Chrysin (5,7-dihydroxyflavone) exerts anxiolytic-like effects through GABAA receptors in a surgical menopause model in rats

The present study investigated the effects of the flavonoid chrysin (5,7-dihydroxyflavone) on anxiety-like behavior in rats in a model of surgical menopause and evaluated the participation of gamma-aminobutyric acid-A (GABA(A)) receptors in these actions. At 12 weeks post-ovariectomy, the effects of different doses of chrysin (0.5, 1, 2, and 4 mg/kg) were evaluated in the elevated plus maze, light/dark test, and locomotor activity test, and comparisons were made with the clinically effective anxiolytic diazepam. The participation of GABA(A) receptors in the actions of chrysin was explored by pretreating the rats with the noncompetitive GABA(A) chloride ion channel antagonist picrotoxin (1 mg/kg). The results showed that chrysin (2 and 4 mg/kg) reduced anxiety-like behavior in both the elevated plus maze and light/dark test, and these effects were similar to diazepam. Pretreatment with picrotoxin had no effects on its own but prevented the anxiolytic-like effects of chrysin in both tests. Chrysin also increased rearing and grooming, without significantly altering the number of crossings in the locomotor activity test these effects were also similar to diazepam. In conclusion, the flavonoid chrysin produced anxiolytic-like effects through actions on GABA(A) receptors in a model of surgical menopause in rats. These findings support the hypothesis that this flavonoid could be a future natural alternative for ameliorating symptoms of anxiety after surgical menopause in women.