The Mechanism Of Anti Hypertensive Effect Of Blueberry Leaf Polyphenols

This paper studied on composition and anti-hypertensive mechanism of blueberry leaf polyphenols, which provide a theoretical basis and technical support for the development and application of blueberry anthocyanins as a functional food ingredient or nutraceutical of was by using Nanjing rabbit eye blueberry leaves were used as raw material. Blueberry leaf polyphenols were extracted and purified, then identified to be chlorogenic acid, oligomeric procyanidins, and quercetin's ramification hyperin by high performance liquid chromatography tandem mass spectrometry (HPLC-MS).To study antihypertensive function of blueberry leaf polyphenols, we used human umbilical vein endothelial cells (HUVEC) model. The protective effect of chlorogenic acid, quercetin and hyperin on endothelial cells against damage induced by Tumor Necrosis Factor-a(TNF-a) was confirmed.Effects of different concentrations of blueberry leaf polyphenol on cell viability were detected by MTT method. The results showed that quercetin, hyperin, and chlorogenic acid can protect the endothelial cells.Effects of different concentrations of blueberry leaf polyphenol on the expression of ACE were detected by ELISA to explore their vasodilatory capacity. Quercetin, hyperin, and chlorogenic acid can decrease ACE levels in the endothelial cell supernantant induced by TNF-a. Chlorogenic acid and quercetin both have remarkable effects. It showed that blueberry leaf polyphenol monomers have vasodilatory function.Effects of different concentrations of blueberry leaf polyphenols on HO-1, XO-1, and SOD levels in cell supernatants were detected by ELISA. ROS in cells was detected by fluorescence immunoassay. SOD in cells was detected by WST-8.The results showed that TNF-a promoted the XO-1 expression, increased ROS levels and inhibited HO-1 and SOD levels. Quercetin, hyperin, and chlorogenic acid significantly suppressed overexpression of XO-1 or ROS and increased HO-1 or SOD content. It showed that blueberry leaf polyphenols have antioxidant effects.Effects of different concentrations of blueberry leaf polyphenols on MCP-1, ICAM-1, and VCAM-1 levels in cell supernatants were detected by ELISA. Western Blotting method was used to detect ICAM-1 and VCAM-1 protein expression in cells. The results showed that TNF-a could promote MCP-1, ICAM-1, and VCAM-1 protein expression in vascular endothelial cells supernantants. Quercetin, hyperin, and chlorogenic acid could inhibit MCP-1, ICAM-1, VCAM-1 protein overexpression in both the supernantants and the cells induced by TNF- a.Blueberry leaf polyphenol could reduce cellular inflammation and protect endothelial cells against the damage.Blueberry leaf polyphenols can prevent hypertensive disease based on vasodilatory, anti-oxidation and anti-inflammatory effects, which provide a theoretical basis for the treatment of cardiovascular disease as well as utilization of blueberry byproducts.