The hydroalcoholic extract of Salvia elegans induces anxiolytic- and antidepressant-like effects in rats.

Behavioral effects of a hydroalcoholic (60% ethanol) extract from the leaves of Salvia elegans Vahl (Lamiaceae) were studied in male Sprague-Dawley rats. The extract was administered intraperitoneally and its effects on spontaneous motor activity (total motility, locomotion, rearing and grooming behavior) were monitored. Putative anxiolytic and antidepressant properties of Salvia elegans were studied in the elevated plus-maze test (EPM) and in the forced swimming test (FST), respectively. Deleterious effects of Salvia elegans on learning and memory were also studied by using active and passive avoidance paradigms. The results revealed that all doses (3.12, 12.5, 25 and 50 mg/kg) of the extract caused a significant decrease in total motility, locomotion, rearing and grooming behavior. Only the dose of 12.5 mg/kg increased the exploration of the EPM open arms in a similar way to that of diazepam (1 mg/kg). In the FST, all doses of the extract induced a reduction of immobility, in a similar way to that of fluoxetine (10 mg/kg) and imipramine (12.5 mg/kg), along with a significant increase in the time spent in swimming behavior. Acquisition of active avoidance responses was disrupted by pre-treatment with the extract, but retention of a passive avoidance response was not significantly modified. These results suggest that some of the components of the hydroalcoholic extract of Salvia elegans have psychotropic properties, which deserve further investigation.

Anxiolytic and antidepressant-like effects of the hydroalcoholic extract from Aloysia polystachya in rats.

Behavioral effects of a hydroalcoholic extract from leaves of Aloysia polystachya (Griseb.) Moldenke (Verbenaceae) were studied in female Sprague-Dawley rats. The extract was administered intraperitoneally and its effects on spontaneous motor activity (total motility, locomotion, rearing and grooming behavior) were monitored. Anxiolytic-like properties were studied in the elevated plus-maze (EPM) test and the possible antidepressant-like actions were evaluated in the forced swimming test (FST). The results revealed that high doses of the extract (25 and 50 mg/kg, i.p.) caused a significant decrease in total motility, locomotion, rearing and grooming behavior. All doses injected (from 1.56 to 50 mg/kg) increased the exploration of the EPM open arms in a similar way to that of diazepam (1 mg/kg, i.p.). In the FST, the extract (12.5, 25 and 50 mg/kg) was as effective as fluoxetine (10 mg/kg, i.p.) and imipramine (12.5 mg/kg, i.p.) in reducing immobility, along with a significant increase in swimming and climbing, respectively. These results suggest that some of the components of the hydroalcoholic extract of A. polystachya, such as thujone and carvone among others, may have sedative, anxiolytic and antidepressant-like properties which deserve further investigation.

Central nervous system activity of the hydroalcoholic extract of Casimiroa edulis in rats and mice.

In order to evaluate the effects produced by the hydroalcoholic extract of leaves from Casimiroa edulis on the central nervous system, different behavioral tests and animal models of depression and anxiety were performed. The extract was administered intraperitoneally in male and female rats and tested on spontaneous motor activity, locomotor activity, exploration of an elevated plus-maze (EPM) and in the forced swimming test (FST). In addition, the extract was administered orally in male and female mice and evaluated in the following tests: general observation, pentobarbital-induced hypnosis, EPM, rota-rod, hole-board, and marble-burying. The results revealed that, in rats, the extract caused considerable reduction of locomotor and exploratory activities and increased the exploration of the EPM open arms in a similar way that diazepam. In the FST, the extract was as effective as fluoxetine in inducing shortening of immobility, along with a significant increase on climbing duration. On the other hand, in mice, the extract prolonged pentobarbital-induced hypnosis, increased exploration of the EPM open arms and partially protected from the pentylenetetrazol-induced convulsions. No significant effect was evident on motor coordination, hole-board and marble-burying tests. These results suggest that the hydroalcoholic extract of Casimiroa edulis may contain sedative principles with potential anxiolytic and antidepressant properties, which need further investigation.

Inhibition of DT-diaphorase potentiates the in vivo neurotoxic effect of intranigral injection of salsolinol in rats.

The present study shows that intranigral injection of dicoumarol, a DT-diaphorase inhibitor, potentiates the neurotoxic effect of salsolinol (salsolinol 1.25 nmoles plus dicoumarol 2 nmoles; in 2 microl). Rats treated with dicoumarol plus salsolinol presented a characteristic contralateral rotational behaviour when they were stimulated with apomorphine (0.5 mg/kg, s.c.), similar to rats injected unilaterally with 6-hydroxydopamine (6-OHDA). These rats also exhibited impairment of motor and cognitive behaviours. The results support the hypothesis that DT-diaphorase plays a protective role in the nigrostriatal dopaminergic systems.