Aqueous extract of Whitmania pigra Whitman ameliorates ferric chloride-induced venous thrombosis in rats via antioxidation

Whitmania pigra Whitman ( W. pigra ) has been widely employed in decoction for the treatment of blood stasis syndrome for many years in China. The aim of the present study was to explore the anti-venous thrombosis (VT) mechanism of the aqueous extract of W. pigra (AEW) in rats. Rats were orally administered with AEW. A inferior vena cava (IVC) thrombosis model was established. Thrombosed IVC was weighed and histopathological analyses were performed. Blood coagulation, blood fibrinolysis, blood cell count, blood viscosity and platelet activity were evaluated. Reactive oxygen species (ROS) accumulation was analyzed. Malondialdehyde (MDA) content in thrombosed IVC and antioxidants in serum were detected. Protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in thrombosed IVC was determined. AEW significantly reduced thrombus weight. It did not affect blood coagulation, blood fibrinolysis, blood cell count, platelet activity, or whole blood viscosity. However, AEW remarkably alleviated vascular injury, reduced ROS accumulation and MDA content, enhanced the total antioxidant capacity and the activities of superoxide dismutase, glutathione peroxidase and glutathione reductase. It increased the glutathione/oxidized glutathione ratio and the protein expression levels of Nrf2 and HO-1. In summary, W. pigra may prevent VT via Nrf2-mediated antioxidation.