Glycyrrhizic Acid Prevents Sepsis-Induced Acute Lung Injury and Mortality in Rats.

Glycyrrhizic acid (GA), an active ingredient in licorice, has multiple pharmacological activities. However, the effects of GA on sepsis-induced acute lung injury (ALI) have not been determined. Tthe aim of this study was to investigate the molecular mechanism involved in the effects of GA against sepsis-induced ALI in rats. We found that GA alleviated sepsis-induced ALI through improvements in various pathological changes, as well as decreases in the lung wet/ dry weight ratio and total protein content in bronchoalveolar lavage fluid, and a significant increase in the survival rate of treated rats. Additionally, GA markedly inhibited sepsis-induced pulmonary inflammatory responses. Moreover, we found that treatment with GA inhibited oxidative stress damage and apoptosis in lung tissue induced by ALI. Finally, GA treatment significantly inhibited NF-kappa B, JNK and P38 MAPK activation. Our data indicate that GA has a protective effect against sepsis-induced ALI by inhibiting the inflammatory response, damage from oxidative stress, and apoptosis via inactivation of NF-kappa B and MAPK signaling pathways, providing a molecular basis for a new medical treatment for sepsis-induced ALI.