Quercetin prevents progression of disease in elastase/LPS-exposed mice by negatively regulating MMP expression

A Lactobacillus Combination Ameliorates Lung Inflammation in an Elastase/LPS-induced Mouse Model of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is the world's leading lung disease and lacks effective and specific clinical strategies. Probiotics are increasingly used to support the improvement of the course of inflammatory diseases. In this study, we evaluated the potential of a lactic acid bacteria (LAB) combination containing Limosilactobacillus reuteri GMNL-89 and Lacticaseibacillus paracasei GMNL-133 to decrease lung inflammation and emphysema in a COPD mouse model. This model was induced by intranasal stimulation with elastase and LPS for 4 weeks, followed by 2 weeks of oral LAB administration. The results showed that the LAB combination decreased lung emphysema and reduced inflammatory cytokines (IL-1β, IL-6, TNF-α) in the lung tissue of COPD mice. Microbiome analysis revealed that Bifidobacterium and Akkermansia muciniphila, reduced in the gut of COPD mice, could be restored after LAB treatment. Microbial α-diversity in the lungs decreased in COPD mice but was reversed after LAB administration, which also increased the relative abundance of Candidatus arthromitus in the gut and decreased Burkholderia in the lungs. Furthermore, LAB-treated COPD mice exhibited increased levels of short-chain fatty acids, specifically acetic acid and propionic acid, in the cecum. Additionally, pulmonary emphysema and inflammation negatively correlated with C. arthromitus and Adlercreutzia levels. In conclusion, the combination of L. reuteri GMNL-89 and L. paracasei GMNL-133 demonstrates beneficial effects on pulmonary emphysema and inflammation in experimental COPD mice, correlating with changes in gut and lung microbiota, and providing a potential strategy for future adjuvant therapy.

Evidence Construction of Chuankezhi Injection Against Chronic Obstructive Pulmonary Disease: A Systematic Review and Network Pharmacology

Objective

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease with high prevalence, morbidity, and mortality. Chuankezhi (CKZ) injection, a Chinese patent medicine, has been commonly used for treating COPD. This study evaluated the clinical efficacy of CKZ injections in COPD patients and explored potential underlying mechanisms by integrating meta-analysis and network pharmacology.

Research Methods

Randomized controlled trials (RCTs) were search in database by Web of Science, Cochrane Library and PubMed as of November 2022 for literature collection, and the Review Manager 5.4 was used to analyze the data. Through the network pharmacology method, the chemical components and their targets, as well as the disease targets were further analyzed.

Results

A total of 15 RCTs including 1212 patients were included. The results of meta-analysis showed that CKZ injection can significantly improve the clinical effective rate (RR = 1.25, 95% CI: 1.14 to 1.36), and the clinical advantage was that it can significantly reduced acute exacerbation rate (RR = 0.29, 95% CI: 0.12 to 0.70) and COPD assessment test (CAT) scores (MD =-4.62, 95% CI:-8.966 to-0.28). A total of 31 chemical compounds and 178 potential targets for CKZ injection were obtained from the online databases. Molecular docking revealed that most key components and targets could form stable structure.

Conclusion

This systematic review with meta-analysis and network pharmacology demonstrates that CKZ could effectively improve the clinical efficacy and safety in the treatment of COPD. Such efficacy may be related to an anti-inflammatory effect and immunoregulation of CKZ via multiple components, multiple targets and multiple pathways.

In vitro and in vivo protective potential of quercetin-3-glucuronide against lipopolysaccharide-induced pulmonary injury through dual activation of nuclear factor-erythroid 2 related factor 2 and autophagy

In vitro and in vivo models of lipopolysaccharide (LPS)-induced pulmonary injury, quercetin-3-glucuronide (Q3G) has been previously revealed the lung-protective potential via downregulation of inflammation, pyroptotic, and apoptotic cell death. However, the upstream signals mediating anti-pulmonary injury of Q3G have not yet been clarified. It has been reported that concerted dual activation of nuclear factor-erythroid 2 related factor 2 (Nrf2) and autophagy may prove to be a better treatment strategy in pulmonary injury. In this study, the effect of Q3G on antioxidant and autophagy were further investigated. Noncytotoxic doses of Q3G abolished the LPS-caused cell injury, and reactive oxygen species (ROS) generation with inductions in Nrf2-antioxidant signaling. Moreover, Q3G treatment repressed Nrf2 ubiquitination, and enhanced the association of Keap1 and p62 in the LPS-treated cells. Q3G also showed potential in inducing autophagy, as demonstrated by formation of acidic vesicular organelles (AVOs) and upregulation of autophagy factors. Next, the autolysosomes formation and cell survival were decreased by Q3G under pre-treatment with a lysosome inhibitor, chloroquine (CQ). Furthermore, mechanistic assays indicated that anti-pulmonary injury effects of Q3G might be mediated via Nrf2 signaling, as confirmed by the transfection of Nrf2 siRNA. Finally, Q3G significantly alleviated the development of pulmonary injury in vivo, which may result from inhibiting the LPS-induced lung dysfunction and edema. These findings emphasize a toxicological perspective, providing new insights into the mechanisms of Q3G's protective effects on LPS-induced pulmonary injury and highlighting its role in dual activating Nrf2 and autophagy pathways.

Quercetin improves epithelial regeneration from airway basal cells of COPD patients

BACKGROUND

Airway basal cells (BC) from patients with chronic obstructive pulmonary disease (COPD) regenerate abnormal airway epithelium and this was associated with reduced expression of several genes involved in epithelial repair. Quercetin reduces airway epithelial remodeling and inflammation in COPD models, therefore we examined whether quercetin promotes normal epithelial regeneration from COPD BC by altering gene expression.

METHODS

COPD BC treated with DMSO or 1 µM quercetin for three days were cultured at air/liquid interface (ALI) for up to 4 weeks. BC from healthy donors cultured at ALI were used as controls. Polarization of cells was determined at 8 days of ALI. The cell types and IL-8 expression in differentiated cell cultures were quantified by flow cytometry and ELISA respectively. Microarray analysis was conducted on DMSO or 1 µM quercetin-treated COPD BC for 3 days to identify differentially regulated genes (DEG). Bronchial brushings obtained from COPD patients with similar age and disease status treated with either placebo (4 subjects) or 2000 mg/day quercetin (7 subjects) for 6 months were used to confirm the effects of quercetin on gene expression.

RESULTS

Compared to placebo-, quercetin-treated COPD BC showed significantly increased transepithelial resistance, more ciliated cells, fewer goblet cells, and lower IL-8. Quercetin upregulated genes associated with tissue and epithelial development and differentiation in COPD BC. COPD patients treated with quercetin, but not placebo showed increased expression of two developmental genes HOXB2 and ELF3, which were also increased in quercetin-treated COPD BC with FDR < 0.001. Active smokers showed increased mRNA expression of TGF-β (0.067) and IL-8 (22.0), which was reduced by 3.6 and 4.14 fold respectively after quercetin treatment.

CONCLUSIONS

These results indicate that quercetin may improve airway epithelial regeneration by increasing the expression of genes involved in epithelial development/differentiation in COPD.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov on 6-18-2019. The study number is NCT03989271.

Targeting accelerated pulmonary ageing to treat chronic obstructive pulmonary disease-induced neuropathological comorbidities

Chronic obstructive pulmonary disease (COPD) is a major incurable health burden, ranking as the third leading cause of death worldwide, mainly driven by cigarette smoking. COPD is characterised by persistent airway inflammation, lung function decline and premature ageing with the presence of pulmonary senescent cells. This review proposes that cellular senescence, a state of stable cell cycle arrest linked to ageing, induced by inflammation and oxidative stress in COPD, extends beyond the lungs and affects the systemic circulation. This pulmonary senescent profile will reach other organs via extracellular vesicles contributing to brain inflammation and damage, and increasing the risk of neurological comorbidities, such as stroke, cerebral small vessel disease and Alzheimer's disease. The review explores the role of cellular senescence in COPD-associated brain conditions and investigates the relationship between cellular senescence and circadian rhythm in COPD. Additionally, it discusses potential therapies, including senomorphic and senolytic treatments, as novel strategies to halt or improve the progression of COPD.

Sodium butyrate (SB) ameliorated inflammation of COPD induced by cigarette smoke through activating the GPR43 to inhibit NF-κB/MAPKs signaling pathways

Cigarette smoke is recognized as a major trigger for individuals with chronic obstructive pulmonary disease (COPD), leading to an amplified inflammatory response. The onset and progression of COPD are affected by multiple environmental and genetic risk factors, such as inflammatory mechanisms, oxidative stress, and an imbalance between proteinase and antiprotease. As a result, conventional drug therapies often have limited effectiveness. This study aimed to investigate the anti-inflammatory effect of sodium butyrate (SB) in COPD and explore its molecular mechanism, thereby deepening our understanding of the potential application of SB in the treatment of COPD. In our study, we observed an increase in the mRNA and protein expressions of inflammatory factors interleukin-1beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), Matrix metallopeptidase 9 (MMP9) and MMP12 in both NR8383 cell and rat models of COPD. However, these expressions were significantly reduced after SB treatment. Meanwhile, SB treatment effectively decreased the phosphorylation levels of nuclear transcription factor-kappa B (NF-κB) p65, c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) and inhibited the nuclear translocation of these proteins in the COPD cells, leading to a reduction in the expression of various inflammatory cytokines. Additionally, SB also inhibited the expression level of the Nod-like receptor pyrin domain 3 (NLRP3) inflammasome, which consists of NLRP3, apoptosis-associated speck-like protein (ASC), and Caspase-1 in the cigeratte smoke extract (CSE)-stimulated cells. Our results showed that CSE down-regulated the mRNA levels of G-protein-coupled receptor 43 (GPR43) and GPR109A, while SB only up-regulated the expression of GPR43 and had no effect on GPR109A. Moreover, additional analysis demonstrated that the knockdown of GPR43 diminishes the anti-inflammatory effects of SB. It is evident that siRNA-mediated knockdown of GPR43 prevented the reduction in mRNA expression of IL-1β, IL-6, TNF-α, MMP9, and MMP12, as well as the expression of phosphorylated proteins NF-κB p65, JNK, and p38 MAPKs with SB treatment. These findings revealed a SB/GPR43 mediated pathway essential for attenuating pulmonary inflammatory responses in COPD, which may offer potential new treatments for COPD.

Immune Diseases Associated with Aging: Molecular Mechanisms and Treatment Strategies

Aging is associated with a decline in immune function, thereby causing an increased susceptibility to various diseases. Herein, we review immune diseases associated with aging, focusing on tumors, atherosclerosis, and immunodeficiency disorders. The molecular mechanisms underlying these conditions are discussed, highlighting telomere shortening, tissue inflammation, and altered signaling pathways, e.g., the mammalian target of the rapamycin (mTOR) pathway, as key contributors to immune dysfunction. The role of the senescence-associated secretory phenotype in driving chronic tissue inflammation and disruption has been examined. Our review underscores the significance of targeting tissue inflammation and immunomodulation for treating immune disorders. In addition, anti-inflammatory medications, including corticosteroids and nonsteroidal anti-inflammatory drugs, and novel approaches, e.g., probiotics and polyphenols, are discussed. Immunotherapy, particularly immune checkpoint inhibitor therapy and adoptive T-cell therapy, has been explored for its potential to enhance immune responses in older populations. A comprehensive analysis of immune disorders associated with aging and underlying molecular mechanisms provides insights into potential treatment strategies to alleviate the burden of these conditions in the aging population. The interplay among immune dysfunction, chronic tissue inflammation, and innovative therapeutic approaches highlights the importance of elucidating these complex processes to develop effective interventions to improve the quality of life in older adults.

Quercetin improves epithelial regeneration from airway basal cells of COPD patients

Background

Airway basal cells from patients with chronic obstructive pulmonary disease (COPD) regenerate abnormal airway epithelium and this was associated with reduced expression of several genes involved in epithelial repair. Quercetin reduces goblet cell metaplasia and the expression of pro-inflammatory cytokines in COPD models. This study assessed whether quercetin improves epithelial regeneration from COPD airway basal cells.

Methods

COPD airway basal cells were treated with DMSO or 1 μM quercetin for three days. The cells were then cultured at air/liquid interface (ALI) for up to 4 weeks. Basal cells from healthy donors cultured at air/liquid interface were used as controls. Polarization of cells was determined at 8 days of ALI. The cell types and IL-8 expression in differentiated cell cultures were quantified by flow cytometry and ELISA. Microarray analysis was conducted on DMSO or quercetin-treated COPD basal cells to identify differentially regulated genes (DEG) and the enriched biological pathways. Bronchial brushings from COPD patients treated with either placebo or quercetin for 6 months were used to confirm the effects of quercetin on gene expression.

Results

Compared to DMSO, quercetin-treated COPD basal cells showed an increase in TER and regenerated the airway epithelium with more ciliated cells, and less goblet cells and IL-8. Comparison of DMSO- and quercetin-treated COPD basal cell transcriptomic profiles indicated that quercetin upregulated genes associated with tissue and epithelial development and differentiation. COPD patients treated with quercetin, but not placebo showed significantly increased expression of two developmental genes HOXB2 and ELF3, which were also increased in quercetin-treated COPD basal cells. Bronchial brushings from active smokers showed significantly increased mRNA expression of TGF-β and IL-8, and it was reduced after quercetin treatment.

Conclusions

These results indicate that quercetin may improve airway epithelial regeneration by increasing the expression of genes involved in epithelial development/differentiation in COPD.

Trial registration

This study was registered at ClinicalTrials.gov on 6-18-2019. The study number is NCT03989271.

Airway Epithelium Senescence as a Driving Mechanism in COPD Pathogenesis

Cellular senescence is a state of permanent cell cycle arrest triggered by various intrinsic and extrinsic stressors. Cellular senescence results in impaired tissue repair and remodeling, loss of physiological integrity, organ dysfunction, and changes in the secretome. The systemic accumulation of senescence cells has been observed in many age-related diseases. Likewise, cellular senescence has been implicated as a risk factor and driving mechanism in chronic obstructive pulmonary disease (COPD) pathogenesis. Airway epithelium exhibits hallmark features of senescence in COPD including activation of the p53/p21WAF1/CIP1 and p16INK4A/RB pathways, leading to cell cycle arrest. Airway epithelial senescent cells secrete an array of inflammatory mediators, the so-called senescence-associated secretory phenotype (SASP), leading to a persistent low-grade chronic inflammation in COPD. SASP further promotes senescence in an autocrine and paracrine manner, potentially contributing to the onset and progression of COPD. In addition, cellular senescence in COPD airway epithelium is associated with telomere dysfunction, DNA damage, and oxidative stress. This review discusses the potential mechanisms of airway epithelial cell senescence in COPD, the impact of cellular senescence on the development and severity of the disease, and highlights potential targets for modulating cellular senescence in airway epithelium as a potential therapeutic approach in COPD.

Elastin-targeted nanoparticles delivering doxycycline mitigate cytokine storm and reduce immune cell infiltration in LPS-mediated lung inflammation

BACKGROUND AND PURPOSE

Cytokine storm invoked during acute and chronic lung injury promotes alveolar damage and remodeling. The current study shows that degraded elastin-targeted nanoparticles releasing doxycycline (Doxy NPs) are potent in mitigating cytokines storm, migration of immune cells in the lungs, and inhibiting inflammasome pathways in the LPS mouse model.

EXPERIMENTAL APPROACH

Cytokine storm and lung injury were induced using LPS and elastase in C57BL/6 mice (rodent model for emphysema). The mice were then treated with I.V. Doxy NPs, blank NPs, or Doxy a day before LPS administration. Cytokine levels, immune cell population, and MMP activity were analyzed in broncheo-alveolar lavage fluid (BALF) 4 hours after LPS administration. Additionally, gene expression of IL-6, IL-1beta, MCP-1, NLRP3, Caspase 1 and MMPs were investigated in alveolar cells on day 3 after LPS administration.

KEY RESULTS

Doxycycline NPs but not Doxycycline significantly decreased IL-6, TNF-α, IL-23 and were significantly more effective in decreasing the percentage of immune cells in the BALF. This is the first in-vivo study to demonstrate that Doxycycline can effectively inhibit inflammasome pathways in the lungs.

CONCLUSION AND IMPLICATIONS

IV administration of elastin antibody conjugated Doxycycline-loaded albumin NPs can effectively modulate the local immune environment in the lungs, which is not achieved by IV Doxycycline even at 100-fold higher dose. This novel method of drug delivery can effectively lead to the repurposing of traditional Doxycycline as a potential adjunct treatment for managing the cytokine storm in the lungs in COPD and viral infections.

Antioxidant Activities of Natural Compounds from Caribbean Plants to Enhance Diabetic Wound Healing

Diabetic wound healing is a global medical challenge. Several studies showed that delayed healing in diabetic patients is multifactorial. Nevertheless, there is evidence that excessive production of ROS and impaired ROS detoxification in diabetes are the main cause of chronic wounds. Indeed, increased ROS promotes the expression and activity of metalloproteinase, resulting in a high proteolytic state in the wound with significant destruction of the extracellular matrix, which leads to a stop in the repair process. In addition, ROS accumulation increases NLRP3 inflammasome activation and macrophage hyperpolarization in the M1 pro-inflammatory phenotype. Oxidative stress increases the activation of NETosis. This leads to an elevated pro-inflammatory state in the wound and prevents the resolution of inflammation, an essential step for wound healing. The use of medicinal plants and natural compounds can improve diabetic wound healing by directly targeting oxidative stress and the transcription factor Nrf2 involved in the antioxidant response or the mechanisms impacted by the elevation of ROS such as NLRP3 inflammasome, the polarization of macrophages, and expression or activation of metalloproteinases. This study of the diabetic pro-healing activity of nine plants found in the Caribbean highlights, more particularly, the role of five polyphenolic compounds. At the end of this review, research perspectives are presented.

Protective Effect of Lonicera japonica on PM2.5-Induced Pulmonary Damage in BALB/c Mice via the TGF-β and NF-κB Pathway

This study aimed to assess the protective effect of an extract of Lonicera japonica against particulate-matter (PM)_2.5-induced pulmonary inflammation and fibrosis. The compounds with physiological activity were identified as shanzhiside, secologanoside, loganic acid, chlorogenic acid, secologanic acid, secoxyloganin, quercetin pentoside, and dicaffeoyl quinic acids (DCQA), including 3,4-DCQA, 3,5-DCQA, 4,5-DCQA, and 1,4-DCQA using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS^E). The extract of Lonicera japonica reduced cell death, reactive oxygen species (ROS) production, and inflammation in A549 cells. The extract of Lonicera japonica decreased serum T cells, including CD4⁺ T cells, CD8⁺ T cells, and total T helper 2 (Th2) cells, and immunoglobulins, including immunoglobulin G (IgG) and immunoglobulin E (IgE), in PM_2.5-induced BALB/c mice. The extract of Lonicera japonica protected the pulmonary antioxidant system by regulating superoxide dismutase (SOD) activity, reduced glutathione (GSH) contents, and malondialdehyde (MDA) levels. In addition, it ameliorated mitochondrial function by regulating the production of ROS, mitochondrial membrane potential (MMP), and ATP contents. Moreover, the extract of Lonicera japonica exhibited a protective activity of apoptosis, fibrosis, and matrix metalloproteinases (MMPs) via TGF-β and NF-κB signaling pathways in lung tissues. This study suggests that the extract of Lonicera japonica might be a potential material to improve PM_2.5-induced pulmonary inflammation, apoptosis, and fibrosis.

Role of cellular senescence in inflammatory lung diseases

Cellular senescence, a characteristic sign of aging, classically refers to permanent cell proliferation arrest and is a vital contributor to the pathogenesis of cancer and age-related illnesses. A lot of imperative scientific research has shown that senescent cell aggregation and the release of senescence-associated secretory phenotype (SASP) components can cause lung inflammatory diseases as well. In this study, the most recent scientific progress on cellular senescence and phenotypes was reviewed, including their impact on lung inflammation and the contributions of these findings to understanding the underlying mechanisms and clinical relevance of cell and developmental biology. Within a dozen pro-senescent stimuli, the irreparable DNA damage, oxidative stress, and telomere erosion are all crucial in the long-term accumulation of senescent cells, resulting in sustained inflammatory stress activation in the respiratory system. An emerging role for cellular senescence in inflammatory lung diseases was proposed in this review, followed by the identification of the main ambiguities, thus further understanding this event and the potential to control cellular senescence and pro-inflammatory response activation. In addition, novel therapeutic strategies for the modulation of cellular senescence that might help to attenuate inflammatory lung conditions and improve disease outcomes were also presented in this research.

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.

The therapeutic potential of quercetin for cigarette smoking-induced chronic obstructive pulmonary disease: a narrative review

Quercetin is a flavonoid with antioxidant and anti-inflammatory properties. Quercetin has potentially beneficial therapeutic effects for several diseases, including cigarette smoking-induced chronic obstructive pulmonary disease (CS-COPD). Many studies have shown that quercetin's antioxidant and anti-inflammatory properties have positive therapeutic potential for CS-COPD. In addition, quercetin's immunomodulatory, anti-cellular senescence, mitochondrial autophagy-modulating, and gut microbiota-modulating effects may also have therapeutic value for CS-COPD. However, there appears to be no review of the possible mechanisms of quercetin for treating CS-COPD. Moreover, the combination of quercetin with common therapeutic drugs for CS-COPD needs further refinement. Therefore, in this article, after introducing the definition and metabolism of quercetin, and its safety, we comprehensively presented the pathogenesis of CS-COPD related to oxidative stress, inflammation, immunity, cellular senescence, mitochondrial autophagy, and gut microbiota. We then reviewed quercetin's anti-CS-COPD effects, performed by influencing these mechanisms. Finally, we explored the possibility of using quercetin with commonly used drugs for treating CS-COPD, providing a basis for future screening of excellent drug combinations for treating CS-COPD. This review has provided meaningful information on quercetin's mechanisms and clinical use in treating CS-COPD.

Selected Phytochemicals to Combat Lungs Injury: Natural Care

The human has two lungs responsible for respiration and drug metabolism. Severe lung infection caused by bacteria, mycobacteria, viruses, fungi, and parasites may lead to lungs injury. Smoking and tobacco consumption may also produce lungs injury. Inflammatory and pain mediators are secreted by alveolar macrophages. The inflammatory mediators, such as cytokines, interleukin (IL)-1, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α, neutrophils, and fibroblasts are accumulated in the alveoli sac, which becomes infected. It may lead to hypoxia followed by severe pulmonary congestion and the death of the patient. There is an urgent need for the treatment of artificial respiration and ventilation. However, the situation may be the worst for patients suffering from lung cancer, pulmonary tuberculosis, and acute pneumonia caused by acute respiratory distress syndrome (ARDS). Re-urgency has been happening in the case of coronavirus disease of 2019 (COVID-19) patients. Therefore, it is needed to protect the lungs with the intake of natural phytomedicines. In the present review, several selected phyto components having the potential role in lung injury therapy have been discussed. Regular intake of natural vegetables and fruits bearing these constituents may save the lungs even in the dangerous attack of SARS-CoV-2 in lung cancer, pulmonary TB, and pneumatic patients.

Analysis of the Clinical Efficacy and Molecular Mechanism of Xuefu Zhuyu Decoction in the Treatment of COPD Based on Meta-Analysis and Network Pharmacology

Background

Chronic obstructive pulmonary disease (COPD) is becoming a major public health burden worldwide. It is urgent to explore more effective and safer treatment strategy for COPD. Notably, Xuefu Zhuyu Decoction (XFZYD) is widely used to treat respiratory system diseases, including COPD, in China.

Objective

This study is aimed at comprehensively evaluating the therapeutic effects and molecular mechanism of XFZYD on COPD.

Methods

Original clinical studies were searched from eight literature databases. Meta-analysis was conducted using the Review Manager software (version 5.4.1). Network pharmacology and molecular docking experiments were utilized to explore the mechanisms of action of XFZYD.

Results

XFZYD significantly enhanced the efficacy of clinical treatment and improved the pulmonary function and hypoventilation of COPD patients. In addition, XFZYD significantly improved the hypercoagulability of COPD patients. The subgroup analysis suggested that XFZYD exhibited therapeutic effects on both stable and acute exacerbation of COPD. XFZYD exerted its therapeutic effects on COPD through multicomponent, multitarget, and multipathway characteristics. The intervention of the PI3K-AKT pathway may be the critical mechanism.

Conclusion

The application of XFZYD based on symptomatic relief and supportive treatment is a promising clinical decision. More preclinical and clinical studies are still needed to evaluate the safety and therapeutic effects of long-term use of XFZYD on COPD.

Exploiting the potential of lung stem cells to develop pro-regenerative therapies

Acute and chronic lung diseases are a leading cause of morbidity and mortality globally. Unfortunately, these diseases are increasing in frequency and we have limited treatment options for severe lung diseases. New therapies are needed that not only treat symptoms or slow disease progression, but also enable the regeneration of functional lung tissue. Both airways and alveoli contain populations of epithelial stem cells with the potential to self-renew and produce differentiated progeny. Understanding the mechanisms that determine the behaviour of these cells, and their interactions with their niches, will allow future generations of respiratory therapies that protect the lungs from disease onset, promote regeneration from endogenous stem cells or enable regeneration through the delivery of exogenous cells. This review summarises progress towards each of these goals, highlighting the challenges and opportunities of developing pro-regenerative (bio)pharmaceutical, gene and cell therapies for respiratory diseases.

Network Pharmacology and Experimental Verification Revealed the Mechanism of Yiqi Jianpi Recipe on Chronic Obstructive Pulmonary Disease

Objective

The study aimed to explore the active ingredients, targets, and mechanism of action of Yiqi Jianpi recipe (YQJPR) in the treatment of COPD based on the network pharmacology and COPD rat models.

Methods

The active ingredients and targets of YQJPR were collected by TCMSP. Disease-related protein targets were obtained from GeneCards. The Venn diagram was used to show the key therapeutic targets of COPD in YQJPR. The PPI network was established by STRING, and cytoHubba plug-in was used to screen the core targets within the network. GO functional enrichment and KEGG pathway enrichment analysis were performed to describe the functions and pathways of the core targets. Cytoscape software was used to construct the ingredient-target network and the core target-enrichment pathway network. The chemical constituents of YQJPR were analyzed by HPLC-MS/MS.

Results

The network pharmacology showed 152 active ingredients and 225 targets in YQJPR for the treatment of COPD. The key active ingredients were quercetin, luteolin, kaempferol, tanshinone IIA, and baicalein. The contents of quercetin and luteolin in YQJPR were quantitatively measured by HPLC-MS/MS. 22 core genes were screened, including AKT1, IL-6, JUN, VEGFA, and CASP3, which were mainly involved in BPs such as cell proliferation and differentiation, oxidative/chemical stress, and regulation of DNA-binding transcription factor activity and regulated viral infection, tumor, HIF-1, MAPK, TNF, and IL-17 pathways. Animal experiments showed that YQJPR could significantly reduce the expression of p-ERK1/2, p-Akt, c-Myc, cleaved caspase-3, and p-Stat3 in lung tissue (p < 0.05). HE staining showed that, compared with the model group, YQJPR significantly improved lung tissue morphology and reduced lung inflammation in rats.

Conclusion

The effects of YQJPR on COPD may involve multiple components, pathways, and targets. This study provides new ideas for further and more comprehensive exploration of the therapeutic effect of YQJPR on COPD in the future.

Network Pharmacology and Molecular Docking Study of Yupingfeng Powder in the Treatment of Allergic Diseases

Objective

To explore the potential mechanisms of Yupingfeng Powder (YPFP) in the treatment of allergic diseases by using network pharmacology and molecular docking technology.

Methods

The active components and targets of YPFP were screened by the TCMSP database. The targets associated with atopic dermatitis, asthma, allergic rhinitis, and food allergy were obtained from GeneCards and OMIM databases, respectively. The intersection of the above disease-related targets was identified as allergy-related targets. Then, allergy-related targets and YPFP-related targets were crossed to obtain the potential targets of YPFP for allergy treatment. A protein-protein-interaction (PPI) network and a drug-target-disease topology network were constructed to screen hub targets and key ingredients. Next, GO and KEGG pathway enrichment analyses were performed separately on the potential targets and hub targets to identify the biological processes and signaling pathways involved. Finally, molecular docking was conducted to verify the binding affinity between key ingredients and hub targets.

Results

In this study, 45 active ingredients were identified from YPFP, and 48 allergy-related targets were predicted by network pharmacology. IL6, TNF, IL1B, PTGS2, CXCL8, JUN, CCL2, IL10, IFNG, and IL4 were screened as hub targets by the PPI network. However, quercetin, kaempferol, wogonin, formononetin, and 7-O-methylisomucronulatol were identified as key ingredients by the drug-target-disease topological network. GO and KEGG pathway enrichment analysis indicated that the therapeutic effect of YPFP on allergy involved multiple biological processes and signaling pathways, including positive regulation of fever generation, positive regulation of neuroinflammatory response, vascular endothelial growth factor production, negative regulation of cytokine production involved in immune response, positive regulation of mononuclear cell migration, type 2 immune response, and negative regulation of lipid storage. Molecular docking verified that all the key ingredients had good binding affinity with hub targets.

Conclusion

This study revealed the key ingredients, hub targets, and potential mechanisms of YPFP antiallergy, and these data can provide some theoretical basis for subsequent allergy treatment and drug development.

Natural products in the treatment of pulmonary emphysema: Therapeutic effects and mechanisms of action

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a class of lung diseases including chronic bronchitis, asthma, and emphysema. Long-time smoking is considered the main reason for developing emphysema. Emphysema can be defined as damage to the walls of the air sacs (alveoli) of the lung. It has been demonstrated that natural compounds with antioxidant and anti-inflammatory effects can effectively improve or protect the lung against this disease. This paper is dedicated to systematically review the effective natural compounds in the treatment of pulmonary emphysema.

PURPOSE

This is the first systematic and comprehensive review on the role of plant-derived secondary metabolites in managing and/or treating pulmonary emphysema STUDY DESIGN AND METHODS: A systematic and comprehensive review was done based on Scopus, PubMed, and Cochrane Library databases were searched using the "emphysema", "plant", "herb", and "phytochemical" keywords. Non-English, review, and repetitive articles were excluded from the study. Search results were included in the Prisma diagram.

RESULTS

From a total of 1285 results, finally, 22 articles were included in the present study. The results show that some herbs such as Scutellaria baicalensis Georgi and Monascus adlay and some phytochemicals such as gallic acid and quercetin and blackboard tree indole alkaloids affect more factors in improving the lung emphysema. Also, some natural compounds such as marijuana smoke and humic acid also play an aggravating role in this disease. It also seems that some of the medicinal plants such as PM014 herbal formula, pomegranate juice and açaí berry sometimes have side effects that are inconsistent with their therapeutic effects.

CONCLUSION

We concluded that natural compounds can effectively improve pulmonary emphysema due to their antioxidant, anti-inflammatory, and anti-apoptotic properties. However, additional studies are suggested to prove efficacy and side effects.

Unraveling the Molecular Mechanism of Xuebijing Injection in the Treatment of Chronic Obstructive Pulmonary Disease by Combining Network Pharmacology and Affymetrix Array

Xuebijing injection (XBJ), one of the classical prescriptions for treating inflammation-related diseases, has been used to chronic obstructive pulmonary disease (COPD) in clinical practice. However, its molecular mechanism is still unclear. Network pharmacology combined with Affymetrix arrays and molecular docking techniques were applied to explore the molecular mechanism of XBJ for COPD. Predictive analysis of 728 active compounds in XBJ and 6 sets of Affymetrix arrays expression data resulted in 106 potential therapeutic targets. Next, based on the active compound-co-target network topology analysis, most of these targets were found to be modulated by quercetin, myricetin, and ellagic acid. Furthermore, protein–protein interaction (PPI) analysis revealed that the key targets may be EGFR, STAT3, AKT1, CCND1, MMP9, AR, ESR1, and PTGS2. Then, by constructing a component-target-pathway network, we found that XBJ was a multi-pathway, multi-target, multi-compound synergistic therapy for COPD, and four key targets were involved in the FoxO signaling pathway. Luteolin and salvianolic acid b had the optimal binding ability to several key proteins. Therefore, we hypothesize that quercetin, myricetin, ellagic acid, luteolin, and salvianolic acid b mainly contribute to the therapeutic effect of XBJ on COPD by modulating the FoxO signaling pathway by regulating EGFR, STAT3, AKT1, and CCND1. XBJ exerts anti-inflammatory and antioxidative stress effects through the PI3K/Akt/FoxO axis combined with MMP9, AR, ESR1, and PTGS2 to regulate other signaling pathways.

A critical evaluation of risk to reward ratio of quercetin supplementation for COVID-19 and associated comorbid conditions

The interim results of the large, multinational trials on coronavirus disease 2019 (COVID‐19) using a combination of antiviral drugs appear to have little to no effect on the 28‐day mortality or the in‐hospital course. Therefore, there is a still vivid interest in finding alternate re‐purposed drugs and nutrition supplements, which can halt or slow the disease severity. We review here the multiple preclinical studies, partially supported by clinical evidence showing the quercetin's possible therapeutic/prophylaxis efficacy against severe acute respiratory syndrome coronavirus (SARS‐CoV) as well as comorbidities like chronic obstructive pulmonary disease (COPD), diabetes mellitus, obesity, coagulopathy, and hypertension. Currently, 14 interventional clinical trials are underway assessing the efficacy of quercetin along with other antiviral drugs/nutritional supplements as prophylaxis/treatment option against COVID‐19. The present review is tempting to suggest that, based on circumstantial scientific evidence and preliminary clinical data, the flavonoid quercetin can ameliorate COVID‐19 infection and symptoms acting in concert on two parallel and independent paths: inhibiting key factors responsible for SARS‐CoV‐2 infections and mitigating the clinical manifestations of the disease in patients with comorbid conditions. Despite the broad therapeutic properties of quercetin, further high power randomized clinical trials are needed to firmly establish its clinical efficacy against COVID‐19.

Potential Natural Small Molecular Compounds for the Treatment of Chronic Obstructive Pulmonary Disease: An Overview

Chronic obstructive pulmonary disease (COPD) is one of the major diseases threatening human life and health. According to the report released by the World Health Organization (WHO) in 2020, COPD has become the third leading cause of death in the world, featuring a sustainable growth of incidence rate as well as population age. The purpose of this review focuses on the advancement of bioactive natural compounds, such as baicalin, quercetin, resveratrol, and curcumin, which demonstrate promising therapeutic/interventional effects on CODP in vitro and in vivo. Information emphasizing on COPD was systematically collected from several authoritative internet databases including Web of Science, PubMed, Elsevier, Wiley Online Library, and Europe PMC, with a combination of keywords containing “COPD” and “natural small molecular compounds”. The new evidence indicated that these valuable molecules featured unique functions in the treatment of COPD through various biological processes such as anti-inflammatory, anti-oxidant, anti-apoptosis, and anti-airway fibrosis. Moreover, we found that the promising effects of these natural compounds on COPD were mainly achieved through JAK3/STAT3/NF-κB and MAPK inflammatory signaling pathways, Nrf2 oxidative stress signaling pathway, and TGF-β1/Smad 2/3 fibrosis signaling pathway, which referenced to multiple targets like TNF-α, IL-6, IL-8, TIMP-1, MMP, AKT, JAK3, IKK, PI3K, HO-1, MAPK, P38, ERK, etc. Current challenges and future directions in this promising field are also discussed at the end of this review. For the convenience of the readers, this review is divided into ten parts according to the structures of potential natural small molecular compounds. We hope that this review brings a quick look and provides some inspiration for the research of COPD.

Role of oxidative stress in the pathogenesis of COPD

Chronic inhalation of cigarette smoke is a prominent cause of chronic obstructive pulmonary disease (COPD) and provides an important source of exogenous oxidants. In addition, several inflammatory and structural cells are a source of endogenous oxidants in the lower airways of COPD patients, even in former smokers. This suggests that oxidants play a key role in the pathogenesis of COPD. This oxidative stress is counterbalanced by the protective effects of the various endogenous antioxidant defenses of the lower airways. A large amount of data from animal models and patients with COPD have shown that both the stable phase of the disease, and during exacerbations, have increased oxidative stress in the lower airways compared with age-matched smokers with normal lung function. Thus, counteracting the increased oxidative stress may produce clinical benefits in COPD patients. Smoking cessation is currently the most effective treatment of COPD patients and reduces oxidative stress in the lower airways. In addition, many drugs used to treat COPD have some antioxidant effects, however, it is still unclear if their clinical efficacy is related to pharmacological modulation of the oxidant/antioxidant balance. Several new antioxidant compounds are in development for the treatment of COPD.

Quercetin Improves Pulmonary Function and Prevents Emphysema Caused by Exposure to Cigarette Smoke in Male Mice

Chronic obstructive pulmonary disease (COPD) is the major cause of morbidity and mortality worldwide, and cigarette smoke is a key factor in the development of COPD. Thus, the development of effective therapies to prevent the advancement of COPD has become increasingly essential. We hypothesized that quercetin protects lungs in mice exposed to long-term cigarette smoke. Thirty-five C57BL/6 mice were exposed to cigarette smoke (12 cigarettes per day) for 60 days and pretreated with 10 mg/kg/day of quercetin via orogastric gavage. After the experimental protocol, the animals were euthanized and samples were collected for histopathological, antioxidant defense, oxidative stress and inflammatory analysis. The animals exposed to cigarette smoke showed an increase in respiratory rate and hematological parameters, cell influx into the airways, oxidative damage and inflammatory mediators, besides presenting with alterations in the pulmonary histoarchitecture. The animals receiving 10 mg/kg/day of quercetin that were exposed to cigarette smoke presented a reduction in cellular influx, less oxidative damage, reduction in cytokine levels, improvement in the histological pattern and improvement in pulmonary emphysema compared to the group that was only exposed to cigarette smoke. These results suggest that quercetin may be an agent in preventing pulmonary emphysema induced by cigarette smoke.

Reactive Oxygen Species and Antioxidative Defense in Chronic Obstructive Pulmonary Disease

The respiratory system is continuously exposed to endogenous and exogenous oxidants. Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation of the airways, leading to the destruction of lung parenchyma (emphysema) and declining pulmonary function. It is increasingly obvious that reactive oxygen species (ROS) and reactive nitrogen species (RNS) contribute to the progression and amplification of the inflammatory responses related to this disease. First, we described the association between cigarette smoking, the most representative exogenous oxidant, and COPD and then presented the multiple pathophysiological aspects of ROS and antioxidative defense systems in the development and progression of COPD. Second, the relationship between nitric oxide system (endothelial) dysfunction and oxidative stress has been discussed. Third, we have provided data on the use of these biomarkers in the pathogenetic mechanisms involved in COPD and its progression and presented an overview of oxidative stress biomarkers having clinical applications in respiratory medicine, including those in exhaled breath, as per recent observations. Finally, we explained the findings of recent clinical and experimental studies evaluating the efficacy of antioxidative interventions for COPD. Future breakthroughs in antioxidative therapy may provide a promising therapeutic strategy for the prevention and treatment of COPD.

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.

Randomised clinical trial to determine the safety of quercetin supplementation in patients with chronic obstructive pulmonary disease

Introduction

Quercetin is a plant flavonoid and has potent antioxidant and anti-inflammatory properties. In a preclinical model of chronic obstructive pulmonary disease (COPD), quercetin reduced markers of both oxidative stress and lung inflammation and also reduced rhinovirus-induced progression of lung disease. Although quercetin appears to be an attractive natural alternative to manage COPD, the safety of quercetin supplementation in this population is unknown.

Methods

We recruited COPD patients with mild-to-severe lung disease with FVE1 ranging between >35% and <80% and supplemented with either placebo or quercetin at 500, 1000 or 2000 mg/day in a dose-escalation manner. The duration of quercetin supplementation was 1 week.

Results

Patients had no study drug-related severe adverse events based on blood tests, which included both complete blood counts and evaluation of comprehensive metabolic panel. One of the patients reported mild adverse events included gastro-oesophageal reflux disease, which was observed in both placebo and quercetin groups.

Conclusions

Quercetin was safely tolerated up to 2000 mg/day as assessed by lung function, blood profile and COPD assessment test questionnaire.

Trial registration number

NCT01708278

Treatment of chronic airway diseases using nutraceuticals: Mechanistic insight

Respiratory diseases, both acute and chronic, are reported to be the leading cause of morbidity and mortality, affecting millions of people globally, leading to high socio-economic burden for the society in the recent decades. Chronic inflammation and decline in lung function are the common symptoms of respiratory diseases. The current treatment strategies revolve around using appropriate anti-inflammatory agents and bronchodilators. A range of anti-inflammatory agents and bronchodilators are currently available in the market; however, the usage of such medications is limited due to the potential for various adverse effects. To cope with this issue, researchers have been exploring various novel, alternative therapeutic strategies that are safe and effective to treat respiratory diseases. Several studies have been reported on the possible links between food and food-derived products in combating various chronic inflammatory diseases. Nutraceuticals are examples of such food-derived products which are gaining much interest in terms of its usage for the well-being and better human health. As a consequence, intensive research is currently aimed at identifying novel nutraceuticals, and there is an emerging notion that nutraceuticals can have a positive impact in various respiratory diseases. In this review, we discuss the efficacy of nutraceuticals in altering the various cellular and molecular mechanisms involved in mitigating the symptoms of respiratory diseases.

The Role of Chronic Inflammation in Various Diseases and Anti-inflammatory Therapies Containing Natural Products

Chronic inflammation represents a long-term reaction of the body's immune system to noxious stimuli. Such a sustained inflammatory response sometimes results in lasting damage to healthy tissues and organs. In fact, chronic inflammation is implicated in the development and progression of various diseases, including cardiovascular diseases, respiratory diseases, metabolic diseases, neurodegenerative diseases, and even cancers. Targeting nonresolving inflammation thus provides new opportunities for treating relevant diseases. In this review, we will go over several chronic inflammation-associated diseases first with emphasis on the role of inflammation in their pathogenesis. Then, we will summarize a number of natural products that exhibit therapeutic effects against those diseases by acting on different markers in the inflammatory response. We envision that natural products will remain a rich resource for the discovery of new drugs treating diseases associated with chronic inflammation.

Oxidative Imbalance as a Crucial Factor in Inflammatory Lung Diseases: Could Antioxidant Treatment Constitute a New Therapeutic Strategy?

Inflammatory lung disease results in a high global burden of death and disability. There are no effective treatments for the most severe forms of many inflammatory lung diseases, such as chronic obstructive pulmonary disease, emphysema, corticosteroid-resistant asthma, and coronavirus disease 2019; hence, new treatment options are required. Here, we review the role of oxidative imbalance in the development of difficult-to-treat inflammatory lung diseases. The inflammation-induced overproduction of reactive oxygen species (ROS) means that endogenous antioxidants may not be sufficient to prevent oxidative damage, resulting in an oxidative imbalance in the lung. In turn, intracellular signaling events trigger the production of proinflammatory mediators that perpetuate and aggravate the inflammatory response and may lead to tissue damage. The production of high levels of ROS in inflammatory lung diseases can induce the phosphorylation of mitogen-activated protein kinases, the inactivation of phosphoinositide 3-kinase (PI3K) signaling and histone deacetylase 2, a decrease in glucocorticoid binding to its receptor, and thus resistance to glucocorticoid treatment. Hence, antioxidant treatment might be a therapeutic option for inflammatory lung diseases. Preclinical studies have shown that antioxidants (alone or combined with anti-inflammatory drugs) are effective in the treatment of inflammatory lung diseases, although the clinical evidence of efficacy is weaker. Despite the high level of evidence for the efficacy of antioxidants in the treatment of inflammatory lung diseases, the discovery and clinical investigation of safer, more efficacious compounds are now a priority.

Benefit of Physiologically Variable Over Pressure-Controlled Ventilation in a Model of Chronic Obstructive Pulmonary Disease: A Randomized Study

Introduction

The advantages of physiologically variable ventilation (PVV) based on a spontaneous breathing pattern have been demonstrated in several respiratory conditions. However, its potential benefits in chronic obstructive pulmonary disease (COPD) have not yet been characterized. We used an experimental model of COPD to compare respiratory function outcomes after 6 h of PVV versus conventional pressure-controlled ventilation (PCV).

Materials and Methods

Rabbits received nebulized elastase and lipopolysaccharide throughout 4 weeks. After 30 days, animals were anesthetized, tracheotomized, and randomized to receive 6 h of physiologically variable (n = 8) or conventional PCV (n = 7). Blood gases, respiratory mechanics, and chest fluoroscopy were assessed hourly.

Results

After 6 h of ventilation, animals receiving variable ventilation demonstrated significantly higher oxygenation index (PaO₂/FiO₂ 441 ± 37 (mean ± standard deviation) versus 354 ± 61 mmHg, p < 0.001) and lower respiratory elastance (359 ± 36 versus 463 ± 81 cmH₂O/L, p < 0.01) than animals receiving PCV. Animals ventilated with the variable mode also presented less lung derecruitment (decrease in lung aerated area, –3.4 ± 9.9 versus –17.9 ± 6.7%, p < 0.01) and intrapulmonary shunt fraction (9.6 ± 4.1 versus 17.0 ± 5.8%, p < 0.01).

Conclusion

PVV applied to a model of COPD improved oxygenation, respiratory mechanics, lung aeration, and intrapulmonary shunt fraction compared to conventional ventilation. A reduction in alveolar derecruitment and lung tissue stress leading to better aeration and gas exchange may explain the benefits of PVV.

The role of phytochemicals in sepsis: A mechanistic and therapeutic perspective

Sepsis and septic shock are still a leading cause of mortality and morbidity in intensive care units worldwide. Sepsis is an uncontrolled and excessive response of the innate immune system toward the invading infectious microbes, characterized by the hyper-production of pro-inflammatory mediators such as interleukin (IL)-1β, IL-6, tumor-necrosis factor (TNF)-α, and high-mobility group box 1 (HMGB1). In severe sepsis, the overwhelming production of pro-inflammatory cytokines and reactive oxygen species may compromise organ function and lead to the induction of abnormal apoptosis in different organs, resulting in multiple organ dysfunction syndrome and death. Hence, compounds that are able to attenuate inflammatory responses may have therapeutic potential for sepsis treatment. Understanding the pathophysiology and underlying molecular mechanisms of sepsis may provide useful insights in the discovery and development of new effective therapeutics. Therefore, numerous studies have invested much effort into elucidating the mechanisms involved with the onset and development of sepsis. The present review mainly focuses on the molecules and signaling pathways involved in the pathogenicity of sepsis. Additionally, several well-known natural bioactive herbal compounds and phytochemicals, which have shown protective and therapeutic effects with regard to sepsis, as well as their mechanisms of action, are presented. This review suggests that these phytochemicals are able to attenuate the overwhelming inflammatory responses developed during sepsis by modulating different signaling pathways. Moreover, the anti-inflammatory and cytoprotective activities of phytochemicals make them potent compounds to be included as complementary therapeutic agents in the diets of patients suffering from sepsis in an effort to alleviate sepsis and its life-threatening complications, such as multi-organ failure.

New Insight into the Mechanisms of Ginkgo Biloba Extract in Vascular Aging Prevention

BACKGROUND

Aging-associated vascular dysfunction promotes cardiovascular diseases. Recently, Ginkgo biloba extract (GBE) has attracted considerable attention in the prevention of aged vasculature.

METHODS

This review discusses the pathophysiological alterations in aged vasculature and the underlying mechanisms of GBE in vascular aging suppression.

RESULTS

Both arterial stiffening and endothelial dysfunction are critical aging-related vascular phenotypes that result in the progression of cardiovascular diseases in the general population. Consistent oxidative stress and inflammatory reaction lead to vascular dysfunction. GBE ameliorates aging-related vascular dysfunction, due to its antioxidant and anti-inflammatory properties. The main effects of GBE in aged vasculature might be associated with the longevity signaling pathways. GBE also attenuates the progression of vascular aging in diabetes mellitus via regulation of glucose and lipid metabolism.

CONCLUSION

GBE plays an important role in the prevention of vascular aging process. It is a promising therapeutic approach to ameliorate aging-related vascular dysfunction and cardiovascular diseases.

A mechanistic insight of phytoestrogens used for Rheumatoid arthritis: An evidence-based review

Assessment of the potential therapeutic benefits offered by naturally occurring phytoestrogens necessitate inspection of their potency and sites of action in impeding the chronic, systemic, autoimmune, joint destructing disorder Rheumatoid arthritis (RA). Possessing structural and functional similarity with human estrogen, phytoestrogen promisingly replaces the use of hormone therapy in eradicating RA symptoms with their anti-inflammatory, anti-oxidative, anti-proliferative, anti-angiogenesis, immunomodulatory, joint protection properties abolishing the harmful side effects of synthetic drugs. Scientific evidences revealed that use of phytoestrogens from different chemical categories including flavonoids, alkaloids, stilbenoids derived from different plant species manifest beneficial effects on RA through various cellular mechanisms including suppression of pro-inflammatory cytokines in particular tumor necrosis factor (TNF-α), interleukin(IL-6) and nuclear factor kappa B (NF-κB) and destructive metalloproteinases, inhibition of oxidative stress, suppressing inflammatory signalling pathways, attenuating osteoclastogenesis ameliorating cartilage degradation and bone erosion. This review summarizes the evidences of different phytoestrogen treatment and their pharmacological mechanisms in both in vitro and in vivo studies along with discussing clinical evaluations in RA patients showing phytoestrogen as a promising agent for RA therapy. Further investigations and more clinical trials are mandatory to clarify the utility of these plant derived compounds in RA prevention and in managing oestrogen deficient diseases in patients.

Cellular and molecular features of senescence in acute lung injury

A wide range of insults can trigger acute injury in the lungs, which eventually may lead to respiratory failure and death of patients. Current treatment relies mainly on supportive measures and mechanical ventilation. Even so, survivors frequently develop important sequels that compromise quality of life. In the search for new approaches to prevent and treat acute lung injury, many investigations have focused on molecular and cellular pathways which could exert a pathogenic role in this disease. Herein, we review recent findings in the literature suggesting that cellular senescence could be involved in lung injury and discuss the potential use of senotherapies to prevent disease progression.

Protective Effects of Quercetin on Livers from Mice Exposed to Long-Term Cigarette Smoke

Cigarette smoke is highly toxic, and it can promote increased production of reactive species and inflammatory response and leads to liver diseases. Quercetin is a flavonoid that displays antioxidant and anti-inflammatory activities in liver diseases. This study aimed at evaluating the protective effects of quercetin on livers from mice exposed to long-term cigarette smoke exposure. Male C57BL/6 mice were divided into five groups: control (CG), vehicle (VG), quercetin (QG), cigarette smoke (CSG), quercetin, and cigarette smoke (QCSG). CSG and QCSG were exposed to cigarette smoke for sixty consecutive days; at the end of the exposures, all animals were euthanized. Mice that received quercetin daily and were exposed to cigarette smoke showed a reduced influx of inflammatory cells, oxidative stress, inflammatory reaction, and histopathological changes in the liver, compared to CSG. These results suggest that quercetin may be an effective adjuvant for treating damage to the liver due to cigarette smoke exposure.

Sirtuins as endogenous regulators of lung fibrosis: A current perspective

Fibrotic lung diseases qualify among the most dreaded irreversible interstitial pulmonary complications with progressive yet largely unpredictable clinical course. Idiopathic pulmonary fibrosis (IPF) is the most challenging prototype characterized by unknown and complex molecular etiology, severe dearth of non-invasive therapeutic options and average lifespan of 2-5 years in patients post diagnosis. Lung fibrosis (LF) is a leading cause of death in the industrialized world with the propensity to contract, significantly increasing with age. Approximately 45% deaths in US are attributed to fibrotic diseases while around 7% respiratory disease-associated deaths, annually in UK, are actually attributed to IPF. Recent developments in the field of LF have unambiguously pointed towards the pivotal role of Sirtuins (SIRTs) in regulating disease progression, thereby qualifying as potential anti-fibrotic drug targets. These NAD⁺-dependent lysine deacetylases, deacylases and ADP-ribosyltransferases are evolutionarily conserved proteins, regulated by diverse metabolic/environmental factors and implicated in age-related degenerative and inflammatory disorders. While SIRT1, SIRT6 and SIRT7 are predominantly nuclear, SIRT3, SIRT4, SIRT5 are mainly mitochondrial and SIRT2 is majorly cytosolic with occasional nuclear translocation. SIRT1, SIRT3, SIRT6 and SIRT7 are documented as cytoprotective sirtuins implicated in cardiovascular, pulmonary and metabolic diseases including fibrosis; however functional roles of remaining sirtuins in pulmonary pathologies are yet elusive. Here, we provide a comprehensive recent update on the regulatory role of sirtuins on LF along with discussion on potential therapeutic modulation of endogenous Sirtuin expression through synthetic/plant-derived compounds which can help synthetic chemists and ethnopharmacologists to design new-generation cheap, non-toxic Sirtuin-based drugs against LF.

miR-138-5p targets sirtuin1 to regulate acute lung injury by regulation of the NF-κB signaling pathway

Acute lung injury (ALI), a disease with a high mortality rate, is a noncardiogenic pulmonary inflammatory response and characterized by damage to the pulmonary system. In this study, we explored the mechanism of the occurrence and development of ALI. It was firstly found that miR-138-5p could inhibit the expression of sirtuin1 (SIRT1), and we further demonstrated that miR-138-5p targets directly SIRT1 through the luciferase assay, while the latter negatively regulated the expression of NF-κB. A549 cells were treated with lipopolysaccharide in vitro to simulate ALI cells and induce ALI in the model mice. The results showed that inhibiting the expression of miR-138-5p could effectively increase the viability of damaged cells, promote cell proliferation, reduce apoptosis, inhibit the inflammatory response, reduce oxidative stress, and then relieve ALI symptoms. Collectively, our results suggested that miR-138-5p can inhibit SIRT1 expression and indirectly activate the NF-κB signaling pathway, thus regulating the development of ALI.

Quercetin and Vitamin C: An Experimental, Synergistic Therapy for the Prevention and Treatment of SARS-CoV-2 Related Disease (COVID-19)

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) represents an emergent global threat which is straining worldwide healthcare capacity. As of May 27th, the disease caused by SARS-CoV-2 (COVID-19) has resulted in more than 340,000 deaths worldwide, with 100,000 deaths in the US alone. It is imperative to study and develop pharmacological treatments suitable for the prevention and treatment of COVID-19. Ascorbic acid is a crucial vitamin necessary for the correct functioning of the immune system. It plays a role in stress response and has shown promising results when administered to the critically ill. Quercetin is a well-known flavonoid whose antiviral properties have been investigated in numerous studies. There is evidence that vitamin C and quercetin co-administration exerts a synergistic antiviral action due to overlapping antiviral and immunomodulatory properties and the capacity of ascorbate to recycle quercetin, increasing its efficacy. Safe, cheap interventions which have a sound biological rationale should be prioritized for experimental use in the current context of a global health pandemic. We present the current evidence for the use of vitamin C and quercetin both for prophylaxis in high-risk populations and for the treatment of COVID-19 patients as an adjunct to promising pharmacological agents such as Remdesivir or convalescent plasma.

Investigational treatments in phase I and II clinical trials: a systematic review in chronic obstructive pulmonary disease (COPD)

Introduction. The current pharmacological treatments for the management of stable COPD permit the reduction of symptoms and frequency and severity of exacerbations, and the improvement of exercise tolerance and health status. However, they do not modify the long-term decline in lung function and patient health. Consequently, there is the strong need for 'highly innovative' medications that are focused on new targets and/or mechanisms for the treatment of COPD. Areas covered. This systematic review assesses investigational agents in Phase I and II clinical trials over the last six years. It offers insights on whether drugs and/or formulations in clinical development offer future effective treatments of COPD. Expert opinion. There is no evidence to suggest that current investigational agents can reduce lung function decline and cure COPD. However, looking forward, investigational, innovative treatments in combination with the therapies already recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) may provide future suitable tools to counteract the progression of COPD.

Quercetin Attenuates Acute Lung Injury Caused by Cigarette Smoke Both In Vitro and In Vivo

Cigarette smoke is highly toxic and is a major risk factor for airway inflammation, oxidative stress, and decline in lung function-the starting points for chronic obstructive pulmonary disease. Quercetin is a potent dietary antioxidant that displays anti-inflammatory activities. The goal of this study was to evaluate the effects of quercetin on reducing the redox imbalance and inflammation induced by short-term cigarette smoke exposure. In vitro, 25 and 50 μM quercetin attenuated the effects of cigarette smoke extract (increased generation of reactive oxygen species and nitric oxide) on J774A.1 cells (macrophages). We further examined the effects of quercetin in vivo. Male C57Bl/6 mice that received 10 mg/kg/day of quercetin via orogastric gavage before exposure to five days of cigarette smoke demonstrated reduced levels of leukocyte, oxidative stress, histological pattern changes of pulmonary parenchyma, and lung function alterations compared to the group that did not receive quercetin. These results suggest that quercetin may be an effective adjuvant for treating the effects of cigarette smoke exposure.

Cellular Senescence as a Mechanism and Target in Chronic Lung Diseases

Cellular senescence is now considered an important driving mechanism for chronic lung diseases, particularly chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis. Cellular senescence is due to replicative and stress-related senescence with activation of p53 and p16^INK4a, respectively, leading to activation of p21^CIP1 and cell cycle arrest. Senescent cells secrete multiple inflammatory proteins known as the senescence-associated secretory phenotype, leading to low-grade chronic inflammation, which further drives senescence. Loss of key antiaging molecules sirtuin-1 and sirtuin-6 may be important in acceleration of aging and arises from oxidative stress reducing phosphatase PTEN (phosphatase tensin homolog), thereby activating PI3K (phosphoinositide-3-kinase) and mTOR (mammalian target of rapamycin). MicroRNA-34a (miR-34a), which is regulated by PI3K-mTOR signaling, plays a pivotal role in reducing sirtuin-1/6, and its inhibition with an antagomir results in their restoration, reducing markers of senescence, reducing senescence-associated secretory phenotype, and reversing cell cycle arrest in epithelial cells from peripheral airways of patients with COPD. miR-570 is also involved in reduction of sirtuin-1 and cellular senescence and is activated by p38 mitogen-activated protein kinase. These miRNAs may be released from cells in extracellular vesicles that are taken up by other cells, thereby spreading senescence locally within the lung but also outside the lung through the circulation; this may account for comorbidities of COPD and other lung diseases. Understanding the mechanisms of cellular senescence may result in new treatments for chronic lung disease, either by inhibiting PI3K-mTOR signaling, by inhibiting specific miRNAs, or by deletion of senescent cells with senolytic therapies, already shown to be effective in experimental lung fibrosis.

Preclinical Evaluation of the Antimicrobial-Immunomodulatory Dual Action of Xenohormetic Molecules against Haemophilus influenzae Respiratory Infection

Chronic obstructive pulmonary disease (COPD) is characterized by abnormal inflammation and impaired airway immunity, providing an opportunistic platform for nontypeable Haemophilus influenzae (NTHi) infection. In this context, therapies targeting not only overactive inflammation without significant adverse effects, but also infection are of interest. Increasing evidence suggests that polyphenols, plant secondary metabolites with anti-inflammatory and antimicrobial properties, may be protective. Here, a Cistus salviifolius plant extract containing quercetin, myricetin, and punicalagin was shown to reduce NTHi viability. Analysis of these polyphenols revealed that quercetin has a bactericidal effect on NTHi, does not display synergies, and that bacteria do not seem to develop resistance. Moreover, quercetin lowered NTHi airway epithelial invasion through a mechanism likely involving inhibition of Akt phosphorylation, and reduced the expression of bacterially-induced proinflammatory markers il-8, cxcl-1, il-6, pde4b, and tnfα. We further tested quercetin’s effect on NTHi murine pulmonary infection, showing a moderate reduction in bacterial counts and significantly reduced expression of proinflammatory genes, compared to untreated mice. Quercetin administration during NTHi infection on a zebrafish septicemia infection model system showed a bacterial clearing effect without signs of host toxicity. In conclusion, this study highlights the therapeutic potential of the xenohormetic molecule quercetin against NTHi infection.

Rhinovirus-Induced SIRT-1 via TLR2 Regulates Subsequent Type I and Type III IFN Responses in Airway Epithelial Cells

IFN responses to viral infection are necessary to establish intrinsic antiviral state, but if unchecked can lead to heightened inflammation. Recently, we showed that TLR2 activation contributes to limitation of rhinovirus (RV)-induced IFN response in the airway epithelial cells. We also demonstrated that compared with normal airway epithelial cells, those from patients with chronic obstructive pulmonary disease (COPD) show higher IFN responses to RV, but the underlying mechanisms are not known. Initially, RV-induced IFN responses depend on dsRNA receptor activation and then are amplified via IFN-stimulated activation of JAK/STAT signaling. In this study, we show that in normal cells, TLR2 limits RV-induced IFN responses by attenuating STAT1 and STAT2 phosphorylation and this was associated with TLR2-dependent SIRT-1 expression. Further, inhibition of SIRT-1 enhanced RV-induced IFN responses, and this was accompanied by increased STAT1/STAT2 phosphorylation, indicating that TLR2 may limit RV-induced IFN responses via SIRT-1. COPD airway epithelial cells showed attenuated IL-8 responses to TLR2 agonist despite expressing TLR2 similar to normal, indicating dysregulation in TLR2 signaling pathway. Unlike normal, COPD cells failed to show RV-induced TLR2-dependent SIRT-1 expression. Pretreatment with quercetin, which increases SIRT-1 expression, normalized RV-induced IFN levels in COPD airway epithelial cells. Inhibition of SIRT-1 in quercetin-pretreated COPD cells abolished the normalizing effects of quercetin on RV-induced IFN expression in these cells, confirming that quercetin exerts its effect via SIRT-1. In summary, we show that TLR2 is required for limiting RV-induced IFNs, and this pathway is dysregulated in COPD airway epithelial cells, leading to exaggerated IFN production.

Ginkgo Flavonol Glycosides or Ginkgolides Tend to Differentially Protect Myocardial or Cerebral Ischemia-Reperfusion Injury via Regulation of TWEAK-Fn14 Signaling in Heart and Brain

Shuxuening injection (SXNI), one of the pharmaceutical preparations of Ginkgo biloba extract, has significant effects on both ischemic stroke and heart diseases from bench to bedside. Its major active ingredients are ginkgo flavonol glycosides (GFGs) and ginkgolides (GGs). We have previously reported that SXNI as a whole protected ischemic brain and heart, but the active ingredients and their contribution to the therapeutic effects remain unclear. Therefore, we combined experimental and network analysis approach to further explore the specific effects and underlying mechanisms of GFGs and GGs of SXNI on ischemia–reperfusion injury in mouse brain and heart. In the myocardial ischemia–reperfusion injury (MIRI) model, pretreatment with GFGs at 2.5 ml/kg was superior to the same dose of GGs in improving cardiac function and coronary blood flow and reducing the levels of lactate dehydrogenase and aspartate aminotransferase in serum, with an effect similar to that achieved by SXNI. In contrast, pretreatment with GGs at 2.5 ml/kg reduced cerebral infarction area and cerebral edema similarly to that of SXNI but more significantly compared with GFGs in cerebral ischemia–reperfusion injury (CIRI) model. Network pharmacology analysis of GFGs and GGs revealed that tumor necrosis factor-related weak inducer of apoptosis (TWEAK)–fibroblast growth factor-inducible 14 (Fn14) signaling pathway as an important common mechanism but with differential targets in MIRI and CIRI. In addition, immunohistochemistry and enzyme linked immunosorbent assay (ELISA) assays were performed to evaluate the regulatory roles of GFGs and GGs on the common TWEAK–Fn14 signaling pathway to protect the heart and brain. Experimental results confirmed that TWEAK ligand and Fn14 receptor were downregulated by GFGs to mitigate MIRI in the heart while upregulated by GGs to improve CIRI in the brain. In conclusion, our study showed that GFGs and GGs of SXNI tend to differentially protect brain and heart from ischemia–reperfusion injuries at least in part by regulating a common TWEAK–Fn14 signaling pathway.