Quercetin ameliorates acute lung injury in a rat model of hepatopulmonary syndrome

Flavonoids of Tetrastigma hemsleyanum Diels et Gilg Against Acute Hepatic Injury by Blocking PI3K/AKT Signaling Pathway

Objective: This study aims to investigate the mechanism of Tetrastigma hemsleyanum Diels et Gilg flavonoids (THF) on acute hepatic injury (AHI). Methods: First, high-performance liquid chromatography (HPLC) fingerprints were established to obtain the main chemical components of THF. According to the network pharmacology databases, collect active targets of AHI and potential targets. Using interaction targets to construct a protein-protein interaction (PPI) network, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Finally, the affinity between the core targets and the main active ingredients was verified by molecular docking. Next, verified network pharmacology predictions with animal experiments. Mice were treated with THF (20, 40, and 80 mg/kg) for 7 days, and then built an acute liver injury model (lipopolysaccharide [LPS], 10 mg/kg). Detecting the liver biochemical indices, observe the liver pathological changes, and verify the key signaling pathway targets. Results: HPLC showed that the main components of THF were quercetin and kaempferol. Seven active ingredients and 193 potential targets were screened, and 259 disease targets related to acute liver injury, quercetin, and kaempferol may be the main active ingredients in THF. PPI network analysis showed that tumor necrosis factor (TNF), interleukin-6 (IL-6), and tumor protein 53 (TP53) were potential targets of THF for the treatment of AHI. KEGG analysis showed that the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway might be one of the main pathways in the treatment of AHI. The molecular docking results showed that active compounds both have strong binding activity with potential targets in PPI. In vivo experiments showed that THF could reduce the fibrosis and inflammation of liver tissue etc. Meanwhile, it could downregulate the alanine aminotransferase (ALT), aspartate aminotransferase (AST), IL-6, tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP) levels, and the protein expressions of phosphorylated phosphoinositide 3-kinase (p-PI3K), phosphorylated protein kinase B (p-AKT), and the ratio of BCL2-associated X (BAX)/B-cell lymphoma-2 (BCL-2) in the liver tissue of the mice with acute liver injury and upregulate the level of interleukin-10 (IL-10). Conclusion: The treatment of acute liver injury with THF is characterized by multicomponents and multitargets, and its mechanism may be related to the alleviation of the inflammatory response, reduction of apoptosis, and regulation of the PI3K/AKT signaling pathway.

New updates on hepatopulmonary syndrome: A comprehensive review

Hepatopulmonary syndrome (HPS) is a serious pulmonary vascular complication that causes arterial hypoxemia in the setting of liver disease. HPS has a progressive course and is associated with a two-fold increased risk of mortality relative to cirrhotic patients without HPS. It primarily affects patients with portal hypertension. The key pathological features of HPS include intrapulmonary angiogenesis and vascular dilations (IPVDs). The prevalence of HPS varies widely due to inconsistent diagnostic criteria and a lack of standardized protocols. Despite advances in understanding its pathophysiology, no effective curative treatments for HPS exist. Liver transplantation remains the only definitive treatment, improving survival and altering the disease natural course. This review explores the pathophysiology, clinical features, and therapeutic strategies for HPS, highlighting recent advances in the literature.

Possible protective effect of quercetin on lung injury induced by skeletal muscle ischemia reperfusion (IR) injury of adult male albino rats: Histological and biochemical study

When a lower limb is injured, the most delicate organs that are at risk of harm are the lungs. Among the flavonoids, quercetin is a significant component that is found in apples and onions in the highest proportions. Numerous biological actions, including as anti-inflammatory, antioxidant, and anti-cancer properties, have been linked to quercetin. To investigate the impact of quercetin on lung injury induced by skeletal muscle ischemia reperfusion (IR) injury. Three equal groups of twenty-four adult rats were used: control, Ischemia-reperfusion (IR) group and IR group treated with quercetin. Rats in (IR) group were exposed to ischemia by ligation of femoral artery for 2h then after removal of the clamp, reperfusion was estabilished for another 24h. IR group treated with quercetin, rats were underwent hind limb IR as described in group II then were given quercetin that was administered at a dose of 20mg/kg intraperitoneally. Measurement of cytokines in serum, MDA in tissue homogenate and VEGF in serum and tissue homogrnate in addition to mRNA expression level and detection of protein level of both sirtuin-1(SIRT1) and NF-κB were assessed at the end of experiment. Histological and immunohistochemical assessment of the lungs were also carried. IR group showed notable rise of inflammatory cytokines such as IL-1β, IL-6 and TNF-α in addition to high level of VEGF and MDA in IR group when compared to the IR group treated with quercetin. Also, gene expression and protein level of SIRT1 were reduced while NF-κB mRNA expression and protein level were significantly upregulated in IR group compared to IR group treated with quercetin. Histologically, IR group indicated marked histological alterations of lung tissue. Also, IR showed strong brownish cytoplasmic immunostaining for iNOS and abundance of Ki67-positive cells. These alterations were significantly reversed in IR group treated with quercetin. Biochemical and immunohistochemical findings of this study demonstrate that quercetin administration have protective effects against lung injury induced by lower limb IR.

Pathophysiological basis of hepatopulmonary syndrome

Circulatory changes with increased blood flow and vasodilatation/vasoconstriction imbalance are an integral consequence of liver cirrhosis and portal hypertension and can affect the pulmonary circulation with the development of vascular disorders, with hepatopulmonary syndrome (HPS) being the most common. HPS is a serious pulmonary complication of progressive liver disease, resulting in a poor clinical prognosis. Vascular tone decrease, monocytic infiltration of pulmonary vessels, formation of intrapulmonary arteriovenous shunts, dysfunction of alveolar type II cells, destruction of the endothelial glycocalyx are important in the pathogenesis of HPS. Abnormalities of pulmonary capillaries lead to hypoxemia caused by a violation of the ventilation/perfusion ratio, diffusion disorders, and the development of arteriovenous anastomoses. Infiltration of the pulmonary vessels by monocytes is one of the key factors of HPS. This migration is facilitated by the intestinal microbiota translocation into the portal bloodstream with increased expression of proinflammatory cytokines (tumor necrosis factor α, interleu­kins 1, 6), leading to the activation of monocytes. Monocytes located in the pulmonary circulation promote the vasodilation through the activation of inducible nitric oxide (NO) synthase and thus NO production. This is also associated with endothelial dysfunction due to a decreased hepatic secretion of bone morphogenetic protein 9 and increased endothelin 1, endothelial overexpression of endothelin B receptors, and increased endothelial NO production. Proangiogenic factors such as vascular endothelial growth factor, platelet-derived growth factor, and placental growth factor play an important role in the proliferation of pulmonary capillaries. Circulation of tumor necrosis factor α, bile acids and monocyte infiltration in the pulmonary circulation lead to increased apoptosis of alveolar type II cells and decreased surfactant synthesis. Chronic inflammation in HPS disrupts the continuity of the endothelial glycocalyx layer. This article provides an overview of the current knowledge on the pathogenesis of HPS, summarizes many features of the disease based on the literature research in MEDLINE database on the PubMed platform.

Quercetin attenuates Pseudomonas aeruginosa-induced acute lung inflammation by inhibiting PI3K/AKT/NF-κB signaling pathway

Pseudomonas aeruginosa is an opportunistic pathogen that commonly causes infections in immunocompromised individuals with significant morbidity and mortality. Quercetin is a natural flavonoid abundantly present in fruits and vegetables, exerting potent anti-inflammatory effects in treatment of various diseases. However, the molecular mechanisms of quercetin in treatment of P. aeruginosa-induced acute lung inflammation are unclear. In this study, we exploited network pharmacology- and molecular docking-based approach to explore the potential mechanisms of quercetin against P. aeruginosa pneumonia, which was further validated via in vivo and in vitro experiments. The in vivo experiments demonstrated that quercetin alleviated the P. aeruginosa-induced lung injury by diminishing neutrophil infiltration and production of proinflammatory cytokines (IL-1β, IL-6, and TNF), which was associated with decreased mortality. Moreover, the quercetin-treated mice displayed decreased phosphorylation levels of PI3K, AKT, IκBα, and NF-κB p65 in lung tissues compared to non-drug-treated mice. Similarly, the in vitro study showed that the phosphorylation of these regulatory proteins and production of the proinflammatory cytokines were impaired in the quercetin-pretreated macrophages upon P. aeruginosa infection. Altogether, this study suggested that quercetin reduced the P. aeruginosa-induced acute lung inflammation by suppressing PI3K/AKT/NF-κB signaling pathway.

Discovery of the Active Compounds of the Ethyl Acetate Extract Site of Ardisia japonica (Thunb.) Blume for the Treatment of Acute Lung Injury

The objective of this study was to identify and evaluate the pharmacodynamic constituents of Ardisiae Japonicae Herba (AJH) for the treatment of acute lung injury (ALI). To fully analyze the chemical contents of various extraction solvents (petroleum ether site (PE), ethyl acetate site (EA), n-butanol site (NB), and water site (WS)) of AJH, the UPLC-Orbitrap Fusion-MS technique was employed. Subsequently, the anti-inflammatory properties of the four extracted components of AJH were assessed using the lipopolysaccharide (LPS)-induced MH-S cellular inflammation model. The parts that exhibited anti-inflammatory activity were identified. Additionally, a technique was developed to measure the levels of specific chemical constituents in the anti-inflammatory components of AJH. The correlation between the "anti-inflammatory activity" and the constituents was analyzed, enabling the identification of a group of pharmacodynamic components with anti-inflammatory properties. ALI model rats were created using the tracheal drip LPS technique. The pharmacodynamic indices were evaluated for the anti-inflammatory active portions of AJH. The research revealed that the PE, EA, NB, and WS extracts of AJH included 215, 289, 128, and 69 unique chemical components, respectively. Additionally, 528 chemical components were discovered after removing duplicate values from the data. The EA exhibited significant anti-inflammatory activity in the cellular assay. A further analysis was conducted to determine the correlation between anti-inflammatory activity and components. Seventeen components, such as caryophyllene oxide, bergenin, and gallic acid, were identified as potential pharmacodynamic components with anti-inflammatory activity. The pharmacodynamic findings demonstrated that the intermediate and high doses of the EA extract from AJH exhibited a more pronounced effect in enhancing lung function, blood counts, and lung histology in a way that depended on the dosage. To summarize, when considering the findings from the previous study on the chemical properties of AJH, it was determined that the EA contained a group of 13 constituents that primarily contributed to its pharmacodynamic effects against ALI. The constituents include bergenin, quercetin, epigallocatechingallate, and others.