Chikusetsusaponin V attenuates lipopolysaccharide-induced acute lung injury in mice by modulation of the NF-κB and LXRα

Targeting neutrophils extracellular traps, a promising anti-thrombotic therapy for natural products from traditional Chinese herbal medicine

Thrombi are the main cause of vascular occlusion and contribute significantly to cardiovascular events and death. Neutrophils extracellular traps (NETs)-induced thrombosis plays a vital role in thrombotic complications and it takes the main responsibility for the resistance of fibrinolysis. However, the conventional anti-thrombotic therapies are inadequate to treat NETs-induced thrombotic complications but carry a high risk of bleeding. Consequently, increased attention has shifted towards exploring novel anti-thrombotic treatments targeting NETs. Interestingly, accumulating evidences prove that natural products from traditional Chinese herbal medicines have a great potential to mitigate thrombosis through inhibiting generous NETs formation and degrading excessive NETs. In this review, we elaborated the formation and degradation of NETs and highlighted its pivotal role in immunothrombosis through interactions with platelets and coagulation factors. Since available anti-thrombotic drugs targeting NETs are deficient, we further summarized the natural products and compounds from traditional Chinese herbal medicines which exert effective actions on regulating NETs formation and also have anti-thrombotic effects. Our findings underscore the diverse effects of natural products in targeting NETs, including relieving inflammation and oxidative stress of neutrophils, inhibiting neutrophils activation and DNA efflux, suppressing granule proteins release, reducing histones and promoting DNA degradation. This review aims to highlight the significance of natural medicines in anti-thrombotic therapies through targeting NETs and to lay a groundwork for developing novel anti-thrombotic agents from traditional Chinese herbal medicines.

Lonicera japonica Thunb extract ameliorates lipopolysaccharide-induced acute lung injury associated with luteolin-mediated suppression of NF-κB signaling pathway

OBJECTIVE

Lonicera japonica Thunb (LJT) is a commonly used herbal soup to treat inflammation-related diseases. However, the effect of LJT on ALI is unknown. The present study was aimed at investigating the protective effects of LJT extract (LTE) and its active ingredient luteolin (Lut) on lipopolysaccharide (LPS)-stimulated ALI and investigate its potential mechanism.

MATERIALS AND METHODS

The effects of LTE and Lut were explored in an ALI mouse model induced by intraperitoneal injection of lipopolysaccharide (LPS). Besides, the LPS-induced inflammation model in BEAS-2B cells was used to clarify the underlying mechanisms. The ALI pathological changes in lung tissues were tested through Haematoxylin and eosin (HE) staining. The apoptosis of cells in lung tissue and the cell model in vitro was evaluated by TUNEL assays, respectively. Meanwhile, the viability of cells in vitro was evaluated by Cell Counting Kit-8 (CCK-8) assay. The levels/concentrations of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β and IL-10 in BALF were detected by enzyme-linked immunosorbent assay (ELISA). Besides, through quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting, the expression of the above-mentioned inflammatory factors and key factors in the NF-κB signaling pathway was examined. The distribution of inflammatory factors in tissue was observed through immunohistochemistry (IHC) assays .

RESULTS

In relative to LPS-stimulated group, the in vivo study showed that LTE and different concentrations of Lut dramatically alleviated LPS-evoked lung pathological injury and lung edema based on the changes in total protein levels and lung wet/dry (W/D) ratio in the bronchoalveolar lavage fluid (BALF) from ALI mice. LTE and different concentrations of Lut also suppressed the inflammatory response, as reflected by the variations of neutrophil accumulation and the production of proinflammatory and anti-inflammatory cytokines in the lung tissues and BALF of ALI mice. The in vitro research also demonstrated that LTE and Lut visibly facilitated cell viability and restrained the apoptosis of BEAS-2B cells stimulated by LPS. Lut hindered LPS-inducible activation of NF-κB pathway in BEAS-2B cells.

CONCLUSION

The present study proved that LTE might suppress LPS-induced acute injury and inflammation in mice and BEAS-2B cells through the Lut-caused suppression of NF-κB signal path (Figure 1).

Emerging Insights into Liver X Receptor α in the Tumorigenesis and Therapeutics of Human Cancers

Liver X receptor α (LXRα), a member of the nuclear receptor superfamily, is identified as a protein activated by ligands that interacts with the promoters of specific genes. It regulates cholesterol, bile acid, and lipid metabolism in normal physiological processes, and it participates in the development of some related diseases. However, many studies have demonstrated that LXRα is also involved in regulating numerous human malignancies. Aberrant LXRα expression is emerging as a fundamental and pivotal factor in cancer cell proliferation, invasion, apoptosis, and metastasis. Herein, we outline the expression levels of LXRα between tumor tissues and normal tissues via the Oncomine and Tumor Immune Estimation Resource (TIMER) 2.0 databases; summarize emerging insights into the roles of LXRα in the development, progression, and treatment of different human cancers and their diversified mechanisms; and highlight that LXRα can be a biomarker and therapeutic target in diverse cancers.

Dihydrotanshinone Attenuates LPS-Induced Acute Lung Injury in Mice by Upregulating LXRα

Dihydrotanshinone (DIH) is an extract of Salvia miltiorrhiza Bunge. It has been reported that DIH could regulate NF-κB signaling pathway. The aim of this study was to investigate whether DIH could protect mice from lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. In this study, sixty mice were randomly divided into five groups, one group as blank control group, the second group as LPS control group, and the last three groups were pre-injected with different doses of DIH and then inhaled LPS for experimental comparison. After 12 h of LPS treatment, the wet-dry ratio, histopathlogical changes, and myeloperoxidase (MPO) activity of lungs were measured. In addition, ELISA kits were used to measure the levels of TNF-α and IL-1β inflammatory cytokines in bronchoalveolar lavage fluids (BALF), and western blot analysis was used to measure the activity of NF-κB signaling pathway. The results demonstrated that DIH could effectively reduce pulmonary edema, MPO activity, and improve the lung histopathlogical changes. Furthermore, DIH suppressed the levels of inflammatory cytokines in BALF, such as TNF-α and IL-1β. In addition, DIH could also downregulate the activity of NF-κB signaling pathway. We also found that DIH dose-dependently increased the expression of LXRα. In addition, DIH could inhibit LPS-induced IL-8 production and NF-κB activation in A549 cells. And the inhibitory effects were reversed by LXRα inhibitor geranylgeranyl pyrophosphate (GGPP). Therefore, we speculate that DIH regulates LPS-induced ALI in mice by increasing LXRα expression, which subsequently inhibiting NF-κB signaling pathway.

Herbal Active Ingredients: Potential for the Prevention and Treatment of Acute Lung Injury

Acute lung injury (ALI) is a life-threatening clinical syndrome with high morbidity and mortality. The main pathological features of ALI are increased alveolar-capillary membrane permeability, edema, uncontrolled migration of neutrophils to the lungs, and diffuse alveolar damage, resulting in acute hypoxemic respiratory failure. Glucocorticoids, aspirin, and other anti-inflammatory drugs are commonly used to treat ALI. Respiratory supports, such as a ventilator, are used to alleviate hypoxemia. Many treatment methods are available, but they cannot significantly ameliorate the quality of life of patients with ALI and reduce mortality rates. Herbal active ingredients, such as flavonoids, terpenoids, saponins, alkaloids, and quinonoids, exhibit advantages for ALI prevention and treatment, but the underlying mechanism needs further study. This paper summarizes the role of herbal active ingredients in anti-ALI therapy and progresses in the understanding of their mechanisms. The work also provides some references and insights for the discovery and development of novel drugs for ALI prevention and treatment.

The roles of liver X receptor α in inflammation and inflammation-associated diseases

Liver X receptor α (LXRα; also known as NR1H3), an isoform of LXRs, is a member of the nuclear receptor family of transcription factors and plays essential roles in the transcriptional control of cholesterol homeostasis. Previous in-depth phenotypic analyses of mouse models with deficient LXRα have also demonstrated various physiological functions of this receptor within inflammatory responses. LXRα activation exerts a combination of metabolic and anti-inflammatory actions resulting in the modulation and the amelioration of inflammatory disorders. The tight "repercussions" between LXRα and inflammation, as well as cholesterol homeostasis, have suggested that LXRα could be pharmacologically targeted in pathologies such as atherosclerosis, acute lung injury, and Alzheimer's disease. This review gives an overview of the recent advances in understanding the roles of LXRα in inflammation and inflammation-associated diseases, which will help in the design of future experimental researches on the potential of LXRα and advance the investigation of LXRα as pharmacological inflammatory targets.

The Anti-Inflammatory Effect of Trichilia martiana C. DC. in the Lipopolysaccharide-Stimulated Inflammatory Response in Macrophages and Airway Epithelial Cells and in LPS-Challenged Mice

A number of species of the genus Trichilia (Meliaceae) exhibit anti-inflammatory effects. However, the effect of Trichilia martiana C. DC. (TM) on lipopolysaccharide (LPS)-induced inflammation has not, to the best of our knowledge, yet been determined. Therefore, in the present study, the antiinflammatory effect of TM on LPS-stimulated RAW264.7 macrophages was evaluated. The ethanol extract of TM (TMEE) significantly inhibited LPS-induced nitric oxide (NO), prostaglandin 2 (PGE₂), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). TMEE also reduced the levels of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β and IL-6. The upregulation of mitogen-activated protein kinases (MAPKs) and NF-κB activation was revealed to be downregulated following TMEE pretreatment. Furthermore, TMEE was indicated to lead to the nucleus translocation of nuclear factor erythroid-derived 2-related factor 2 (Nrf2) and the expression of heme oxygenase-1 (HO-1). In H292 airway epithelial cells, the pretreatment of TMEE significantly downregulated the production of LPS-stimulated IL-1β, and TMEE was indicated to increase the expression of HO-1. In animal models exhibiting LPS-induced acute lung injury (ALI), treatment with TMEE reduced the levels of macrophages influx and TNF-α production in the bronchoalveolar lavage fluid (BALF) of ALI mice. Additionally, TMEE significantly downregulated the activation of ERK, JNK and IκB, and upregulated the expression of HO-1 in the lungs of ALI mice. In conclusion, the results of the current study demonstrated that TMEE could exert a regulatory role in the prevention or treatment of the endotoxin-mediated inflammatory response.

The therapeutic effect of verapamil in lipopolysaccharide-induced acute lung injury

The objective of this study was to investigate the exact therapeutic effects of Verapamil on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and the molecular mechanism involved, through using LPS-induced animal models as well as LPS-stimulated mouse primary peritoneal macrophages models. Our results demonstrated that Verapamil reduced LPS-induced pathological damage of the lung tissue, infiltration of inflammatory cells and the production of IL-1β, TNF-α, and MCP-1 in the serum. The MPO activity, MDA content, lung wet/dry ratio and LDH activity were also attenuated by Verapamil. In addition, Verapamil attenuated LPS-induced inflammatory cytokine production and oxidative stress in primary murine peritoneal macrophages in vitro. Moreover, we confirmed that NF-κB/NLRP3 pathway was involved in the therapeutic effect of Verapamil against LPS-induced injury in vivo and in vitro. In conclusion, these findings indicate that Verapamil has a therapeutic effect on LPS-induced ALI in mice. The mechanism may be related to the inhibition of NF-κB and NLRP3 signaling pathways. Verapamil may be a potential therapeutic agent for the treatment of ALI.