The protective effect of the flavonoid fraction of Abutilon theophrasti Medic. leaves on LPS-induced acute lung injury in mice via the NF-κB and MAPK signalling pathways

Abstract

Accompanied by the damages of epithelial and capillary endothelial cell, acute lung injury is diagnosed with the typical pathological symptoms in clinic, including diffusing of pulmonary interstitial, alveolar oedema and hypoxic respiratory insufficiency. Current study focused on the investigation the anti-inflammatory action and mechanisms of total flavonoids extract (TFE) from Abutilon theophrasti Medic. leaves on ALI mice induced by LPSs. Mice were administrated intragastrically with TFE at the concentrations of 0.25, 0.5, or 1.0 g/kg for 5 days, and on last day, nasal administration of LPSs for 6 h after 30 min for intragastric administration of TFE. Pretreatment with TFE not only reduced oxidative damage but also alleviated lung edema in ALI mice. Increased secretion of pro-inflammatory cytokines TNF-α, IL-1β and IL-6, caused by LPSs was reversed by TFE; on the contrary, the anti-inflammatory cytokine IL-10 was upregulated. The proteins expressions of pro-inflammatory mediators iNOS and COX-2 induced by LPSs, were down-regulated by TFE. Moreover, the activation of NF-κB and MAPK signalling pathways was inhibited by TFE in LPSs induced ALI mice. The results revealed that the anti-inflammatory mechanisms of TFE were via inhibition of NF-κB and MAPK activation. Combined, the results suggested that TFE might exert in vivo antioxidant and anti-inflammatory functions in LPSs stimulated mice, and will be potential in adjuvant treatment in oxidative stress and inflammation diseases.