Xanthohumol isolated from Humulus lupulus prevents thrombosis without increased bleeding risk by inhibiting platelet activation and mtDNA release

Abstract

Aim As the global population has reached 7 billion and the baby boom generation reaches old age, thrombosis has become the major contributor to the global disease burden. It has been reported that, in moderate doses, beer may protect against thrombosis. Xanthohumol (XN), an antioxidant, is found at high concentrations in hop cones (Humulus lupulus L.) and is a common ingredient of beer. Here, the aim of the present work was to investigate the effects of XN on antithrombotic and antiplatelet activities, and study its mechanism. Approach and Results Using ferric chloride-induced carotid artery injury, inferior vena cava ligation model, and platelet function tests, we demonstrated that XN uniquely prevents both venous and arterial thrombosis by inhibiting platelet activation. Interestingly, in tail bleeding time studies, XN did not increase bleeding risk, which is recognized as a major limitation of current antithrombotic therapies. We also demonstrated that XN induces Sirt1 expression and thereby decreases reactive oxygen species (ROS) overload, prevents mitochondrial dysfunction, and reduces activated platelet-induced mitochondrial hyperpolarization, respiratory disorders, and associated membrane damage at low concentrations. In mitochondrial function assays designed to detect amounts of extracellular mitochondrial DNA (mtDNA), we found that XN prevents mtDNA release, which induces platelet activation in a DC-SIGN-dependent manner. Conclusions XN exemplifies a promising new class of antiplatelet agents that are highly effective at inhibiting platelet activation by decreasing ROS accumulation and platelet mtDNA release without incurring a bleeding risk. This study has also provided novel insights into mechanisms of thrombotic diseases with possible therapeutic implications.

Characterization and Regulation of Carrier Proteins of Mitochondrial Glutathione Uptake in Human Retinal Pigment Epithelium Cells

“…Mitochondrial DNA (mtDNA) was isolated from cells treated with 5 mM of PS or BM for 24 hours using a commercial kit (Mitochondria DNA Isolation Kit, BioVision, Mountain View, CA, USA) following the instructions of the manufacturer. The concentration of mtDNA was measured by a multi-mode microplate reader (Spectramax iD5; Molecular Devices, San Jose, CA, USA) 22…”

Chlorinated emodin as a natural antibacterial agent against drug-resistant bacteria through dual influence on bacterial cell membranes and DNA

“…We stained the bacterial cells with DAPI and PI using previously reported methods 12 , 31 , 38 , 39 with some modification. PI and DAPI were diluted in 0.1 M PBS (pH 7.2, using 0.85% NaCl to equilibrate the osmotic pressure) to final concentration of 1 mg/ml and were stored in the dark at 4 °C before use.…”

Xanthohumol Blocks Proliferation and Migration of Vascular Smooth Muscle Cellsin Vitroand Reduces Neointima Formationin Vivo

“… 17 − 19 It also prevents platelet activation and aggregation, with an apparent contribution of diminished AKT, p38, and PLCγ2/PKC signaling as well as reduced thromboxane 2 formation and [Ca 2+ ] i . 20 − 22 A modulated calcium signaling may also account for potential antiarrhythmic properties of 1 . 23 Furthermore, inhibition of cholesteryl ester transfer protein and promotion of reverse cholesterol transport afford protection from atherosclerosis by 1 .…”