Protective effects of ethyl acetate extracts of Rimulus Cinnamon on systemic inflammation and lung injury in endotoxin-poisoned mice.

Rimulus cinnamon is the dried twig of Cinnamomum cassia Presl. It is widely used in China for the treatment of inflammatory processes, amenorrhea, and other diseases. We aimed to study the protective effects of ethyl acetate extracts of R. cinnamon (EAE) on systemic inflammation and lung injury in endotoxin-poisoned mice. EAE was administered 5 d prior to lipopolysaccharide (LPS) challenge with 15 mg/kg LPS. The administration of EAE increased the levels of interferon-gamma (IFN-gamma) and decreased the levels of interleukin-18 (IL-18) and tumor necrosis factor-alpha (TNF-alpha) in the serum. Additionally, EAE relieved the pathological changes in the tissues of the lungs and spleen, and significantly reduced the number of neutrophils in the lung tissues. In addition, treatment with EAE decreased the mRNA expression of the NLR family, pyrin domain-containing protein 3 (NLRP3), caspase-1, and interleukin-1 beta (IL-1 beta) in the lungs, as well as the expression of NLRP3, caspase-1 (p20), and pro-IL-1 beta proteins. These results demonstrated the promising anti-inflammatory effects of EAE in endotoxin-poisoned mice. Furthermore, EAE could alleviate the lung injury of endotoxin-poisoned mice by antagonizing the activation of the NLRP3 inflammasome.