Effect of hop mixture containing xanthohumol on sleep enhancement in a mouse model and ROS scavenging effect in oxidative stress-induced HT22 cells

Hops (Humulus lupulus L. [Cannabaceae]), used to increase storage and palatability of food, exert various pharmacological effects, including sleep-promoting and antioxidant effects. Here, we evaluated the effects of Saaz, Saphir, Simcoe, and their mixtures on pentobarbital-induced sleep in mice and reactive oxygen species (ROS) production in H2O2-treated HT22 cells. Compared to administration of Saaz, Simcoe, and Saphir alone, the administration of Saaz/Saphir (75:25) and Simcoe/Saphir (50:50) mixtures resulted in slightly longer sleep durations in pentobarbital-administered mice. The Saaz/Saphir (75:25) group showed a longer sleep duration in the caffeine-induced insomnia model and slightly lower IC50 values for radicals than the Simcoe/Saphir (50:50) group. Xanthohumol present in hop mixtures suppressed ROS production and increased the expression of superoxide dismutase-1, catalase, and glutathione peroxidase-1 in H2O2-treated HT22 cells. Collectively, Simcoe/Saphir (50:50) and Saaz/Saphir (75:25) mixtures were more effective in removing ROS in brain cells and promoting sleep than hops alone.