Impact of xanthohumol (a prenylated flavonoid from hops) on DNA stability and other health-related biochemical parameters: Results of human intervention trials

Scope Xanthohumol (XN) is a hop flavonoid found in beers and refreshment drinks. Results of in vitro and animal studies indicate that it causes beneficial health effects due to DNA protective, anti‐inflammatory, antioxidant, and phytoestrogenic properties. Aim of the present study was to find out if XN causes alterations of health‐related parameters in humans. Methods and results The effects of the flavonoid were investigated in a randomized crossover intervention trial (n = 22) in which the participants consumed a XN drink (12 mg XN/P/day). We monitored alterations of the DNA stability in single cell gel electrophoresis assays in lymphocytes and of several health‐related biomarkers. A decrease of oxidatively damaged purines and protection toward reactive oxygen species induced DNA damage was found after the consumption of the beverage; also the excretion of 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine and 8‐oxo‐guanosine in urine was reduced. The assumption that the flavonoid causes DNA protection was confirmed in a randomized follow‐up study with pure XN (n = 10) with a parallel design. Other biochemical parameters reflecting the redox‐ and hormonal status and lipid‐ and glucose metabolism were not altered after the intervention. Conclusion Taken together, our data indicate that low doses of XN protect humans against oxidative DNA damage. The effects of xanthohumol were investigated in a crossover intervention trial in which the participants consumed a drink containing 12 mg XN/P/day. Alterations of the DNA stability were monitored in single cell gel electrophoresis assays in lymphocytes. A decrease of oxidatively damaged purines and protection toward reactive oxygen species (ROS)‐induced DNA damage was found after consumption of the beverage; furthermore, also urinary 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine and 8‐oxo‐guanosine were reduced.