Abstract: Objective: To investigate the protective effect and mechanism of fibrinolytic enzyme from Lyophyllum ulmarium (LUFE) on alcohol-induced injury in human umbilical vein endothelial cells (HUVECs). Methods: Cell viability was evaluated by the methyl thiazolyl tetrazolium assay and the activity of lactate dehydrogenase (LDH) in cell-free culture supernatants was determined. The activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and the content of malondialdehyde (MDA) were measured by colorimetry. The apoptosis changes of HUVECs were detected with acridine orange/ethidium bromide staining. The level of reactive oxygen species (ROS) and mitochondrial transmembrane potential (Δφm) were evaluated by dihydrorhodamine123 and rhodamine 123 staining, respectively. The protein expression of Bax, Bcl-2, cytochrome c, cleaved cysteinyl aspartate specific proteinase (caspase)-9 and cleaved caspase-3 was determined using Western blot assay. Results: Compared with the model group, LUFE could increase the survival rate, decrease the contents of LDH and MDA, and increase the activity of SOD and GSH-Px in HUVECs. LUFE could also reduce intracellular ROS production, increase mitochondrial transmembrane potential and inhibit apoptosis induced by alcohol. LUFE could down-regulate the expression of cytochrome c, cleaved caspase-9 and cleaved caspase-3, and up-regulate the expression of Bcl-2. Conclusion: LUFE has a protective effect on alcohol-induced injury of HUVECs, which may be related to its antioxidant capacity and its ability to regulate the mitochondrial signal pathway.

Key words: Lyophyllum ulmarium, fibrinolytic enzyme, human umbilical vein endothelial cells, alcohol, protective effect