Mimosa pudica may possess antidepressant actions in the rat

In Mexico, aqueous extracts from dried leaves of Mimosa puolica are employed to alleviate depression. In this study, the behavioral actions of aqueous extracts of M. pudica at various concentrations were tested. Rats having received saline (0.9%; 0.30 ml; I.P.), clomipramine, desipramine or several dosages of aqueous extracts from M. pudica (ml = 2.0 mg/kg; m2 = 4.0 mg/kg; m3 = 6.0 mg/kg; m4 = 8.0 mg/kg) during a 30-day period were submitted to the forced swimming test and to the test for differential reinforcement of low rates of response at 72 sec (DRL-72s). Any possible anxiolytic action resulting from several doses (ml = 2.0 mg/kg; m2 = 4.0 mg/kg; m3 = 6.0 mg/kg; m4 = 8.0 mg/kg) of extracts of M. pudica were compared with those caused by diazepam (1.3 mg/kg, I.P.) in the elevated plus-maze test. Results showed that clomipramine (1.25 mg/kg, I.P.), desipramine (2.14 mg/kg, I.P.) and M. pudica (6.0 mg/kg and 8.0 mg/kg, I.P.) reduced immobility in the forced swimming test and increased the rate of reinforcers received in the DRL-72s test; these data suggest that M. pudica produces antidepressant effects in the rat. Diazepam increased the open-arms exploration time in the elevated plus-maze test, but M. pudica did not show any comparable action at any tested dose. M. pudica therefore produced an antide-pressant-like profile similar to two tricyclic antidepressants.