Protective effect of quercetin on lipopolysaccharide-induced acute lung injury in mice by inhibiting inflammatory cell influx

Abstract

Sepsis may result in lung injury through a complex cascade of events including interstitium infiltration of inflammatory cells. Quercetin, the most abundant dietary flavonoid found in various plants and food products, possesses potent anti-inflammatory and antioxidative properties. The purpose of this study was to investigate whether preventive administration of quercetin could exert beneficial effects on experimental septic acute lung injury induced by lipopolysaccharide (LPS). C57/BL6 mice were challenged with LPS and survival time was monitored from 0-96 h after LPS treatment. Quercetin markedly rescued lethality, improved survival time, and inhibited serum necrosis factor α, interleukin 1β, and interleukin 6, and nitric oxide (NO), and increased IL-10 secretion. Moreover, quercetin decreased lung pathological changes, myeloperoxidase activity, and malondialdehyde levels. Quercetin also reduced the lung permeability changes and neutrophil and macrophage recruitment to the bronchoalveolar lavage fluid compared to the vehicle. Additionally, quercetin significantly reduced COX-2, HMGB1, iNOS expression, and NF-κB p65 phosphorylation. These results suggest that treatment with quercetin in septic mice improved survival time and lung injury. Quercetin may be a promising potential therapeutic reagent for LPS-induced acute lung injury.

Inhibition of endotoxin-induced airway epithelial cell injury by a novel family of pyrrol derivates

“…reported by other compounds, such as inosine, 14 bupleurum polysaccharides, 21 proxylin A, 22 and quercetin, 23 and by other pyrrol compounds, such as T-686, an inhibitor of plasminogen activator inhibitor-1 that was associated with a mortality reduction in mice exposed to LPS. 24 However, none of those compounds had described any antiapoptotic activity in sepsisinduced lung injury.…”

Effect of the Lipid Peroxidation Product 4-Hydroxynonenal on Neuroinflammation in Microglial Cells: Protective Role of Quercetin and Monochloropivaloylquercetin

“…On the other hand, quercetin acts as an anti-inflammatory agent in lipopolysaccharide-induced acute lung injury by significantly reducing COX-2 and iNOS expression, and NFkB p65 phosphorylation. 52 In another study, intratracheal administration of quercetin affected the protective agent by modulating HO-1 activity against lipopolysaccharideinduced acute lung injury. 53 Quercetin was previously shown to downregulate proinflammatory responses, involving iNOS expression and NO generation in BV-2 cells through inducing Nrf-2 mediated HO-1 expression.…”

Preclinical Evaluation of the Antimicrobial-Immunomodulatory Dual Action of Xenohormetic Molecules against Haemophilus influenzae Respiratory Infection

“…In the present study, our search of plant xenohormetic molecules effective against NTHi led us to focus on quercetin, a flavonoid ubiquitously present in vegetables, fruits, tea, and wine, claimed to exert beneficial effects linked to being one of the most prominent dietary antioxidants, with high accumulation observed in rat lung tissue [59]. Protective effects of quercetin in lung lesions have been reported on lipopolysaccharide-induced acute lung injury and elastase-induced emphysema murine model systems [22,60,61]. Moreover, quercetin seems to restore corticosteroid sensitivity in cells from COPD patients by activation of the adenosine monophosphate-activated protein kinase (AMPK) [62], and a community clinical trial showed a reduction of upper respiratory tract infection total sick days and severity in middle age and older subjects ingesting 1000 mg quercetin/day for 12 weeks [63].…”