JFNE-A isolated from Jing-Fang n-butanol extract attenuates lipopolysaccharide-induced acute lung injury by inhibiting oxidative stress and the NF-κB signaling pathway via promotion of autophagy

Lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells is inhibited by microRNA-494-3p via targeting lipoprotein-associated phospholipase A2

BACKGROUND

Gram-negative bacterial lipopolysaccharide (LPS) is a major component of inflammation and plays a key role in the pathogenesis of sepsis. According to our previous study, the expression of lipoprotein-associated phospholipase A2 (Lp-PLA2) is significantly upregulated in septic patients and is positively correlated with the severity of this disease. Herein, we investigated the potential roles of Lp-PLA2-targeting microRNAs (miRNAs) in LPS-induced inflammation in murine mononuclear macrophages (RAW264.7 cells).

METHODS

In LPS-stimulated RAW264.7 cells, Lp-PLA2 was confirmed to be expressed during the inflammatory response. The function of microRNA-494-3p (miR-494-3p) in the LPS-induced inflammatory response of RAW264.7 cells was determined by the transfection of a miR-494-3p mimic or inhibitor in vitro.

RESULTS

Compared to the control, LPS induced a significant increase in the Lp-PLA2 level, which was accompanied by the release of inflammatory mediators. The bioinformatics and qRT‒PCR results indicated that the miR-494-3p level was associated with Lp-PLA2 expression in the LPS-induced inflammatory response of RAW264.7 cells. Dual-luciferase reporter assay results confirmed that the 3'-UTR of Lp-PLA2 was a functional target of microRNA-494-3p. During the LPS-induced inflammatory response of RAW264.7 cells, targeting Lp-PLA2 and transfecting miR-494-3p mimics significantly upregulated the expression of miR-494-3p, leading to a reduction in the release of inflammatory factors and conferring a protective effect on LPS-stimulated RAW264.7 cells.

CONCLUSION

By targeting Lp-PLA2, miR-494-3p suppresses Lp-PLA2 secretion, thereby alleviating LPS-induced inflammation, which indicates that miR-494-3p may be a potential target for sepsis treatment.

Jing-Fang n-butanol extract and its isolated JFNE-C inhibit ferroptosis and inflammation in LPS induced RAW264.7 macrophages via STAT3/p53/SLC7A11 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine has accumulated valuable experience in the treatment of inflammatory diseases caused by Ferroptosis. Jing Jie and Fang Feng are two warm acrid exterior-resolving medicinal herbs that play an important role in the prevention and treatment of inflammatory diseases. The pairing of the two forms a drug pair (Jing-Fang) that shows significant advantages in fighting oxidative stress and inflammation. Whereas, the underlying mechanism needs to be further improved.

AIM OF THE STUDY

In this study, the anti-inflammatory effect of Jing-Fang n-butanol extract (JFNE) and its isolate C (JFNE-C) on LPS-induced RAW264.7 cells and the regulation effect on ferroptosis were investigated, and also the mechanism of STAT3/p53/SLC7A11 signal pathway-related to ferroptosis.

MATERIALS AND METHODS

Jing-Fang n-butanol extract (JFNE) and its active isolate (JFNE-C) were extracted and isolated. LPS-induced inflammation model in RAW264.7 cells was established to assess the anti-inflammatory effect and ferroptosis mechanism of JFNE and JFNE-C. The levels of interleukin 6 (IL-6), interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) were measured. The activity levels of antioxidant substances such as glutathione (GSH), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were measured. Flow cytometry, immunofluorescence and transmission electron microscopy were used to assess ROS level, ferrous iron content and mitochondrial morphological changes. Through administration of Ferrostatin-1 (Fer-1), an ferroptosis inhibitor, to verify the role of JFNE and JFNE-C in regulating ferroptosis in resistance to the inflammatory response. Western blotting was used to determine whether the JFNE and JFNE-C exerted effectiveness by modulating the STAT3/p53/SLC7A11 signaling pathway. In addition, the important role of STAT3/p53/SLC7A11 signaling pathway in drug regulation of ferroptosis and inflammatory response was further validated by administration of S3I-201 (STAT3 inhibitor). Finally, high performance liquid chromatography-mass spectrometry (HPLC-MS) was used to determine the major active components of JFNE and JFNE-C.

RESULTS

The results showed that treated with JFNE-C significantly reduced the contents of interleukin 6 (IL-6), interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) in the supernatant of LPS-induced RAW264.7 cells. The pretreatment with JFNE and JFNE-C significantly decreased intracellular oxidative stress levels, including reductions of ROS and MDA levels, and increases of GSH-Px, SOD and GSH levels. In addition, JFNE and JFNE-C obviously reduced intracellular ferrous iron level, and JFNE-C was effective in alleviating mitochondrial damage which includes mitochondrial shrinkage, increase of mitochondrial membrane density and reduction and absence of cristae. Further results indicated that JFNE-C showed a reduction of p53 and p-p53 protein levels in LPS-induced RAW264.7 cells, while significantly increasing the protein expression levels of STAT3, p-STAT3, SLC7A11 and GPX4. Besides, JFNE-C contains key active substances such as 5-O-Methylvisammioside, Hesperidin and Luteolin. Remarkably, this is different from JFNE, which is rich in nutrients such as sucrose, choline and various amino acids.

CONCLUSION

These results suggest that JFNE and JFNE-C may exert anti-inflammatory effect through activating the STAT3/p53/SLC7A11 signaling pathway to inhibit ferroptosis.

Role of endoplasmic reticulum autophagy in acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), the prime causes of morbidity and mortality in critically ill patients, are usually treated by general supportive treatments. Endoplasmic reticulum autophagy (ER-phagy) maintains cellular homeostasis by degrading damaged endoplasmic reticulum (ER) fragments and misfolded proteins. ER-phagy is crucial for maintaining ER homeostasis and improving the internal environment. ER-phagy has a particular role in some aspects, such as immunity, inflammation, cell death, pathogen infection, and collagen quality. In this review, we summarized the definition, epidemiology, and pathophysiology of ALI/ARDS and described the regulatory mechanisms and functions of ER-phagy as well as discussed the potential role of ER-phagy in ALI/ARDS from the perspectives of immunity, inflammation, apoptosis, pathogen infection, and fibrosis to provide a novel and effective target for improving the prognosis of ALI/ARDS.

Research Progress on Autophagy Regulation by Active Ingredients of Traditional Chinese Medicine in the Treatment of Acute Lung Injury

Autophagy is a highly conserved process that maintains cell stability in eukaryotes, participates in the turnover of intracellular substances to maintain cell function, helps to resist pathogen invasion, and improves cell tolerance to environmental changes. Autophagy has been observed in many diseases, and the symptoms of these diseases are significantly improved by regulating autophagy. Autophagy is also involved in the development of lung diseases. Studies have shown that autophagy may play a beneficial or harmful role in acute lung injury (ALI), and ALI has been treated with traditional Chinese medicine designed to promote or inhibit autophagy. In this paper, the molecular mechanism and common pathways regulating autophagy and the relationship between autophagy and ALI are introduced, and the active ingredients of traditional Chinese medicine that improve ALI symptoms by regulating autophagy are summarized.

Cupping alleviates lung injury through the adenosine/A2BAR pathway

Background

Acute lung injury (ALI) is a serious condition. Inflammation plays a crucial role in the pathogenesis of ALI. Cupping, as a part of traditional Chinese medicine, is still a popular complementary and alternative therapy for a variety of ailments including respiratory diseases. However, reliable scientific data about cupping therapy are scarce. Adenosine, a purine nucleoside produced under metabolic stress by the action of extracellular ectonucleotidases (i.e. CD39 and CD73), can attenuate ALI through the A_2BAR receptor. The aim of this study was to investigate the protective effect of cupping in a rat model of ALI and the role of adenosine in it.

Methods

Male adult rats were subjected to ALI by intratracheal LPS instillation (0.3 mg/kg). Immediately after intratracheal LPS instillation, vacuum pressure was applied to a sanitized plastic bell cup on the back of the rat by suction for 10 min. Pulmonary injury and inflammation were assessed at 4 h after LPS challenge. The role of adenosine and A_2BAR in cupping's protection after LPS instillation were evaluated.

Results

Cupping alleviated LPS-induced lung injury, reduced inflammation and inhibited NF-kB activation in rats. Cupping upregulated CD39 and CD73 mRNA expression of the skin tissue at the cupping site and increased circulating levels of adenosine. Administration of PSB1115, a specific adenosine A_2BAR receptor antagonist, abolished cupping's beneficial effects in LPS-induced ALI.

Conclusions

Cupping attenuates lung inflammation and injury through the adenosine/A_2BAR pathway. The current study provides evidence-based information about cupping therapy in ALI.

An anticomplement homogeneous polysaccharide from Hedyotis diffusa attenuates lipopolysaccharide-induced acute lung injury and inhibits neutrophil extracellular trap formation

BACKGROUND

Owing to the involvement of the overactivated complement system in acute lung injury (ALI) development, anticomplement components may attenuate ALI. Hedyotis diffusa is a traditional Chinese medicine for treating lung heat and its crude polysaccharides (HDP) exhibit significant anticomplement activity in vitro.

PURPOSE

To obtain an anticomplement homogeneous polysaccharide from HDP and verify its therapeutic effect and mechanism on ALI.

METHODS

Diethylaminoethyl-52 (DEAE-52) cellulose and gel permeation columns were used to isolate a homogeneous polysaccharide HD-PS-3, which was then characterized using nuclear magnetic resonance (NMR) and methylation analysis. In vitro, the anticomplement activities of HD-PS-3 through classical and alternative pathways were determined using a hemolytic test. The therapeutic effects of HDP and HD-PS-3 on ALI were evaluated in lipopolysaccharide (LPS) intratracheal instilled mice. Hematoxylin and eosin (H&E) staining, enzyme-linked immunosorbent assay (ELISA), and immunohistochemical staining were used to assess histological changes, measure cytokine levels, and evaluate the degree of complement component 3c (C3c) deposition and neutrophil infiltration, respectively. ELISA, western blotting, and immunofluorescence were used to analyze neutrophil extracellular trap (NET) formation.

RESULTS

From HDP, 1.5 g of the homogeneous polysaccharide HD-PS-3 was obtained. HD-PS-3 was an acidic heteropolysaccharide with an acetyl group, which was composed of →4,6)-α-Glcp-(1→, →3,4)-α-Glcp-(1→, →4)-α-Glcp-(1→, →4,6)-α-Galp-(1→, →5)-α-Araf-(1→, α-Rhap-(1→, α-Araf-(1→, α-GlcpA-(1→, →4)-β-Manp-(1→, β-Manp-(1→ and →3)-β-Manp-(1→. The in vitro results suggest that HD-PS-3 exhibited anticomplement activity with CH₅₀ and AP₅₀ values of 115 ± 12 μg/ml and 307 ± 11 μg/ml, respectively. After confirming the efficacy of HDP (200 mg/kg) in attenuating lung injury, the effect of HD-PS-3 on ALI was also investigated. HD-PS-3 (75 and 150 mg/kg) attenuated LPS-induced ALI as well, evidenced by lung pathology, lung injury scores, protein concentration, leukocyte counts, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) contents in bronchoalveolar lavage fluid (BALF). Mechanistically, HD-PS-3 inhibited complement activation, manifested in reduced pulmonary C3c deposition in lung tissue and complement component 3a (C3a) content in BALF. Neutrophil recruitment was also reduced by HD-PS-3, with significantly reduced pulmonary neutrophil infiltration and lower levels of C-X-C motif chemokine ligand 1 (CXCL1) and myeloperoxidase (MPO) in BALF. In addition, HD-PS-3 reduced the levels of MPO-DNA complex in BALF, decreased citrullinated histone H3 (Cit H3) expression and NET formation (colocalization of MPO, Cit H3, and DNA) in lung tissue.

CONCLUSION

An anticomplement homogeneous polysaccharide HD-PS-3 was isolated from H. diffusa. HD-PS-3 exhibited a therapeutic effect against ALI, and the mechanism might be related to its inhibitory effects on complement activation, neutrophil recruitment, and NET formation.

Ethanol extracts of Rhaponticum uniflorum (L.) DC inflorescence ameliorate LPS-mediated acute lung injury by alleviating inflammatory responses via the Nrf2/HO-1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Rhaponticum uniflorum (L.) DC is a member of the Compositae family. Loulu flowers (LLF) is the inflorescence of this plant, which is a commonly used Mongolian medicine for the treatment of inflammatory diseases due to its heat-clearing and detoxifying properties. It is used caused by. However, its anti-inflammatory mechanisms are not clear.

AIM OF THIS STUDY

We investigated whether ethanol extracts of LLF can alleviate LPS-induced acute lung injury and explored the mechanism involved.

MATERIAL AND METHODS

BALB/C mice were intragastrically administered with sodium carboxymethyl cellulose (0.5%, 1 mL/100 g) or ethanol extracts of LLF at a dose of 100, 200, and 400 mg/kg, once daily, for 3 days. Subsequently, mice models of acute lung injury were established by LPS and used for the determination of anti-inflammatory effects of LLF. After 6 h of treatment, mice were sacrificed to collect lung tissues and bronchoalveolar lavage fluid (BALF). H&E staining assay was performed on the tissues for pathological analysis. The ELISA test was conducted to measure NO, IL-6, TNF-α, MPO, SOD, CAT, MDA and GSH-PX levels. The expression level of proteins associated with the Nrf2/HO-1 and MAPK/NF-κB signaling pathways were determined using Western blot analysis. Levels of F4/80 and Nrf2 in lungs were quantified using immunohistochemistry.

RESULTS

Oral administration of LLF extracts alleviated LPS-induced pathological alterations, reduced lung W/D weight ratio, decreased levels of TP, pro-inflammatory factors (TNF-α and IL-6), and NO in BALF. Pretreatment with LLF extract downregulated F4/80 expression in lung tissue and suppressed LPS-induced elevations in BALF and lung tissue levels of MPO. Moreover, treatment with LLF extract reduced the expression level of proteins associated with the MAPK signaling pathway (p-p38, p-JNK, p-ERK) and TLR4/NF-κB signaling pathways (TLR4, Myd88, p-IκB, p-p65). Moreover, LLF extract upregulated Nrf2, HO-1 and NQO1 protein levels, downregulated Keap1 protein level. Immunohistochemical analysis revealed that LLF reduced the LPS-induced increase in Nfr2 expression in lung tissues.

CONCLUSION

Ethanol extracts of LLF ameliorated LPS-induced acute lung injury by suppressing inflammatory response and enhancing antioxidation capacity, which correlated with the MAPK/NF-κB and Nfr2/HO-1 signaling pathways.

Traditional Chinese medicine prescriptions (XJZ, JSS) ameliorate spleen inflammatory response and antioxidant capacity by synergistically regulating NF-κB and Nrf2 signaling pathways in piglets

Weaning transition generally impairs the immune system, inducing immune disturbance, which may be associated with post-weaning diarrhea and high mortality in piglets. The spleen is a pivotal lymphatic organ that plays a key role in the establishment of the immune system. Traditional Chinese medicine (TCM) prescriptions, XiaoJianZhong (XJZ) and Jiansananli-sepsis (JSS), are widely used prescriptions for treating spleen damage and diarrhea. Here, we hypothesized that XJZ and JSS maintain the spleen physiological function by ameliorating antioxidant capacity and inflammatory response in weaned piglets. In this study, 18 weaned piglets were assigned to the Control, XJZ and JSS groups. By hematoxylin and eosin staining, hematological analysis, flow cytometric analysis, qRT-PCR and western blot, the effects of both TCM prescriptions on the spleen antioxidant defense system and inflammatory pathway were explored. Results showed that both TCM treatment significantly ameliorated the weaning-induced morphological damage in piglets, as evidenced by clearer and more perfect spleen histology, as well as higher relative area of white pulp. Meanwhile, both XJZ and JSS exerted better blood parameters, as supported by the changes of monocyte level and lymphocyte subpopulations CD4+/CD8+ ratio. Furthermore, the levels of inflammatory markers, IL1β, IL6, IL8, and TNF-α in the spleen were markedly decreased after supplemented with both TCM prescriptions. Importantly, the inhibition of nuclear factor-kappaB (NF-κB) and its downstream effector genes (IL6, IL8, and TNF-α) in both XJZ and JSS treatment groups further confirmed alleviation of inflammatory responses in the spleen. In addition, both XJZ and JSS enhanced the antioxidant capacity of the spleen by activating the nuclear factor erythroid 2-related factor 2 (Nrf2)-activated antioxidant defense system. Notably, the results of PCA and network correlation analysis indicated that XJZ and JSS treatment altered the expression profiles of inflammatory and antioxidant-related factors in the spleen of weaned-piglets, which may involve the synergy of NF-κB and Nrf2 signaling pathways. In summary, our study showed that TCM prescriptions, XJZ and JSS could ameliorate inflammatory response and antioxidant capacity in the spleen by synergistically regulating NF-κB and Nrf2 signaling pathways in piglets.

Huangkui lianchang decoction attenuates experimental colitis by inhibiting the NF-κB pathway and autophagy

Ulcerative colitis (UC) is a chronic inflammatory colorectal disease characterized by excessive mucosal immune response activation and dysfunction of autophagy in intestinal epithelial cells. Traditional herbal preparations, including the Huangkui lianchang decoction (HLD), are effective in UC clinical treatment in East Asia, but the underlying mechanism is unclear. This study evaluated the therapeutic effects and associated molecular mechanisms of HLD in UC in vivo and in vitro. A C57BL/6 UC mouse model was established using 2.5% dextran sulfate sodium. The effects of HLD on the colonic structure and inflammation in mice were evaluated using mesalazine as the control. The anti-inflammatory effects of HLD were assessed using disease activity index (DAI) scores, histological scores, enzyme-linked immunosorbent assay, immunohistochemistry, immunofluorescence, and western blotting. HLD displayed a protective effect in UC mice by reducing the DAI and colonic histological scores, as well as levels of inflammatory cytokines and NF-κB p65 in colonic tissues. NCM460 lipopolysaccharide-induced cells were administered drug serum-containing HLD (HLD-DS) to evaluate the protective effect against UC and the effect on autophagy. HLD-DS exhibited anti-inflammatory effects in NCM460 cells by reducing the levels of inflammatory cytokines and increasing interleukin 10 levels. HLD-DS reduced p-NF-κB p65, LC3II/I, and Beclin 1 expression, which suggested that HLD alleviated colitis by inhibiting the NF-κB pathway and autophagy. However, there was no crosstalk between the NF-κB pathway and autophagy. These findings confirmed that HLD was an effective herbal preparation for the treatment of UC.

Fengreqing Oral Liquid Exerts Anti-Inflammatory Effects by Promoting Apoptosis and Inhibiting PI3K/AKT and NF-κB Signaling Pathways

Fengreqing oral liquid (FOL), a Chinese patent drug frequently used in clinical practice in China, is effective in treating inflammatory diseases of the upper respiratory tract such as colds and flu. However, its anti-inflammatory effects and mechanisms remain to be elucidated. In this study, the anti-inflammatory effects of FOL and its mechanisms on PI3K/AKT and NF-κB signaling pathways in LPS-induced RAW264.7 cells were explored, as well as the regulatory effect of FOL on apoptosis. In addition, the potential of FOL for the treatment of acute lung injury was explored in LPS-induced ALI mice. The results showed that treatment with FOL significantly reduced the levels of interleukin 1β (IL-1β), interleukin 6 (IL-6), nitric oxide (NO), and tumor necrosis factor α (TNF-α) in the supernatant of LPS-induced RAW264.7 cells, and also significantly reduced the phosphorylated protein levels of PI3K and AKT in the PI3K/AKT signaling pathway and also protein levels of NF-κB p50, phosphorylated NF-κB p65, and IκBα in the NF-κB signaling pathway. In addition, the results showed that FOL induced apoptosis in LPS-induced RAW264.7 cells at the level of 80%–90%, and significantly increased the protein expression levels of the pro-apoptotic Bax and cleaved-caspase-3. In LPS-induced ALI mice, FOL administration showed inhibition of IL-1β, IL-6, and TNF-α in Bronchoalveolar lavage fluid (BALF) and decreased protein expression levels of PI3K, AKT, NF-κB p50, and NF-κB p65, and elevated protein expression levels of Bax and cleaved-caspase-3 significantly. These results suggest that FOL may exert anti-inflammatory effects by inhibiting the PI3K/AKT signaling pathway to promote apoptosis and leading to attenuated activation of the NF-κB signaling pathway.