Investigation of the anxiolytic effects of xanthohumol, a component of humulus lupulus (Hops), in the male Sprague-Dawley rat.

The purpose of this study was to investigate the anxiolytic effects of xanthohumol, a component of Humulus lupulus (hops), and its potential interaction with the benzodiazepine binding site on the y-aminobutyric acid (GABAA) receptor in the male Sprague-Dawley rat. This was a prospective, randomized, between-subjects experimental study. Fifty-five rats were assigned to 1 Sof 5 groups with 11 rats per group: control (vehicle), xanthohumol, midazolam, midazolam with xanthohumol, and flumazenil with xanthohumol. In this study the elevated plus maze measured the behavioral components of anxiety and motor movements. A 2-tailed multivariate analysis of variance and least significant difference post hoc test was used to determine if a significant difference existed. Our data suggest that xanthohumol does not produce anxiolysis by modulation of the GABAA receptor; however, there may be a possible interaction between xanthohumol and midazolam, or xanthohumol may influence the modulation of another neurotransmitter site in the central nervous system. Alone, xanthohumol does not show significant modulation of the benzodiazepine receptor. Additional research should investigate if xanthohumol acts as a benzodiazepine GABAA partial agonist or antagonist or if it modulates another neurotransmitter system in the central nervous system.