Ginkgo biloba Extract Protects Mesenteric Arterioles of Old Rats via Improving Vessel Elasticity through Akt/FoxO3a Signaling Pathway

Abstract

Previous studies have shown that Ginkgo biloba extract (GBE) dietary diminished salt-related elevation of blood pressure and ameliorated ischemic diseases. However, whether GBE could improve vascular elasticity to protect mesenteric arterioles of old rats is still elusive. In this study, we aimed to investigate the effects of GBE on vascular elasticity of old rats and its possible underlying mechanism. Morphological changes of mesenteric arterioles were observed using hematoxylin and eosin and Verhoeff-Van Gieson staining, and diameters of mesenteric arterioles under various pressure were detected after GBE administration. In addition, phosphorylation level of Akt and FoxO3a proteins from mesenteric arterioles were detected. The results implicated that GBE treatment narrowed endothelial cell gap and increased the curvature of inner elastic membrane with reduced middle layer collagen fiber. Meanwhile, compared with young rats, old rats appeared to have lower vascular elasticity while GBE treatment at 50, 100, and 200mg/kg dosage through intragastric administration per day for 3weeks could effectively improve the vascular elasticity under different pressures in a dose-dependent manner. Furthermore, phosphorylation level of Akt and FoxO3a was also reduced in GBE-treated rats. This is the first report to indicate that GBE might exert protective effect on mesenteric arterioles of old rats via improving vascular elasticity and Akt/FoxO3a signaling pathway might be involved in this action.