RETRACTED: Quercetin ameliorates lipopolysaccharide-caused inflammatory damage via down-regulation of miR-221 in WI-38 cells

Quercetin-loaded chitosan nanoparticles ameliorate adjuvant-induced arthritis in rats by regulating anti-oxidant enzymes and downregulating pro- and inflammatory cytokines

Rheumatoid arthritis (RA) is an inflammatory condition and associated with the symmetrical synovitis of the joints and cause joint pain. The use of anti-rheumatic drugs is associated with many adverse effects. Quercetin, an important polyphenolic flavonoid, possess anti-inflammatory and anti-rheumatic effects. Quercetin use is limited due to poor absorption and bioavailability. Nanomedicines are used for the targeted drug delivery, hence it reduces the adverse effects of the drug. Based upon these factors, quercetin-loaded chitosan nanoparticles (Q-NPs) were prepared by solvent evaporation method, characterized and their better anti-rheumatic effect with mechanistic insights was validated in Freund's complete adjuvant (FCA)-induced arthritic rats along with safety studies. The animals were divided into five groups, each containing 5 animals. Group I was normal control, group II was arthritic control, while groups III, IV and V were administered with quercetin (15 mg/Kg) and Q-NPs (10 and 20 mg/Kg), respectively. The reduction in ankle diameter, serum oxidative stress markers as well as pro- and inflammatory cytokines, e.g., tumor necrosis factor (TNFα), interleukin (IL-6) were determined. The prepared Q-NPs showed hydrodynamic size of 83.9 nm, polydispersity index of 0.687, entrapment efficiency 90.5% as well as no interaction between quercetin and chitosan in Fourier transform infrared spectroscopy (FTIR). A significant reduction (p < 0.001) in ankle diameter was observed after administration of high-dose Q-NPs (4.32 ± 0.14 cm to 5.13 ± 0.62 cm). There was also reduction (p < 0.001) in levels of TNFα and IL-6 following high-dose Q-NPs (72.56 ± 2.30 and 308.19 ± 11.5 pg). The effect on biochemical tests, hematological parameters and oxidative stress parameters was also found to be significant. Histopathological changes of kidney, liver and ankle also confirmed the anti-rheumatic effect of high-dose Q-NPs. The study concludes that administration of Q-NPs (20 mg/Kg) may be used for the treatment of FCA-induced RA in rats.

Flavonols and Flavones as Potential anti-Inflammatory, Antioxidant, and Antibacterial Compounds

Plant preparations have been used to treat various diseases and discussed for centuries. Research has advanced to discover and identify the plant components with beneficial effects and reveal their underlying mechanisms. Flavonoids are phytoconstituents with anti-inflammatory, antimutagenic, anticarcinogenic, and antimicrobial properties. Herein, we listed and contextualized various aspects of the protective effects of the flavonols quercetin, isoquercetin, kaempferol, and myricetin and the flavones luteolin, apigenin, 3 $\prime$ ,4 $\prime$ -dihydroxyflavone, baicalein, scutellarein, lucenin-2, vicenin-2, diosmetin, nobiletin, tangeretin, and 5-O-methyl-scutellarein. We presented their structural characteristics and subclasses, importance, occurrence, and food sources. The bioactive compounds present in our diet, such as fruits and vegetables, may affect the health and disease state. Therefore, we discussed the role of these compounds in inflammation, oxidative mechanisms, and bacterial metabolism; moreover, we discussed their synergism with antibiotics for better disease outcomes. Indiscriminate use of antibiotics allows the emergence of multidrug-resistant bacterial strains; thus, bioactive compounds may be used for adjuvant treatment of infectious diseases caused by resistant and opportunistic bacteria via direct and indirect mechanisms. We also focused on the reported mechanisms and intracellular targets of flavonols and flavones, which support their therapeutic role in inflammatory and infectious diseases.

Molecular Mechanism of YuPingFeng in the Treatment of Asthma Based on Network Pharmacology and Molecular Docking Technology

Objective

To explore the molecular targets and mechanism of YuPingFeng (YPF) for the treatment of asthma by using network pharmacology and molecular docking.

Methods

The potential active ingredients and relevant targets of YPF were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Asthma-related gene targets were retrieved from GeneCards, OMIM, DrugBank, PharmGKB, and TTD databases. The protein-protein (PPI) network between YPF and asthma common targets was constructed by SRING online database and Cytoscape software. GO and KEGG analyses were performed to explore the complicated molecular biological processes and potential pathways. Finally, a molecular docking approach was carried out to verify the results.

Results

We obtained 100 potential targets of the 35 active ingredients in YPF and 1610 asthma-related targets. 60 YPF-asthma common targets were selected to perform PPI analysis. Seven core genes were screened based on two topological calculation methods. GO and KEGG results showed that the main pathways of YPF in treating asthma include TNF signaling pathway and PI3K-Akt signaling pathway. Finally, the molecular docking results indicated that the key ingredients of YPF had a good affinity with the relevant core genes.

Conclusion

This study reflects the multicomponent, multitarget, and multipathway characteristics of YPF in treating asthma, providing a theoretical and scientific basis for the intervention of asthma by traditional Chinese medicine YPF.

Anti-Cancer Effects of Dietary Polyphenols via ROS-Mediated Pathway with Their Modulation of MicroRNAs

Consumption of coffee, tea, wine, curry, and soybeans has been linked to a lower risk of cancer in epidemiological studies. Several cell-based and animal studies have shown that dietary polyphenols like chlorogenic acid, curcumin, epigallocatechin-3-O-gallate, genistein, quercetin and resveratrol play a major role in these anticancer effects. Several mechanisms have been proposed to explain the anticancer effects of polyphenols. Depending on the cellular microenvironment, these polyphenols can exert double-faced actions as either an antioxidant or a prooxidant, and one of the representative anticancer mechanisms is a reactive oxygen species (ROS)-mediated mechanism. These polyphenols can also influence microRNA (miR) expression. In general, they can modulate the expression/activity of the constituent molecules in ROS-mediated anticancer pathways by increasing the expression of tumor-suppressive miRs and decreasing the expression of oncogenic miRs. Thus, miR modulation may enhance the anticancer effects of polyphenols through the ROS-mediated pathways in an additive or synergistic manner. More precise human clinical studies on the effects of dietary polyphenols on miR expression will provide convincing evidence of the preventive roles of dietary polyphenols in cancer and other diseases.

Quercetin: an effective polyphenol in alleviating diabetes and diabetic complications

Various studies, especially in recent years, have shown that quercetin has beneficial therapeutic effects in various human diseases, including diabetes. Quercetin has significant anti-diabetic effects and may be helpful in lowering blood sugar and increasing insulin sensitivity. Quercetin appears to affect many factors and signaling pathways involved in insulin resistance and the pathogenesis of type 2 of diabetes. TNFα, NFKB, AMPK, AKT, and NRF2 are among the factors that are affected by quercetin. In addition, quercetin can be effective in preventing and ameliorating the diabetic complications, including diabetic nephropathy, cardiovascular complications, neuropathy, delayed wound healing, and retinopathy, and affects the key mechanisms involved in the pathogenesis of these complications. These positive effects of quercetin may be related to its anti-inflammatory and anti-oxidant properties. In this article, after a brief review of the pathogenesis of insulin resistance and type 2 diabetes, we will review the latest findings on the anti-diabetic effects of quercetin with a molecular perspective. Then we will review the effects of quercetin on the key mechanisms of pathogenesis of diabetes complications including nephropathy, cardiovascular complications, neuropathy, delayed wound healing, and retinopathy. Finally, clinical trials investigating the effect of quercetin on diabetes and diabetes complications will be reviewed.

Autophagy as a molecular target of quercetin underlying its protective effects in human diseases

Autophagy, known as a "self-eating" process, is associated with degradation of aged or damaged components and organelles. Generally, autophagy is a survival mechanism that provides energy during nutritional deprivation. This mechanism plays a remarkable role during the physiological condition by maintaining homeostasis and energy balance and several pathological conditions, particularly neurological disorders. Due to the critical role of autophagy in cancer, much attention has been made in the regulation of autophagy using both naturally occurring and synthetic drugs. Quercetin is a plant-derived chemical belonging to the family of flavonoids. Quercetin has valuable biological and therapeutic effects such as anti-tumor, antioxidant, anti-inflammatory, anti-diabetic, hepatoprotective, and cardioprotective. At the present review, we first provide an introduction about quercetin and autophagy with its related molecular pathways. We also describe how quercetin modulates autophagy mechanism to exert its therapeutic effects.

A Preliminary Inquiry Into the Potential Mechanism of Huang-Lian-Jie-Du Decoction in Treating Rheumatoid Arthritis via Network Pharmacology and Molecular Docking

Huang-Lian-Jie-Du decoction (HLJDD) has been widely applied to treat inflammation-associated diseases for thousands of years in China. However, the concrete molecular mechanism of HLJDD in the treatment of rheumatoid arthritis (RA) remains unclear. In this work, network pharmacology and molecular docking were applied to preliminarily analyze the potential active ingredients, drug targets, and related pathways of HLJDD on treating RA. A total of 102 active compounds with corresponding 189 targets were identified from HLJDD, and 41 common targets were further identified by intersecting with RA-related targets. Functional enrichment analysis was performed to screen the biological pathways associated with RA. Ten hub targets were further identified through constructing the protein–protein interaction (PPI) network of common targets, which were mainly enriched in the interleukin-17 (IL-17) signaling pathway, tumor necrosis factor (TNF) signaling pathway, and Toll-like receptor signaling pathway. Furthermore, a complex botanical drugs-ingredients-hub-targets-disease network was successfully constructed. The molecular docking results exhibited that these vital ingredients of HLJDD had a stable binding to the hub targets. Among these ingredients, quercetin (MOL000098) was the most common molecule with stable binding to all the targets, and PTGS2 was considered the most important target with multiple regulations by the most active ingredients. In vitro, we successfully validated the inhibitory role of quercetin in the cellular proliferation of human RA fibroblast-like synoviocyte cell line (MH7A cells). These findings indicated that the potential mechanisms of HLJDD for RA treatment might be attributed to inhibiting the immune-inflammatory response, reducing the release of chemokines, and alleviating the destruction of extracellular matrix (ECM) in the synovial compartment.

Circ-UQCRC2 aggravates lipopolysaccharide-induced injury in human bronchial epithelioid cells via targeting miR-495-3p/MYD88-mediated inflammatory response and oxidative stress

Infantile pneumonia is a common inflammatory disease with the infections of various pathogens in lower respiratory tracts. Here, the role and working mechanism of circular RNA (circRNA) ubiquinol-cytochrome c reductase core protein 2 (circ-UQCRC2; hsa_circ_0038467) in infantile pneumonia were investigated. Cell viability, apoptosis, and inflammatory response were assessed by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and enzyme-linked immunosorbent assay (ELISA). Cell oxidative stress was analyzed by measuring the production of malondialdehyde (MDA) and superoxide dismutase (SOD). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot assay were performed to determine the expression of RNAs and proteins. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to confirm the interaction between microRNA-495-3p (miR-495-3p) and circ-UQCRC2 or myeloid differentiation primary response protein 88 (MYD88). Lipopolysaccharide (LPS) treatment suppressed the viability while induced the apoptosis, inflammation, and oxidative stress of 16HBE cells in a dose-dependent manner. LPS exposure dose-dependently up-regulated the expression of circ-UQCRC2 in 16HBE cells. Circ-UQCRC2 absence attenuated LPS-induced injury in 16HBE cells. miR-495-3p was a target of circ-UQCRC2, and circ-UQCRC2 silencing-mediated protective effects in LPS-induced 16HBE cells were partly reversed by anti-miR-495-3p. MYD88 was a target of miR-495-3p, and MYD88 overexpression partly counteracted miR-495-3p accumulation-mediated influences in 16HBE cells upon LPS exposure. Circ-UQCRC2 interference decreased the protein expression of MYD88 partly by up-regulating miR-495-3p in LPS-induced 16HBE cells. In conclusion, circ-UQCRC2 contributed to LPS-induced injury of 16HBE cells by targeting miR-495-3p/MYD88 signalling-mediated inflammatory response and oxidative stress.

Molecular Mechanism of Jinchan Oral Liquid in the Treatment of Children with Respiratory Syncytial Virus Pneumonia Based on Network Pharmacology and Molecular Docking Technology

Objective

Exploration of the underlying molecular mechanism of Jinchan Oral Liquid (JOL) in treating children with the respiratory syncytial virus (RSV) pneumonia to provide new evidence for the clinical application.

Methods

The active components and target genes of JOL were screened by the TCMSP database. The targets of RSV pneumonia were obtained from the GeneCards, OMIM, DrugBank, and PharmGKB database. Then, we constructed the active component-target network and screened the core genes. The overlaps were screened for PPI network analysis, GO analysis, and KEGG analysis. Finally, result validation was performed by molecular docking.

Results

According to the screening criteria of the ADME, 74 active compounds of JOL were obtained; after removing redundant targets, we selected 180 potential targets. By screening the online database, 893 RSV pneumonia-related targets were obtained. A total of 82 overlapping genes were chosen by looking for the intersection. The STRING online database was used to acquire PPI relationships, and 16 core genes were obtained. GO and KEGG analyses showed that the main pathways of JOL in treating RSV pneumonia include TNF signaling pathway and IL17 signaling pathway. The molecular docking results showed that the active compounds of JOL had a good affinity with the core genes.

Conclusion

In this study, we preliminarily discussed the main active ingredients, related targets, and pathways of JOL and predicted the pharmacodynamic basis and the potential therapeutic mechanisms of RSV pneumonia. In summary, the network pharmacology strategy may be helpful for the discovery of multitarget drugs against complex diseases.

MiR-221-3p and miR-92a-3p enhances smoking-induced inflammation in COPD

Background

Smoking is likely to facilitate airway inflammation and finally contributes to chronic obstructive pulmonary disease (COPD). This investigation was intended to elucidate miRNAs that were involved in smoking‐induced COPD.

Methods

Altogether 155 COPD patients and 77 healthy volunteers were recruited, and their serum levels of miR‐221‐3p and miR‐92a‐3p were determined. Besides, human bronchial epithelial cells (16HBECs) were purchased, and they were treated by varying concentrations of cigarette smoke extract (CSE). The 16HBECs were, additionally, transfected by miR‐221‐3p mimic, miR‐92a‐3p mimic, miR‐221‐3p inhibitor or miR‐92a‐3p inhibitor, and cytokines released by them, including TNF‐α, IL‐8, IL‐1β, and TGF‐β1, were monitored using enzyme linked immunosorbent assay (ELISA) kits.

Results

Chronic obstructive pulmonary disease patients possessed higher serum levels of miR‐221‐3p and miR‐92a‐3p than healthy volunteers (p < 0.05), and both miR‐221‐3p and miR‐92a‐3p were effective biomarkers in diagnosing stable COPD from acute exacerbation COPD. Moreover, viability of 16HBECs was undermined by CSE treatment (p < 0.05), and exposure to CSE facilitated 16HBECs’ release of TNF‐α, IL‐8, IL‐1β, and TGF‐β1 (p < 0.05). Furthermore, miR‐221‐3p/miR‐92a‐3p expression in 16HBECs was significantly suppressed after transfection of miR‐221‐3p/miR‐92a‐3p inhibitor (p < 0.05), which abated CSE‐triggered increase in cytokine production and decline in viability of 16HBECs (p < 0.05).

Conclusion

MiR‐221‐3p and miR‐92a‐3p were involved in CSE‐induced hyperinflammation of COPD, suggesting that they were favorable alternatives in diagnosing COPD patients with smoking history.

Ginsenoside Rb1 Alleviates Lipopolysaccharide-Induced Inflammatory Injury by Downregulating miR-222 in WI-38 Cells

Pneumonia is a serious respiratory tract infection disease in children, which threatens to the health or life of children patients. Ginsenoside Rb1 (Rb1) is a principle active ingredient extracted from the root of Panax notoginseng (Burk.) F.H. Chen with anti-inflammatory effect. Our study aimed to determine the effects and molecular mechanisms of Rb1 on lipopolysaccharide (LPS)-induced inflammatory injury of lung fibroblasts WI-38 cells. Cell viability and apoptosis were evaluated by CCK-8 and flow cytometry, respectively. The production of inflammatory cytokines were measured by ELISA and RT-qPCR. miR-222 expression was examined by RT-qPCR. The expression levels of the nuclear factor-kappa B (NF-κB) p65 and phosphorylated p65 were detected by western blot. We found that LPS stimulation induced WI-38 cell inflammatory injury by inhibiting cell viability, and inducing apoptosis and inflammatory cytokine production, while treatment with Rb1 significantly attenuated LPS-induced inflammatory injury in WI-38 cells. Additionally, Rb1 decreased LPS-induced upregulation of miR-222 and activation of the NF-κB pathway in WI-38 cells. Overexpression of miR-222 abolished the inhibitory effects of Rb1 on LPS-induced viability reduction, apoptosis, inflammatory cytokine production and activation of the NF-κB pathway. In conclusion, Rb1 alleviated LPS-induced inflammatory injury in WI-38 cells via downregulating miR-222 and inactivation of the NF-kB pathway.

Decoding the Mechanism of Huanglian Jiedu Decoction in Treating Pneumonia Based on Network Pharmacology and Molecular Docking

Huang-Lian-Jie-Du decoction (HLJDD) has been used to treat pneumonia for thousands of years in China. However, our understanding of its mechanisms on treating pneumonia is still unclear. In the present work, network pharmacology was used to analyze the potential active ingredients and molecular mechanisms of HLJDD on treating pneumonia. A total of 102 active ingredients were identified from HLJDD, among which 54 were hit by the 69 targets associated with pneumonia. By performing Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, we obtained the main pathways associated with pneumonia and those associated with the mechanism of HLJDD in the treatment of pneumonia. By constructing the protein-protein interaction network of common targets, 10 hub genes were identified, which were mainly involved in the tumor necrosis factor (TNF) signaling pathway, interleukin 17 (IL-17) signaling pathway, and nucleotide-binding oligomerization domain (NOD)-like receptor signaling pathway. Moreover, the results of molecular docking showed that the active ingredients of HLJDD had a good affinity with the hub genes. The final results indicate that HLJDD has a greater effect on bacterial pneumonia than on viral pneumonia. The therapeutic effect is mainly achieved by regulating the host immune inflammatory response and oxidative stress reaction, antibacterial microorganisms, alleviating the clinical symptoms of pneumonia, repairing damaged cells, and inhibiting cell migration.

Nutraceutical Targeting of Inflammation-Modulating microRNAs in Severe Forms of COVID-19: A Novel Approach to Prevent the Cytokine Storm

The coronavirus disease 2019 (COVID-19) pandemic has become the number one health problem worldwide. As of August 2020, it has affected more than 18 million humans and caused over 700,000 deaths worldwide. COVID-19 is an infectious disease that can lead to severe acute respiratory syndrome. Under certain circumstances, the viral infection leads to excessive and uncontrolled inflammatory response, which is associated with the massive release of inflammatory cytokines in pulmonary alveolar structures. This phenomenon has been referred to as the “cytokine storm,” and it is closely linked to lung injury, acute respiratory syndrome and mortality. Unfortunately, there is currently no vaccine available to prevent the infection, and no effective treatment is available to reduce the mortality associated with the severe form of the disease. The cytokine storm associate with COVID-19 shows similarities with those observed in other pathologies such as sepsis, acute respiratory distress syndrome, acute lung injury and other viral infection including severe cases of influenza. However, the specific mechanisms that cause and modulate the cytokine storm in the different conditions remain to be determined. micro-RNAs are important regulators of gene expression, including key inflammatory cytokines involved in the massive recruitment of immune cells to the lungs such as IL1β, IL6, and TNFα. In recent years, it has been shown that nutraceutical agents can modulate the expression of miRs involved in the regulation of cytokines in various inflammatory diseases. Here we review the potential role of inflammatory-regulating-miRs in the cytokine storm associated with COVID-19, and propose that nutraceutical agents may represent a supportive therapeutic approach to modulate dysregulated miRs in this condition, providing benefits in severe respiratory diseases.

MiR-221/SIRT1/Nrf2 signal axis regulates high glucose induced apoptosis in human retinal microvascular endothelial cells

Background

Diabetic retinopathy (DR) is a serious symptom associated with diabetes and could cause much suffer to patients. MiR-221, SIRT1 and Nrf2 were associated with apoptosis and proliferation and their expression were altered in DR patients. However, their roles and regulatory mechanisms in human retinal microvascular endothelial cells (hRMEC) were not clear.

Methods

Expression of mRNA was detected by qRT-PCR. Protein expression was detected by Western blot. Interaction between miR-221 and SIRT1 was predicted by bioinformatics analysis and validated by dual-luciferase reporter assay. We analyzed the viability and apoptosis of hRMEC by MTT assay and FACS assay, respectively.

Results

High glucose (HG) treatment enhanced expression of miR-221 and inhibited expression of SIRT1 and Nrf2. MiR-221 overexpression promoted apoptosis under HG condition. Moreover, miR-221 directly interacted with mRNA of SIRT1 and inhibited SIRT1 expression in hRMEC, through which miR-221 inhibited Nrf2 pathway and induced apoptosis of hRMEC.

Conclusion

Our data demonstrated that miR-221/SIRT1/Nrf2 signal axis could promote apoptosis in hRMEC under HG conditions. This finding could provide theoretical support for future studies and may contribute to development of new treatment options to retard the process of DR development.

Therapeutic Potential of Quercetin: New Insights and Perspectives for Human Health

Quercetin (Que) and its derivatives are naturally occurring phytochemicals with promising bioactive effects. The antidiabetic, anti-inflammatory, antioxidant, antimicrobial, anti-Alzheimer's, antiarthritic, cardiovascular, and wound-healing effects of Que have been extensively investigated, as well as its anticancer activity against different cancer cell lines has been recently reported. Que and its derivatives are found predominantly in the Western diet, and people might benefit from their protective effect just by taking them via diets or as a food supplement. Bioavailability-related drug-delivery systems of Que have also been markedly exploited, and Que nanoparticles appear as a promising platform to enhance their bioavailability. The present review aims to provide a brief overview of the therapeutic effects, new insights, and upcoming perspectives of Que.

Circular RNA ANKRD36 attends to lipopolysaccharide-aroused MRC-5 cell injury via regulating microRNA-31-3p

BACKGROUND

Some circular RNAs (circRNAs) are reported to attend to the pathogenesis of pneumonia. This study tested the impact of circRNA ankyrin repeat domain 36 (circANKRD36) on human embryonic lung fibroblast MRC-5 cell injury irritated by lipopolysaccharide (LPS).

METHODS

After LPS irritation, viability, apoptosis, ROS, protein, and cytokines, along with circANKRD36 were tested by CCK-8, Annexin V-FITC, DCFH-DA, and ELISA or Western blot. si-circANKRD36 and microRNA-31-3p/5p (miR-31-3p/5p) inhibitor were applied to silence circANKRD36 and miR-31-3p/5p. miR-31-3p/5p mimic was utilized to upregulate miR-31-3p/5p. RT-qPCR was used to detect miRNAs. The relationship between miRNAs and MyD88 or IL-34 was analyzed by luciferase activity reporter assay.

RESULTS

LPS aroused a decrease in viability, increases in apoptosis, ROS, and IL-6, IL-8, and TNF-α, along with circANKRD36, and activation of NF-κB pathway. Silencing circANKRD36 weakened the above-mentioned influences of LPS. Moreover, silencing circANKRD36 hoisted miR-31-3p expression. Silencing miR-31-3p mitigated the impacts of circANKRD36 silence on LPS-irritated MRC-5 cells. Besides, MyD88 was a downstream target of miR-31-3p, and 3'UTR of IL-34 mRNA was targeted by miR-31-5p. LPS induced the accumulation of MyD88. Silencing MyD88 was constructive to maintain cell viability, retard apoptosis and inhibit adverse oxidation and inflammation.

CONCLUSION

This research verified that silencing circANKRD36 could weaken LPS-irritated MRC-5 cell injury via regulating miR-31/MyD88-mediated repression of NF-κB pathway.