Quercetin protects against lipopolysaccharide-induced acute lung injury in rats through suppression of inflammation and oxidative stress

Fischer's oligopeptide ratio in ischemic hypoxia: prophylactic amendment of sophoretin and melatonin supplementation

Aim: The fundamental pathophysiology of ischemic-hypoxia is oxygen depletion. Fischer's ratio is essential for monitoring hypoxia intensity. Methods: the current study highlighted the prophylactic role of sophoretin (QRC) and/or melatonin (MLN) versus sodium nitrite (SN) brain hypoxia. Results: Prophylactic treatment with sophoretin and MLN, was preceded with hypoxia-induction via sodium nitrite (60 mg/kg, S.C.). SN decreased hemoglobin (Hb), elevated HIF-α, HSP-70, IL-6 and TNF-α. Sophoretin and/or MLN restored the ameliorated inflammatory biomarkers, modulated norepinephrine, dopamine, serotonin and gamma-aminobutyric acid (GABA). Similarly, single-cell gel electrophoresis (SCGE or COMET) DNA damage assay confirmed this finding. Conclusion: Treatment via sophoretin and MLN was the most effective therapy for improving sodium nitrite-induced brain injury.

The effect of chronic, non-pathogenic maternal immune activation on offspring postnatal muscle and immune outcomes

The objective was to determine the effects of maternal inflammation on offspring muscle development and postnatal innate immune response. Sixteen first-parity gilts were randomly allotted to repeated intravenous injections with lipopolysaccharide (LPS; n = 8, treatment code INFLAM) or comparable volume of phosphate buffered saline (CON, n = 8). Injections took place every other day from gestational day (GD) 70 to GD 84 with an initial dose of 10 μg LPS/kg body weight (BW) increasing by 12% each time to prevent endotoxin tolerance. On GD 70, 76, and 84, blood was collected at 0 and 4 h postinjection via jugular or ear venipuncture to determine tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β concentrations. After farrowing, litter mortality was recorded, and the pig closest to litter BW average was used for dissection and muscle fiber characterization. On weaning (postnatal day [PND] 21), pigs were weighed individually and 2 barrows closest to litter BW average were selected for another study. The third barrow closest to litter BW average was selected for the postnatal LPS challenge. On PND 52, pigs were given 5 μg LPS/kg BW via intraperitoneal injection, and blood was collected at 0, 4, and 8 h postinjection to determine TNF-α concentration. INFLAM gilt TNF-α concentration increased (P < 0.01) 4 h postinjection compared to 0 h postinjection, while CON gilt TNF-α concentration did not differ between time points. INFLAM gilt IL-6 and IL-1β concentrations increased (P = 0.03) 4 h postinjection compared to 0 h postinjection on GD 70, but did not differ between time points on GD 76 and 84. There were no differences between INFLAM and CON gilts litter mortality outcomes (P ≥ 0.13), but INFLAM pigs were smaller (P = 0.04) at birth and tended (P = 0.09) to be smaller at weaning. Muscle and organ weights did not differ (P ≥ 0.17) between treatments, with the exception of semitendinosus, which was smaller (P < 0.01) in INFLAM pigs. INFLAM pigs tended (P = 0.06) to have larger type I fibers. INFLAM pig TNF-α concentration did not differ across time, while CON pig TNF-α concentration peaked (P = 0.01) 4 h postinjection. TNF-α concentration did not differ between treatments at 0 and 8 h postinjection, but CON pigs had increased (P = 0.01) TNF-α compared to INFLAM pigs 4 h postinjection. Overall, maternal immune activation did not alter pig muscle development, but resulted in suppressed innate immune activation.

Quercetin alleviates lipopolysaccharide‑induced acute lung injury by inhibiting ferroptosis via the Sirt1/Nrf2/Gpx4 pathway

Acute lung injury (ALI) causes high morbidity and mortality rates in critically ill patients, and there are currently no effective therapeutic drugs. Ferroptosis is a newly discovered mode of regulated cell death that contributes to the progression of ALI. Quercetin possesses anti‑inflammatory and antioxidant properties. However, whether quercetin can protect against lipopolysaccharide (LPS)‑induced ALI by inhibiting ferroptosis and its underlying mechanisms remains unclear. The present study evaluated the protective effects of quercetin and underlying molecular mechanisms in LPS‑induced ALI by establishing an ALI mouse model and an alveolar epithelial cell injury model via treatment of the mice or alveolar epithelial cells with LPS. Mouse lung injury was assessed by evaluating the histological lung injury score, bronchoalveolar lavage fluid cell count and inflammatory cytokine levels; alveolar epithelial cell injury was assessed by Cell counting kit‑8, lactate dehydrogenase and EDU assays; and ferroptosis was assessed by detecting the changes in the levels of malondialdehyde, glutathione, iron, glutathione peroxidase 4 (Gpx4) and 4‑hydroxynonenal in vivo and vitro. The present study indicated that quercetin effectively ameliorated LPS‑induced ALI in the mouse model by reducing histopathological changes, proinflammatory cytokine release and reactive oxygen species generation and inhibiting ferroptosis. Quercetin significantly decreased ferroptosis and improved the proliferative ability of LPS‑treated alveolar epithelial cells. Additionally, it was demonstrated that quercetin markedly enhanced the alveolar epithelial barrier, as evidenced by the upregulation of tight junction protein expression both in vivo and in vitro. Mechanistically, quercetin effectively activated the sirtuin 1 (Sirt1)/nuclear factor erythroid 2‑related factor 2 (Nrf2)/Gpx4 signaling pathway, and targeted in vivo inhibition or in vitro knockdown of Sirt1 significantly reduced the anti‑ferroptotic functions of quercetin. In conclusion, the results demonstrated that quercetin exerts its therapeutic effects against LPS‑induced ALI by inhibiting ferroptosis via the activation of the Sirt1/Nrf2/Gpx4 signaling pathway.

Basis of preventive and non-pharmacological interventions in asthma

Asthma is one of the most common atopic disorders in all stages of life. Its etiology is likely due to a complex interaction between genetic, environmental, and lifestyle factors. Due to this, different non-pharmacological interventions can be implemented to reduce or alleviate the symptoms caused by this disease. Thus, the present narrative review aimed to analyze the preventive and non-pharmacological interventions such as physical exercise, physiotherapy, nutritional, ergonutritional, and psychological strategies in asthma treatment. To reach these aims, an extensive narrative review was conducted. The databases used were MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. Asthma is an immune-mediated inflammatory condition characterized by increased responsiveness to bronchoconstrictor stimuli. Different factors have been shown to play an important role in the pathogenesis of asthma, however, the treatments used to reduce its incidence are more controversial. Physical activity is focused on the benefits that aerobic training can provide, while physiotherapy interventions recommend breathing exercises to improve the quality of life of patients. Nutritional interventions are targeted on implement diets that prioritize the consumption of fruits and vegetables and supplementation with antioxidants. Psychological interventions have been proposed as an essential non-pharmacological tool to reduce the emotional problems associated with asthma.

The potential mechanism of Choulingdan mixture in improving acute lung injury based on HPLC-Q-TOF-MS, network pharmacology and in vivo experiments

Choulingdan mixture (CLDM) is an empirical clinical prescription for the adjuvant treatment of acute lung injury (ALI). CLDM has been used for almost 30 years in the clinic. However, its mechanism for improving ALI still needs to be investigated. In this study, high-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (HPLC-Q-TOF-MS/MS) was applied to characterize the overall chemical composition of CLDM. A total of 93 ingredients were characterized, including 25 flavonoids, 20 organic acids, 11 saponins, nine terpenoids, seven tannins and 21 other compounds. Then network pharmacology was applied to predict the potential bioactive components, target genes and signaling pathways of CLDM in improving ALI. Additionally, molecular docking was performed to demonstrate the interaction between the active ingredients and the disease targets. Finally, animal experiments further confirmed that CLDM significantly inhibits pulmonary inflammation, pulmonary edema and oxidative stress in lipopolysaccharide-induced ALI mice by inhibiting the PI3K-AKT signaling pathway. This study enhanced the amount and accuracy of compounds of CLDM and provided new insights into CLDM preventing and treating ALI.

Identification of biomarkers associated with diagnosis of acute lung injury based on bioinformatics and machine learning

BACKGROUND

Acute lung injury (ALI) is an acute inflammatory disease characterized by excess production of inflammatory factors in lung tissue and has a high mortality. This research was designed for the identification of novel diagnostic biomarkers for ALI and analyzing the possible association between critical genes and infiltrated immune cells.

METHODS

The study used 2 datasets (GSE2411 and GSE18341) to identify differentially expressed genes (DEGs) between 2 groups. Then we performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses to identify the functions of these DEGs. The study also used SVM-recursive feature elimination analysis and least absolute shrinkage and selection operator regression model to screen possible markers. The study further analyzed immune cell infiltration via CIBERSORT. Gene Set Enrichment Analysis was used to explore the molecular mechanism of the critical genes.

RESULTS

DEGs were identified between 2 groups. In total, 690 DEGs were obtained: 527 genes were upregulated and 163 genes were downregulated. We identified PDZK1IP1, CCKAR, and CXCL2 as critical genes. And we then found that these critical genes correlated with Mast Cells, Neutrophil Cells, M1 Macrophage, dendritic cell Actived, Eosinophil Cells, B Cells Naive, Mast Cells, and dendritic cell Immature. Furthermore, we investigated the specific signaling pathways involved in key genes and derived some potential molecular mechanisms by which key genes affect disease progression by use of Gene Set Enrichment Analysis. Moreover, we predict transcription factors. Also, we obtained critical gene-related microRNAs through the targetscan database, and visualized the microRNA network of the genes.

CONCLUSION

Our findings might provide some novel clue for the exploration of novel markers for ALI diagnosis. The critical genes and their associations with immune infiltration may offer new insight into understanding ALI developments.

Efficacy analysis and research progress of complementary and alternative medicines in the adjuvant treatment of COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has impacted human lifestyles around the world, causing huge distress in terms of public health systems, emergency response capacity and economic development. The causative agent of COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with respiratory involvement, cardiovascular-related diseases, and ultimately causes multiple organ failure and death in severely affected individuals. Thus, effective prevention or early treatment of COVID-19 is critical. An effective vaccine offers a way out of the pandemic for governments, the scientific community and people worldwide, but we still lack effective drug therapies, including treatments for the prevention and treatment of COVID-19. This had led to a high global demand for many complementary and alternative medicines (CAMs). Moreover, many healthcare providers are now requesting information about CAMs that prevent, relieve, or treat the symptoms of COVID-19 and even alleviate vaccine-related side effects. Experts and scholars must therefore become familiar with the use of CAMs in COVID-19, current research directions and effectiveness of CAMs for COVID-19. This narrative review updates the current status and research worldwide on the use of CAMs for COVID-19. The review provides reliable evidence on theoretical viewpoints and therapeutic efficacies of CAM combinations, and evidence in support of the therapeutic strategy of Taiwan Chingguan Erhau (NRICM102) against moderate-to-severe novel coronavirus infectious disease in Taiwan.

Deciphering suppressive effects of Lianhua Qingwen Capsule on COVID-19 and synergistic effects of its major botanical drug pairs

The COVID-19 pandemic has resulted in excess deaths worldwide. Conventional antiviral medicines have been used to relieve the symptoms, with limited therapeutic effect. In contrast, Lianhua Qingwen Capsule is reported to exert remarkable anti-COVID-19 effect. The current review aims to: 1) uncover the main pharmacological actions of Lianhua Qingwen Capsule for managing COVID-19; 2) verify the bioactive ingredients and pharmacological actions of Lianhua Qingwen Capsule by network analysis; 3) investigate the compatibility effect of major botanical drug pairs in Lianhua Qingwen Capsule; and 4) clarify the clinical evidence and safety of the combined therapy of Lianhua Qingwen Capsule and conventional drugs. Numerous bioactive ingredients in Lianhu Qingwen, such as quercetin, naringenin, β-sitosterol, luteolin, and stigmasterol, were identified to target host cytokines, and to regulate the immune defence in response to COVID-19. Genes including androgen receptor (AR), myeloperoxidase (MPO), epidermal growth factor receptor (EGFR), insulin (INS), and aryl hydrocarbon receptor (AHR) were found to be significantly involved in the pharmacological actions of Lianhua Qingwen Capsule against COVID-19. Four botanical drug pairs in Lianhua Qingwen Capsule were shown to have synergistic effect for the treatment of COVID-19. Clinical studies demonstrated the medicinal effect of the combined use of Lianhua Qingwen Capsule and conventional drugs against COVID-19. In conclusion, the four main pharmacological mechanisms of Lianhua Qingwen Capsule for managing COVID-19 are revealed. Therapeutic effect has been noted against COVID-19 in Lianhua Qingwen Capsule.

Analyzing cross-talk of EPO and EGF genes along with evaluating therapeutic potential of Cinnamomum verum in cigarette-smoke-induced lung pathophysiology in rat model

The integrity of the distal alveolar epithelium is crucial for lung regeneration following an injury. The present study aimed to evaluate the effect of Cinnamomum verum extract; cross-talk of epidermal growth factor (EGF) and erythropoietin (EPO) genes in a smoke-induced lung injury rat model. For experimentation (n = 27), albino rats were divided equally into three groups, i.e., negative control (NC), positive control (PC), and treatment group (TG). Cigarette smoke was exposed to PC and TG (4 CG/day). C. verum was given orally (350 mg/kg body weight) for 21 days. Decapitation (n = 3) was done on 14th, 18th, and 21st days, respectively. Analyses (hematology, biochemical, high performance liquid chromatography [HPLC], histology, and gene expression) were carried out and results were statistically analyzed by two-way analysis of variance. HPLC analysis of ethanolic extract of C. verum was done to identify the presence of phenolic constituents which showed high concentrations of quercetin and P-coumaric acid. Serum oxidative parameters such as total oxidant status, malondialdehyde, and hematological parameters such as red blood cells, hemoglobin, hematocrit, and white blood cells were significantly (p < .05) elevated in the PC group; however, these parameters were significantly (p < .05) improved in TG. While total antioxidant capacity and serum parameters such as total protein, albumin, and globulin were significantly (p < .05) reduced in the PC group but significantly improved (p < .05) in TG. Histological analysis revealed that smoke exposure resulted in a measurable increase in alveolar septal thickening while ethanolic extract of C. verum greatly ameliorated the histopathological changes in the lung alveoli. The gene expression analysis of EGF and EPO genes showed a significant upregulation (p < .05) of both genes in PC group while in TG, the level of both genes downregulated, in which lung damage was ameliorated due to cytoprotective effects of ethanolic extract of C. verum.

Dietary Intervention with Quercetin Attenuates Diesel Exhaust Particle-Instilled Pulmonary Inflammation and Behavioral Abnormalities in Mice

Exposure to diesel exhaust particles (DEPs) is inevitable and closely linked with increased health hazards, causing pulmonary abnormalities by increasing inflammation, hypoxia, and so on. Moreover, long-term exposure to DEPs may trigger whole-body toxicity with behavioral alterations. Therefore, nutritional intervention with natural components may be desirable to prevent and/or ameliorate DEP-inducible pathophysiology in mammals. Quercetin has been demonstrated to reduce metabolic complications by possessing antioxidative, anti-inflammatory, and antimutagenic effects. In this study, we investigated the effects of quercetin on pulmonary inflammation and behavioral alteration in male C57BL/6 mice against DEP instillation. The experimental mice were separated into four treatment groups (n = 8 per group), which include: vehicle control, DEP instillation, dietary intervention with a low dose of quercetin (20 mg/kg) for 14 days with DEP instillation for 7 days, or dietary intervention with a high dose of quercetin (100 mg/kg) for 14 days with DEP instillation for 7 days. Compared with the DEP-instilled group, dietary intervention with quercetin significantly attenuated eosinophils in the bronchoalveolar lavage fluid analysis, pulmonary cytokine, and hypoxic mRNA expressions regardless of quercetin concentrations. DEP instillation triggered hyperactivities in the experimental mice, while quercetin pretreatment successfully normalized DEP-inducible abnormalities regardless of the dosage. Therefore, dietary intervention with quercetin may be an applicable means to prevent DEP-triggered pulmonary and behavioral abnormalities.

Tanshinone IIA loaded bioactive nanoemulsion for alleviation of lipopolysaccharide induced acute lung injury via inhibition of endothelial glycocalyx shedding

Acute lung injury (ALI) and its more serious form; acute respiratory distress syndrome are major causes of COVID-19 related mortality. Finding new therapeutic targets for ALI is thus of great interest. This work aimed to prepare a biocompatible nanoformulation for effective pulmonary delivery of the herbal drug; tanshinone-IIA (TSIIA) for ALI management. A nanoemulsion (NE) formulation based on bioactive natural ingredients; rhamnolipid biosurfactant and tea-tree oil, was developed using a simple ultrasonication technique, optimized by varying oil concentration and surfactant:oil ratio. The selected TSIIA-NE formulation showed 105.7 nm diameter and a PDI ∼ 0.3. EE exceeded 98 % with biphasic sustained drug release and good stability over 3-months. In-vivo efficacy was evaluated in lipopolysaccharide (LPS)-induced ALI model. TSIIA-NE (30 µg/kg) was administered once intratracheally 2 h after LPS instillation. Evaluation was performed 7days post-treatment. Pulmonary function assessment, inflammatory, oxidative stress and glycocalyx shedding markers analysis in addition to histopathological examination of lung tissue were performed. When compared to untreated rats, in-vivo efficacy study demonstrated 1.4 and 1.9-fold increases in tidal volume and minute respiratory volume, respectively, with 32 % drop in wet/dry lung weight ratio and improved levels of arterial blood gases. Lung histopathology and biochemical analysis of different biomarkers in tissue homogenate and bronchoalveolar lavage fluid indicated that treatment may ameliorate LPS-induced ALI symptoms thorough anti-oxidative, anti-inflammatory effects and inhibition of glycocalyx degradation. TSIIA-NE efficacy was superior to free medication and blank-NE. The enhanced efficacy of TSIIA bioactive nanoemulsion significantly suggests the pharmacotherapeutic potential of bioactive TSIIA-NE as a promising nanoplatform for ALI.

Chinese herbal prescriptions for COVID-19 management: Special reference to Taiwan Chingguan Yihau (NRICM101)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. As at June 2022, increasing numbers of newly diagnosed COVID-19-associated pneumonia cases worldwide have attracted close attention from the international community. The present review analyzes and summarizes the treatment of COVID-19 with traditional Chinese medicine (TCM). A systematic analysis of the efficacies and benefits of TCM for the treatment of COVID-19 was performed, and the mechanisms underlying such treatment are summarized. This analysis of the literature highlights the potential of TCM to prevent and treat COVID-19 via antiviral, anti-inflammatory and immunomodulatory activities, with evidence showing that many TCM components act upon multiple targets and pathways. Famous TCM formulas include Qing-Fei-Pai-Du-Tang (QFPDT), Lianhuaqingwen Capsule (LHC), Taiwan Chingguan Yihau (NRICM101), and Jing Si herbal drink (JSHD). In particular, the botanical preparation NRICM101 was developed in 2020 for use in viral respiratory tract infections and is recommended for treating non-severe and mild COVID-19 infections. NRICM101 has been adopted for use in Taiwan for the clinical treatment of COVID-19. The common components and active ingredients of 10 TCM preparations have been analyzed for the most promising substances. This review aims to provide reliable evidence demonstrating the therapeutic efficacy of TCM substances in support of their further development against novel coronavirus infectious diseases in Taiwan.

Quercetin attenuates sepsis-induced acute lung injury via suppressing oxidative stress-mediated ER stress through activation of SIRT1/AMPK pathways

Endoplasmic reticulum (ER) stress and mitochondrial dysfunction play a pivotal role in the pathological process of sepsis-induced acute lung injury (ALI). Quercetin has been proved to exert anti-inflammation in ALI. This study aimed to explore the protection mechanism of quercetin against sepsis-induced ALI via suppressing ER stress and mitochondrial dysfunction. Cecal ligation and puncture (CLP) mouse model was established to mimic sepsis, and LPS was used to stimulate murine lung epithelial (MLE-12) cells. We observed that quercetin ameliorated pulmonary pathological lesion and oxidative damage in sepsis-induced mice. In LPS-stimulated MLE-12 cells, quercetin could inhibit the level of ER stress as evidenced by decreased mRNA expression of PDI, CHOP, GRP78, ATF6, PERK, IRE1α and improve mitochondrial function, as presented by increased MMP, SOD level and reduced production of ROS, MDA. Meanwhile, transcriptome analysis revealed that quercetin upregulated SIRT1/AMPK mRNA expression. Furthermore, we used siRNA to knockdown SIRT1 in MLE-12 cells, and we found that SIRT1 knockdown could abrogate the quercetin-elicited antioxidation in vitro. Therefore, quercetin could protect against sepsis-induced ALI by suppressing oxidative stress-mediated ER stress and mitochondrial dysfunction via induction of the SIRT1/AMPK pathways.

Phytochemical Profiling of the Leaf Extract of Ximenia americana var. caffra and Its Antioxidant, Antibacterial, and Antiaging Activities In Vitro and in Caenorhabditis elegans: A Cosmeceutical and Dermatological Approach

We previously annotated the phytochemical constituents of a root extract from Ximenia americana var. caffra and highlighted its hepatoprotective and hypoglycemic properties. We here extended our study on the leaf extract and identified its phytoconstituents using HPLC-PDA-ESI-MS/MS. In addition, we explored its antioxidant, antibacterial, and antiaging activities in vitro and in an animal model, Caenorhabditis elegans. Results from HPLC-PDA-ESI-MS/MS confirmed that the leaves contain 23 secondary metabolites consisting of condensed tannins, flavonol glycosides, flavone glycosides, and flavonol diglycosides. The leaf extract demonstrated significant antioxidant activity in vitro with IC50 value of 5 μg/mL in the DPPH assay and 18.32 μg/mL in the FRAP assay. It also inhibited four enzymes (collagenase, elastase, hyaluronidase, and tyrosinase) crucially involved in skin remodeling and aging processes with comparable activities to reference drugs along with four pure secondary metabolites identified from the extract. In accordance with the in vitro result, in vivo tests using two transgenic strains of C. elegans demonstrated its ability to reverse oxidative stress. Evidence included an increased survival rate in nematodes treated with the prooxidant juglone to 68.9% compared to the 24.8% in untreated worms and a reduced accumulation of intracellular reactive oxygen species (ROS) in a dose-dependent manner to 77.8%. The leaf extract also reduced levels of the expression of HSP 16.2 in a dose-dependent manner to 86.4%. Nuclear localization of the transcription factor DAF-16 was up to 10 times higher in worms treated with the leaf extract than in the untreated worms. The extract also inhibited the biofilm formation of Pseudomonas aeruginosa (a pathogen in skin infections) and reduced the swimming and swarming mobilities in a dose-dependent fashion. In conclusion, leaves of X. americana are a promising candidate for preventing oxidative stress-induced conditions, including skin aging.

Focus on the high therapeutic potentials of quercetin and its derivatives

BACKGROUND

Polyphenols and particularly flavonoids are of constant interest to the scientific community. Flavonoids are investigated for their biological and pharmacological purposes, notably as antioxidant, anticancer, antiviral and for their anti-inflammatory activities. Certainly, one of the best-known flavonols recognized for its therapeutic and preventive properties, is quercetin. Despite its biological interest, quercetin suffer from some drawbacks, mainly related to its bioavailability. Hence, its synthetic or biosynthetic derivatives have been the subject of intensive research. The health-promoting biological activities of flavonols and derivatives mainly arise from their capacity to disrupt the host-pathogen interactions and/or to regulate host cellular functions including oxidative processes and immunological responses. In the age of coronavirus pandemic, the anti-inflammatory and antiviral potential of flavonols should be put forward to explore these substances for decreasing the viral load and inflammatory storm caused by the infection.

PURPOSE OF STUDY

The present review will decipher and discuss the antioxidant, anti-inflammatory and antiviral capacities of major flavonol with a focus on the molecular basis and structure-activity relationships.

STUDY DESIGN

Current study used a combination of quercetin derivatives, pathway, antioxidant, anti-inflammatory, antiviral activities as keywords to retrieve the literature. This study critically reviewed the current literature and presented the ability of natural analogs of quercetin having superior antioxidant, anti-inflammatory and antiviral effects than the original molecule.

RESULTS

This review allowed the identification of relevant key structure-activity relationship elements and highlight approaches on the mechanisms governing the antioxidant, antiviral and anti-inflammatory activities.

CONCLUSION

Through a critical analysis of the literature, flavonols and more precisely quercetin derivatives reviewed and found to act simultaneously on inflammation, virus and oxidative stress, three key factors that may lead to life threatening diseases.

2,4,6-Trihydroxy-3-geranyl acetophenone suppresses vascular leakage and leukocyte infiltration in lipopolysaccharide-induced endotoxemic mice

CONTEXT

Lipopolysaccharide (LPS) exacerbates systemic inflammatory responses and causes excessive fluid leakage. 2,4,6-Trihydroxy-3-geranyl acetophenone (tHGA) has been revealed to protect against LPS-induced vascular inflammation and endothelial hyperpermeability in vitro.

OBJECTIVE

This study assesses the in vivo protective effects of tHGA against LPS-induced systemic inflammation and vascular permeability in endotoxemic mice.

MATERIALS AND METHODS

BALB/c mice were intraperitoneally pre-treated with tHGA for 1 h, followed by 6 h of LPS induction. Evans blue permeability assay and leukocyte transmigration assay were performed in mice (n = 6) pre-treated with 2, 20 and 100 mg/kg tHGA. The effects of tHGA (20, 40 and 80 mg/kg) on LPS-induced serum TNF-α secretion, lung dysfunction and lethality were assessed using ELISA (n = 6), histopathological analysis (n = 6) and survivability assay (n = 10), respectively. Saline and dexamethasone were used as the negative control and drug control, respectively.

RESULTS

tHGA significantly inhibited vascular permeability at 2, 20 and 100 mg/kg with percentage of inhibition of 48%, 85% and 86%, respectively, in comparison to the LPS control group (IC₅₀=3.964 mg/kg). Leukocyte infiltration was suppressed at 20 and 100 mg/kg doses with percentage of inhibition of 73% and 81%, respectively (IC₅₀=17.56 mg/kg). However, all tHGA doses (20, 40 and 80 mg/kg) failed to prevent endotoxemic mice from lethality because tHGA could not suppress TNF-α overproduction and organ dysfunction.

DISCUSSION AND CONCLUSIONS

tHGA may be developed as a potential therapeutic agent for diseases related to uncontrolled vascular leakage by combining with other anti-inflammatory agents.

Network pharmacology-based strategy to investigate the active ingredients and molecular mechanisms of Scutellaria Barbata D. Don against radiation pneumonitis

INTRODUCTION

Herbal medicines combined with radiotherapy significantly reduced the incidence of radiation pneumonitis (RP), and the Scutellaria barbata D. Don (SBD) is a perennial herb that has been reported to protect against radiation-induced pneumonitis. However, the exact molecular mechanism is not known. The objective of this research was to investigate the against radiation pneumonitis ingredients and their functional mechanisms in SBD.

METHODS

Based on the network pharmacology approaches, we collected active ingredients and target genes in SBD against RP through Traditional Chinese Medicine System Pharmacology (TCMSP) Database, and the "Herb-Ingredients-Target Genes-Disease" Network was constructed by using of Cytoscape. STRING analysis was performed to reveal the protein-protein interactions, and then we applied enrichment analysis on these target proteins, gene function, and pathways.

RESULTS

A total of 18 ingredients in SBD regulate 65 RP related target proteins, which show that quercetin, luteolin, baicalein, wogonin may be the key active ingredients, while IL6, AKT1, VEGFA, MMP9, CCL2, prostaglandin-endoperoxide synthase 2 (PTGS2) (cyclooxygenase-2 [COX-2]), CXCL8, IL1B, mitogen-activated protein kinase (MAPK1), and IL10 were identified as critical targets. Besides, the results of Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that predicted targets of SBD are mostly associated with the pathological process of oxidative stress and inflammation. AGE- Receptor of Advanced Glycation Endproducts (RAGE) signaling pathway in diabetic complications, IL-17 signaling pathway, hypoxia-inducible factor-1 (HIF-1) signaling pathway, NF-kappa B signaling pathway might serve as the principal pathways for RP treatment.

CONCLUSION

In our study, the pharmacological and molecular mechanism of SBD against RP was predicted from a holistic perspective, and the results provided theoretical guidance for researchers to explore the mechanism in further research.

High concentration of hydrogen ameliorates lipopolysaccharide-induced acute lung injury in a sirt1-dependent manner

The aim of this study was to investigate the efficacy and underlying mechanism of high concentration of hydrogen on lipopolysaccharide (LPS)-induced acute lung injury (ALI). We have established a corresponding mouse model and examined the function of hydrogen inhalation on lung pathology and pulmonary edema induced by LPS, as well as contents of IL-1β, TNF-α and IL-8. The pulmonary microvascular permeability and 66.7 % hydrogen on the expression of sirt1 and its downstream signaling molecules were tested. Results showed that 66.7 % hydrogen alleviated lung pathological changes and pulmonary edema caused by LPS, and reduced the degree of ALI by inhibiting pro-inflammatory cytokine release and oxidative stress response, thereby decreasing the expression of molecules related to intercellular adhesion. sirt1 contributed to the repair of LPS-induced ALI by hydrogen through the regulation of NF-κB and catalase expression. In conclusion, 66.7 % hydrogen protected against LPS-induced ALI by suppressing inflammatory response and oxidative stress mediated by NF-κB and catalase in a sirt1-dependent manner.

Plicosepalus acacia Extract and Its Major Constituents, Methyl Gallate and Quercetin, Potentiate Therapeutic Angiogenesis in Diabetic Hind Limb Ischemia: HPTLC Quantification and LC-MS/MS Metabolic Profiling

Plicosepalus acacia (Fam. Loranthaceae) has been reported to possess hypoglycemic, antioxidant, antimicrobial, and anti-inflammatory effects. Liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) analysis revealed the presence of a high content of polyphenolic compounds that are attributed to the therapeutic effects of the crude extract. In addition, methyl gallate and quercetin were detected as major phytomedicinal agents at concentrations of 1.7% and 0.062 g%, respectively, using high-performance thin layer chromatography (HPTLC). The present study investigated the effect of the P. acacia extract and its isolated compounds, methyl gallate and quercetin, on hind limb ischemia induced in type 1 diabetic rats. Histopathological examination revealed that treatment with P. acacia extract, methyl gallate, and quercetin decreased degenerative changes and inflammation in the ischemic muscle. Further biochemical assessment of the hind limb tissue showed decreased oxidative stress, increased levels of nitric oxide and endothelial nitric oxide synthase (eNOS), and enhancement of the levels of heme oxygenase-1 (HO-1) and vascular endothelial growth factor (VEGF) in the groups treated with methyl gallate and quercetin. Expression levels of hypoxia inducible factor-1 alpha (HIF-1α), VEGF, fibroblast growth factor-2 (FGF-2), and miR-146a were upregulated in the muscle tissue of methyl gallate- and quercetin-treated groups along with downregulation of nuclear factor kappa B (NF-κB). In conclusion, P. acacia extract and its isolated compounds, methyl gallate and quercetin, mediated therapeutic angiogenesis in diabetic hind limb ischemia.

Role of ACE2-Ang (1-7)-Mas axis in post-COVID-19 complications and its dietary modulation

Severe acute respiratory syndrome-coronavirus-2 (COVID-19) virus uses Angiotensin-Converting Enzyme 2 (ACE2) as a gateway for their entry into the human body. The ACE2 with cleaved products have emerged as major contributing factors to multiple physiological functions and pathogenic complications leading to the clinical consequences of the COVID-19 infection Decreased ACE2 expression restricts the viral entry into the human cells and reduces the viral load. COVID-19 infection reduces the ACE2 expression and induces post-COVID-19 complications like pneumonia and lung injury. The modulation of the ACE2-Ang (1–7)-Mas (AAM) axis is also being explored as a modality to treat post-COVID-19 complications. Evidence indicates that specific food components may modulate the AAM axis. The variations in the susceptibility to COVID-19 infection and the post-COVID its complications are being correlated with varied dietary habits. Some of the food substances have emerged to have supportive roles in treating post-COVID-19 complications and are being considered as adjuvants to the COVID-19 therapy. It is possible that some of their active ingredients may emerge as the direct treatment for the COVID-19.

Antiviral, immunomodulatory, and anticoagulant effects of quercetin and its derivatives: Potential role in prevention and management of COVID-19

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has caused a devastating health crisis worldwide. In this review, we have discussed that prophylactic phytochemical quercetin supplementation in the form of foods or nutraceuticals may help manage the COVID-19 pandemic. The following evidence supports our argument. First, nuclear factor erythroid-derived 2-like 2 (NRF2) agonists abrogate replication of SARS-CoV-2 in lung cells, and quercetin is a potent NRF2 agonist. Second, quercetin exerts antiviral activity against several zoonotic coronaviruses, including SARS-CoV-2, mainly by inhibiting the entry of virions into host cells. Third, inflammatory pathways activated by nuclear factor kappa B, inflammasome, and interleukin-6 signals elicit cytokine release syndrome that promotes acute respiratory distress syndrome in patients with COVID-19, and quercetin inhibits these pro-inflammatory signals. Fourth, patients with COVID-19 develop thrombosis, and quercetin mitigates coagulation abnormalities by inhibiting plasma protein disulfide isomerase. This review provides a strong rationale for testing quercetin for the management of COVID-19.

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Quercetin may inhibit SARS-CoV-2 entry into cells by altering viral envelope proteins.

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Quercetin may inhibit SARS-CoV-2 replication by activating the NRF2 pathway.

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Quercetin attenuates proinflammatory signals and cytokine release syndrome.

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Quercetin may reduce coagulopathy by inhibiting protein disulphide isomerase.

Protective Effect of Quercetin, a Flavonol against Benzo(a)pyrene-Induced Lung Injury via Inflammation, Oxidative Stress, Angiogenesis and Cyclooxygenase-2 Signalling Molecule

Quercetin (Qu) is an important polyphenolic flavonoid which exhibits tremendous antioxidant, anti-inflammatory and other health promoting effects. The aim of the current study was to explore the therapeutic role of Qu on benzo(a)pyrene [B(a)P]-induced lung injury in rats. B(a)P was given to the rats at dose of 50 mg/kg b.w. for continues 8 weeks through oral gavage. The rats were treated with Qu at dose of 50 mg/kg b.w prior 30 min before the oral administration of B(a)P. The effects of Qu were studied by measuring the level of lactate dehydrogenase (LDH), anti-oxidant enzymes, lipid peroxidation, inflammatory cytokines, lung tissues architecture and expression of cyclooxygenase-2 (COX-2). The level of pro-inflammatory cytokines such as IL-1β (27.30 vs. 22.80 pg/mL), IL-6 (90.64 vs. 55.49 pg/mL) and TNF-α (56.64 vs. 40.49 pg/mL) increased significantly and antioxidant enzymes decreased significantly in benzopyrene-induced lung injury in comparison to the control group. The treatment with Qu potentially reversed the effects of B(a)P to a great extent, as it led to the enhancement of antioxidant enzymes and decreased proinflammatory cytokines level. A significant surge of VEGF level was noticed in the B(a)P group as compared to the control group, while the Qu treatment groups exhibited less angiogenesis as lower level of VEGF levels, compared with the B(a)P treatment group. The Qu treatment significantly decreased the degrees of histopathological changes and collagen deposition in B(a)P-induced lung injury. The B(a)P-treated group showed higher cytoplasmic expression of COX-2 protein, which significantly decreased in the Qu treatment group. These outcomes recommend an effective role of Qu in the protection of lung injury against B(a)P through the regulation of the inflammatory factors, oxidative stress and the maintenance lung tissue architecture.

Experimental and clinical studies on the effects of Portulaca oleracea L. and its constituents on respiratory, allergic, and immunologic disorders, a review

Various pharmacological effects for Portulaca oleracea were shown in previous studies. Therefore, the effects of P. oleracea and its derivatives on respiratory, allergic, and immunologic diseases according to update experimental and clinical studies are provided in this review article. PubMed/Medline, Scopus, and Google Scholar were searched using appropriate keywords until the end of December 2020. The effects of P. oleracea and its constituents such as quercetin and kaempferol on an animal model of asthma were shown. Portulaca oleracea and its constituents also showed therapeutic effects on chronic obstructive pulmonary disease and chronic bronchitis in both experimental and clinical studies. The possible bronchodilatory effect of P. oleracea and its ingredients was also reported. Portulaca oleracea and its constituents showed the preventive effect on lung cancer and a clinical study showed the effect of P. oleracea on patients with lung adenocarcinoma. In addition, a various constituents of P. oleracea including, quercetin and kaempferol showed therapeutic effects on lung infections. This review indicates the therapeutic effect of P. oleracea and its constituents on various lung and allergic disorders but more clinical studies are required to establish the clinical efficacy of this plant and its constituents on lung and allergic disorders.

Quercetin amelioratesAspergillus fumigatuskeratitis by inhibiting fungal growth, toll-like receptors and inflammatory cytokines

PURPOSE

To investigate the antifungal and anti-inflammatory effects of quercetin on Aspergillus fumigatus (A. fumigatus) keratitis.

METHODS

Human corneal epithelial cells (HCECs) and C57BL/6 mice were stimulated by A. fumigatus and treated with quercetin or dimethyl sulfoxide (DMSO) after infection. In HCECs, minimum inhibitory concentration (MIC) and cytotoxicity tests (CCK-8) were used to detect the antifungal effect and cytotoxicity of quercetin. In mice with A. fumigatuskeratitis, clinical score, plate counting and hematoxylin-eosin (HE) staining were performed to evaluate the effects of quercetin in vivo. Myeloperoxidase (MPO) assay and immunofluorescence staining were applied to assess neutrophil recruitment and infiltration. Real time PCR (RT-PCR), enzyme-linked immunosorbent assay (ELISA) and western blot were used to detect the mRNA and protein expressions of inflammatory mediators.

RESULTS

Compared with DMSO control, quercetin (16-64 μM) significantly inhibited the growth of A. fumigatus in a concentration-dependent manner without affecting cell viability in HCECs. In corneas of mice with A. fumigatuskeratitis, quercetin decreased clinical score and fungal load, and reduced neutrophil recruitment and infiltration to the corneal stroma. Moreover, quercetin attenuated the expression of inflammatory mediators including toll-like receptor-4 (TLR-4), TLR-2, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and high mobility group box 1 (HMGB1) in vitro and in vivo.

CONCLUSIONS

Our study demonstrated that quercetin treatment can ameliorate A. fumigatus keratitis by inhibiting the growth of A. fumigatus, decreasing neutrophil recruitment and infiltration, and downregulating the productions of TLR-4, TLR-2, TNF-α, IL-1β and HMGB1, indicating quercetin is likely to become a potential therapeutic agent in FK treatment.

Airway Redox Homeostasis and Inflammation Gone Awry: From Molecular Pathogenesis to Emerging Therapeutics in Respiratory Pathology

As aerobic organisms, we are continuously and throughout our lifetime subjected to an oxidizing atmosphere and, most often, to environmental threats. The lung is the internal organ most highly exposed to this milieu. Therefore, it has evolved to confront both oxidative stress induced by reactive oxygen species (ROS) and a variety of pollutants, pathogens, and allergens that promote inflammation and can harm the airways to different degrees. Indeed, an excess of ROS, generated intrinsically or from external sources, can imprint direct damage to key structural cell components (nucleic acids, sugars, lipids, and proteins) and indirectly perturb ROS-mediated signaling in lung epithelia, impairing its homeostasis. These early events complemented with efficient recognition of pathogen- or damage-associated recognition patterns by the airway resident cells alert the immune system, which mounts an inflammatory response to remove the hazards, including collateral dead cells and cellular debris, in an attempt to return to homeostatic conditions. Thus, any major or chronic dysregulation of the redox balance, the air-liquid interface, or defects in epithelial proteins impairing mucociliary clearance or other defense systems may lead to airway damage. Here, we review our understanding of the key role of oxidative stress and inflammation in respiratory pathology, and extensively report current and future trends in antioxidant and anti-inflammatory treatments focusing on the following major acute and chronic lung diseases: acute lung injury/respiratory distress syndrome, asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, and cystic fibrosis.

Manipulation of Quercetin and Melatonin in the Down-Regulation of HIF-1α, HSP-70 and VEGF Pathways in Rat's Kidneys Induced by Hypoxic Stress

Hypoxia may lead to inflammatory responses by numerous signaling pathways. This investigation intended to inspect the defensive role of Quercetin (Quer) and/ or Melatonin (Mel) against reno toxicity induced by Sodium nitrite (Sod ntr). Sod ntr injection significantly decreased blood hemoglobin concentration (Hb) with a concurrent increase in serum tumor necrosis factor- α, interleukin-6, C-reactive protein, creatinine, and urea levels. Over protein-expression of vascular endothelial growth factor and heat shock, protein-70 and mRNA of HIF-1α were also observed. Pretreatment of the Sod ntr- injected rats with the aforementioned antioxidants; either alone or together significantly improved such parameters. Histopathological examination reinforced the previous results. It was concluded that the combined administration of Quer and Mel may be useful as a potential therapy against renal injury induced by Sod ntr. HIF-1α and HSP-70 are implicated in the induction of hypoxia and its treatment.

Quercetin and curcumin effects in experimental pleural inflammation

Background

The inflammatory mechanisms occur with the highest prevalence in pulmonary pathology in addition to oxidative stress and activation of intracellular signaling pathways. The oxidative stress represents the imbalance between pro-oxidants and antioxidants which can lead to the activation of the oxidative mechanisms with noxious potential to the body. Therefore, finding a therapy that would counteract the injurious effects of free radicals and inflammation is highly attractive. Quercetin is the most active flavonoid, with important anti-inflammatory and antioxidant effects, while curcumin has antioxidant effects that are similar to the standard antioxidants and exerts direct anti-inflammatory activity.

Aims

The aim of this study is to evaluate the antioxidant effects of quercetin and curcumin on an experimental model, pleural inflammation induced by carrageenan.

Methods

Eight groups of adult male rats were used: Ia and Ib – control groups, IIa and IIb – with carrageenan administration, IIIa and IIIb – received curcumin and carrageenan, IVa and IVb – quercetin and carrageenan administration. Blood and lung samples were taken at 4 hours (Ia, IIa, IIIa, IVa groups) and at 24 hours (Ib, IIb, IIIb, IVb groups) after carrageenan injection.

Results

At 4 and at 24 hours, curcumin and quercetin have shown protective systemic effects, decreasing significantly the oxidative stress (malondialdehyde level) and stimulating significantly the antioxidant protection (ceruloplasmin and glutathione levels) compared to the group that received only carrageenan. In the lungs, at 4 hours, the redox misbalance was significantly reduced only in animals that were treated with quercetin, modifications that were not observed at 24 hours.

Conclusions

In serum, curcumin presented higher antioxidant effects, compared to quercetin. In lungs, quercetin administration showed superior beneficial effects, but only temporarily.

Spiraea prunifolia var. simpliciflora Attenuates Oxidative Stress and Inflammatory Responses in a Murine Model of Lipopolysaccharide-Induced Acute Lung Injury and TNF-α-Stimulated NCI-H292 Cells

Spiraea prunifolia var. simpliciflora (SP) is traditionally used as an herbal remedy to treat fever, malaria, and emesis. This study aimed to evaluate the anti-oxidative and anti-inflammatory properties of the methanol extract of SP leaves in tumor necrosis factor (TNF)-α-stimulated NCI-H292 cells and in a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. SP decreased the number of inflammatory cells and the levels of TNF-α, interleukin (IL)-1β, and IL-6 in the bronchoalveolar lavage fluid, and inflammatory cell infiltration in the lung tissues of SP-treated mice. In addition, SP significantly suppressed the mRNA and protein levels of TNF-α, IL-1β, and IL-6 in TNF-α-stimulated NCI-H292 cells. SP significantly suppressed the phosphorylation of the mitogen-activated protein kinases (MAPKs) and p65-nuclear factor-kappa B (NF-κB) in LPS-induced ALI mice and TNF-α-stimulated NCI-H292 cells. SP treatment enhanced the nuclear translocation of nuclear factor erythroid 2-related factor (Nrf2) with upregulated antioxidant enzymes and suppressed reactive oxygen species (ROS)-mediated oxidative stress in the lung tissues of LPS-induced ALI model and TNF-α-stimulated NCI-H292 cells. Collectively, SP effectively inhibited airway inflammation and ROS-mediated oxidative stress, which was closely related to its ability to induce activation of Nrf2 and inhibit the phosphorylation of MAPKs and NF-κB. These findings suggest that SP has therapeutic potential for the treatment of ALI.

Toonaciliatin K attenuates the lung injury induced by lung infection of H1N1 influenza virus by regulating the NF-κB/MyD88/TLR-7 pathway in mice

INTRODUCTION

H1N1 infection has a high mortality rate due to lung injury and respiratory distress. The present study determines the protective effect of toonaciliatin K against the lung injury induced by the lung infection of H1N1 influenza mice and also postulates the molecular mechanism.

MATERIAL AND METHODS

Infection was induced by exposing the anesthetized mice to H1N1 virus (10 LD50 in a volume of 30 ml) intranasally at day zero and mice were treated with toonaciliatin K 16.5 and 33 mg/kg intragastrically for 2 weeks. The effect of toonaciliatin K was assessed by estimating survival rate and lung edema by the lung index. Histopathological changes were determined by H + E staining and western blot and an RT-PCR study was also performed on the lung tissue homogenate.

RESULTS

Data of the study suggest that toonaciliatin K treatment enhances the survival rate and reduces the lung index compared to infected mice. There was a decrease in the level of chemokines and cytokines in the lung tissue of the toonaciliatin K treated group compared to infected mice. Moreover, expression of TLR-7, NF-κB p65 and MyD88 protein was found to be reduced in the lung tissue of the toonaciliatin K treated group compared to infected mice.

CONCLUSIONS

Data of the study suggested that toonaciliatin K protects against lung injury in lung H1N1 lung infection by regulating the TLR-7/Myd88/NF-κB p65 pathway.

Quercetin and Quercitrin Attenuates the Inflammatory Response and Oxidative Stress in LPS-Induced RAW264.7 Cells: In Vitro Assessment and a Theoretical Model

BACKGROUND

Nowadays, atmospheric pollutants, ultraviolet rays, and other factors cause the imbalance of cell redox, resulting in skin oxidative damage. There is an interaction between inflammatory response and oxidative stress, which often involve networks of reactions and serve to amplify each other. Quercetin and quercitrin, with strong antioxidant and anti-inflammatory properties, were widely applied in cardiovascular disease, osteoporsis, pulmonary disease, etc. However, the regulation mechanism of quercetin and quercitrin on various inflammatory skin diseases is still not clear.

PURPOSE

In this study, quercetin and quercitrin were used to investigate whether they had anti-inflammatory and anti-ROS effects. Besides, theoretical calculation method was also adopted to preliminarily explore the mechanism of the anti-inflammatory and antioxidant effects of these two substances.

METHODS

CCK-8 assay was employed to investigate the cytotoxicity. The concentration of NO measured by Griess Reaction System. Moreover, the inflammatory factors (TNF-α, IL-1β, and IL-6) were reduced in LPS-stimulated RAW264.7 cells were tested by ELISA kits. The trend of ROS changes was detected by DCFH-DA method. Finally, the mechanism of the anti-inflammatory and antioxidant effects of these two substances was carried out by DMol3 package in Materials Studio.

RESULTS

CCK-8 assay results guided that the safe concentration of quercetin and quercitrin was lower than 15.0 μg/mL and 22.4 μg/mL, respectively. Also, the concentration of NO could significantly be inhibited by quercetin and quercitrin. Besides, the ELISA results showed that TNF-α, IL-1β, and IL-6 were reduced in LPS-stimulated RAW264.7 cells after interfering with quercetin and quercitrin. The trend of ROS changes was similar to that of inflammatory factors. Finally, the theoretical calculation illustrated that the oxygen atom on B rings may be the main site of electron cloud density changes, which may suggest a possible mechanism for the anti-inflammatory and ROS scavenging effects of quercetin and quercitrin.

CONCLUSIONS

This experiment shows that LPS can induce the overactivating of macrophages and the activated macrophages can subsequently induce inflammatory storms and oxidative stress. Both quercetin and quercitrin can inhibit LPS-induced macrophage inflammation and oxidative stress by experiment and theoretical calculations.

Chamazulene reverses osteoarthritic inflammation through regulation of matrix metalloproteinases (MMPs) and NF-kβ pathway in in-vitro and in-vivo models

This study was conducted to evaluate the protective effects of chamazulene against IL-1β-induced rat primary chondrocytes and complete Freund's adjuvant (CFA)-induced osteoarthritic inflammation in rats. Oxidative stress markers, pro-inflammatory cytokines, and regulatory proteins were measured. Chamazulene significantly reverted (p < 0.05) the levels of lipid peroxidation and enhanced the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) enzymes against IL-1β and CFA-induced oxidative stress. The levels of TNF-α and IL-6 were reduced (p < 0.05) in chamazulene treatment against IL-1β and CFA-induced inflammation. Western blot analysis results on the expressions of MMP-3, MMP-9, p65 NF-kβ, iNOS, and COX-2 showed chamazulene was able to protect the chondrocytes against IL-1β-induced osteoarthritic inflammation. Histopathology of rat hind ankle showed chamazulene significantly protected against CFA-induced osteoarthritic inflammation. Therefore, chamazulene can be recommended as a therapeutic agent for clinical trials against osteoarthritic inflammation.

Flavonoids reduces lipopolysaccharide-induced release of inflammatory mediators in human bronchial epithelial cells: Structure-activity relationship

Flavonoids are polyphenolic compounds that are widely present in food and Chinese medicine. The aim of the present study was to identify the flavonoids with anti-inflammatory effects in the airway; and to determine the role of anti-oxidant and cyclic adenosine monophosphate (cAMP) in the anti-inflammatory effect. Human bronchial epithelial BEAS-2B cells were exposed to bacterial endotoxin lipopolysaccharide (LPS) in the absence or presence of different flavonoids, which are categorized according to their chemical structures in seven subclasses [anthocyanidins, chalcones, flavanes, flavanones, flavones, flavonols, isoflavones]. Among the 17 flavonoids tested, only apigenin (flavones), luteolin (flavones), daidzein (isoflavones) and genistein (isoflavones) reduced LPS-induced release of inflammatory cytokines/chemokines interleukin (IL)-6, IL-8 and monocyte chemoattractant protein-1 in BEAS-2B cells. Quercetin caused further increase in LPS-induced IL-6 and IL-8 levels. It alone significantly increased nuclear factor-kappa B (NF-κB) p65 activity and the cellular oxidative stress marker malondialdehyde (MDA) level in BEAS-2B cells. By contrast, apigenin and genistein reduced LPS-induced increases in nuclear NF-κB activity and MDA level. Apigenin and genistein, but not quercetin, increased the cAMP level in BEAS-2B cells, and the cell-permeable cAMP analogue, 8-Br-cAMP, inhibited LPS-induced increase of IL-8 level. These findings suggest that the presence of C5-OH, C7-OH, C2=C3 and C4=O functional groups in the flavonoids is associated with greater anti-inflammatory effect, while that of C3-OH or glycosylation group at the A-ring greatly decreased the anti-inflammatory effect. The anti-inflammatory effect of these flavonoids may be related to their anti-oxidant properties, and partly to their ability in increasing cAMP level.

Treating empyema thoracis using video-assisted thoracoscopic surgery and open decortication procedures: a systematic review and meta-analysis by meta-mums tool

INTRODUCTION

The optimal treatment of empyema thoracis is still debatable between academics and surgeons. This study reviews advantages and disadvantages of video-assisted thoracoscopic surgery (VATS) and open thoracotomy decortication (OTD) considering outcomes of empyema thoracis.

MATERIALS AND METHODS

A descriptive Boolean query was used for searching three databases to extract the published studies up to 27 March 2017. The outcomes of VATS and OTD were extracted and assessed by random-effects model of meta-analysis. The Egger's test and trim-and-fill method were used for analyzing publication bias, and, meta-regression and subgroup analyses were done for determining heterogeneity.

RESULTS

A total of 2219 patients, from 13 studies, meeting the inclusion criteria were selected and subjected to further analyses. Of 2219 patients, 1120 were treated by VATS and the remaining were subjected to OTD. During VATS, 252 patients were converted to OTD. Forest plots showed that VATS was far superior in terms of incidence of duration of hospital stay and operative time (SMDs = 1.189, 1.565; p < 0.001, < 0.001) compared to OTD. Mortality, prolonged air leakage, wound infection, and recurrence rates (ORs = 1.234, 2.564, 1.363, 1.962; p = 0.576, 0.077, 0.0692, 0.4) had no advantages for both procedures while failure or conversion rate (OR = 0.198, p < 0.001) of VATS was more than those of OTD.

CONCLUSIONS

The results of the current research suggest no trends of superior outcomes with VATS in the treatment of empyema thoracis. Hence, VATS and OTD could be recommended as treatments for empyema thoracis.

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

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Given the comments of Dr Elisabeth Bik regarding this article “… the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy/pasted from other sources, or computer generated”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Antioxidant Activities of Quercetin and Its Complexes for Medicinal Application

Quercetin is a bioactive compound that is widely used in botanical medicine and traditional Chinese medicine due to its potent antioxidant activity. In recent years, antioxidant activities of quercetin have been studied extensively, including its effects on glutathione (GSH), enzymatic activity, signal transduction pathways, and reactive oxygen species (ROS) caused by environmental and toxicological factors. Chemical studies on quercetin have mainly focused on the antioxidant activity of its metal ion complexes and complex ions. In this review, we highlight the recent advances in the antioxidant activities, chemical research, and medicinal application of quercetin.

The ameliorative effect of quercetin on bisphenol A-induced toxicity in mitochondria isolated from rats

Recent studies have demonstrated that bisphenol A (BPA) has an adverse or toxic effect on the kidney. This study was designed to evaluate the ability of quercetin (QUER) to prevent BPA-induced mitochondrial dysfunction. Thirty-two healthy adult male Wistar rats were randomly divided into four groups, as follows: control group (olive oil), BPA group (250 mg/kg), BPA þ QUER group (250 mg/kg + 75 mg/kg), and QUER group (75 mg/kg). All treatments were orally administered for 14 days. Kidney mitochondria were isolated by administration of the different centrifugation method. Uric acid and creatinine were considered to be biomarkers of nephrotoxicity. The ameliorative effects of QUER on BPA toxicity were evaluated by determining the glutathione (GSH) content, CAT, the damage to the mitochondrial membrane, the reactive oxygen species (ROS), and lipid peroxidation (LPO). Administration of BPA significantly decreased kidney weight. In the kidney, BPA can deplete GSH content and CAT activity, increase the mitochondrial ROS formation, and enhances LPO and mitochondrial membrane damage. The pretreatment of mitochondria with QUER has the ability to reduce the toxic effects of BPA in isolated mitochondria. These findings suggest a potential role for QUER in protecting mitochondria from oxidative damage in kidney tissue.

Identification of Key Metabolites for Acute Lung Injury in Patients with Sepsis

BACKGROUND

The study aimed to detect critical metabolites in acute lung injury (ALI).

METHODS

A comparative analysis of microarray profile of patients with sepsis-induced ALI compared with sepsis patients with was conducted using bioinformatic tools through constructing multi-omics network. Multi-omics composite networks (gene network, metabolite network, phenotype network, gene-metabolite association network, phenotype-gene association network, and phenotype-metabolite association network) were constructed, following by integration of these composite networks to establish a heterogeneous network. Next, seed genes, and ALI phenotype were mapped into the heterogeneous network to further obtain a weighted composite network. Random walk with restart (RWR) was used for the weighted composite network to extract and prioritize the metabolites. On the basis of the distance proximity among metabolites, the top 50 metabolites with the highest proximity were identified, and the top 100 co-expressed genes interacted with the top 50 metabolites were also screened out.

RESULTS

Totally, there were 9363 nodes and 10,226,148 edges in the integrated composite network. There were 4 metabolites with the scores > 0.009, including CHITIN, Tretinoin, sodium ion, and Celebrex. Adenosine 5'-diphosphate, triphosadenine, and tretinoin had higher degrees in the composite network and the co-expressed network.

CONCLUSION

Adenosine 5'-diphosphate, triphosadenine, and tretinoin may be potential biomarkers for diagnosis and treatment of ALI.

Quercetin rescued TNF-alpha-induced impairments in bone marrow-derived mesenchymal stem cell osteogenesis and improved osteoporosis in rats

To investigate the effect of quercetin on promoting the proliferation of bone marrow mesenchymal stem cells (BMSCs) and improving osteoporosis in rats. Rats were randomly divided into the sham, OVX and quercetin+OVX groups. In the sham and OVX groups, rats were given carboxymethyl cellulose sodium (CMC-Na). In the quercetin+OVX group, rats were given quercetin (50 mg/kg) once a day. Eight weeks after rats were treated, femurs were subjected to micro-CT scans, and bone biomechanical properties were analysed by the three-point flexural test. In addition, BMSCs were isolated and characterised by MTT, RT-PCR and Western blot analysis. In vivo, quercetin increased bone mineral density (BMD) and improved bone biomechanical properties in postmenopausal osteoporosis rat models. In vitro, TNF-α led to the activation of nuclear factor-kappa B (NF-κB) and the degradation of β-catenin, which were significantly inhibited by quercetin. Furthermore, quercetin promoted BMSC proliferation and osteogenic differentiation. In conclusion, quercetin improved in vitro models of osteoporosis and protected against TNF-α-induced impairments in BMSC osteogenesis.

Protective Effect of Quercetin in LPS-Induced Murine Acute Lung Injury Mediated by cAMP-Epac Pathway

Quercetin (Que) as an abundant flavonol element possesses potent antioxidative properties and has protective effect in lipopolysaccharide (LPS)-induced acute lung injury (ALI), but the specific mechanism is still unclear, so we investigated the effect of Que from in vivo and in vitro studies and the related mechanism of cAMP-PKA/Epac pathway. The results in mice suggested that Que can inhibit the release of inflammatory cytokine, block neutrophil recruitment, and decrease the albumin leakage in dose-dependent manners. At the same time, Que can increase the cAMP content of lung tissue, and Epac content, except PKA. The results in epithelial cell (MLE-12) suggested that Que also can inhibit the inflammatory mediators keratinocyte-derived chemokines release after LPS stimulation; Epac inhibitor ESI-09 functionally antagonizes the inhibitory effect of Que; meanwhile, PKA inhibitor H89 functionally enhances the inhibitory effect of Que. Overexpression of Epac1 in MLE-12 suggested that Epac1 enhance the effect of Que. All those results suggested that the protective effect of quercetin in ALI is involved in cAMP-Epac pathway.

Quercetin manipulates the expression of genes involved in the reactive oxygen species (ROS) process in chicken heterophils

Chicken heterophils generate reactive oxygen species (ROS) molecules to defend against invading pathogens. The present study examined effects of quercetin on chicken heterophils. Heterophils were stimulated with PBS, 50 µM quercetin (QH), PMA or Escherichia coli (EC) and the resulting intracellular ROS molecules were determined. Flow cytometry results showed that cells stimulated with QH, PMA and EC had a higher ROS production. Increases in intracellular ROS molecules were identified in all treatment groups by fluorescence microscopy. Determination of the ability of quercetin to manipulate mRNA expression of ROS subunits was assessed using real-time RT-PCR. Quercetin and other stimulants up-regulated the majority of genes involved in ROS production: CYBB (NOX2), NCF1 (p47^phox), NCF2 (p67^phox), NOX1 and RAC2. The antioxidant property of QH was explored by measuring mRNA expression of CAT and SOD1. The data indicate increased levels of CAT with all treatments; however, only QH attenuated the expression of the SOD1 gene. To further investigate the effects of ROS-driven inflammation or cell death, IL6, CASP8 and MCL1 genes were preferentially tested. The inflammatory gene (IL6) was profoundly down-regulated in the QH- and PMA-treated groups while EC induced a strikingly high IL6 expression level. Investigation of the known apoptotic (CASP8) and anti-apoptotic (MCL1) genes found down-regulation of CASP8 in the QH- and PMA-treated groups which were contradicted to the MCL1 gene. In conclusion, quercetin can enhance ROS production by regulating the expression of genes involved in ROS production as well as in subsequent processes.

Lutein prevents osteoarthritis through Nrf2 activation and downregulation of inflammation

INTRODUCTION

Osteoarthritis is an inflammatory disorder associated with oxidative stress and apoptosis leading to cartilage destruction and impairment of cartilage formation. In the present study, we studied the protective effect of lutein against monosodium iodoacetate (MIA)-induced osteoarthritis in primary chondrocyte cells.

MATERIAL AND METHODS

Oxidative stress was determined through testing antioxidant status, reactive oxygen species levels and lipid peroxide content. Also, Nrf2 expression and its downstream target genes HO-1 and NQO-1 were determined. Inflammation was analyzed through NF-κB, COX-2 and pro-inflammatory cytokines (IL-6, TNF-α, IL-1β). In addition, the effects of MIA and lutein on mitochondrial membrane potential and caspase-3 levels were analyzed.

RESULTS

The results showed that lutein treatment significantly increased the cell viability of chondrocytes and offered significant cytoprotection by enhancing the antioxidant defense mechanisms and reducing oxidative stress (reactive oxygen species and lipid peroxidation). Lutein treatment showed anti-inflammatory effects by downregulating inflammatory proteins (NF-κB, COX-2) and pro-inflammatory cytokines (IL-6, TNF-α, IL-1β). Lutein reduced MIA-induced apoptosis through maintaining mitochondrial membrane potential and downregulating caspase-3 activity.

CONCLUSIONS

The present study shows significant cytoprotection offered by lutein against MIA-induced oxidative stress, inflammation and apoptosis by the modulatory effect of NF-κB and Nrf2 activation.

Oxidative stress and cellular pathways of asthma and inflammation: Therapeutic strategies and pharmacological targets

Asthma is a complex inflammatory disease characterized by airway inflammation and hyperresponsiveness. The mechanisms associated with the development and progression of asthma have been widely studied in multiple populations and animal models, and these have revealed involvement of various cell types and activation of intracellular signaling pathways that result in activation of inflammatory genes. Significant contributions of Toll-like-receptors (TLRs) and transcription factors such as NF-кB, have been reported as major contributors to inflammatory pathways. These have also recently been associated with mechanisms of oxidative biology. This is of important clinical significance as the observed inefficacy of current available treatments for severe asthma is widely attributed to oxidative stress. Therefore, targeting oxidizing molecules in conjunction with inflammatory mediators and transcription factors may present a novel therapeutic strategy for asthma. In this review, we summarize TLRs and NF-кB pathways in the context of exacerbation of asthma pathogenesis and oxidative biology, and we discuss the potential use of polyphenolic flavonoid compounds, known to target these pathways and possess antioxidant activity, as potential therapeutic agents for asthma.

The disturbed redox-balance in pulmonary fibrosis is modulated by the plant flavonoid quercetin

Idiopathic pulmonary fibrosis (IPF) is characterized by a disturbed pulmonary redox balance associated with inflammation. To restore this balance, antioxidants are often suggested as therapy for IPF but previous clinical trials with these compounds and their precursors have not been successful in the clinic. The exogenous antioxidant quercetin, which has a versatile antioxidant profile and is effective in restoring a disturbed redox balance, might be a better candidate. The aim of this study was to evaluate the protective effect of quercetin on oxidative and inflammatory markers in IPF. Here, we demonstrate that IPF patients have a significantly reduced endogenous antioxidant defense, shown by a reduced total antioxidant capacity and lowered glutathione and uric acid levels compared to healthy controls. This confirms that the redox balance is disturbed in IPF. Ex vivo incubation with quercetin in blood of both IPF patients and healthy controls reduces LPS-induced production of the pro-inflammatory cytokines IL-8 and TNFα. This anti-inflammatory effect was more pronounced in the blood of the patients. Our pro-fibrotic in vitro model, consisting of bleomycin-triggered BEAS-2B cells, shows that quercetin boosts the antioxidant response, by increasing Nrf2 activity, and decreases pro-inflammatory cytokine production in a concentration-dependent manner. Collectively, our findings implicate that IPF patients may benefit from the use of quercetin to restore the disturbed redox balance and reduce inflammation.

Anti-inflammatory Effects of Quercetin and Vitexin on Activated Human Peripheral Blood Neutrophils: - The effects of quercetin and vitexin on human neutrophils

Objectives

Polymorphonuclear neutrophils (PMNs) constitute the first line of defense against invading microbial pathogens. Early events in inflammation involve the recruitment of neutrophils to the site of injury or damage where changes in intracellular calcium can cause the activation of pro-inflammatory mediators from neutrophils including superoxide generation, degranulation and release of myeloperoxidase (MPO), productions of interleukin (IL)-8 and tumor necrosis factor α (TNF-α), and adhesion to the vascular endothelium. To address the anti-inflammatory role of flavonoids, in the present study, we investigated the effects of the flavonoids quercetin and vitexin on the stimulus-induced nitric oxide (NO), TNF-α, and MPO productions in human neutrophils.

Methods

Human peripheral blood neutrophils were isolated, and their viabilities were determined by using the Trypan Blue exclusion test. The polymorphonuclear leukocyte (PMNL) preparations contained more than 98% neutrophils as determined by morphological examination with Giemsa staining. The viabilities of cultured neutrophils with various concentrations of quercetin and vitexin (1 – 100 μM) were studied using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. Neutrophils were cultured in complete Roswell Park Memorial Institute (RPMI) medium, pre-incubated with or without quercetin and vitexin (25 μM) for 45 min, and stimulated with phorbol 12-myristate 13-acetate (PMA) (10⁻⁷ M). NO production was carried out through nitrite determination by using the Griess method. Also, the TNF-α and the MPO productions were measured using enzyme-linked immunosorbent assay (ELISA) kits and MPO assay kits.

Results

Neutrophil viability was not affected up to a concentration of 100 μM of quercetin or vitexin. Both quercetin and vitexin significantly inhibited TNF-α, NO, and MPO productions in human neutrophils (P < 0.001).

Conclusion

The present study showed that both quercetin and vitexin had significant anti-inflammatory effects. Thus, treatment with either quercetin or vitexin may be considered as a therapeutic strategy for treating patients with neutrophil-mediated inflammatory diseases.

Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats

Background

This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine.

Methods

32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d), 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS)/p38 mitogen activated protein kinase (p38MAPK) pathway was determined to explore the potential mechanism.

Results

Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA) and creatinine levels, malonaldehyde (MDA) content, and superoxide dismutase (SOD) activity in serum and the increases of calcium and alkaline phosphatase (ALP) activity in the aorta (P < 0.05) and attenuated calcification and calcium accumulation in the medial layer of vasculature in histopathology. Western blot analysis showed that iNOS/p38MAPK pathway was normalized by the quercetin supplementation.

Conclusions

Quercetin exerted a protective effect on vascular calcification in adenine-induced chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway.

ANTIOXIDANT AND ANTI-INFLAMMATORY EFFECTS OF RHAMNAZIN ON LIPOPOLYSACCHARIDE-INDUCED ACUTE LUNG INJURY AND INFLAMMATION IN RATS

Background:

Acute Lung Injury (ALI) results into severe inflammation and oxidative stress to the pulmonary tissue. Rhamnazin is a natural flavonoid and known for its antioxidant and anti-inflammatory properties.

Materials and methods:

The antioxidative and anti-inflammatory properties rhamnazin were tested for protection against the acute lung injury. We investigated whether rhamnazin improves the lipopolysaccharide (LPS)-induced ALI in an animal model (rat). We also studied the probable molecular mechanism of action of rhamnazin. Rhamnazin was injected intraperitoneally (i.p.) (5, 10 and 20 mg/kg) two days before intratracheal LPS challenge (5mg/kg). The changes in lung wet-to-dry weight ratio, LDH activity, pulmonary histopathology, BALF protein concentration, MPO activity, oxidative stress, cytokine production were estimated.

Results:

The results showed a significant attenuation of all the inflammatory parameters and a marked improvement in the pulmonary histopathology in the animal groups pretreated with rhamnazin. The rhamnazin pretreated group also showed activation of Nrf2 pathway and attenuation of ROS such as H₂O₂, MDA and hydroxyl ion. These results indicated that rhamnazin could attenuate the symptoms of ALI in rats due to its strong antioxidant and anti-inflammatory properties.

Conclusion:

The results strongly demonstrated that rhamnazin provides protection against LPS-induced ALI. The underlying mechanisms of its anti-inflammatory action may include inhibition of Nrf2 mediated antioxidative pathway.