Asatone Prevents Acute Lung Injury by Reducing Expressions of NF-κB, MAPK and Inflammatory Cytokines

Abstract

Asatone is an active component extracted from the Chinese herb Radix et Rhizoma Asari. Our preliminary studies have indicated that asatone has an anti-inflammatory effect on RAW 264.7 culture cells challenged with lipopolysaccharide (LPS). Acute lung injury (ALI) has high morbidity and mortality rates due to the onset of serious lung inflammation and edema. Whether asatone prevents ALI LPS-induced requires further investigation. In vitro studies revealed that asatone at concentrations of 2.5–20[Formula: see text][Formula: see text]g/mL drastically prevented cytotoxicity and concentration-dependently reduced NO production in the LPS-challenged macrophages. In an in vivo study, the intratracheal administration of LPS increased the lung wet/dry ratio, myeloperoxidase activity, total cell counts, white blood cell counts, NO, iNOS, COX, TNF-[Formula: see text], IL-1[Formula: see text], and IL-6 in the bronchoalveolar lavage fluid as well as mitogen-activated protein kinases in the lung tissues. Pretreatment with asatone could reverse all of these effects. Asatone markedly reduced the levels of TNF-[Formula: see text] and IL-6 in the lung and liver, but not in the kidney of mice. By contrast, LPS reduced anti-oxidative enzymes and inhibited NF-[Formula: see text]B activations, whereas asatone increased anti-oxidative enzymes in the bronchoalveolar lavage fluid and NF-[Formula: see text]B activations in the lung tissues. Conclusively, asatone can prevent ALI through various anti-inflammatory modalities, including the major anti-inflammatory pathways of NF-[Formula: see text]B and mitogen-activated protein kinases. These findings suggest that asatone can be applied in the treatment of ALI.