The effects of resveratrol on rat behaviour in the forced swim test

The trans-isomer of resveratrol is the active ingredient of Poligonum cuspidatum, known for its medicinal properties and traditionally used in the treatment of neuropsychiatric disorders. It is also found abundantly in the skin of red grapes and red wine. Previous studies have suggested that trans-resveratrol demonstrates a variety of pharmacological activities including antioxidant, anti-inflammatory, as well as neuroprotective properties and procognitive effects. The goal of the present study was to examine the influence of trans-resveratrol on behavior in rats and its antidepressant properties. Male Wistar rats were treated intraperitoneally (i.p.) with the increasing doses of trans-resveratrol (5, 10 and 20 mg/kg) or vehicle (dimethyl sulfoxide--DMSO), 30 minutes before testing of the spontaneous locomotor activity or forced swimming. For the experiments, the behavior of the animals was recorded by a digital camera, and the data were analyzed by one-way ANOVA, followed by Tukey post-hoc test. Testing of spontaneous locomotor activity, after the application of vehicle or increasing doses of trans-resveratrol, showed no statistically significant difference between groups (p > 0.05). In the forced swim test, one-way ANOVA indicated statistically significant effects of trans-resveratrol (p < 0.001).Tukey post-hoc test showed that resveratrol significantly decreased immobility time at the doses of 10 mg/kg and 20 mg/kg, manifesting the acute antidepressant-like effects. There were no statistically significant differences between the resveratrol treatment of 5 mg/kg and vehicle (p > 0.05). The results from our study suggest that transresveratrol produces significant effects in the central nervous system. After single application, it has acute antidepressant effects, but without influence on locomotor activity.