Psychopharmacological Profile of Ascorbate in aged Wistar Rats

Abstract

Clinical and preclinical findings have suggested a role for ascorbate in mood disorders. The present study was designed to investigate the effect of acute and chronic ascorbate treatment in animal models of memory, anxiety and depression using discriminative avoidance, forced swimming, light-dark box and openfield tests. Aged male Wistar rats (18 months) were treated with saline or ascorbate (50, 500 or 1000 mg/kg body weight) during 25 days. The acute treatment did not improve learning and memory parameters evaluated in the plus maze discriminative avoidance test. Besides, in the training session, ascorbate (1000 mg/kg) decreased the time spent in the open arms and 500 and 1000 mg/kg doses increased the time spent in the nonaversive enclosed arm, indicating anxiety-like behavior. On the 10 th day of treatment, ascorbate (1000 mg/kg) showed an antidepressant-like activity, since the treated animals showed decreased immobility time when compared to the saline group in the forced swimming test. The treatment with ascorbate did not alter any parameters in the light-dark box test evaluated on the 15 th day; however, on the 25 th day, ascorbate (500 mg/kg and 1000 mg/kg) decreased the number of entries into peripheral squares and the number of rearings in the open field test, suggesting an anxiolytic-like profile. In conclusion, our findings suggest that acute ascorbate treatment may induces an anxiety state, while at long term seems to exert anxiolytic activity, as well as exhibiting an antidepressant-like activity in aged rats.