Anxiolytic-like effects of ursolic acid in mice

Ursolic acid is a pentacyclic triterpenoid that possesses several biological and neuropharmacological effects including antidepressant-like activity. Anxiety disorders represent common and disability psychiatric conditions that are often associated with depressive symptoms. This work investigated the anxiolytic-like effects of ursolic acid administration in different behavioral paradigms that evaluate anxiety in mice: open field test, elevated plus maze test, light/dark box test and marble burying test. To this end, mice were administered with ursolic acid (0.1, 1 and 10 mg/kg, p.o.) or diazepam (2 mg/kg, p.o.), positive control, and submitted to the behavioral tests. The results show that ursolic acid (10 mg/kg) elicited an anxiolytic-like effect observed by the increased total time in the center and decreased number of rearings responses in the open field test and an increased percentage of entries and total time spent in the open arms of elevated plus maze, similarly to diazepam. No significant effects of ursolic acid were shown in the light/dark box and marble burying test. These data indicate that ursolic acid exhibits anxiolytic-like effects in the open field and elevated plus maze test, but not in the light/dark box and marble burying test, showing the relevance of testing several behavioral paradigms in the evaluation of anxiolytic-like actions. Of note, the results extend the understanding on the effects of ursolic acid in the central nervous system and suggest that it may be a novel approach for the management of anxiety-related disorders.