Euscaphic acid and Tormentic acid protect vascular endothelial cells against hypoxia-induced apoptosis via PI3K/AKT or ERK 1/2 signaling pathway

Aims: Euscaphic acid and Tormentic acid are aglycones of Kaji-ichigoside F1 and Rosamultin, respectively. These four compounds are pentacyclic triterpenoid, isolated from the subterranean root of the Potentilla anserina L. Based on the protective roles against hypoxia-induced apoptosis of Euscaphic acid and Tormentic acid in vascular endothelial cells, this study was designed to determine the mechanisms. Main methods: The model of hypoxic injuries in EA. hy926 cells was established. Through applications of PI3K/AKT inhibitor, LY294002 and ERK1/2 inhibitor, PD98059, we explored the relationships between pharmacodynamic mechanisms and PI3K/AKT or ERK 1/2 signaling pathway. The anti-hypoxic effects were studied by methyl-thiazolyl-tetrazolium (MTT) assay, Hematoxylin-Eosin (HE) staining, DAPI staining, and flow cytometry. The mechanisms of anti-mitochondrial apoptosis were explored by western blot. The expressions of p-ERK 1/2, ERK 1/2, p-AKT, AKT, p-NF-kappa B, NF-kappa B, Bcl-2, Box, Cyt C, cleaved caspase-9 and cleaved caspase-3 were detected. Key findings: Euscaphic acid protected vascular endothelial cells against hypoxia-induced apoptosis via ERK1/2 signaling pathway, and Tormentic acid brought its efficacy into full play via PI3K/AKT and ERK1/2 signaling pathways. In addition, PI3K/AKT signaling pathway positively regulated ERK1/2 pathway, and ERK1/2 pathway negatively regulated PI3K/AKT pathway. Significance: This evidence provides theoretical and experimental basis for the following research on anti-hypoxic drugs of Potentilla anserina L.