Protective and Therapeutic Effects of Engeletin on LPS-Induced Acute Lung Injury

Acute lung injury (ALI) is a serious disease with morbidity and mortality in patients. Engeletin (dihydrokaempferol 3-rhamnoside) is a flavanonol glycoside. It can be found in the skin of white grapes and white wine and is widely distributed in southeast Asia. In our study, we evaluated the protective and therapeutic effects of engeletin on lipopolysaccharide (LPS)-induced ALI in animal model. We determined the level of peroxisome proliferator-activated receptor-gamma (PPAR-gamma), nuclear factor kappaB (NF-kappaB), and IkappaBalpha by western blotting. The myeloperoxidase (MPO) activity and lung wet/dry (W/D) ratio in lung tissues were also detected. Histopathological changes and the pro-inflammatory cytokines TNF-alpha, IL-6, and IL-1beta were determined by H&E staining and ELISA. The MPO activity and lung W/D ratio induced by LPS were attenuated by engeletin. The numbers of inflammatory cells and the levels of inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were ameliorated by engeletin. Furthermore, the results also showed that engeletin significantly suppressed LPS-induced NF-kappaB activation. The expression of PPAR-gamma was upregulated by treatment of engeletin. In conclusion, we found that engeletin had protective and therapeutic effects against LPS-induced ALI by activating PPAR-gamma. Engeletin is a potentially effective agent for the treatment of lung injury.