Esculin alleviates LPS-induced acute lung injury via inhibiting neutrophil recruitment and migration

Targeting neutrophil dysfunction in acute lung injury: Insights from active components of Chinese medicine

BACKGROUNDS

Acute lung injury (ALI) is a lethal condition characterized by uncontrolled pulmonary inflammatory responses, with high morbidity and mortality rates that pose a significant threat to patient health. The persistent retention of neutrophils in lung tissue and subsequent inflammatory damage represents a primary mechanism underlying the early onset of ALI disorders. In recent years, pharmaceutical research targeting these pathological processes has garnered considerable attention. Traditional Chinese medicines (TCM) and their active ingredients, known for their safety and stability, show promising potential in treating ALI through their ability to modulate neutrophil function via multiple pathways.

PURPOSE

This review examines the mechanisms of neutrophil involvement in the pathogenesis of ALI, investigates potential therapeutic targets and pathways through which Chinese medicines and their active ingredients regulate neutrophil function, and provides a theoretical foundation for developing novel clinical treatment strategies.

METHODS

A comprehensive literature search was conducted using multiple databases, including Science Direct, PubMed, Google Scholar, and Web of Science. Search terms included 'lung injury,' 'acute lung injury,' 'inflammatory lung injury,' 'inflammation,' 'active ingredient,' 'herbal,' 'traditional Chinese medicine,' 'mechanism,' 'drug,' and 'neutrophils.' The selected literature was systematically categorized and analyzed.

RESULTS

Our review reveals that TCM and active ingredients influence neutrophil function through four primary mechanisms to impede ALI progression: 1) reduction of neutrophil-mediated uncontrolled inflammatory responses by suppressing neutrophil hyperactivation and inhibiting neutrophil migration and infiltration; 2) attenuation of lung tissue inflammatory damage by inhibiting neutrophil-produced cytotoxic substances, including elastase granules, neutrophil extracellular traps (NETs), and reactive oxygen species (ROS); 3) suppression of inflammatory responses by decreasing the secretion of neutrophil-derived cytokines, such as interleukin (IL) -1β, IL-6 and tumor necrosis factor-alpha (TNF-α); and 4) enhancement of neutrophil phagocytosis and accelerate the removal of apoptotic neutrophils to eliminate harmful pathogens and promote late-stage tissue repair. These findings demonstrate that Chinese medicines and their active ingredients exhibit significant therapeutic potential in ALI disorders through the modulation of neutrophil function, providing a robust theoretical framework for their clinical applications.

CONCLUSION

Traditional Chinese medicines and their active ingredients demonstrate significant anti-inflammatory efficacy through multiple mechanisms of neutrophil function regulation, showing considerable promise for the treatment of ALI with broad clinical applications.

Kirenol ameliorates endotoxin-induced acute lung injury by inhibiting the ERK and JNK phosphorylation-mediated NFκB pathway in mice

Acute lung injury (ALI) is a pathological condition characterised by varying degrees of lung damage in patients. Kirenol exerts anti-inflammatory, immunosuppressive, and antioxidative effects. We investigated the protective effects of kirenol on lipopolysaccharide-induced ALI in mice. Pretreatment with kirenol significantly ameliorated lung oedema and neutrophil infiltration in ALI mice. Kirenol downregulated the chemokines (MIP-2) expression and the adhesion molecules (ICAM-1 and VCAM-1) secretion. Furthermore, kirenol inhibited the production of the proinflammatory mediators nitric oxide and prostaglandin (PG)E2 through the upstream factors iNOS and cyclooxygenase (COX)-2, respectively. Kirenol suppressed the IKK-IκB-NFκB pathway, which is involved in lipopolysaccharide-induced inflammation. Kirenol inhibited the lipopolysaccharide-induced phosphorylation of ERK and JNK, to a lesser extent, p38 MAPK and Akt. In conclusion, our findings suggest that kirenol exerts ameliorative effects against ALI by suppressing the production of chemokines, adhesion molecules, and proinflammatory mediators and inhibiting the IKK-IκB-NFκB pathway and its upstream factors, phosphorylated ERK and JNK.

Clinical observation of esculin and digitalisglycosides eye drops with 0.3% sodium hyaluronate eye drops for dry eye disease: a randomized controlled trial

Dry eye disease (DED) is a common ocular surface disorder. Esculin and digitalis possess anti-inflammatory and anti-oxidant properties, which may benefit patients with DED. This study aimed to assess the therapeutic efficacy of esculin and digitalis glycosides (EAD) eye drops, either alone or in combination with 0.3% sodium hyaluronate (SH) eye drops, in treating DED. In this randomized controlled trial, 78 participants with DED (78 eyes) were included and divided into three groups: Group A received 0.3% SH, Group B received EAD, and Group C received 0.3% SH combined with EAD eye drops for 4 weeks. The efficacy of the treatments was assessed at 2 and 4 weeks using the Ocular Surface Disease Index (OSDI), tear break-up time (TBUT), Schirmer I test (SIt), and corneal fluorescein staining (CFS) as primary evaluation metrics. After 4 weeks of treatment, Group A showed a decrease in OSDI and an increase in SIT (p < 0.05). Group B showed a decrease in OSDI score (P < 0.05) and a significant improvement in SIt (P < 0.01). Group C demonstrated a significant increase in both TBUT and SIt values at the 2-week mark. Improvements were noted across all parameters, including OSDI score, TBUT, SIt, and CFS score after 4 weeks of treatment (P < 0.05). The total effective rate for participants in Group C was 88.46%, significantly higher than Group A's rate of 65.38% (P < 0.05). In conclusion, the combination of EAD eye drops with 0.3% SH eye drops proved more effective than either treatment alone.

Musa paradisiaca L. Inflorescence Abrogates Neutrophil Activation by Downregulating TLR4/NF-KB Signaling Pathway in LPS-Induced Acute Lung Injury Model

Background/Objectives: Acute lung injury (ALI) is an inflammatory disorder affecting patients in intensive care with high mortality. No specific pharmacological treatment is available. Musa paradisiaca L. (banana) is a cosmopolitan plant, and homemade syrup from its inflorescence is used in many countries to treat pulmonary inflammation. Therefore, this study analyzed the hydroalcoholic extract (HEM) of the inflorescence on the ALI experimental model. Methods: Swiss mice were challenged with lipopolysaccharide and treated with HEM after 1, 24, and 48 h (five animals/group, three times). Results: The HEM-treated ALI mice presented a decrease in neutrophil migration in the bronchoalveolar lavage fluid (BALF), in the alveolar region, and in the blood, correlating to downregulation of CD18 expression. The HEM treatment also reduced the protein concentration in the BALF, caused lung edema formation, impaired NF-κB activation via inhibition of TLR4 signaling pathway, and decreased IL-1β, TNF-α production, free DNA release, and myeloperoxidase (MPO) activity. However, the extract induced an increased IL-10 in the BALF. Conclusions: Therefore, HEM's anti-inflammatory and immunomodulatory activities in ALI mice are by deactivating neutrophils by decreasing CD18 receptor, free DNA release, and MPO activity and inducing IL-10 production. Thus, this study supports the use of banana inflorescence in folk medicine and suggests its rational use to develop a phytomedicine to treat pulmonary inflammation.

Esculin alleviates lipopolysaccharide (LPS)-induced pneumonia by regulating the USP7/MAPK14 axis

Pneumonia is a serious and life-threatening lung inflammation with high morbidity and mortality. Accumulating evidence has suggested that esculin, a derivative of coumarin, possesses potent anti-inflammatory effects. This study is designed to explore the pharma role and underlying mechanism of esculin against lipopolysaccharides (LPS)-induced pneumonia. TC-1 cells were stimulated by LPS to mimic the inflammatory injury model in vitro. Cell viability, proliferation, and apoptosis were determined using MTT assay, 5-ethynyl-2'-deoxyuridine assay, and flow cytometry. Interleukin-1β and tumor necrosis factor α levels were analyzed using an enzyme-linked immunosorbent assay. Reactive oxygen species and superoxide dismutase were examined using special assay kits. Macrophage polarization was detected using flow cytometry. Mitogen-activated protein kinase 14 (MAPK14) level was detected by real-time quantitative polymerase chain reaction. MAPK14 and ubiquitin-specific protease 7 (USP7) protein levels were determined using western blot assay. After Ubibrowser database prediction, the interaction between USP7 and MAPK14 was verified using a Co-immunoprecipitation assay. The biological role of esculin was verified in LPS-challenged ALI mice in vivo. Here, we found that esculin significantly relieved LPS-induced TC-1 cell proliferation inhibition, and apoptosis, inflammatory response, oxidative stress, and M1-type macrophage polarization promotion. MAPK14 and USP7 expressions were enhanced in LPS-treated TC-1 cells, which was partly abolished by esculin treatment. Overexpressing MAPK14 attenuated the repression of esculin on LPS-triggered TC-1 cell injury. At the molecular level, USP7 interacted with MAPK14 and maintained its stability by removing ubiquitin. Moreover, esculin repressed the progression of pneumonia in vivo by regulating MAPK14. Taken together, esculin exposure could mitigate LPS-induced TC-1 cell injury partly by targeting the USP7/MAPK14 axis, providing a better understanding of the role of esculin in the anti-inflammatory therapeutics for pneumonia.

Integration of microbiomics, metabolomics, and transcriptomics reveals the therapeutic mechanism underlying Fuzheng-Qushi decoction for the treatment of lipopolysaccharide-induced lung injury in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Fuzheng-Qushi decoction (FZQS) is a practical Chinese herbal formula for relieving cough and fever. Therefore, the action and specific molecular mechanism of FZQS in the treatment of lung injury with cough and fever as the main symptoms need to be further investigated.

AIMS OF THE STUDY

To elucidate the protective effects of FZQS against lung injury in mice and reveal its potential targets and key biological pathways for the treatment of lung injury based on transcriptomics, microbiomics, and untargeted metabolomics analyses.

MATERIALS AND METHODS

Lipopolysaccharide (LPS) was used to induce a mouse model of lung injury, followed by the administration of FZQS. ELISA was used to detect IL-1β, IL-6, IL-17A, IL-4, IL-10, and TNF-α, in mouse lung tissues. Macrophage polarization and neutrophil activation were measured by flow cytometry. RNA sequencing (RNA-seq) was applied to screen for differentially expressed genes (DEGs) in lung tissues. RT-qPCR and Western blot assays were utilized to validate key DEGs and target proteins in lung tissues. 16S rRNA sequencing was employed to characterize the gut microbiota of mice. Metabolites in the gut were analyzed using untargeted metabolomics.

RESULTS

FZQS treatment significantly ameliorated lung histopathological damage, decreased pro-inflammatory cytokine levels, and increased anti-inflammatory cytokine levels. M1 macrophage levels in the peripheral blood decreased, M2 macrophage levels increased, and activated neutrophils were inhibited in mice with LPS-induced lung injury. Importantly, transcriptomic analysis showed that FZQS downregulated macrophage and neutrophil activation and migration and adhesion pathways by reversing 51 DEGs, which was further confirmed by RT-qPCR and Western blot analysis. In addition, FZQS modulated the dysbiosis of the gut microbiota by reversing the abundance of Corynebacterium, Facklamia, Staphylococcus, Paenalcaligenes, Lachnoclostridium, norank_f_Muribaculaceae, and unclassified_f_Lachnospiraceae. Meanwhile, metabolomics analysis revealed that FZQS significantly regulated tryptophan metabolism by reducing the levels of 3-Indoleacetonitrile and 5-Hydroxykynurenine.

CONCLUSION

FZQS effectively ameliorated LPS-induced lung injury by inhibiting the activation, migration, and adhesion of macrophages and neutrophils and modulating gut microbiota and its metabolites.

Revealing the Mechanism of Esculin in Treating Renal Cell Carcinoma Based on Network Pharmacology and Experimental Validation

PURPOSE

This study aims to explore the potential mechanisms of esculin in the treatment of renal cell carcinoma (RCC).

METHODS

We employed network pharmacology to predict the potential mechanisms and targets of esculin in RCC. Molecular docking techniques were then employed to validate the predicted targets. Additionally, a series of in vitro experiments were conducted to verify the anticancer effects of esculin on RCC cells, including the CCK-8 assay, EdU assay, wound healing assay, apoptosis assay, and Western blot.

RESULTS

Network pharmacology and molecular docking results identified GAPDH, TNF, GSK3B, CCND1, MCL1, IL2, and CDK2 as core targets. GO and KEGG analyses suggested that esculin may influence apoptotic processes and target the PI3K/Akt pathway in RCC. Furthermore, the CCK-8 assay demonstrated that esculin inhibited RCC cell viability. Microscopic observations revealed that following esculin treatment, there was an increase in cell crumpling, a reduction in cell density, and an accumulation of floating dead cells. Additionally, with increasing esculin concentrations, the proportion of EdU-positive cells decreased, the wound closure ratio decreased, the proportion of PI-positive cells increased, the expression levels of BAX and cleaved-caspase-3 proteins increased, and the expression level of Bcl2 protein decreased. These findings suggested that esculin inhibits the proliferation and migration of RCC cells while promoting apoptosis. Moreover, esculin was found to target GAPDH and inhibit the PI3K/Akt pathway.

CONCLUSIONS

This study is the first to elucidate the therapeutic effects of esculin on RCC cells. The results provide evidence supporting the clinical application of esculin and introduce a promising new candidate for RCC treatment.

Targeted Reprogramming of Pathogenic Fibroblast Genes at the 3'-Untranslated Regions by DNA Nanorobots for Periodontitis

Periodontitis, with its persistent nature, causes significant distress for most sufferers. Current treatments, such as mechanical cleaning and surgery, often fail to fully address the underlying overactivation of fibroblasts that drives this degradation. Targeting the post-transcriptional regulation of fibroblasts, particularly at the 3'-untranslated regions (3'UTR) of pathogenic genes, offers a therapeutic strategy for periodontitis. Herein, we developed a DNA nanorobot for this purpose. This system uses a dynamic DNA nanoframework to incorporate therapeutic microRNAs through molecular recognition and covalent bonds, facilitated by DNA monomers modified with disulfide bonds. The assembled-DNA nanoframework is encapsulated in a cell membrane embedded with a fibroblast-targeting peptide. By analyzing the 3'UTR regions of pathogenic fibroblast genes FOSB and JUND, we identified the therapeutic microRNA as miR-1-3p and integrated it into this system. As expected, the DNA nanorobot delivered the internal components to fibroblasts by the targeting peptide and outer membrane that responsively releases miR-1-3p under intracellular glutathione. It resulted in a precise reduction of mRNA and suppression of protein function in pathogenic genes, effectively reprogramming fibroblast behavior. Our results confirm that this approach not only mitigates the inflammation but also promotes tissue regeneration in periodontal models, offering a promising therapeutic avenue for periodontitis.

3-methyladenine ameliorates acute lung injury by inhibiting oxidative damage and apoptosis

Background

Acute lung injury (ALI) is a condition characterized by inflammation and oxidative damage. 3-methyladenine (3-MA) has great potential for regulating apoptosis, but its regulatory role in ALI is unknown.

Methods

Lipopolysaccharide (LPS)-treated mice and tert-butyl hydroperoxide (TBHP)-treated bronchial epithelial cells were used to simulate in vivo and in vitro ALI models, respectively. In vivo, lung injury was assessed by histopathological analysis and lung injury scoring. The total cell count, protein content, and inflammatory factors in bronchoalveolar lavage fluid (BALF) were examined. The level of apoptosis in lung tissue was assessed through TUNEL staining. In the vitro ALI model, cell viability and levels of reactive oxygen species and apoptosis were assessed.

Results

3-MA pretreatment ameliorated lung injury, including intra-alveolar hemorrhage and inflammatory cell accumulation, both in vitro and in vivo. 3-MA pretreatment also decreased inflammatory factor levels in the BALF. 3-MA pretreatment alleviated oxidative damage, decreased reactive oxygen species levels, and attenuated morphological changes. TUNEL and Annexin V-FITC/PI staining revealed that pretreatment with 3-MA reduced the level of apoptosis. 3-MA pretreatment significantly decreased the expression of caspase-3 and Bax but increased the expression of Bcl-2 in ALI. Mechanistically, 3-MA pretreatment also affected the PKCα/NOX4 and Nrf2 pathways, which decreased the level of apoptosis in ALI.

Conclusions

3-MA pretreatment inhibited inflammation and oxidative damage in ALI and inhibited apoptosis to mitigate ALI in part by inhibiting the PKCα/NOX4 pathway and activating the Nrf2 pathway. Based on these results, 3-MA might be a viable medication to treat with ALI.

Esculin inhibits hepatic stellate cell activation and CCl4-induced liver fibrosis by activating the Nrf2/GPX4 signaling pathway

BACKGROUND

Liver fibrosis (LF) is a pathological process of the liver that threatens human health. Currently, effective treatments are still lacking. Esculin, a prominent constituent found in the Fraxinus rhynchophylla. (bark), Aesculus hippocastanum. (bark), and Cichorium intybus. (herb), has been shown to possess significant anti-inflammatory, antioxidant, and antibacterial properties. However, to date, there have been no studies investigating its potential efficacy in the treatment of LF.

OBJECTIVE

The study aims to investigate the therapeutic effect of esculin on LF and elucidate its potential molecular mechanism.

METHODS

Carbon tetrachloride (CCl4) was injected intraperitoneally to induce LF in mice, and transforming growth factor β1 (TGF-β1) was injected to induce LX-2 cells to investigate the improvement effect of esculin on LF. Kit, histopathological staining, immunohistochemistry (IHC), immunofluorescence (IF), polymerase chain reaction (PCR), and western blot (WB) were used to detect the expression of fiber markers and nuclear factor erythroid 2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPX4) signaling pathway in liver tissue and LX-2 cells. Finally, molecular docking, cellular thermal shift assay (CETSA), and drug affinity responsive target stability (DARTS) were used to verify the targeting between Nrf2 and esculin.

RESULTS

Esculin significantly inhibited CCl4-induced hepatic fibrosis and inflammation in mice. This was evidenced by the improvement of liver function indexes, fibrosis indicators, and histopathology. Additionally, esculin treatment prominently reduced the levels of pro-inflammatory factors, oxidative stress, and liver Fe2+ in CCl4-induced mice. In vitro studies also showed that esculin treatment significantly inhibited TGF-β1-induced LX-2 cell activation and decreased alpha-smooth muscle actin (α-SMA) and collagen I expression. Mechanism experiments proved that esculin can activate the Nrf2/GPX4 signaling pathway and inhibit liver ferroptosis. However, when LX-2 cells were treated with the Nrf2 inhibitor (ML385), the therapeutic effect of esculin significantly decreased.

CONCLUSION

This study is the first to demonstrate that esculin is a potential natural active ingredient in the treatment of LF, which can inhibit the activation of hepatic stellate cells (HSC) and improve LF. Its therapeutic effect is related to the activation of the Nrf2/GPX4 signaling pathway.

Esculin targets TLR4 to protect against LPS-induced septic cardiomyopathy

BACKGROUND

Esculin, a main active ingredient from Cortex fraxini, possesses biological activities such as anti-thrombosis, anti-inflammatory, and anti-oxidation effects. However, the effects of Esculin on septic cardiomyopathy remains unclear. This study aimed to explore the protective properties and mechanisms of Esculin in countering sepsis-induced cardiac trauma and dysfunction.

METHODS AND RESULTS

In lipopolysaccharide (LPS)-induced mice model, Esculin could obviously improve heart injury and function. Esculin treatment also significantly reduced the production of inflammatory and apoptotic cells, the release of inflammatory cytokines, and the expression of oxidative stress-associated and apoptosis-associated markers in hearts compared to LPS injection alone. These results were consistent with those of in vitro experiments based on neonatal rat cardiomyocytes. Database analysis and molecular docking suggested that TLR4 was targeted by Esculin, as shown by stable hydrogen bonds formed between Esculin with VAL-308, ASN-307, CYS-280, CYS-304 and ASP-281 of TLR4. Esculin reversed LPS-induced upregulation of TLR4 and phosphorylation of NF-κB p65 in cardiomyocytes. The plasmid overexpressing TLR4 abolished the protective properties of Esculin in vitro.

CONCLUSION

We concluded that Esculin could alleviate LPS-induced septic cardiomyopathy via binding to TLR4 to attenuate cardiomyocyte inflammation, oxidative stress and apoptosis.

Pharmacological activities of esculin and esculetin: A review

Esculin and esculetin are 2 widely studied coumarin components of Cortex Fraxini, which is a well-known herbal medicine with a 2000-year history. In vivo and in vitro studies have demonstrated that both have a variety of pharmacological activities, including antioxidant, anti-tumor, anti-inflammatory, antibacterial, antidiabetic, immunomodulatory, anti-atherosclerotic, and so on. Their underlying mechanisms of action and biological activities include scavenging free radicals, modulating the nuclear factor erythroid 2-related factor 2 pathway, regulating the cell cycle, inhibiting tumor cell proliferation and migration, promoting mitochondrial pathway apoptosis, inhibiting the NF-κB and MAPK signaling pathways, regulating CD4+ T cells differentiation and associated cytokine release, inhibiting vascular smooth muscle cells, etc. This review aims to provide comprehensive information on pharmacological studies of esculin and esculetin, which is of noteworthy importance in exploring the therapeutic potential of both coumarin compounds.