Onychiol B attenuates lipopolysaccharide-induced inflammation via MAPK/NF-κB pathways and acute lung injury in vivo

Echinatin attenuates acute lung injury and inflammatory responses via TAK1-MAPK/NF-κB and Keap1-Nrf2-HO-1 signaling pathways in macrophages

Echinatin is an active ingredient in licorice, a traditional Chinese medicine used in the treatment of inflammatory disorders. However, the protective effect and underlying mechanism of echinatin against acute lung injury (ALI) is still unclear. Herein, we aimed to explore echinatin-mediated anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated ALI and its molecular mechanisms in macrophages. In vitro, echinatin markedly decreased the levels of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated murine MH-S alveolar macrophages and RAW264.7 macrophages by suppressing inducible nitric oxide synthase and cyclooxygenase-2 (COX-2) expression. Furthermore, echinatin reduced LPS-induced mRNA expression and release of interleukin-1β (IL-1β) and IL-6 in RAW264.7 cells. Western blotting and CETSA showed that echinatin repressed LPS-induced activation of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways through targeting transforming growth factor-beta-activated kinase 1 (TAK1). Furthermore, echinatin directly interacted with Kelch-like ECH-associated protein 1 (Keap1) and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway to enhance heme oxygenase-1 (HO-1) expression. In vivo, echinatin ameliorated LPS-induced lung inflammatory injury, and reduced production of IL-1β and IL-6. These findings demonstrated that echinatin exerted anti-inflammatory effects in vitro and in vivo, via blocking the TAK1-MAPK/NF-κB pathway and activating the Keap1-Nrf2-HO-1 pathway.

Synthetic steroid of 5α-Androst-3β,5α,6β-Triol alleviates acute lung injury via inhibiting inflammation and oxidative stress

Acute lung injury (ALI) is a severe and potentially fatal respiratory condition with limited treatment options. The pathological evolution of ALI is driven by persistent inflammation, destruction of the pulmonary vascular barrier and oxidative stress. Evidence from prior investigations has identified 5α-androst-3β,5α,6β-Triol (TRIOL), a synthetic analogue of the naturally occurring neuroprotective compound cholestane-3β,5α,6β-triol, possesses notable anti-inflammatory and antioxidative properties. However, the precise effects of TRIOL on alleviating lung injury along with the mechanisms, have remained largely unexplored. Here, TRIOL exhibited pronounced inhibitory actions on lipopolysaccharide (LPS)-induced inflammation and oxidative stress damage in both lung epithelial and endothelial cells. This protective effect is achieved by its ability to mitigate oxidative stress and restrain the inflammatory cascade orchestrated by nuclear factor-kappa B (NF-κB), thereby preserving the integrity of the pulmonary epithelial barrier. We further validated that TRIOL can attenuate LPS-induced lung injury in rats and mice by reducing inflammatory cell infiltration and improving pulmonary edema. Furthermore, TRIOL decreased the pro-inflammatory factors and increased of anti-inflammatory factors induced by LPS. In conclusion, our study presents TRIOL as a promising novel candidate for the treatment of ALI.

Rosavin Alleviates LPS-Induced Acute Lung Injure by Modulating the TLR-4/NF-κB/MAPK Singnaling Pathways

Acute lung injury (ALI) is a serious inflammatory disease with high morbidity and mortality. Rosavin is an anti-inflammatory and antioxidant phenylpropanoid and glucoside, which is isolated from Rhodiola rosea L. However, its potential molecular mechanisms and whether it has protective effects against lipopolysaccharide (LPS)-induced ALI remain to be elucidated. To assess the in vitro anti-inflammatory effects and anti-lung injury activity of rosavin, RAW264.7 and A549 cells were stimulated using 1 μg/mL LPS. Rosavin attenuated LPS-induced activation of the TLR-4/NF-κB signaling pathway in RAW264.7 cells and inhibited LPS-induced release of inflammatory factors in A549 cells. A mouse model of acute lung injury was constructed by intraperitoneal injection of 5 mg/kg LPS to observe the therapeutic effect of rosavin. Transcriptomics analysis and Western blot assays were utilized to verify the molecular mechanism, rosavin (20, 40, and 80 mg/kg) dose-dependently ameliorated histopathological alterations, reduced the levels of inflammatory factors, and inhibited the TLR-4/NF-κB/MAPK signaling pathway and apoptosis activation. Rosavin is a promising therapeutic candidate for acute lung injury by inhibiting the TLR-4/NF-κB/MAPK pathway.

Signaling pathways and potential therapeutic targets in acute respiratory distress syndrome (ARDS)

Acute respiratory distress syndrome (ARDS) is a common condition associated with critically ill patients, characterized by bilateral chest radiographical opacities with refractory hypoxemia due to noncardiogenic pulmonary edema. Despite significant advances, the mortality of ARDS remains unacceptably high, and there are still no effective targeted pharmacotherapeutic agents. With the outbreak of coronavirus disease 19 worldwide, the mortality of ARDS has increased correspondingly. Comprehending the pathophysiology and the underlying molecular mechanisms of ARDS may thus be essential to developing effective therapeutic strategies and reducing mortality. To facilitate further understanding of its pathogenesis and exploring novel therapeutics, this review provides comprehensive information of ARDS from pathophysiology to molecular mechanisms and presents targeted therapeutics. We first describe the pathogenesis and pathophysiology of ARDS that involve dysregulated inflammation, alveolar-capillary barrier dysfunction, impaired alveolar fluid clearance and oxidative stress. Next, we summarize the molecular mechanisms and signaling pathways related to the above four aspects of ARDS pathophysiology, along with the latest research progress. Finally, we discuss the emerging therapeutic strategies that show exciting promise in ARDS, including several pharmacologic therapies, microRNA-based therapies and mesenchymal stromal cell therapies, highlighting the pathophysiological basis and the influences on signal transduction pathways for their use.

Anti-inflammatory activities of several diterpenoids isolated from Hemionitis albofusca

Hemionitis albofusca (Baker) Christenh is a plant that grows in various regions of China. Although it is not recognized as a traditional medicine, it is often mistakenly labelled and used as Aleuritopteris argentea (S. G. Gmél.) Fée to alleviate menstruation-related issues. Recently, several diterpenoids such as ent-16-oxo-17-norkauran-19-oic acid (Compound A), 14-oxy-7β,20-dihydroxycyath-12,18-diene (Compound B), ent-8(14),15-pimaradiene-2β,19-diol (Compound C), ent-kaurane-16-ene-2β,18α-diol (Compound D), ent-kaurane-2β,16α,18α-triol (Compound E), and onychiol B have been extracted from H. albofusca. In this study, we investigated the anti-inflammatory activity of these diterpenes. We confirmed that compounds A ~ D suppressed the amount of cellular NO production by inhibiting the expression and transcription of iNOS protein. They also significantly inhibited the expression and transcription of inflammatory factors TNF-α and IL-6. Additionally, Compounds A and C suppressed the activation of the NF-κB signaling pathway and inhibited the phosphorylation level of p38, ultimately down-regulating inflammation. Compound B suppressed the activation of the NF-κB signaling pathway, while Compound D inhibited the phosphorylation level of p38 and down-regulated the activation of the p38 MAPK signaling pathway. In a word, our investigation supports the potential application of natural diterpenes as lead compounds for developing anti-inflammatory agents.