Costunolide alleviates HKSA-induced acute lung injury via inhibition of macrophage activation

Costunolide attenuates LPS-induced inflammation and lung injury through inhibiting IKK/NF-κB signaling

Inflammation is an important pathological process of many acute and chronic diseases, such as sepsis, arthritis, and cancer. Many factors can lead to an inflammatory state of the body, among which bacterial infection plays an important role. Bacterial infection often leads to sepsis, acute lung injury (ALI), or its more serious form of acute respiratory distress syndrome, which are the main fatal diseases in intensive care units. Costunolide has been reported to possess excellent anti-inflammatory activity; however, whether it can affect inflammation induced by gram-negative bacterial is still unclear. Lipopolysaccharide (LPS) stimulated mouse peritoneal macrophages (MPMs) to release proinflammatory cytokines was used as the cell model. The mouse model of sepsis and ALI was built through injecting intravenously and intratracheally of LPS. In the present study, costunolide inhibited LPS-induced inflammatory response through IKK/NF-κB signaling pathway in macrophages. In vivo, costunolide attenuated LPS-induced septic death in mice. Meanwhile, costunolide treatment alleviated LPS-induced lung injury and inflammation via inhibiting the infiltration of inflammatory cells and the expression of inflammatory cytokines. Taken together, these results demonstrated that costunolide could attenuate gram-negative bacterial induced inflammation and diseases and might be a potential candidate for the treatment of inflammatory diseases.

Targeting different phenotypes of macrophages: A potential strategy for natural products to treat inflammatory bone and joint diseases

BACKGROUND

Macrophages, a key class of immune cells, have a dual role in inflammatory responses, switching between anti-inflammatory M2 and pro-inflammatory M1 subtypes depending on the specific environment. Greater numbers of M1 macrophages correlate with increased production of inflammatory chemicals, decreased osteogenic potential, and eventually bone and joint disorders. Therefore, reversing M1 macrophages polarization is advantageous for lowering inflammatory factors. To better treat inflammatory bone disorders in the future, it may be helpful to gain insight into the specific mechanisms and natural products that modulate macrophage polarization.

OBJECTIVE

This review examines the impact of programmed cell death and different cells in the bone microenvironment on macrophage polarization, as well as the effects of natural products on the various phenotypes of macrophages, in order to suggest some possibilities for the treatment of inflammatory osteoarthritic disorders.

METHODS

Using 'macrophage polarization,' 'M1 macrophage' 'M2 macrophage' 'osteoporosis,' 'osteonecrosis of femoral head,' 'osteolysis,' 'gouty arthritis,' 'collagen-induced arthritis,' 'freund's adjuvant-induced arthritis,' 'adjuvant arthritis,' and 'rheumatoid arthritis' as search terms, the relevant literature was searched using the PubMed, the Cochrane Library and Web of Science databases.

RESULTS

Targeting macrophages through different signaling pathways has become a key mechanism for the treatment of inflammatory bone and joint diseases, including HIF-1α, NF-κB, AKT/mTOR, JAK1/2-STAT1, NF-κB, JNK, ERK, p-38α/β, p38/MAPK, PI3K/AKT, AMPK, AMPK/Sirt1, STAT TLR4/NF-κB, TLR4/NLRP3, NAMPT pathway, as well as the programmed cell death autophagy, pyroptosis and ERS.

CONCLUSION

As a result of a search of databases, we have summarized the available experimental and clinical evidence supporting herbal products as potential treatment agents for inflammatory osteoarthropathy. In this paper, we outline the various modulatory effects of natural substances targeting macrophages in various diseases, which may provide insight into drug options and directions for future clinical trials. In spite of this, more mechanistic studies on natural substances, as well as pharmacological, toxicological, and clinical studies are required.

Costunolide alleviates hyperglycaemia-induced diabetic cardiomyopathy via inhibiting inflammatory responses and oxidative stress

Hyperglycaemia-induced myocardial injury promotes the induction of heart failure in diabetic patients. Impaired antioxidant capability and sustained chronic inflammation play a vital role in the progression of diabetic cardiomyopathy (DCM). Costunolide (Cos), a natural compound with anti-inflammatory and antioxidant properties, has exhibited therapeutic effects in various inflammatory diseases. However, the role of Cos in diabetes-induced myocardial injury remains poorly understood. In this study, we investigated the effect of Cos on DCM and explored the potential mechanisms. C57BL/6 mice were administered intraperitoneal streptozotocin for DCM induction. Cos-mediated anti-inflammatory and antioxidation activities were examined in heart tissues of diabetic mice and high glucose (HG)-stimulated cardiomyocytes. Cos markedly inhibited HG-induced fibrotic responses in diabetic mice and H9c2 cells, respectively. The cardioprotective effects of Cos could be correlated to the reduced expression of inflammatory cytokines and decreased oxidative stress. Further investigations demonstrated Cos reversed diabetes-induced nuclear factor-κB (NF-κB) activation and alleviated impaired antioxidant defence system, principally via activation of nuclear factor-erythroid 2 p45-related factor-2 (Nrf-2). Cos alleviated cardiac damage and improved cardiac function in diabetic mice by inhibiting NF-κB-mediated inflammatory responses and activating the Nrf-2-mediated antioxidant effects. Therefore, Cos could be a potential candidate for the treatment of DCM.

Heat-Killed Staphylococcus aureus Induces Bone Mass Loss through Telomere Erosion

The mechanism of systemic osteoporosis caused by chronic infection is not completely clear, and there is a lack of reasonable interventions for this disease. In this study, heat-killed S. aureus (HKSA) was applied to simulate the inflammation caused by the typical clinical pathogen and to explore the mechanism of systemic bone loss caused by it. In this study, we found that the systemic application of HKSA caused bone loss in mice. Further exploration found that HKSA caused cellular senescence, telomere length shortening, and telomere dysfunction-induced foci (TIF) in limb bones. As a well-known telomerase activator, cycloastragenol (CAG) significantly alleviated HKSA-induced telomere erosion and bone loss. These results suggested that telomere erosion in bone marrow cells is a possible mechanism of HKSA-induced bone loss. CAG may protect against HKSA-induced bone loss by alleviating telomere erosion in bone marrow cells.

Costunolide alleviates atherosclerosis in high-fat diet-fed ApoE-/- mice through covalently binding to IKKβ and inhibiting NF-κB-mediated inflammation

Costunolide (CTD) is a sesquiterpene lactone isolated from costus root and exhibits various biological activities including anti-inflammation. Since atherosclerosis is a chronic inflammatory disease, we herein investigated the anti-atherosclerotic effects of CTD and the underlying mechanism. Atherosclerosis was induced in ApoE-/- mice by feeding them with a high-fat diet (HFD) for 8 weeks, followed by administration of CTD (10, 20 mg ·kg-1·d-1, i.g.) for 8 weeks. We showed that CTD administration dose-dependently alleviated atherosclerosis in HFD-fed ApoE-/- mice. Furthermore, we found that CTD dose-dependently reduced inflammatory responses in aortas of the mice, as CTD prevented infiltration of inflammatory cells in aortas and attenuated oxLDL uptake in macrophages, leading to reduced expression of pro-inflammatory and pro-fibrotic molecules in aortas. Similar results were observed in oxLDL-stimulated mouse primary peritoneal macrophages (MPMs) in vitro. We showed that pretreatment with CTD (2.5, 5. 10 μM) restrained oxLDL-induced inflammatory responses in MPMs by blocking pro-inflammatory NF-κB/p65 signaling pathway. We further demonstrated that CTD inactivated NF-κB via covalent binding to cysteine 179 on IKKβ, a canonical upstream regulator of NF-κB, reducing its phosphorylation and leading to conformational change in the active loop of IKKβ. Our results discover IKKβ as the target of CTD for its anti-inflammatory activity and elucidate a molecular mechanism underlying the anti-atherosclerosis effect of CTD. CTD is a potentially therapeutic candidate for retarding inflammatory atherosclerotic diseases.

A Dual-Action Molecule Suppresses S. aureus Infection as an Inhibitor Targeting Hla Pore Formation and TLR2 Signaling

Antibiotic resistance is the greatest challenge for the treatment of Staphylococcus aureus (S. aureus) infection under the global antibiotic resistance crisis. With the bottleneck period of the development of new antibiotics, novel alternative agents are urgently in need. In this study, the small molecule amentoflavone is identified as a dual-action inhibitor of Hla, a pore-forming virulence determinant particularly important for S. aureus pathogenicity and Toll-like receptor 2 (TLR2) signaling, which triggers inflammation response upon recognizing pathogen-associated molecular patterns. Amentoflavone treatment conferred effective protection against S. aureus pneumonia through this dual-action mechanism. Mechanically, amentoflavone effectively inhibited Hla pore formation, thereby reducing Hla-mediated cytotoxicity and tissue damage; at the same time, amentoflavone suppressed TLR2-mediated inflammatory response by blocking the interaction between TLR2 and its adapter myeloid differentiation primary response gene 88 (MyD88). Surprisingly, TLR2 signaling induced by synthetic bacterial TLR2 agonists and other heat-killed gram-positive bacteria is also blocked by amentoflavone. In summary, these results presented amentoflavone as a potential antibiotic alternative that curbed S. aureus infection by simultaneously suppressing host-damaging virulence determinants derived from bacteria and the detrimental effect of excessive inflammation derived from the host rather than bacteria viability.

Sesquiterpene lactones-rich fraction from Aucklandia lappa Decne. alleviates dextran sulfate sodium induced ulcerative colitis through co-regulating MAPK and Nrf2/Hmox-1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Aucklandia lappa Decne. (ALDE) is the general name for Asteraceae plants Yunmuxiang, which has traditionally been proven to have the efficacy in relieving depression by regulating qi, alleviating cold by warming, attenuating pain in stomach and relieving diarrhea in intestines. Therefore, ALDE is always recommended as an herbal remedy for gastrointestinal dysfunction.

AIM OF THE STUDY

The purpose of this study was to explore the therapeutic potential and mechanism of action of the sesquiterpene lactone-rich fraction (SLRF) of ALDE extracts in vivo and in vitro.

MATERIALS AND METHODS

An aqueous extract (AE) and SLRF of ALDE were prepared and the contents of the main components were quantified by high performance liquid chromatography (HPLC). The therapeutic effects of the extracts were evaluated in C57BL/6 mice with dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). Body weight, disease activity index (DAI), and colon length were recorded, and histopathological changes in the colon were characterized using hematoxylin and eosin (H&E) staining. The in vitro anti-inflammatory activity and possible mechanisms of the two main sesquiterpene lactones in ALDE (costunolide and dehydrocostus lactone) were studied by quantitative proteomic analysis. Finally, based on bioinformatic analysis, we used polymerase chain reaction (PCR), immunofluorescence, and western blot experiments to verify the anti-inflammatory mechanism of the extracts in C57BL/6 mice.

RESULTS

The SLRF of ALDE significantly improved the pathological symptoms and inflammatory pathology of UC, whereas the AE had a weak protective effect. In RAW264.7 cells stimulated with lipopolysaccharide (LPS), costunolide and dehydrocostus lactone significantly reduced the mRNA levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, suggesting that these two sesquiterpene lactones had strong anti-inflammatory activity. Quantitative proteomics results indicated that the anti-inflammatory mechanism of these lactones was associated with the NF-κB/MAPK and Nrf2-Hmox-1 pathways. These results were further validated in SLRF-treated mice.

CONCLUSION

This study confirmed that the SLRF of ALDE exerted protective activity against UC by regulating the Nrf2-Hmox-1, NF-κB, and MAPK pathways.

Codonopsis pilosula polysaccharide attenuates Escherichia coli-induced acute lung injury in mice

Acute lung injury (ALI) is an inflammatory lung disease could be caused by bacterial infection. Lipopolysaccharide (LPS), a prototype pathogen-associated molecular pattern (PAMP) from gram-negative bacteria such as Escherichia coli...

Aucklandiae Radix and Vladimiriae Radix: A systematic review in ethnopharmacology, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Aucklandiae Radix (AR) and Vladimiriae Radix (VR), as commonly used traditional Chinese herbal medicine, were widely used in the treatment of gastrointestinal diseases. The two herbal medicines were warm, pungent and bitter. They entered the spleen, stomach, large intestine and gallbladder meridians, and had the effect of promoting qi circulation to relieve pain. It is usually used for chest and hypochondrium, abdominal fullness and pain, tenesmus, indigestion, and warming the middle to harmonize the stomach in clinically.

AIM OF THIS REVIEW

To provide a reference for the identification of traditional use, the material basis of efficacy and preclinical research between AR and VR, this review systematically summarized the similarities and differences in ethnopharmacology, phytochemistry and modern pharmacology.

MATERIALS AND METHODS

The literature information was collected systematically from the electronic scientific databases, including PubMed, Science Direct, Google Scholar, Web of Science, Geen Medical, China National Knowledge Infrastructure, as well as other literature sources, such as classic books of herbal medicine, master's thesis, doctoral thesis.

RESULTS

In the plateau areas of Sichuan Province, VR used to be regarded as substitute or local habit for AR, which is regularly used for chest, abdominal fullness and pain, diarrhea, and other related diseases. In Chinese Pharmacopoeia (ChP) 2020 edition, 145 prescription preparations with AR were collected, such as Xianglian Wan, Muxiang Shunqi Wan, Liuwei Muxiang San. However, only one prescription preparation (Jiuxiang Zhitong Wan) contained VR. Additionally, 237 and 254 chemical components were separately isolated and identified from AR and VR, 69 kinds of compounds were common among them, and the significant differences were presented in sesquiterpene lactones, monoterpenoids, triterpenoids and phenylpropanoids. Moreover, Costunolide (COS) and Dehydrocostus lactone (DEH), two main research objects of modern pharmacology, showed multiple pharmacological activities. Not only could they inhibit the activity of some cancer cells (such as breast cancer and leukemia cells), but they regulated the levels of various inflammatory factors (including TNF-α, NF-κB, IL-1β, IL-6) and repressed the growth and reproduction of various microorganisms (like Helicobacter pylori, Staphylococcus aureus).

CONCLUSION

COS and DEH as the common active components, provide a certain basis for local medicine about the substitution of VR for AR in Sichuan province of China in the past. In addition, the sesquiterpenoids are the main common compounds in AR and VR by collecting and collating a large number of literature and various data websites. Furthermore, AR and VR have significant differences in ethnopharmacology and phytochemistry, especially in sesquiterpene lactones, monoterpenoids, triterpenoids and phenylpropanoids, and are probably viewed as reference of a separate list of AR and VR in Chinese Pharmacopoeia.

Epigallocatechin gallate (EGCG) attenuates staphylococcal alpha-hemolysin (Hla)-induced NLRP3 inflammasome activation via ROS-MAPK pathways and EGCG-Hla interactions

Alpha-hemolysin (Hla), the virulence factor secreted by Staphylococcus aureus (S. aureus), plays a critical role in infection and inflammation, which is a severe health burden worldwide. Therefore, it is necessary to develop a drug against Hla. Epigallocatechin gallate (EGCG), a polyphenol extracted from green tea, has excellent anti-inflammatory activity. In this study, we investigated the inhibitory effect of EGCG on Hla-induced NLRP3 inflammasome activation in vitro and in vivo and elucidated the potential molecular mechanism. We found that EGCG attenuated the hemolysis of Hla by inhibiting its secretion. Besides, EGCG significantly decreased overproduction of ROS and activation of MAPK signaling pathway induced by Hla, thereby markedly attenuating the expression of NLRP3 inflammasome-related proteins in THP-1 cells. Notably, EGCG could spontaneously bind to Hla with affinity constant of 1.71 × 10-4 M, thus blocking the formation of the Hla heptamer. Moreover, Hla-induced expression of NLRP3, ASC and caspase-1 protein and generation of IL-1β and IL-18 in the damaged liver tissue of mice were also significantly suppressed by EGCG in a dose-dependent manner. Collectively, EGCG could be a promising candidate for alleviating Hla-induced the activation of NLRP3 inflammasome, depending on ROS mediated MAPK signaling pathway, and inhibition of Hla secretion and heptamer formation. These findings will enlighten the applications of EGCG to reduce the S. aureus infection by targeting Hla in food and related pharmaceutical fields.

Suppression of lncRNA NLRP3 inhibits NLRP3-triggered inflammatory responses in early acute lung injury

Acute lung injury (ALI) is a common lung pathology that is accompanied by alveolar macrophage (AM) activation and inflammatory response. This study investigated the role of the long non-coding RNA NONRATT004344 (hereafter named lncRNA NLRP3) in regulating the Nod-like receptor protein 3 (NLRP3)-triggered inflammatory response in early ALI and the underlying mechanism as well. We established LPS-induced ALI models to explore their interactive mechanisms in vitro and in vivo. Luciferase reporter assays were performed to determine that miR-138-5p could bind to lncRNA NLRP3 and NLRP3. We observed increased lncRNA NLRP3 expression, decreased miR-138-5p expression, NLRP3 inflammasome activation, and upregulated caspase-1, IL-1β, and IL-18 expression in the LPS-induced ALI model. Furthermore, lncRNA NLRP3 overexpression activated the NLRP3 inflammasome and promoted IL-1β and IL-18 secretion; the miR-138-5p mimic abolished these effects in vivo and in vitro. Consistently, miR-138-5p inhibition reversed the effects of lncRNA NLRP3 silencing on the expression of NLRP3-related molecules and inhibition of the NLRP3/caspase-1/IL-1β signalling pathway. Mechanistically, lncRNA NLRP3 sponging miR-138-5p facilitated NLRP3 activation through a competitive endogenous RNA (ceRNA) mechanism. In summary, our results suggested that lncRNA NLRP3 binding miR-138-5p promotes NLRP3-triggered inflammatory response via lncRNA NLRP3/miR-138-5p/NLRP3 ceRNA network (ceRNET) and provides insights into the treatment of early ALI.

β-Caryophyllene attenuates lipopolysaccharide-induced acute lung injury via inhibition of the MAPK signalling pathway

OBJECTIVES

Acute lung injury (ALI) is a pulmonary manifestation of an acute systemic inflammatory response, which is associated with high morbidity and mortality. Accordingly, from the perspective of treating ALI, it is important to identify effective agents and elucidate the underlying modulatory mechanisms. β-Caryophyllene (BCP) is a naturally occurring bicyclic sesquiterpene that has anti-cancer and anti-inflammatory activities. However, the effects of BCP on ALI have yet to be ascertained.

METHODS

ALI was induced intratracheally, injected with 5 mg/kg LPS and treated with BCP. The bone marrow-derived macrophages (BMDMs) were obtained and cultured then challenged with 100 ng/ml LPS for 4 h, with or without BCP pre-treatment for 30 min.

KEY FINDINGS

BCP significantly ameliorates LPS-induced mouse ALI, which is related to an alleviation of neutrophil infiltration and reduction in cytokine production. In vitro, BCP was found to reduce the expression of interleukin-6, interleukin-1β and tumour necrosis factor-α, and suppresses the MAPK signalling pathway in BMDMs, which is associated with the inhibition of TAK1 phosphorylation and an enhancement of MKP-1 expression.

CONCLUSIONS

Our data indicate that BCP protects against inflammatory responses and is a potential therapeutic agent for the treatment of LPS-induced acute lung injury.

Chemical profile of Xian-He-Cao-Chang-Yan formula and its effects on ulcerative colitis

ETHNOPHARMACOLOGICAL RELEVANCE

Xian-He-Cao-Chang-Yan formula (XHCF) is consisting of six crude drugs including Agrimoniae Herba, Coptidis Rhizoma, Aucklandiae Radix, Cicadae Periostracum, Acori Tatarinowii Rhizoma, and Platycodonis Radix at the ratio of 5:1.5:1.5:1.5:1.5:1. It has been used to improve syndromes of ulcerative colitis (UC) for many years.

AIM OF THE STUDY

This study was designed to study the bioactive ingredients and therapeutic mechanisms of XHCF.

MATERIALS AND METHODS

The chemical profile of XHCF was characterized by UHPLC-QTOF-MS/MS. The effects and mechanisms of XHCF on UC were investigated in colitis mice induced by dextran sulfate sodium (DSS) and LPS-stimulated RAW 264.7 cells.

RESULTS

A total of 103 compounds were characterized in XHCF. XHCF could effectively improve acute colitis induced by DSS. More importantly, XHCF significantly decreased M1 macrophage markers (CD11c, IL-6 and IL-1β) whereas increased M2 macrophage markers (CD206) in colitis mice, suggesting it could regulate macrophage polarization. Furthermore, the levels of HK2 and lactic acid in colon tissues were significantly reduced by XHCF, indicating that XHCF could inhibit glycolysis. It also down-regulated HK2 expression in macrophages challenged by LPS. In addition, XHCF enhanced the phosphorylation of AMPK both in vivo and in vitro, suggesting the involvement of AMPK in XHCF function.

CONCLUSIONS

XHCF ameliorated DSS-induced colitis in mice via inhibition of M1 macrophage polarization, probably by the modulation of macrophage metabolic reprogramming via AMPK, contributing to its anti-inflammatory activity. The synergistic actions of multiple ingredients might be responsible for the therapeutic benefits of XHCF on UC.

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.

Fisetin alleviates sepsis-induced multiple organ dysfunction in mice via inhibiting p38 MAPK/MK2 signaling

Sepsis-induced multiple organ dysfunction and inflammatory response are life-threatening symptoms without effective treatment. Fisetin, a dietary flavonoid extracted from berries and family Fabaceae, has displayed neuroprotective and anti-oxidant activities. In this study we investigated whether fisetin exerted a protective effect against sepsis-induced multiple organ dysfunction in mouse cecum ligation and puncture (CLP) model. The mice were injected with fisetin (10 mg/kg, ip) 0.5 h prior to CLP, and sacrificed 18 h after CLP. We found that fisetin administration significantly alleviated CLP-induced lung, liver and kidney injury, as well as the expression levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α and IL-1β in bronchoalveolar lavage fluid (BALF). In lipopolysaccharide (LPS)-treated mouse bone marrow-derived macrophages (BMDMs), application of fisetin (3–10 μM) dose-dependently inhibited the expression levels of IL-6, TNF-α, IL-1β, and inducible nitric oxide synthase (iNOS). Furthermore, fisetin dose-dependently inhibited the phosphorylation of p38 MAPK, MK2, and transforming growth factor-β-activated kinase (TAK) 1 via attenuating the interaction between TAK1 and TAK-binding proteins (TAB) 1. These results demonstrate that fisetin is a promising agent for protecting against sepsis-induced inflammatory response and organ injury via inhibiting macrophage activation.

Costunolide improved dextran sulfate sodium-induced acute ulcerative colitis in mice through NF-κB, STAT1/3, and Akt signaling pathways

Costunolide (CTL) is the major sesquiterpene lactone from Radix Aucklandiae, which is widely used on the treatment of gastrointestinal diseases. However, the therapeutic effect of costunolide in ulcerative colitis (UC) is still unknown. Herein, we sought to evaluate the therapeutic effects and underlying mechanisms of costunolide on UC. ICR mice were intraperitoneally administered with costunolide (10 mg/kg) for 10 days. Beginning on the 4th day of drug administration, acute colitis was induced by feeding 4% dextran sulfate sodium (DSS) for additional 7 days. Costunolide markedly attenuated DSS-induced body weight loss, colonic shortening, elevation in disease activity index, and pathological damage of colon, and decreased the number of CD4⁺ T cells in colon tissues. Furthermore, costunolide significantly inhibited myeloperoxidase (MPO) activity and nitric oxide (NO) level in colon tissues in DSS-exposed mice. Meanwhile, costunolide also suppressed DSS-induced expression of induced nitric oxide synthase (iNOS), interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) in both mRNA and protein levels. Mechanistically, costunolide repressed the phosphorylation of nuclear factor kappa-B (NF-κB) p65 and degradation of inhibitor of NF-κB (IκB), as well as the excessive activation of signal transducers and activators of transcription 1/3 (STAT1/3) and serine/threonine protein kinase Akt (Akt) in colon tissues in DSS-challenged mice. These findings successfully demonstrated that costunolide ameliorated DSS-induced murine acute colitis by suppressing inflammation through inactivation of NF-κB, STAT1/3, and Akt pathways. These results also suggested that costunolide may be a potential therapeutic agent for the treatment of acute UC.

Applications of Sesquiterpene Lactones: A Review of Some Potential Success Cases

Sesquiterpene lactones, a vast range of terpenoids isolated from Asteraceae species, exhibit a broad spectrum of biological effects and several of them are already commercially available, such as artemisinin. Here the most recent and impactful results of in vivo, preclinical and clinical studies involving a selection of ten sesquiterpene lactones (alantolactone, arglabin, costunolide, cynaropicrin, helenalin, inuviscolide, lactucin, parthenolide, thapsigargin and tomentosin) are presented and discussed, along with some of their derivatives. In the authors’ opinion, these compounds have been neglected compared to others, although they could be of great use in developing important new pharmaceutical products. The selected sesquiterpenes show promising anticancer and anti-inflammatory effects, acting on various targets. Moreover, they exhibit antifungal, anxiolytic, analgesic, and antitrypanosomal activities. Several studies discussed here clearly show the potential that some of them have in combination therapy, as sensitizing agents to facilitate and enhance the action of drugs in clinical use. The derivatives show greater pharmacological value since they have better pharmacokinetics, stability, potency, and/or selectivity. All these natural terpenoids and their derivatives exhibit properties that invite further research by the scientific community.

Protostemonine alleviates heat-killed methicillin-resistant Staphylococcus aureus-induced acute lung injury through MAPK and NF-κB signaling pathways

Acute lung injury (ALI) and its most severe form acute respiratory distress syndrome (ARDS) caused by gram-positive bacteria threatens human life because effective treatments and medicines is unavailable. Protostemonine (PSN), an active alkaloid mainly isolated from the roots of Stemona sesslifolia, has anti-inflammatory effects on asthma and gram-negative bacteria-induced ALI. Here, we found that PSN exhibits anti-inflammatory effects and alleviates heat-killed methicillin-resistant Staphylococcus aureus (HKMRSA)-induced pneumonia. PSN treatment significantly attenuated HKMRSA-induced pathological injury, pulmonary neutrophil infiltration, tissue permeability and the production of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) in murine ALI model. In addition, PSN decreased the content of TNF-α, IL-1β, IL-6 and the expression of iNOS, as well as the production of NO in HKMRSA-induced bone marrow derived macrophages (BMDMs). Furthermore, treatment with PSN suppressed the activation of MAPKs (e.g. p38 MAPK, JNK and ERK) and NF-κB. Collectively, our results suggest that PSN ameliorates gram-positive bacteria-induced ALI in mice by inhibition of the MAPK and NF-κB signaling pathways, and our studies suggest that PSN might be a novel candidate for treating ALI/ARDS.

NLRP3 Inflammasome Activation by MicroRNA-495 Promoter Methylation May Contribute to the Progression of Acute Lung Injury

Acute lung injury (ALI) is a pulmonary disorder that causes acute respiratory failure, thus leading to relative high mortality worldwide. However, the molecular mechanisms of ALI remain largely unknown. MicroRNA (miRNA)-dependent control of gene expression at a post-transcriptional level has been recently reported. Herein, we identify a candidate miRNA, miR-495, that affects the progression of ALI. Alveolar macrophages (NR8383) were treated with 1 μg/mL lipopolysaccharide (LPS) to establish a cell-injury model. Combined with the data from western blot, methylation-specific PCR, methylated DNA immunoprecipitation, and chromatin immunoprecipitation assays, NLRP3 inflammasome activation and methylation-dependent repression of miR-495 were found in LPS-exposed NR8383 cells. Dual-luciferase reporter gene assay and miR-495 gain-of-function experiments confirmed that NLRP3 was a target of miR-495. Next, the expression of miR-495 and NLRP3 was overexpressed or silenced to assess their effects on NLRP3 inflammasome activation, alveolar macrophage inflammation, and pyroptosis in vitro. As demonstrated, overexpressed miR-495 alleviated alveolar macrophage inflammation and pyroptosis and inhibited NLRP3 inflammasome activation by negatively regulating the NLRP3 gene. Consistently, elevated miR-495 alleviated lung injury and reduced the neutrophil infiltration and inflammation in rat models of LPS-induced ALI. Taken together, the data in our study demonstrated that methylation of the miR-495 promoter could downregulate miR-495, whose elevation could attenuate the activation of the NLRP3 inflammasome to protect against ALI, which provides novel therapeutic targets for ALI treatment.