Esculin ameliorates cognitive impairment in experimental diabetic nephropathy and induces anti-oxidative stress and anti-inflammatory effects via the MAPK pathway

Esculin alleviates lipopolysaccharide (LPS)-induced pneumonia by regulating the USP7/MAPK14 axis

Pneumonia is a serious and life-threatening lung inflammation with high morbidity and mortality. Accumulating evidence has suggested that esculin, a derivative of coumarin, possesses potent anti-inflammatory effects. This study is designed to explore the pharma role and underlying mechanism of esculin against lipopolysaccharides (LPS)-induced pneumonia. TC-1 cells were stimulated by LPS to mimic the inflammatory injury model in vitro. Cell viability, proliferation, and apoptosis were determined using MTT assay, 5-ethynyl-2'-deoxyuridine assay, and flow cytometry. Interleukin-1β and tumor necrosis factor α levels were analyzed using an enzyme-linked immunosorbent assay. Reactive oxygen species and superoxide dismutase were examined using special assay kits. Macrophage polarization was detected using flow cytometry. Mitogen-activated protein kinase 14 (MAPK14) level was detected by real-time quantitative polymerase chain reaction. MAPK14 and ubiquitin-specific protease 7 (USP7) protein levels were determined using western blot assay. After Ubibrowser database prediction, the interaction between USP7 and MAPK14 was verified using a Co-immunoprecipitation assay. The biological role of esculin was verified in LPS-challenged ALI mice in vivo. Here, we found that esculin significantly relieved LPS-induced TC-1 cell proliferation inhibition, and apoptosis, inflammatory response, oxidative stress, and M1-type macrophage polarization promotion. MAPK14 and USP7 expressions were enhanced in LPS-treated TC-1 cells, which was partly abolished by esculin treatment. Overexpressing MAPK14 attenuated the repression of esculin on LPS-triggered TC-1 cell injury. At the molecular level, USP7 interacted with MAPK14 and maintained its stability by removing ubiquitin. Moreover, esculin repressed the progression of pneumonia in vivo by regulating MAPK14. Taken together, esculin exposure could mitigate LPS-induced TC-1 cell injury partly by targeting the USP7/MAPK14 axis, providing a better understanding of the role of esculin in the anti-inflammatory therapeutics for pneumonia.

Antioxidant and anti‑inflammatory effects of esculin and esculetin (Review)

Fraxinus chinensis Roxb is a deciduous tree, which is distributed worldwide and has important medicinal value. In Asia, the bark of Fraxinus chinensis Roxb is a commonly used traditional Chinese medicine called Qinpi. Esculetin is a coumarin compound derived from the bark of Fraxinus chinensis Roxb and its glycoside form is called esculin. The aim of the present study was to systematically review relevant literature on the antioxidant and anti-inflammatory effects of esculetin and esculin. Esculetin and esculin can promote the expression of various endogenous antioxidant proteins, such as superoxide dismutase, glutathione peroxidase and glutathione reductase. This is associated with the activation of the nuclear factor erythroid-derived factor 2-related factor 2 signaling pathway. The anti-inflammatory effects of esculetin and esculin are associated with the inhibition of the nuclear factor κ-B and mitogen-activated protein kinase inflammatory signaling pathways. In various inflammatory models, esculetin and esculin can reduce the expression levels of various proinflammatory factors such as tumor necrosis factor-α, interleukin (IL)-1β and IL-6, thereby inhibiting the development of inflammation. In summary, esculetin and esculin may be promising candidates for the treatment of numerous diseases associated with inflammation and oxidative stress, such as ulcerative colitis, acute lung and kidney injury, lung cancer, acute kidney injury.

Chemo- and bio-informatics insight into anti-cholinesterase potentials of berries and leaves of Myrtus communis L., Myrtaceae: an in vitro/in silico study

BACKGROUND

Myrtus communis L. (MC) has been used in Mesopotamian medicine. Here, the cholinesterase (ChE) inhibitory potential of its methyl alcohol extracts has been investigated and computationally dissected.

METHOD

The ChE inhibition has been measured based on usual Ellman's colorimetric method compared to a canonical ChE inhibitor, eserine. Through a deep text mining, the structures of phytocompounds (= ligands) of MC were curated from ChemSpider, PubChem, and ZINC databases and docked into protein targets, AChE (PDB 1EVE) and BChE (PDB 1P0I) after initial in silico preparedness and binding affinity (BA; kcal/mol) reported as an endpoint. The calculation of ADMET (absorption, distribution, metabolism, excretion, and toxicity) features of phytocompounds were retrieved from SwissADME ( http://www.swissadme.ch/ ) and admetSAR software to predict the drug-likeness or lead-likeness fitness. The Toxtree v2.5.1, software platforms ( http://toxtree.sourceforge.net/ ) have been used to predict the class of toxicity of phytocompounds. The STITCH platform ( http://stitch.embl.de ) has been employed to predict ChE-chemicals interactions.

RESULTS

The possible inhibitory activities of AChE of extracts of leaves and berries were 37.33 and 70.00%, respectively as compared to that of eserine while inhibitory BChE activities of extracts of leaves and berries of MC were 19.00 and 50.67%, respectively as compared to that of eserine. Phytochemicals of MC had BA towards AChE ranging from -7.1 (carvacrol) to -9.9 (ellagic acid) kcal/mol. In this regard, alpha-bulnesene, (Z)-gamma-Bisabolene, and beta-bourbonene were top-listed low toxic binders of AChE, and (Z)-gamma-bisabolene was a more specific AChE binder. Alpha-cadinol, estragole, humulene epoxide II, (a)esculin, ellagic acid, patuletin, juniper camphor, linalyl anthranilate, and spathulenol were high class (Class III) toxic substances which among others, patuletin and alpha-cadinol were more specific AChE binders. Among intermediate class (Class II) toxic substances, beta-chamigrene was a more specific AChE binder while semimyrtucommulone and myrtucommulone A were more specific BChE binders.

CONCLUSION

In sum, the AChE binders derived from MC were categorized mostly as antiinsectants (e.g., patuletin and alpha-cardinal) due to their predicted toxic classes. It seems that structural amendment and stereoselective synthesis like adding sulphonate or sulphamate groups to these phytocompounds may make them more suitable candidates for considering in preclinical investigations of Alzheimer's disease.

Potential protective effects of Huanglian Jiedu Decoction against COVID-19-associated acute kidney injury: A network-based pharmacological and molecular docking study

Corona virus disease 2019 (COVID-19) is prone to induce multiple organ damage. The kidney is one of the target organs of SARS-CoV-2, which is susceptible to inducing acute kidney injury (AKI). Huanglian Jiedu Decoction (HLJDD) is one of the recommended prescriptions for COVID-19 with severe complications. We used network pharmacology and molecular docking to explore the therapeutic and protective effects of HLJDD on COVID-19-associated AKI. Potential targets related to "HLJDD," "COVID-19," and "Acute Kidney Injury/Acute Renal Failure" were identified from several databases. A protein-protein interaction (PPI) network was constructed and screened the core targets according to the degree value. The target genes were then enriched using gene ontology and Kyoto Encyclopedia of Genes and Genomes. The bioactive components were docked with the core targets. A total of 65 active compounds, 85 common targets for diseases and drugs were obtained; PPI network analysis showed that the core protein mainly involved JUN, RELA, and AKT1; functional analysis showed that these target genes were mainly involved in lipid and atherosclerosis signaling pathway and IL-17 signal pathway. The results of molecular docking showed that JUN, RELA, and AKT1 had good binding activity with the effective chemical components of HLJDD. In conclusion, HLJDD can be used as a potential therapeutic drug for COVID-19-associated AKI.

Co-treatment with Esculin and erythropoietin protects against renal ischemia-reperfusion injury via P2X7 receptor inhibition and PI3K/Akt activation

Renal ischemia/reperfusion (RI/R) is a critical clinical outcome with slightly reported improvement in mortality and morbidity. Effective therapies are still crucially required. Accordingly, the therapeutic effects of esculin (ESC, LCESI-MS/MS-isolated compound from Vachellia farnesiana flowers extract, with reported P2X7 receptor inhibitor activity) alone and in combination with erythropoietin (EPO) were investigated against RI/R injury and the possible underlying mechanisms were delineated. ESC and EPO were administered for 7 days and 30 min prior to RI, respectively. Twenty-four hour following reperfusion, blood and kidney samples were collected. Results revealed that pretreatment with either ESC or EPO reduced serum nephrotoxicity indices, renal oxidative stress, inflammatory, and apoptosis markers. They also ameliorated the renal histopathological injury on both endothelial and tubular epithelial levels. Notably, ESC markedly inhibited P2X7 receptors and NLRP3 inflammasome signaling (downregulated NLRP3 and Caspase-1 gene expressions), whereas EPO significantly upregulated PI3K and Akt gene expressions, also p-PI3K and p-Akt levels in renal tissues. ESC, for the first time, demonstrated effective protection against RI/R-injury and its combination with EPO exerted maximal renoprotection when compared to each monotherapy, thereby representing an effective therapeutic approach via inhibiting oxidative stress, inflammation, renal tubular and endothelial injury, apoptosis, and P2X7 receptors expression, and activating PI3K/Akt pathway.

Identification of anti-inflammatory compounds from Zhongjing formulae by knowledge mining and high-content screening in a zebrafish model of inflammatory bowel diseases

BACKGROUND

Inflammatory bowel diseases (IBD) are chronic relapsing intestinal inflammations with increasing global incidence, and new drug development remains in urgent demand for IBD management. To identify effective traditional Chinese medicine (TCM) formulae and compounds in IBD treatment, we innovatively combined the techniques of knowledge mining, high-content screening and high-resolution mass spectrometry, to conduct a systematic screening in Zhongjing formulae, which is a large collection of TCM prescriptions with most abundant clinical evidences.

METHODS

Using Word2vec-based text learning, the correlations between 248 Zhongjing formulae and IBD typical symptoms were analyzed. Next, from the top three formulae with predicted relationship with IBD, TCM fractions were prepared and screened on a transgenic zebrafish IBD model for their therapeutic effects. Subsequently, the chemical compositions of the fraction hits were analyzed by mass spectrometry, and the major compounds were further studied for their anti-IBD effects and potential mechanisms.

RESULTS

Through knowledge mining, Peach Blossom Decoction, Pulsatilla Decoction, and Gegen Qinlian Decoction were predicted to be the three Zhongjing formulae mostly related to symptoms typical of IBD. Seventy-four fractions were prepared from the three formulae and screened in TNBS-induced zebrafish IBD model by high-content analysis, with the inhibition on the intestinal neutrophil accumulation and ROS level quantified as the screening criteria. Six herbal fractions showed significant effects on both pathological processes, which were subsequently analyzed by mass spectrometry to determine their chemical composition. Based on the major compounds identified by mass spectrometry, a second-round screen was conducted and six compounds (palmatine, daidzin, oroxyloside, chlorogenic acid, baicalin, aesculin) showed strong inhibitory effects on the intestinal inflammation phenotypes. The expression of multiple inflammatory factors, including il1β, clcx8a, mmp and tnfα, were increased in TNBS-treated fish, which were variously inhibited by the compounds, with aesculin showing the most potent effects. Moreover, aesculin and daidzin also upregulated e-cadherin's expression.

CONCLUSION

Taken together, we demonstrated the regulatory effects of several TCM formulae and their active compounds in the treatment of IBD, through a highly efficient research strategy, which can be applied in the discovery of effective TCM formulae and components in other diseases.

Coumarins as Modulators of the Keap1/Nrf2/ARE Signaling Pathway

The Keap1/Nrf2/ARE system is a central defensive mechanism against oxidative stress which plays a key role in the pathogenesis and progression of many diseases. Nrf2 is a redox-sensitive transcription factor controlling a variety of downstream antioxidant and cytodefensive genes. Nrf2 has a powerful anti-inflammatory activity mediated via modulating NF-κB. Therefore, pharmacological activation of Nrf2 is a promising therapeutic strategy for the treatment/prevention of several diseases that are underlined by both oxidative stress and inflammation. Coumarins are natural products with promising pharmacological activities, including antioxidant, anticancer, antimicrobial, and anti-inflammatory efficacies. Coumarins are found in many plants, fungi, and bacteria and have been widely used as complementary and alternative medicines. Some coumarins have shown an ability to activate Nrf2 signaling in different cells and animal models. The present review compiles the research findings of seventeen coumarin derivatives of plant origin (imperatorin, visnagin, urolithin B, urolithin A, scopoletin, esculin, esculetin, umbelliferone, fraxetin, fraxin, daphnetin, anomalin, wedelolactone, glycycoumarin, osthole, hydrangenol, and isoimperatorin) as antioxidant and anti-inflammatory agents, emphasizing the role of Nrf2 activation in their pharmacological activities. Additionally, molecular docking simulations were utilized to investigate the potential binding mode of these coumarins with Keap1 as a strategy to disrupt Keap1/Nrf2 protein-protein interaction and activate Nrf2 signaling.