RETRACTED: Polysaccharide from Angelica sinensis ameliorates high-fat diet and STZ-induced hepatic oxidative stress and inflammation in diabetic mice by activating the Sirt1–AMPK pathway

Polysaccharide from Angelica sinensis (Oliv.) Diels (ASP) possesses many bioactivities, such as hematopoiesis, anti-inflammation, antioxidation and metabolism regulation. The aim of this study was to investigate the mechanisms underlying the protection of a combination of high-fat diet and streptozotocininduced liver damage in diabetic Balb/c mice by ASP. Results showed that ASP had beneficial effects on ameliorating hyperglycemia, dyslipidemia and liver injury. Moreover, mechanistic study for the liver-protective role in vivo demonstrated that ASP enhanced the activities of superoxide dismutase and glutathione peroxidase and increased the glutathione content, which resulted in the reduction of hepatic reactive oxygen species (ROS) and malondialdehyde, and reduced the protein expression levels of liver IKK alpha/NF-kappa B/p-I kappa B alpha and the concentrations of serum tumor necrosis factor-alpha/interleukin-6. The antioxidative and antiinflammatory actions of ASP might benefit from activating the Sirtl-AMPK signaling pathway. Furthermore, in vitro experiments using HepG2 cells treated with Sirt1 and AMPK inhibitors or small interfering RNA targeting Sirt1 confirmed that ASP suppressed the nuclear protein NF-kappa B p65 and intracellular ROS via the activation of Sirt1-AMPK signals. Collectively, ASP protects the liver against high-fat diet and streptozotocin-induced injury, which may contribute to the recovery of diabetic symptoms. Our findings strengthen the potential therapeutic role of ASP in nutritional foods or prescription for liver diseases or diabetes. (C) 2017 Elsevier Inc. All rights reserved.