Hederasaponin C Alleviates Lipopolysaccharide-Induced Acute Lung Injury In Vivo and In Vitro Through the PIP2/NF-κB/NLRP3 Signaling Pathway

Abstract

Gene transcription is governed by epigenetic regulation that is essential for the pro-inflammatory mediators surge following pathological triggers. Acute lung injury (ALI) is driven by pro-inflammatory cytokines produced by the innate immune system, which involves the nod-like receptor 3 (NLRP3) inflammasome and nuclear factor-κB (NF-κB) pathways. These two pathways are interconnected and share a common inducer the phosphatidylinositol 4,5-bisphosphate (PIP2), an epigenetic regulator of (Ribosomal ribonucleic acid (rRNA) gene transcription, to regulate inflammation by the direct inhibition of NF-κB phosphorylation and NLRP3 inflammasome activation. Herein, we report that hederasaponin C (HSC) exerted a therapeutic effect against ALI through the regulation of the PIP2/NF-κB/NLRP3 signaling pathway. In lipopolysaccharide (LPS)/lipopolysaccharide + adenosine triphosphate (LPS+ATP)-stimulated macrophages, our results showed that HSC remarkably inhibited the secretion of interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α). Moreover, HSC inhibited NF-κB/p65 nuclear translocation and the binding of PIP2 to transforming growth factor-β activated kinase 1 (TAK1). The intracellular calcium (Ca2+) level was decreased by HSC via the PIP2 signaling pathway, which subsequently inhibited the activation of NLRP3 inflammasome. HSC markedly alleviated LPS-induced ALI, restored lung function of mice, and rescued ALI-induced mice death. In addition, HSC significantly reduced the level of white blood cells (WBC), neutrophils, and lymphocytes, as well as pro-inflammatory mediators like IL-6, IL-1β, and TNF-α. Hematoxylin and eosin (H&E) staining results suggested HSC has a significant therapeutic effect on lung injury of mice. Interestingly, the PIP2/NF-κB/NLRP3 signaling pathway was further confirmed by the treatment of HSC with ALI, which is consistent with the treatment of HSC with LPS/LPS+ATP-stimulated macrophages. Overall, our findings revealed that HSC demonstrated significant anti-inflammatory activity through modulating the PIP2/NF-κB/NLRP3 axis in vitro and in vivo, suggesting that HSC is a potential therapeutic agent for the clinical treatment of ALI.

Saikosaponin A and Its Epimers Alleviate LPS-Induced Acute Lung Injury in Mice

“…The 88 mice were randomly divided into 11 groups ( n = 8), including a control group, model group, dexamethasone group (5 mg/kg), low-dose SSA group (2.5 mg/kg), high-dose SSA group (10 mg/kg), low-dose SSb1 group (2.5 mg/kg), high-dose SSb1 group (10 mg/kg), low-dose SSb2 group (2.5 mg/kg), high-dose SSb2 group (10 mg/kg), low-dose SSD group (2.5 mg/kg), and high-dose SSD group (10 mg/kg). One hour after the last administration, the ALI model was established by instilling intratracheally with LPS (5 mg/kg), and the control group was instilled with PBS [ 49 , 50 ]. The dexamethasone, SSA, SSb1, SSb2, and SSD groups were intraperitoneally given the drugs once per day for 7 consecutive days before the establishment of the model.…”

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

“…Lung tissues were washed with pre-cooled PBS and fixed in 10% formaldehyde, dehydrated in ethanol, embedded in paraffin and sliced into 4 μm sections for hematoxylin-eosin (H&E) staining. Pathological damage scores were assessed as previously described [20] .…”

“…Neutrophils were freshly isolated from whole blood of healthy human volunteers by density gradient centrifugation as previously described [20] . Neutrophil percentage was greater than 95% assessed by Wright-Giemsa staining and viability was greater than 95% evaluated by trypan blue.…”

Hederasaponin C inhibits LPS‐induced acute kidney injury in mice by targeting TLR4 and regulating the PIP2/NF‐κB/NLRP3 signaling pathway

“…The viability of LPS + ATP‐induced HK‐2 cells in each group was measured using MTT assay following the manufacturer's instructions. We incubated HK‐2 cells at concentrations of HSC (0, 10, 20, and 40 μM) (Han et al, 2022) for 24 h to determine the cytotoxicity of HSC by assessing its cell viability. The cells were pre‐treated with HSC (0, 10, 20, 40 μM) for 4 h, and then treated with or without LPS and ATP.…”