标题：Protective Effect of Saponins-Enriched Fraction of Gynostemma pentaphyllum against High Choline-Induced Vascular Endothelial Dysfunction and Hepatic Damage in Mice
摘要：Choline as a quaternary amine nutrient is metabolized to trimethylamine by gut microbiota and subsequently oxidized to circulating trimethylamine- N -oxide (TMAO), a gut-derived metabolite associated with liver toxicity and cardiovascular disease. The study was to probe the possible vasoprotective and hepatoprotective effects of total saponins of Gynostemma pentaphyllum (TSGP) in 3% high-choline water-feeding mice. The purified TSGP was obtained with content of 83.0% saponins, and its antioxidant activities were evaluated in vitro . Furthermore, the mice fed with high choline for 8 weeks significantly expressed vascular endothelial dysfunction and liver oxidative stress ( p < 0.01 vs. Normal). Administration of TSGP at 400 and 800 mg/kg·body weight (b.w.) significantly lowered the serum total cholesterol (TC), triglyceride (TG), low density lipoprotein-cholesterol (LDL-C), endothelin-1 (ET-1) and thromboxane A 2 (TXA 2 ) levels, as well as hepatic malondialdehyde (MDA) formation, but effectively elevated the serum nitric oxide (NO), endothelial nitric oxide synthase (eNOS) and prostaglandin I 2 (PGI 2 ) levels, as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST), T-superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in high choline-fed mice. Hematoxylin–eosin (H&E) and oil red O staining also suggested that TSGP could exert the significant protection against endothelial dysfunction and liver injury in high choline-treated mice. These findings suggest that TSGP is of the saponins-enriched extract, and is a good candidate of dietary supplement and therapeutic application in vascular and hepatic oxidative injury..
