Protective effects of Isofraxidin against lipopolysaccharide-induced acute lung injury in mice

The coumarin component isofraxidin targets the G-protein-coupled receptor S1PR1 to modulate IL-17 signaling and alleviate ulcerative colitis

OBJECTIVE

The increasing global prevalence of ulcerative colitis (UC) underscores the imperative to explore novel therapeutic approaches. Traditional Chinese medicine has historically shown potential in addressing this ailment. The current study aimed to elucidate the functional attributes and underlying mechanisms of isofraxidin, a coumarin derivative from Acanthopanax, in the context of UC.

METHODS

A murine model of dextran sodium sulfate (DSS)-induced UC was established, and we conducted a comprehensive assessment of the influence of isofraxidin on UC symptomatology, colonic histopathological manifestations, the inflammatory response, and apoptosis. The potential receptor of isofraxidin was initially identified through the Target database and molecular docking analysis. Subsequent in vivo and in vitro experiments were conducted to determine the effects of isofraxidin on the identified receptor and associated signaling pathways. Transfection was used to examine the receptor's role in the regulatory mechanism of isofraxidin.

RESULTS

Isofraxidin reduced UC symptoms and colonic histopathological impairments. Furthermore, isofraxidin ameliorated the DSS-induced inflammatory response and apoptosis in tissues. S1PR1 was identified as a target of isofraxidin and effectively suppressed activation of the IL-17 signaling pathway. Intriguingly, cellular experiments indicated that overexpression of S1PR1 counteracted the protective effect of isofraxidin.

DISCUSSION

In summary, our investigation revealed that isofraxidin could modulate S1PR1 and regulate the IL-17 signaling pathway, thus ameliorating DSS-induced UC. These findings establish a robust foundation for considering isofraxidin as a prospective therapeutic intervention to treat UC.

Guben Qingfei decoction attenuates LPS-induced acute lung injury by modulating the TLR4/NF-κB and Keap1/Nrf2 signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury (ALI) is a life-threatening and widespread disease, with exceptionally high morbidity and mortality rates. Unfortunately, effective drugs for ALI treatment are currently lacking. Guben Qingfei decoction (GBQF) is a Chinese herbal compound known for its efficacy in treating viral pneumonia, yet the precise underlying mechanisms remain unknown.

AIM OF THE STUDY

This study aimed to validate the mitigating effect of GBQF on ALI and to further investigate its mechanism.

MATERIALS AND METHODS

An ALI mice model was established by infusing LPS into the endotracheal tube. The effects of GBQF on ALI were investigated by measuring lung W/D; MPO; BALF total protein concentration; total number of cells; TNF-α, IL-1β, and IL-6 levels; pathological changes in lung tissue, and oxidation products. Immunohistochemistry and Western Blotting were performed to verify the underlying mechanisms. MH-S and BEAS-2B cells were induced by LPS, and the effects of GBQF were confirmed by RT-PCR and immunofluorescence.

RESULTS

GBQF significantly reduced LPS-induced ALI in mice, improved lung inflammation, reduced the production of oxidative products, increased the activity of antioxidant enzymes, and reduced the degree of lung tissue damage. GBQF prevents MH-S cells from releasing inflammatory factors and reduces oxidative damage to BEAS-2B cells. In vivo studies have delved deeper into the mechanism of action of GBQF, revealing its correlation with the TLR4/NF-κB and Keap1/Nrf2 pathways.

CONCLUSIONS

Our study demonstrates that GBQF is an effective treatment for ALI, providing a new perspective on medication development for ALI treatment.

A comprehensive review on the chemical constituents, sesquiterpenoid biosynthesis and biological activities of Sarcandra glabra

Sarcandra glabra (Thunb.) Nakai is a perennial evergreen herb categorised within the Sarcandra Gardner genus under the Chloranthaceae family. Indigenous to tropical and subtropical regions of East Asia and India, this species is extensively distributed across China, particularly in the southern regions (Sichuan, Yunnan, and Jiangxi). In addition to its high ornamental value, S. glabra has a rich history of use in traditional Chinese medicine, evident through its empirical prescriptions for various ailments like pneumonia, dysentery, fractures, bruises, numbness, amenorrhea, rheumatism, and other diseases. Besides, modern pharmacological studies have revealed various biological activities, such as antitumour, anti-bacterial, anti-viral anti-inflammatory and immunomodulatory effects. The diverse chemical constituents of S. glabra have fascinated natural product researchers since the 1900s. To date, over 400 compounds including terpenoids, coumarins, lignans, flavonoids, sterols, anthraquinones, organic acids, and organic esters have been isolated and characterised, some featuring unprecedented structures. This review comprehensively examines the current understanding of S. glabra's phytochemistry and pharmacology, with emphasis on the chemistry and biosynthesis of its unique chemotaxonomic marker, the lindenane-type sesquiterpenoids.

Metabolic profiling of Chimonanthus grammatus via UHPLC-HRMS-MS with computer-assisted structure elucidation and its antimicrobial activity

Chimonanthus grammatus is used as Hakka traditional herb to treat cold, flu, etc. So far, the phytochemistry and antimicrobial compounds have not been well investigated. In this study, the orbitrap-ion trap MS was used to characterize its metabolites, combined with a computer-assisted structure elucidation method, and the antimicrobial activities were assessed by a broth dilution method against 21 human pathogens, as well as the bioassay-guided purification work to clarify its main antimicrobial compounds. A total of 83 compounds were identified with their fragmentation patterns, including terpenoids, coumarins, flavonoids, organic acids, alkaloids, and others. The plant extracts can strongly inhibit the growth of three Gram-positive and four Gram-negative bacteria, and nine active compounds were bioassay-guided isolated, including homalomenol C, jasmonic acid, isofraxidin, quercitrin, stigmasta-7,22-diene-3β,5α,6α-triol, quercetin, 4-hydroxy-1,10-secocadin-5-ene-1,10-dione, kaempferol, and E-4-(4,8-dimethylnona-3,7-dienyl)furan-2(5H)-one. Among them, isofraxidin, kaempferol, and quercitrin showed significant activity against planktonic Staphylococcus aureus (IC₅₀ = 13.51, 18.08 and 15.86 µg/ml). Moreover, their antibiofilm activities of S. aureus (BIC₅₀ = 15.43, 17.31, 18.86 µg/ml; BEC₅₀ = 45.86, ≥62.50, and 57.62 µg/ml) are higher than ciprofloxacin. The results demonstrated that the isolated antimicrobial compounds played the key role of this herb in combating microbes and provided benefits for its development and quality control, and the computer-assisted structure elucidation method was a powerful tool for chemical analysis, especially for distinguishing isomers with similar structures, which can be used for other complex samples.

Protective effects of isofraxidin against scopolamine-induced cognitive and memory impairments in mice involve modulation of the BDNF-CREB-ERK signaling pathway

BACKGROUND

Isofraxidin is a coumarin compound mainly isolated from several traditional and functional edible plants beneficial for neurodegenerative diseases, including Sarcandra glabra and Apium graveolens, and Siberian Ginseng.

OBJECTIVE

This study aimed to assess effects of isofraxidin against memory impairments and cognition deficits in a scopolamine-induced mouse model.

MATERIALS & METHODS

Animals were randomly divided into 6 groups, control, vehicle, donepezil (10 mg/kg, p.o.), and isofraxidin (3, 10, and 30 mg/kg, p.o.). Isofraxidin or donepezil was administered for 44 days, once per day. The scopolamine insults (1 mg/kg, i.p.) was given from the 21st day, once per day. Morris water maze test and Y-maze test were used for the behavioral test. After that, brain samples were collected for analysis.

RESULTS

Firstly, isofraxidin significantly improved scopolamine-induced behavioral impairments and cognition deficits in Morris water maze and Y-maze test. Then, isofraxidin facilitated cholinergic activity via inhibiting acetylcholinesterase (AChE) activity. Besides, isofraxidin decreased lipid peroxidation level but enhanced levels of glutathione, glutathione peroxidase, and superoxide dismutase. Moreover, isofraxidin suppressed the expression of inflammatory mediators and cytokines. Further investigations showed that isofraxidin up-regulated expression of brain-derived neurotrophic factor (BDNF), and promoted phosphorylation of tropomyosin-related kinase B (TrkB), cyclic AMP-response element-binding protein (CREB), and extracellular signal-regulated kinase (ERK).

DISCUSSION & CONCLUSIONS

These results suggested that isofraxidin ameliorated scopolamine-induced cognitive and memory impairments, possibly through regulating AChE activity, suppressing oxidative stress and inflammatory response, and modulating BDNF-CREB-ERK pathways.

Aesculetin exhibited anti-inflammatory activities through inhibiting NF-кB and MAPKs pathway in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Aesculetin (6,7-dihydroxy-2H-1-benzopyran-2-one) has been reported to exhibit potent anti-inflammatory property both in vitro and in vivo.

AIMS OF THIS STUDY

In this study, we evaluated the anti-inflammatory effect and investigated underlying molecular mechanisms of aesculetin in LPS-induced RAW264.7 macrophages and DSS-induced colitis.

MATERIALS AND METHODS

In this study, the production of NO, TNF-α, and IL-6 were measured to identify the aesculetin with potent anti-inflammatory effect. Then, the underlying anti-inflammatory mechanisms were explored by western blotting in LPS-induced cells. Next, we verify the anti-inflammatory potential of aesculetin in DSS-induced colitis in vivo. The clinical symptoms of colitis, including weight loss, DAI, colon length and MPO activity, and the secretion of TNF-α and IL-6 were evaluated. Finally, Western blot analysis was applied to further investigate underlying mechanism in DSS-induced colitis model.

RESULTS

Our studies showed that aesculetin exhibited anti-inflammatory potential by inhibiting NO, TNF-α, and IL-6 production and reducing iNOS and NLRP3 expression in LPS-induced RAW264.7 cells. Mechanically, we found that aesculetin significantly inhibited LPS-induced activation of NF-κB and MAPKs signaling pathways. In DSS-induced mouse model, the colitis-related symptoms were relieved by treatment with aesculetin. Besides, aesculetin also inhibited the secretion of TNF-α and IL-6, and the activation of NF-κB and MAPKs signaling pathways in DSS-induced colitis.

CONCLUSIONS

The anti-inflammatory effect of aesculetin was connected with its inhibition on the activation of NF-κB and MAPKs signaling pathways both in vitro and in vivo. Therefore, aesculetin was expected to be developed as an anti-inflammatory drug.

Bacteroides fragilis ameliorates Cronobacter malonaticus lipopolysaccharide-induced pathological injury through modulation of the intestinal microbiota

Cronobacter has attracted considerable attention due to its association with meningitis and necrotizing enterocolitis (NEC) in newborns. Generally, lipopolysaccharide (LPS) facilitates bacterial translocation along with inflammatory responses as an endotoxin; however, the pathogenicity of Cronobacter LPS and the strategies to alleviate the toxicity were largely unknown. In this study, inflammatory responses were stimulated by intraperitoneal injection of Cronobacter malonaticus LPS into Sprague–Dawley young rats. Simultaneously, Bacteroides fragilis NCTC9343 were continuously fed through gavage for 5 days before or after injection of C. malonaticus LPS to evaluate the intervention effect of B. fragilis. We first checked the morphological changes of the ileum and colon and the intestinal microbiota and then detected the generation of inflammatory factors, including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and interleukin-10 (IL-10) and the expression of Toll-like receptor 4 (TLR4), occludin, claudin-4, and iNOs. The results indicated that C. malonaticus LPS exacerbated intestinal infection by altering gut microbe profile, tight junction protein expression, and releasing inflammatory factors in a time- and dose-dependent manner. Intriguingly, treatment with B. fragilis obviously diminished the pathological injuries and expression of TLR4 caused by C. malonaticus LPS while increasing gut microbes like Prevotella-9. We note that Shigella, Peptoclostridium, and Sutterella might be positively related to C. malonaticus LPS infection, but Prevotella-9 was negatively correlated. The results suggested that the intestinal microbiota is an important target for the prevention and treatment of pathogenic injuries induced by C. malonaticus LPS.

Can natural products modulate cytokine storm in SARS-CoV2 patients?

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Immune reaction CoV2 can cause uncontrolled systemic inflammatory responses called cytokine storm.

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Medicinal plants and their secondary metabolites are potential modulators of cytokine storm.

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Secondary metabolites modulate inflammatory signaling associated with CoV2.

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The potential applicability of natural products against CoV2 need to be evaluated in strictly defined clinical research.

Currently, the number of cases and deaths of SARS-CoV2, especially among the chronic disease groups, due to aggressive SARS-CoV2 infection is increasing day by day. Various infections, particularly viral ones, cause a cytokine storm resulting in shortness of breath, bleeding, hypotension, and ultimately multi-organ failure due to over-expression of certain cytokines and necrosis factors. The most prominent clinical feature of SARS-CoV2 is the presence of elevated proinflammatory cytokines in the serum of patients with SARS-CoV2. Severe cases exhibit higher levels of cytokines, leading to a “cytokine storm” that further increases disease severity and causes acute respiratory distress syndrome, multiple organ failure, and death. Therefore, targeted cytokine production could be a potential therapeutic option for patients severely infected with SARS-CoV2.

Given the current scenario, great scientific progress has been made in understanding the disease and its forms of treatment. Because of natural ingredients properties, they have the potential to be used as potential agents with the ability to modulate immune responses. Moreover, they can be used safely because they have no toxic effects, are biodegradable and biocompatible. However, these natural substances can continue to be used in the development of new therapies and vaccines.

Finally, the aim and approach of this review article is to highlight current research on the possible use of natural products with promising potential as immune response activators. Moreover, consider the expected use of natural products when developing potential therapies and vaccines.

Mechanism of Action of Shenerjiangzhi Formulation on Hyperlipidemia Induced by Consumption of a High-Fat Diet in Rats Using Network Pharmacology and Analyses of the Gut Microbiota

Shenerjiangzhi formulation (SEJZ) is a new traditional Chinese medicine formulation (patent number: CN110680850A). SEJZ contains Eleutherococcus senticosus (Rupr. and Maxim.), Maxim (Araliaceae; E. senticosus radix and rhizome), Lonicera japonica Thunb (Caprifoliaceae; Lonicera japonica branch, stem), Crataegus pinnatifida Bunge (Rosaceae; Crataegus pinnatifida fruit), and Auricularia auricula. SEJZ has been designed to treat hyperlipidemia. Despite the therapeutic benefits of SEJZ, its underlying mechanism of action is not known. We explored the efficacy of SEJZ against hyperlipidemia by integrating network pharmacology and 16S rRNA gene sequencing and elucidated its mechanism of action. First, SEJZ targets were found through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and from the literature. Hyperlipidemia-related therapeutic targets were obtained from GeneCards, Online Mendelian Inheritance in Man, and DrugBank databases. Then, Search Tool for the Retrieval of Interacting Genes/Proteins and Cytoscape were applied for the analyses and construction of a protein–protein interaction (PPI) network. The Kyoto Encyclopedia of Genes and Genomes database was employed to identify signaling pathways that were enriched. Second, the therapeutic effects of SEJZ against hyperlipidemia induced by consumption of a high-fat diet in rats were evaluated by measuring body weight changes and biochemical tests. SEJZ treatment was found to alleviate obesity and hyperlipidemia in rats. Finally, 16S rRNA gene sequencing showed that SEJZ could significantly increase the abundance of short-chain fatty acid-producing bacteria, restore the intestinal barrier, and maintain intestinal-flora homeostasis. Using PICRUSt2, six metabolic pathways were found to be consistent with the results of network pharmacology: “African trypanosomiasis”, “amoebiasis”, “arginine and proline metabolism”, “calcium signaling pathway”, “NOD-like receptor signaling pathway”, and “tryptophan metabolism”. These pathways might represent how SEJZ works against hyperlipidemia. Moreover, the “African trypanosomiasis pathway” had the highest association with core genes. These results aid understanding of how SEJZ works against dyslipidemia and provide a reference for further studies.

Macrophage immunomodulatory activity of Acanthopanax senticousus polysaccharide nanoemulsion via activation of P65/JNK/ikkαsignaling pathway and regulation of Th1/Th2 Cytokines

Nanoemulsions (NE) are used widely in pharmaceutical drug formulations and vaccine preparation, and Acanthopanax senticousus polysaccharide (ASPS) is a natural bioactive compound with immunostimulatory activity. Therefore, NE-loaded ASPS is expected to provide immunological enhancement for effective treatment. In the present study, Acanthopanax senticousus polysaccharide (ASPS was encapsulated into nanoemulsions, the resultant ASPS-NE were coated with a negative charge, and the immune enhancement mechanism of these ASPS-NE formulations was analyzed. The immunosuppressive animal models (70 ICR mice, male) for the study were established using cyclophosphamide. In addition, the activation of splenocyte proliferation, phagocytosis of the macrophages, the ratio of CD4⁺ to CD8⁺, the concentrations of the cytokines in serum, Western blot analysis was used for the analysis of the P65/JNK/ikk α signaling pathway in the peritoneal macrophage s. The results revealed that the ASPS-NE could stimulated the proliferation of splenocytes and enhance immunity. The ASPS-NE induced the expression of different cytokines (TNF-α, IFN-γ, IL-2, and IL-6), could activate the expressions of P65, JNK, and ikkα, and regulated the Th1/Th2 cytokines. These findings demonstrated the potential of ASPS-NE formulations for drug delivery and to induce potent and sustained immune responses.

Protocatechuic acid attenuates lipopolysaccharide-induced septic lung injury in mice: The possible role through suppressing oxidative stress, inflammation and apoptosis

Here, we investigated the protective efficacy of protocatechuic acid (PCA) against lipopolysaccharide (LPS)-induced septic lung injury. Eighty-two male Balb/c mice were divided into six groups: control, PCA30 (30 mg/kg), LPS (10 mg/kg), PCA10-LPS, PCA20-LPS, and PCA30-LPS treated with 10, 20 and 30 mg/kg PCA, respectively, for seven days before intraperitoneal LPS injection. PCA pre-treatment, especially at higher dose, significantly reduced LPS-induced lung tissue injury as indicated by increased heat shock protein 70 and antioxidant molecules (reduced glutathione, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) accompanied by lower oxidative stress indices (malondialdehyde and nitric oxide). PCA administration decreased inflammatory mediators including myeloperoxidase, nuclear factor kappa B (NF-κB p65), and pro-inflammatory cytokines, and prevented the development of apoptotic events in the lung tissue. At the molecular level, PCA downregulated mRNA expression of nitric oxide synthase 2, C/EBP homologous protein, and high mobility group box1 in the lungs of all PCA-LPS treated mice. Thus, PCA-pre-treatment effectively counteracted sepsis-induced acute lung injury in vivo by promoting and antioxidant status, while inhibiting inflammation and apoptosis. PRACTICAL IMPLICATIONS: Sepsis-mediated organ dysfunction and high mortality is aggravated by acute lung injury (ALI). Therefore, new therapeutic approaches are needed to encounter sepsis-mediated ALI. Protocatechuic acid (PCA) is a naturally occurring phenolic acid with various biological and pharmacological activities. PCA is abundant in edible plants including Allium cepa L., Oryza sativa L., Hibiscus sabdariffa, Prunus domestica L., and Eucommia ulmoides. In this investigation we studied the potential protective role of pure PCA (10, 20 and 30 mg/kg) on LPS-mediated septic lung injury in mice through examining oxidative challenge, inflammatory response, apoptotic events and histopathological changes in addition to evaluating the levels and mRNA expression of heat shock protein 70, C/EBP homologous protein and high mobility group box1 in the lung tissue. The recorded results showed that PCA pre-administration was able to significantly abrogate the damages in the lung tissue associated septic response. This protective effect comes from its strong antioxidant, anti-inflammatory, and anti-apoptotic activities, suggesting that PCA may be applied to alleviate ALI associated with the development of sepsis.

Suppression of plasmacytoid dendritic cell migration to colonic isolated lymphoid follicles abrogates the development of colitis

BACKGROUND

Dendritic cells (DCs) play a pivotal role in maintaining immunological homeostasis by orchestrating innate and adaptive immune responses via migration to inflamed sites and the lymph nodes (LNs). Plasmacytoid DCs (pDCs) have been reported to accumulate in the colon of inflammatory bowel disease (IBD) patients and dextran sulfate sodium (DSS)-induced colitis mice. However, the role of pDCs in the progression of colonic inflammation remains unclear.

METHODS

80 compounds in natural medicines were searched for inhibitors of pDC migration using bone marrow-derived pDCs (BMpDCs) and conventional DCs (BMcDCs). BALB/c mice were given 3% DSS in the drinking water to induce acute colitis. Compounds, which specifically inhibited pDC migration, were administrated into DSS-induced colitis mice.

FINDINGS

Astragaloside IV (As-IV) and oxymatrine (Oxy) suppressed BMpDC migration but not BMcDC migration. In DSS-induced colitis mice, the number of pDCs was markedly increased in the colonic lamina propria (LP), and the expression of CCL21 was obviously observed in colonic isolated lymphoid follicles (ILFs). As-IV and Oxy reduced symptoms of colitis and the accumulation of pDCs in colonic ILFs but not in the colonic LP. Moreover, in a BMpDC adoptive transfer model, BMpDC migration to colonic ILFs was significantly decreased by treatment with As-IV or Oxy.

INTERPRETATION

pDCs accumulated in the colon of colitis mice, and As-IV and Oxy ameliorated colitis by suppressing pDC migration to colonic ILFs. Accordingly, the selective inhibition of pDC migration may be a potential therapeutic approach for treating colonic inflammatory diseases.

A review of Acanthopanax senticosus (Rupr and Maxim.) harms: From ethnopharmacological use to modern application

ETHNOPHARMACOLOGICAL RELEVANCE

Acanthopanax senticosus (AS), previously classified as Eleutherococcus senticosus, is one of the most commonly used herbs in the Chinese materia medica. However, there is currently no comprehensive review summarising advances in AS research. AS has been used as a functional food and in various preparations since ancient times, to invigorate the liver and kidneys, replenish vitality, strengthen the bones, stimulate appetite, and improve memory. It is widely used in countries such as China, Korea, Japan, and Russia, for specific pharmacologic effects, although it contains various chemical components that ensure its broad-spectrum effect. Its chemical constituents mainly include glycosides and flavonoids. Over the past several decades, researchers worldwide have conducted systematic investigations on this herb. AS has positive pharmacological effects on the cardiovascular, central nervous, and immune systems. Representative pathways stimulated by AS are related to neuroactive ligand-receptor interactions, cancer, and phosphatidylinositol 3 kinase/protein kinase B signalling. Importantly, AS is safe and exerts no significant adverse effects at normal doses.

AIM OF THE STUDY

To provide comprehensive insights into the ethnobotany, medicinal uses, chemical composition, pharmacological activity, and toxicology of AS to aid its future development and utilisation.

MATERIALS AND METHODS

Information about AS was collected from various sources, including classic books about Chinese herbal medicine and scientific databases including scientific journals, books, and pharmacopoeia. We discuss the ethnopharmacology of AS from 1965 to 2020 and summarise the knowledge of AS phytochemicals, pharmacological activity, quality control, and toxicology.

CONCLUSIONS

From the current literature, we conclude that AS is a promising dietary Chinese herb with various potential applications owing to its multiple therapeutic effects.

Isofraxidin Alleviates Myocardial Infarction Through NLRP3 Inflammasome Inhibition

Isofraxidin is a well-known coumarin compound refined from traditional Chinese medicines. It has been previously demonstrated to play an anti-inflammatory role in various inflammatory conditions. However, the effect of isofraxidin on myocardial infarction (MI) remains uncovered. In this study, we aimed to investigate the effect of isofraxidin on MI. MI mice was created and triphenyltetrazolium chloride (TTC) staining as well as echocardiographic evaluation were conducted to analyze the severity of MI. Oxygen-glucose deprivation (OGD) was used for the mimics of ischemic stress in murine cardiomyocytes, and Cell Counting Kit-8 (CCK-8), Annexin V, and lactate dehydrogenase (LDH) release assays were conducted for cell viability. Western blot was used for the detection of NOD-like receptor family, pyrin domain containing 3 (NLRP3), and adapter protein apoptosis-associated speck-like protein (ASC) in heart tissues and cardiomyocytes. Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) were applied for the detection of proinflammatory cytokines. We found that isofraxidin alleviated the severity of MI and produced a cardio-protective effect against OGD damage. Isofraxidin also decreased the overall and local inflammatory reaction in MI. Those effects were through the inhibition of the NLRP3 inflammasome. Taken together, we initially reported the cardio-protective and alleviative effect of isofraxidin on MI and uncovered its underlying mechanism related to the NLRP3 inflammasome inhibition.

Inhibition of inflammation-induced injury and cell migration by coelonin and militarine in PM2.5-exposed human lung alveolar epithelial A549 cells

Accumulating studies suggest that fine particulate matter (PM_2.5) pollutants in the air are easily enter into alveoli and even the bloodstream, resulting in an inflammatory response that not only triggers respiratory disorders but also causes permanent damage to various organs. Recent findings suggest that coelonin and militarine enriched in orchids can inhibit inflammation-induced injury against respiratory diseases. Here, we evaluated the anti-inflammatory properties of coelonin and militarine and examined their underlying molecular mechanisms in A549 cells exposed to PM_2.5. PM_2.5 induced significant intracellular reactive oxidative stress accumulation at a concentration of 250 μg/ml, as determined using the dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence assay. Cell viability was assessed via the MTS assay to determine the concentrations of compounds appropriate for use in subsequent experiments. Data from the enzyme-linked immunosorbent assay (ELISA) showed that both coelonin (10 and 20 μg/ml) and militarine (5 and 10 μg/ml) mitigated PM_2.5-induced inflammation by reducing the generation of inflammatory factors, including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Quantitative real-time PCR (qRT-PCR) analysis revealed a remarkable decrease in IL-6, TNF-α, cyclooxygenase-2 (COX-2) and interleukin-1β (IL-1β) mRNA levels in the coelonin and militarine-pretreated groups. In Western blot analysis, expression of inhibitor of NF-κB (IκBα) protein in the coelonin and militarine pretreatment groups was significantly increased compared with the PM_2.5 (only) treatment group (P < 0.05), concomitant with a significant decrease in phospho-IκB kinase β/IκB kinase β (p-IKKβ/IKKβ), phospho-nuclear factor of kappa B p65/nuclear factor of kappa B p65 (p-NF-κBp65/NF-κBp65) and COX-2 proteins (P < 0.05). Both coelonin and militarine inhibited migration and inflammation by suppressing PM_2.5-induced IKK phosphorylation, and followed by IκBα protein degradation and NF-κB activation. Our collective data strongly supported the utility of coelonin and militarine as novel sources for development of treatments for PM_2.5-induced lung diseases.

Could natural products modulate early inflammatory responses, preventing acute respiratory distress syndrome in COVID-19-confirmed patients?

BACKGROUND

The ARDS (Acute Respiratory Distress Syndrome) is a severe respiratory syndrome that was recently associated as the main death cause in the COVID-19 pandemic outbreak. Hence, in order to prevent ARDS, the pulmonary function maintenance has been the target of several pharmacological approaches. However, there is a lack of reports regarding the use of effective pharmaceutical active natural products (PANPs) for early treatment and prevention of COVID-19-related ARDS. Therefore, the aim of this work was to conduct a systematic review regarding the PANPs that could be further studied as alternatives to prevent ARDS. Consequently, this work can pave the way to spread the use of PANPs on the prevention of ARDS in COVID-19-confirmed or -suspected patients.

METHODS

The search strategy included scientific studies published in English from 2015 to 2020 that promoted the elucidation of anti-inflammatory pathways targeting ARDS by in vitro and/or in vivo experiments using PANPs. Then, 74 studies regarding PANPs, able to maintain or improve the pulmonary function, were reported.

CONCLUSIONS

The PANPs may present different pulmonary anti-inflammatory pathways, wherein (i) reduction/attenuation of pro-inflammatory cytokines, (ii) increase of the anti-inflammatory mediators' levels, (iii) pulmonary edema inhibition and (iv) attenuation of lung injury were the most observed biological effects of such products in in vitro experiments or in clinical studies. Finally, this work highlighted the PANPs with promising potential to be used on respiratory syndromes, allowing their possible use as alternative treatment at the prevention of ARDS in COVID-19-infected or -suspected patients.

Natural product derived phytochemicals in managing acute lung injury by multiple mechanisms

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS) as common life-threatening lung diseases with high mortality rates are mostly associated with acute and severe inflammation in lungs. With increasing in-depth studies of ALI/ARDS, significant breakthroughs have been made, however, there are still no effective pharmacological therapies for treatment of ALI/ARDS. Especially, the novel coronavirus pneumonia (COVID-19) is ravaging the globe, and causes severe respiratory distress syndrome. Therefore, developing new drugs for therapy of ALI/ARDS is in great demand, which might also be helpful for treatment of COVID-19. Natural compounds have always inspired drug development, and numerous natural products have shown potential therapeutic effects on ALI/ARDS. Therefore, this review focuses on the potential therapeutic effects of natural compounds on ALI and the underlying mechanisms. Overall, the review discusses 159 compounds and summarizes more than 400 references to present the protective effects of natural compounds against ALI and the underlying mechanism.

Phytochemicals: Potential Therapeutic Interventions Against Coronavirus-Associated Lung Injury

Since the outbreak of coronavirus disease 2019 (COVID-19) in December 2019, millions of people have been infected and died worldwide. However, no drug has been approved for the treatment of this disease and its complications, which urges the need for finding novel therapeutic agents to combat. Among the complications due to COVID-19, lung injury has attained special attention. Besides, phytochemicals have shown prominent anti-inflammatory effects and thus possess significant effects in reducing lung injury caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Also, the prevailing evidence reveales the antiviral effects of those phytochemicals, including anti-SARS-CoV activity, which could pave the road in providing suitable lead compounds in the treatment of COVID-19. In the present study, candidate phytochemicals and related mechanisms of action have been shown in the treatment/protection of lung injuries induced by various methods. In terms of pharmacological mechanism, phytochemicals have shown potential inhibitory effects on inflammatory and oxidative pathways/mediators, involved in the pathogenesis of lung injury during COVID-19 infection. Also, a brief overview of phytochemicals with anti-SARS-CoV-2 compounds has been presented.

Isofraxidin ameliorated influenza viral inflammation in rodents via inhibiting platelet aggregation

Platelets have been proved to exacerbate influenza infection and its complications. Inhibition of platelet activation may be a feasible method for preventing severe infection and secondary acute lung injury (ALI). Isofraxidin (IFD) is a natural coumarin isolated from the plants Sarcandra glabra and Siberian ginseng, and exerts anticancer, antioxidant and antiinflammatory effects. In the present study, we examined the therapeutic effects of IFD in ADP- or arachidonic acid (AA)-induced platelet aggregation model and in influenza A virus (IAV)-induced ALI mouse model. The results showed that IFD significantly inhibited platelet aggregation induced by ADP and AA in vitro in a concentration-dependent manner as well as the release of soluble P-selectin and platelet factor 4. Moreover, IFD significantly relieved IAV-induced lung inflammation, reduced the expressions of platelet activation biomarkers (P-selectin and CD61), decreased the serum levels of TNF-α, IL-1β, IL-6 and MIP-2, suppressed peripheral platelet aggregation and prolonged the survival time of infected mice. The western blotting results also demonstrated that IFD reduced the phosphorylation levels of PI3K, AKT and p38 in the activated platelets stimulated by ADP and IAV infection. But IFD did not have any effects on IAV replication. It indicated that IFD ameliorated IAV-induced severe lung damage and lethal infection by suppressing platelet aggregation via regulating PI3K/AKT and MAPK pathways.

Impact of Bacterial Toxins in the Lungs

Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na⁺ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.

Glycine Attenuates Lipopolysaccharide-Induced Acute Lung Injury by Regulating NLRP3 Inflammasome and NRF2 Signaling

Glycine supplementation has been reported to alleviate lipopolysaccharide (LPS)-induced lung injury in mice. However, the underlying mechanisms responsible for this beneficial effect remain unknown. In the present study, male C57BL/6 mice were treated with aerosolized glycine (1000 mg in 5 mL of 0.9% saline) or vehicle (0.9% saline) once daily for 7 continuous days, and then were exposed to aerosolized LPS (5 mg in 5 mL of 0.9% saline) for 30 min to induce lung injury. Sera and lung tissues were collected 24 h post LPS challenge. Results showed that glycine pretreatment attenuated LPS-induced decreases of mucin at both protein and mRNA levels, reduced LPS-triggered upregulation of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interferons, granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukins. Further study showed that glycine-reduced LPS challenge resulted in the upregulation of nuclear factor κB (NF-κB), nucleotide binding domain (NOD)-like receptor protein 3 (NLRP3) inflammasome. In addition, LPS exposure led to the downregulation of NRF2 and downstream targets, which were significantly improved by glycine administration in the lung tissues. Our findings indicated that glycine pretreatment prevented LPS-induced lung injury by regulating both NLRP3 inflammasome and NRF2 signaling.

The protective effects of Thalictrum minus L. on lipopolysaccharide-induced acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Thalictrum minus L., a Mongolian folk medicinal plant, was applied for the treatment of bacterial and fungal infection, tuberculosis and lung inflammation.

AIM OF THE STUDY

The present work aims to elucidate the protective effects of Thalictrum minus L.(TML) against lipopolysaccharide (LPS)-induced acute lung injury and the underlying mechanisms.

METHODS

The mice model of acute lung injury was induced by LPS via endotracheal drip, and TML (10, 20, 40 mg/kg) were administered orally 1 h prior to LPS. The efficacy and molecular mechanisms in the presence or absence of TML were investigated.

RESULTS

We demonstrated that treatment with TML aqueous extract protected the mice from acute lung injury induced by LPS administration. TML significantly inhibited weight loss in mice, decreased the lung wet to dry weight (W/D) ratios and attenuated lung histopathological changes, such as infiltration of inflammatory cells and coagulation, pulmonary edema. Furthermore, we found that TML markedly reduced the LPS-induced inflammatory cytokines including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), decreased nitric oxide (NO), and increased superoxide dismutase (SOD) in bronchoalveolar lavage fluid (BALF), and effectively ameliorated LPS-induced increased total protein, leukocyte and macrophages in BALF. In addition, TML pronouncedly suppressed the activation of the MAPKs p38-NLRP3/caspase-1 and COX2, increased the expression of p-AMPK-Nrf2, and suppressed the expression of KEAP, apoptotic-related protein as well as autophagy.

CONCLUSIONS

These results suggested that TML ameliorated LPS-induced acute lung injury by inhibiting the release of inflammatory cytokines and reducing oxidative damage associated with the MAPKs p38-NLRP3/caspase-1 and COX2 signaling pathways, AMPK-Nrf2/KEAP signaling pathways, as well as apoptosis and autophagy.

Therapeutic effect and mechanism study of L-cysteine derivative 5P39 on LPS-induced acute lung injury in mice

Organosulfur compounds, such as L-cysteine, allicin and other sulfur-containing organic compounds in Allium species, have been proposed to possess many important physiological and pharmacological functions. A novel L-cysteine derivative, t-Butyl S-allylthio-L-cysteinate (5P39), was designed and synthesized by combining L-cysteine derivative and allicin pharmacophore through a disulfide bond. This study aimed to explore the effects and mechanisms of 5P39 on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. At the experimental concentration (5, 10 and 20 μM), 5P39 suppressed the excessive secretion of nitric oxide (NO) and interleukin-6 (IL-6) in mice peritoneal macrophages stimulated by LPS. A mouse model of ALI was established by tracheal instillation of LPS for 2 h before 5P39 (30 and 60 mg/kg) administration. The results showed that 5P39 treatment down-regulated the wet/dry weight ratio (W/D ratio) of lungs and reduced the protein concentration, the number of total cells as well as the myeloperoxidase (MPO) activity in bronchoalveolar lavage fluid (BALF). 5P39 administration improved the histopathological changes of lungs in ALI mice with the decreased levels of pro-inflammatory cytokines in BALF. The inhibitory effects of 5P39 on the toll-like receptor 4 (TLR4) expression and macrophages accumulation in lung tissues were observed by immunohistochemistry. Additionally, 5P39 significantly attenuated the LPS-activated high expression of key proteins in TLR4/MyD88 signaling pathway. Taken together, the present study showed that 5P39 effectively alleviate the severity of ALI, and its mechanism might relate to the inhibition of LPS-activated TLR4/MyD88 signaling pathway, demonstrating a promising potential for further development into an anti-inflammatory drug candidate.

Cyclooxygenase-2 Inhibitors as a Therapeutic Target in Inflammatory Diseases

Inflammation plays a crucial role in the development of many complex diseases and disorders including autoimmune diseases, metabolic syndrome, neurodegenerative diseases, and cardiovascular pathologies. Prostaglandins play a regulatory role in inflammation. Cyclooxygenases are the main mediators of inflammation by catalyzing the initial step of arachidonic acid metabolism and prostaglandin synthesis. The differential expression of the constitutive isoform COX-1 and the inducible isoform COX-2, and the finding that COX-1 is the major form expressed in the gastrointestinal tract, lead to the search for COX-2-selective inhibitors as anti-inflammatory agents that might diminish the gastrointestinal side effects of traditional non-steroidal anti-inflammatory drugs (NSAIDs). COX-2 isoform is expressed predominantly in inflammatory cells and decidedly upregulated in chronic and acute inflammations, becoming a critical target for many pharmacological inhibitors. COX-2 selective inhibitors happen to show equivalent efficacy with that of conventional NSAIDs, but they have reduced gastrointestinal side effects. This review would elucidate the most recent findings on selective COX-2 inhibition and their relevance to human pathology, concretely in inflammatory pathologies characterized by a prolonged pro-inflammatory status, including autoimmune diseases, metabolic syndrome, obesity, atherosclerosis, neurodegenerative diseases, chronic obstructive pulmonary disease, arthritis, chronic inflammatory bowel disease and cardiovascular pathologies.

A review on the immunomodulatory activity of Acanthopanax senticosus and its active components

Acanthopanacis Senticosi Radix et Rhizoma seu Caulis, the dried root and rhizome or stem of Acanthopanax senticosus, is commonly known as Siberian ginseng or Ciwujia in Chinese. It is used all over the world as an adaptogen to enhance physical and mental performance for the sake of normal physiological functioning of human bodies under stress. In the theory of traditional Chinese medicine, Ciwujia can strengthen the spleen that is an essential organ for immunological response. Its traditional applications include inflammation, fatigue and cancer in which the immune-regulating function is always involved. In this article, the immunomodulatory activities of Ciwujia extracts, fractions and pure compounds were extensively reviewed first. Then, the possibility of upgrading the chemical markers to bioactive markers was explored. Finally, the potency of aqueous extract and ethanol extract in regulating cytokines production from human peripheral blood mononuclear cells was compared. We conclude that although various phytochemicals such as isofraxidin, syringin and eleutheroside E from Ciwujia have been shown to modulate immunological functions, the aqueous extract of Ciwujia as a whole possesses the most potent efficacy. Therefore, aqueous (rather than ethanol) extract of Ciwujia should be used in order to benefit from its immunomodulatory properties.

Ginsenoside Rb1 ameliorates Staphylococcus aureus-induced Acute Lung Injury through attenuating NF-κB and MAPK activation

Acute lung injury (ALI) is clinically characterized by excessive inflammation leading to acute respiratory distress syndrome (ARDS), having high morbidity and mortality both in human and animals. Ginsenoside Rb1 (Rb1) is a major primary bioactive component extracted by Panax ginseng, which has numerous pharmacological functions such as anti-cancer, anti-inflammatory, and antioxidant. However, the anti-inflammatory effects of Rb1 in Staphylococcus aureus (S. aureus)-induced ALI in mice have not been investigated. The aim of the current study was to determine the anti-inflammatory influence of Rb1 on S. aureus-induced ALI in mice, and to explore its possible underlying principle mechanisms in RAW 264.7 macrophage cells. The results of physical morphology, histopathological variation and wet-to-dry weight ratio of lungs revealed that Rb1 significantly attenuated S. aureus-induced lung injury. Furthermore, qPCR results displayed that Rb1 inhibited IL-1β, IL-6 and TNF-α production both in vivo and in vitro. The activation of Toll-like receptor 2 (TLR2) by S. aureus was inhibited by application of Rb1 as confirmed by results of immunofluorescence assay. The expression of NF-kB and MAPK signaling proteins revealed that Rb1 significantly attenuated the phosphorylation of p65, ERK, as well as JNK. Altogether, the results of this experiment presented that Rb1 has ability to protect S. aureus-induced ALI in mice by attenuating TLR-2-mediated NF-kB and MAPK signaling pathways. Consequently, Rb-1 might be a potential medicine in the treatment of S. aureus-induced lung inflammation.

Effects of glycyrrhizin on lipopolysaccharide-induced acute lung injury in a mouse model

Background

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are serious clinical disease entities characterized by inflammatory pulmonary edema, which lead to acute hypoxic respiratory failure through various etiologies. According to the studies to date, ALI/ARDS has been recognized as a form of multiorgan failure related to overactive immune response, and overproduction of proinflammatory cytokines released from activated inflammatory cells are considered to play a key role in the development of ALI. Glycyrrhizin (GL) is an extractive component derived from Glycyrrhiza glabra (licorice), which has recently been reported to have various pharmacological effects like anti-inflammatory, anti-tumor, hepato-protective, and anti-viral activities. Nevertheless, the therapeutic effect of GL in ALI is still unclear. The aim of this study was to investigate therapeutic effects of GL on lipopolysaccharide (LPS)-induced ALI in a mouse model and to elucidate explicable mechanisms involved.

Methods

A total of 36 BALB/c mice (6-week-old, 27.7±1.9-gram body weight) were randomly divided into 3 groups: the control group (normal saline was administered intravenously, n=10), the LPS group (LPS 50 mg/kg was intraperitoneally administered, n=13), and the LPS + GL group (GL was administered intravenously immediately and 12 hours after LPS injection, n=13). Mice were sacrificed after 24 hours, and bronchoalveolar lavage fluid (BALF) was collected for the estimation of protein content, inflammatory cell counts, proinflammatory cytokines, myeloperoxidase (MPO) activity, and expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and nuclear factor kappa B (NF-κB). Then, the lungs were excised for molecular target, histopathological, and immunohistochemical examinations.

Results

Compared to the LPS group, GL significantly decreased protein content, inflammatory cell counts, tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α), IL-6, MPO activity, and expressions of COX-2, iNOS, and NF-κB in the LPS + GL group. GL attenuated migration and infiltration of inflammatory cells, showing a marked decrease in CD 11b-positive cells (26.77%±0.83% vs. 41.77%±0.81% vs. 23.23%±1.92%, P<0.05) as well as CXCR4-/CXCR1-positive cells (CXCR4: 37.23%±1.00% vs. 59.37%±2.37% vs. 47.45%±4.36%; CXCR1: 32.10%±1.56% vs. 47.03%±1.99% vs. 21.70%±6.50%; all P<0.05) in the control, LPS, and LPS + GL groups. Additionally, immunohistochemistry showed that the expression of Toll-like receptor 4 (TLR-4) was inhibited by GL.

Conclusions

The results of this study indicate that GL may have anti-inflammatory and protective effects on LPS-induced ALI in mice. GL inhibited proinflammatory cytokines playing a key role in the initial phase of inflammatory response, which suggests that inhibition of the TLR-4/NF-κB signal pathway would be a possible mechanism underlying the action of GL. Thus, GL can be used as a novel therapeutic strategy for pulmonary inflammation.

Isofraxidin targets the TLR4/MD-2 axis to prevent osteoarthritis development

Osteoarthritis (OA) is a major cause of joint pain and disability, resulting in large socioeconomic costs worldwide. Isofraxidin (ISO), a bioactive coumarin compound isolated from the functional foods Siberian ginseng and Apium graveolens, exerts anti-inflammatory effects in a variety of diseases. However, no studies have reported the protective effects of ISO against OA development. Accordingly, this study aimed to assess the therapeutic effect of ISO in human OA chondrocytes, and in a mouse model of OA induced by destabilisation of the medial meniscus (DMM). In vitro, lipopolysaccharide (LPS)-induced overproduction of nitric oxide (NO), prostaglandin E2 (PGE2), tumour necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) was decreased by ISO pre-treatment. Furthermore, ISO attenuated the increased expression of inflammatory enzymes, including inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in response to LPS stimulation. Meanwhile, LPS-induced extracellular matrix (ECM) degradation was also reversed by ISO treatment. Mechanistically, ISO competitively inhibited Toll-like receptor 4 (TLR4)/myeloid differentiation protein-2 (MD-2) complex formation, and thus TLR4/nuclear factor kappa B (NF-κB) signalling cascades. In vivo, ISO treatment not only prevented the calcification and erosion of cartilage, as well as the thickening of subchondral bone, but also reduced the serum levels of inflammatory cytokines in the mouse OA model. Taken together, these data suggest that ISO has potential in the treatment of OA.

Isofraxidin attenuates IL-1β-induced inflammatory response in human nucleus pulposus cells

Inflammation has been demonstrated to be the key factor for intervertebral disc degeneration (IVD), which remains a major public health problem. Isofraxidin is a coumarin compound that possesses strong anti-inflammatory activity. However, the role of isofraxidin in IVD remains unclear. The aim of this study was to evaluate the effects of isofraxidin on inflammatory response in human nucleus pulposus cells (NPCs) exposed to interleukin-1β (IL-1β). The results proved that isofraxidin attenuated the IL-1β-induced significant increases in inflammatory mediators and cytokines including nitric oxide (NO), inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), and IL-6. Besides, isofraxidin also inhibited the induction effect of IL-1β on matrix metalloproteinases (MMP)-3 and MMP-13. Moreover, the NF-κB activation caused by IL-1β was significantly inhibited by isofraxidin treatment. These findings suggested that isofraxidin alleviates IL-1β-induced inflammation in NPCs. Our work provided an idea that isofraxidin might act as a novel preventive role in IVD.

Network Pharmacology-Based Investigation of Protective Mechanism of Aster tataricus on Lipopolysaccharide-Induced Acute Lung Injury

Acute lung injury (ALI) is a common clinical condition that badly influences people's health. Recent studies indicated that Aster tataricus (RA) had potential effects on ALI, but the effective components and their mechanism is not clear. In this study, we found that the Fraction-75 eluted from RA extract could significantly protect the lipopolysaccharide (LPS)-induced ALI in mice, including alleviating the severity of lung pathology, attenuating the pulmonary edema, and reducing the release of inflammatory cells. Further ingredient analyses demonstrated that there were mainly 16 components in it, among which 10 components were collected according to their relative peak area and oral bioavailability. Next, the components-disease targets network suggested that the candidate components had extensive associations with 49 known therapeutic targets of ALI, among which 31 targets could be regulated by more than one component. Herein, GO functional and pathway analysis revealed that the common targets were associated with four biological processes, including the inflammatory response to stimulus, cellular process, chemokine biosynthetic process and immune system process. Furthermore, the ELISA validation indicated that the candidate components in RA extract may protect the LPS-induced ALI mainly through inhibiting the release of inflammatory cytokines and promoting the repair of vascular endothelial.

Isofraxidin inhibits interleukin-1β induced inflammatory response in human osteoarthritis chondrocytes

Osteoarthritis (OA) is the most prevalent disease of knee especially in the aged people. Isofraxidin (IF) is a coumarin compound refined from traditional Chinese medicines with potential anti-inflammatory ability. This study aimed to evaluate protective anti-inflammatory effects of IF in human OA chondrocytes. The chondrocytes were isolated from OA patients and pretreated with IF before treatment with IL-1β. The results showed that IF blocked IL-1β-stimulated production of NO and PGE2. In addition, IF inhibited the expression of COX-2, iNOs, MMP-1, MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5, and increased the levels of aggrecan and collagen-II. Mechanistically, IF suppressed IL-1β-induced IκB-α degradation and NF-κB activation. In conclusion, our results demonstrate that IF inhibits inflammation in OA via the regulation of NF-κB signaling, and suggest that IF may be a potential therapeutic agent for OA.

Ginsenoside Rg3 Attenuates Lipopolysaccharide-Induced Acute Lung Injury via MerTK-Dependent Activation of the PI3K/AKT/mTOR Pathway

Acute lung injury (ALI) is a common clinical disease with high morbidity in both humans and animals. Ginsenoside Rg3, a type of traditional Chinese medicine extracted from ginseng, is widely used to cure many inflammation-related diseases. However, the specific molecular mechanism of the effects of ginsenoside Rg3 on inflammation has rarely been reported. Thus, we established a mouse model of lipopolysaccharide (LPS)-induced ALI to investigate the immune protective effects of ginsenoside Rg3 and explore its molecular mechanism. In wild type (WT) mice, we found that ginsenoside Rg3 treatment significantly mitigated pathological damages and reduced myeloperoxidase (MPO) activity as well as the production of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6); furthermore, the production of anti-inflammatory mediators interleukin-10 (IL-10) and transforming growth factor-β (TGF-β), polarization of M2 macrophages and expression levels of the phosphorylation of phosphatidylinositol 3-hydroxy kinase (PI3K), protein kinase B (PKB, also known as AKT), mammalian target of rapamycin (mTOR) and Mer receptor tyrosine kinase (MerTK) were promoted. However, there were no significant differences with regards to the pathological damage, MPO levels, inflammatory cytokine levels, and protein expression levels of the phosphorylation of PI3K, AKT and mTOR between the LPS treatment group and ginsenoside Rg3 group in MerTK^-/- mice. Taken together, the present study demonstrated that ginsenoside Rg3 could attenuate LPS-induced ALI by decreasing the levels of pro-inflammatory mediators and increasing the production of anti-inflammatory cytokines. These processes were mediated through MerTK-dependent activation of its downstream the PI3K/AKT/mTOR pathway. These findings identified a new site of the specific anti-inflammatory mechanism of ginsenoside Rg3.

Anticancer effects of isofraxidin against A549 human lung cancer cells via the EGFR signaling pathway

Lung cancer is the leading cause of mortality due to tumor malignancy worldwide. In recent years, the treatment of lung cancer with chemotherapy has demonstrated notable resistance and insensitivity. Therefore, it is of great importance to investigate anti‑lung cancer drugs with high efficiency and low toxicity. In the present study, the effects of isofraxidin on lung cancer cells and the associated mechanisms were investigated. The results revealed that, in vivo and in vitro, isofraxidin exhibited marked inhibitory effects on the A549 lung cancer cell line. The results of Cell Counting kit‑8, Transwell migration and Matrigel invasion assays, and flow cytometry to determine apoptosis, revealed that isofraxidin significantly inhibited the proliferation, migration and invasion of A549 cells, and induced the cell apoptosis. Furthermore, western blot analysis demonstrated that isofraxidin treatment led to effects on the expression of apoptosis‑associated proteins, including members of the Bcl‑2 protein family, and invasion‑associated proteins, including matrix metallopeptidase (MMP)‑2 and MMP‑9, which may occur via inhibition of the expression of phosphorylated (p)‑epidermal growth factor receptor, p‑AKT and p‑extracellular signal‑regulated kinase. This regulation of protein expression may contribute to the inhibition of proliferation, migration and invasion of A549lung cancer cells by isofraxidin. In addition, despite the inhibitory effects on the A549 lung cancer cell line, the present study revealed that isofraxidin exhibited low toxicity towards BEAS‑2B normal lung epithelial cells within a certain dose range (0‑160 µM), indicating that isofraxidin may be employed for lung cancer treatment with hypotoxicity and fewer side effects. In conclusion, isofraxidin may be a novel candidate for anti‑lung cancer chemotherapy.

RhoA regulates lipopolysaccharide‑induced lung cell injury via the Wnt/β‑catenin pathway

Ras homolog family member A (RhoA) has been reported to be involved in numerous biological processes; however, the effects of RhoA on acute lung injury (ALI) have yet to be reported. The present study aimed to explore how RhoA affects cell viability, reactive oxygen species (ROS) activity and cell apoptosis in a cell model of lipopolysaccharide (LPS)‑induced ALI. An MTT assay, flow cytometry, reverse transcription‑quantitative polymerase chain reaction and western blotting were used to determine the effects of RhoA on cell viability, apoptosis and ROS activity. The results demonstrated that RhoA inactivation was able to promote cell viability, and decrease apoptosis and ROS activity of LPS‑treated cells. The results of western blotting indicated that RhoA activated the downstream Wnt/β‑catenin signaling pathway and inhibited the expression of apoptotic factors. These findings suggested that RhoA may be involved in ALI progression and could be a novel therapeutic target for this disease.

Protective effect of TM6 on LPS-induced acute lung injury in mice

Acute lung injury (ALI) is an acute failure of the respiratory system for which effective treatment is urgently necessary. Previous studies found that several peptides potently inhibited the production of cytokines induced by lipopolysaccharide (LPS). In this study, we synthetized a cell-permeable TIR domain-derived decoy peptide (TM6) and examined its substance for the ability to inhibit TLR signaling in the model of ALI induced by LPS. We demonstrated that TM6 (2.5, 5 and 10 nmol/g) alleviated the histological changes in the lung tissues as well as myeloperoxtidase (MPO) activity, lung W/D ratio, the production of TNF-α, IL-1β and IL-6 induced by LPS. Furthermore, the numbers of total cells, neutrophils and macrophages in the BALF were suppressed by TM6. In vitro, TM6 (5, 10 and 20 µM) inhibited the production of TNF-α, IL-1β and IL-6 in LPS-stimulated alveolar macrophages. Moreover, the activation of Nuclear factor-kappaB (NF-κB) and Mitogen activated protein kinases (MAPK) signaling pathways induced by LPS were also inhibited by TM6. Collectively, our results suggested that TM6 was an effective inhibitor of ALI induced by LPS, and this peptide may very well serve as a future treatment for ALI.

Protective Effects of Li-Fei-Xiao-Yan Prescription on Lipopolysaccharide-Induced Acute Lung Injury via Inhibition of Oxidative Stress and the TLR4/NF-κB Pathway

Li-Fei-Xiao-Yan prescription (LFXY) has been clinically used in China to treat inflammatory and infectious diseases including inflammatory lung diseases. The present study was aimed at evaluating the potential therapeutic effects and potential mechanisms of LFXY in a murine model of lipopolysaccharide- (LPS-) induced acute lung injury (ALI). In this study, the mice were orally pretreated with LFXY or dexamethasone (positive drug) before the intratracheal instillation of LPS. Our data indicated that pretreatment with LFXY enhanced the survival rate of ALI mice, reversed pulmonary edema and permeability, improved LPS-induced lung histopathology impairment, suppressed the excessive inflammatory responses via decreasing the expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and chemokine (MIP-2) and inhibiting inflammatory cells migration, and repressed oxidative stress through the inhibition of MPO and MDA contents and the upregulation of antioxidants (SOD and GSH) activities. Mechanistically, treatment with LFXY significantly prevented LPS-induced TLR4 expression and NF-κB (p65) phosphorylation. Overall, the present study suggests that LFXY protected mice from acute lung injury induced by LPS via inhibition of TLR4/NF-κB p65 activation and upregulation of antioxidative enzymes and it may be a potential preventive and therapeutic agent for ALI in the clinical setting.

Water extract of Helminthostachys zeylanica attenuates LPS-induced acute lung injury in mice by modulating NF-κB and MAPK pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Previous studies showed that Helminthostachys zeylanica (L.) Hook. could reduce inflammatory responses in macrophage and brain astrocytes.

AIM OF THE STUDY

In the present study, we evaluated whether an ethyl acetate extract (HZE) or a water extract (HZW) of H. zeylanica could reduce inflammatory responses in lung epithelial cells and ameliorate lipopolysaccharide (LPS)-induced acute lung injury in mice.

METHODS

Human lung epithelial A549 cells were pre-treated with HZE or HZW (1-10μg/mL), then stimulated with LPS. BALB/c mice received oral HZW for 7 consecutive days, then an intratracheal instillation of LPS to induce lung injury.

RESULTS

HZW reduced chemokine and proinflammatory cytokine production in LPS-activated A549 cells. HZW also suppressed ICAM-1 expression and reduced the adherence of acute monocytic leukemia cells to inflammatory A549 cells. HZE had less efficacy than HZW in suppressing inflammatory responses in A549 cells. In vivo, HZW significantly suppressed neutrophil infiltration and reduced the TNF-α and IL-6 levels in bronchoalveolar lavage fluid and serum from LPS-treated mice. HZW also modulated superoxide dismutase activity, glutathione, and myeloperoxidase activity in lung tissues from LPS-treated mice. HZW decreased the phosphorylation of mitogen-activated protein kinase and nuclear factor kappa B, and promoted heme oxygenase-1 expression in inflamed lung tissue from LPS-treated mice.

CONCLUSION

Our findings suggested that HZW reduced lung injury in mice by reducing oxidative stress and inflammatory responses. HZW also reduced inflammatory responses in human lung epithelial cells.

Protective effect of wogonin on endotoxin-induced acute lung injury via reduction of p38 MAPK and JNK phosphorylation

Acute lung injury (ALI) is a serious inflammatory disorder which remains the primary cause of incidence and mortality in patients with acute pulmonary inflammation. However, there is still no effective medical strategy available clinically for the improvement of ALI. Wogonin, isolated from roots of Scutellaria baicalensis Georgi, is a common medicinal herb which presents biological and pharmacological effects, including antioxidation, anti-inflammation, and anticancer. Preadministration of wogonin inhibited not only lung edema but also protein leakage into the alveolar space in murine model of lipopolysaccharide (LPS)-induced ALI. Moreover, wogonin not only reduced the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 but also inhibited the phosphorylation of mitogen-activated protein kinase (MAPK) induced by LPS. We further found wogonin inhibited the phosphorylation of p38 MAPK and JNK at a concentration lower than ERK. In addition, inhibition of lung edema, protein leakage, expression of iNOS and COX-2, and phosphorylation of p38 MAPK and JNK were all observed in a parallel concentration-dependent manner. These results suggest that wogonin possesses potential protective effect against LPS-induced ALI via downregulation of iNOS and COX-2 expression by blocking phosphorylation of p38 MAPK and JNK. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 397-403, 2017.

In vitro and in vivo anti-inflammatory effects of theaflavin-3,3'-digallate on lipopolysaccharide-induced inflammation

Inflammation is a defensive response against various harmful stimuli and stress conditions, such as tissue injury and one of the most common pathological processes occurring in human diseases. Theaflavin-3,3'-digallate, one of the theaflavins present in black tea, exhibits several bioactive properties, including the ability to lower the incidence of coronary heart disease, a positive effect on the bone mineral density, and the ability to prevent cancer. The aim of this study was to evaluate whether theaflavin-3,3'-digallate could reduce the production of pro-inflammatory cytokines in vivo and in vitro and ameliorate acute lung injury (ALI) in a mouse model. In this study, we demonstrated that theaflavin-3,3'-digallate suppressed the lipopolysaccharide (LPS)-induced phosphorylation of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase in RAW 264.7 macrophages. In addition, we also showed that theaflavin-3,3'-digallate inhibited the expression of tumor necrosis factor alpha, interleukin -1 beta, and interleukin 6 in phorbol myristate acetate -primed U937 and RAW 264.7 cells. Furthermore, theaflavin-3,3'-digallate treatment attenuated the severity of LPS-induced ALI in mice. These results suggested that theaflavin-3,3'-digallate might be a potential therapeutic candidate for the treatment of inflammation and inflammatory diseases.

Sarcandra glabra combined with lycopene protect rats from lipopolysaccharide induced acute lung injury via reducing inflammatory response

Sarcandra glabra (Chinese name, Zhongjiefeng) is an important herb widely used in traditional Chinese medicine. Lycopene has been shown to be a powerful antioxidant. This study aims to test the hypothesis that Sarcandra glabra combined with lycopene protect rats from lipopolysaccharide (LPS) induced acute lung injury (ALI). Metabolomics approach combined with pathological inspection, serum biochemistry examination, enzyme-linked immunosorbent assay and western blotting were used to explore the protective effects of Sarcandra glabra and lycopene on LPS-induced ALI, and to elucidate the underlying mechanisms. Results showed that Sarcandra glabra and lycopene could significantly ameliorate LPS-induced histopathological injuries, improve the anti-oxidative activities of rats, decrease the levels of TNF-α and IL-6, suppress the activations of MAPK and transcription factor NF-κB and reverse the disturbed metabolism towards the normal status. Taken together, this integrated study revealed that Sarcandra glabra combined with lycopene had great potential in protecting rats from LPS-induced ALI, which would be helpful to guide the clinical medication.

Phloretin attenuates LPS-induced acute lung injury in mice via modulation of the NF-κB and MAPK pathways

Phloretin, which can be isolated from apple trees, has demonstrable anti-inflammatory and anti-oxidant effects in macrophages. We previously reported that phloretin could inhibit the inflammatory response and reduce intercellular adhesion molecule 1 (ICAM-1) expression in interleukin (IL)-1β-activated human lung epithelial cells. In the present study we now evaluate whether phloretin exposure could ameliorate lipopolysaccharide (LPS)-induced acute lung injury in mice. Intra-peritoneal injections of phloretin were administered to mice for 7 consecutive days, prior to the induction of lung injury by intra-tracheal administration of LPS. Our subsequent analyses demonstrated that phloretin could significantly suppress LPS-induced neutrophil infiltration of lung tissue, and reduce the levels of IL-6 and tumor necrosis factor (TNF)-α in serum and bronchoalveolar lavage fluid. We also found that phloretin modulated myeloperoxidase activity and superoxide dismutase activity, with decreased gene expression levels for chemokines, proinflammatory cytokines, and ICAM-1 in inflamed lung tissue. Phloretin also significantly reduced the phosphorylation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK), thus limiting the inflammatory response, while promoting expression of heme oxygenase (HO)-1 and nuclear factor erythroid 2-related factor 2, both of which are cytoprotective. Our findings suggest that, mechanistically, phloretin attenuates the inflammatory and oxidative stress pathways that accompany lung injury in mice via blockade of the NF-κB and MAPK pathways.

Post-Intake of S-Ethyl Cysteine and S-Methyl Cysteine Improved LPS-Induced Acute Lung Injury in Mice

The effects of S-ethyl cysteine (SEC) and S-methyl cysteine (SMC) on lipopolysaccharide (LPS)-induced acute lung injury in mice were examined. Eight hours after LPS challenge, SEC or SMC was supplied in drinking water at 0.5% or 1% for 3 days. LPS increased lung myeloperoxidase activity, neutrophil counts and edema. SEC or SMC post-intake attenuated these events. SEC or SMC suppressed LPS-induced lung expression of cyclooxygenase-2, nuclear factor-κB and mitogen-activated protein kinase, and lowered the generation of tumor necrosis factor-alpha, monocyte chemoattractant protein-1 and prostaglandin E₂. LPS enhanced the expression of p47^phox, gp91^phox, Bax and cleaved caspase-3, and increased the production of reactive oxygen species in the lung. SEC or SMC post-intake reversed these alterations. These findings suggest that these agents could protect the lung through their anti-inflammatory, anti-oxidative and anti-apoptotic activities.

Cinnamoyloxy-mammeisin Isolated from Geopropolis Attenuates Inflammatory Process by Inhibiting Cytokine Production: Involvement of MAPK, AP-1, and NF-κB

Chemical compounds belonging to the class of coumarins have promising anti-inflammatory potential. Cinnamoyloxy-mammeisin (CNM) is a 4-phenylcoumarin that can be isolated from Brazilian geopropolis. To our knowledge, its anti-inflammatory activity has never been studied. Therefore, the present study investigated the anti-inflammatory activity of CNM and elucidated its mechanism of action on isolated macrophages. Pretreatment with CNM reduced neutrophil migration into the peritoneal and joint cavity of mice. Likewise, CNM reduced the in vitro and in vivo release of TNF-α and CXCL2/MIP-2. Regarding the possible molecular mechanism of action, CNM reduced the phosphorylation of proteins ERK 1/2, JNK, p38 MAPK, and AP-1 (subunit c-jun) in PG-stimulated macrophages. Pretreatment with CNM also reduced NF-κB activation in RAW 264.7 macrophages stably expressing the NF-κB-luciferase reporter gene. On the other hand, it did not alter IκBα degradation or nuclear translocation of p65. Thus, the results of this study demonstrate promising anti-inflammatory activity of CNM and provide an explanation of its mechanism of action in macrophages via inhibition of MAPK signaling, AP-1, and NF-κB.

Constituents from Chloranthaceae plants and their biological activities

The Chloranthaceae is a small family with only four genera (

Esculin exhibited anti-inflammatory activities in vivo and regulated TNF-α and IL-6 production in LPS-stimulated mouse peritoneal macrophages in vitro through MAPK pathway

Esculin, a coumarinic derivative found in Aesculus hippocastanum L. (Horse-chestnut), has been reported to have potent anti-inflammatory properties. The present study is designed to investigate the protective effects of esculin on various inflammation models in vivo and in vitro and to clarify the possible mechanism. Induced-animal models of inflammation and lipopolysaccharide (LPS)-challenged mouse peritoneal macrophages were used to examine the anti-inflammatory activity of esculin. In present study, xylene-induced mouse ear edema, carrageenan-induced rat paw edema, and carrageenan-induced mouse pleurisy were attenuated by esculin. In vitro, the pro-inflammatory cytokine levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in supernatant were reduced by esculin. Meanwhile, we found that esculin significantly inhibited LPS-induced activation of mitogen-activated protein kinase (MAPK) pathway in peritoneal macrophages. These results suggest that esculin has potent anti-inflammatory activities in vivo and in vitro, which may involve the inhibition of the MAPK pathway. Esculin may be a promising preventive agent for inflammatory diseases in human.