect on BxPC-3 cells than Fe₃O₄-PEG and EMO. The hemolysis experiment proved that Fe₃O₄-PEG-Cy7-EMO can be used in vivo experiments. In vivo analysis demonstrated that Fe₃O₄-PEG-Cy7-EMO enabled FI/MRI dual-modal imaging and targeted therapy in pancreatic tumor xenografted mice.

CONCLUSION

Fe₃O₄-PEG-Cy7-EMO may serve as a potential theranostic nanoplatform for PC.