Antidepressant-like activity of turmerone in behavioral despair tests in mice

Abstract

Background: The present study was undertaken to evaluate the anti-depressive activity of turmerone after one-week administration by using a mouse forced swimming test (FST) and tail suspension test (TST).

Methods: Animals were divided into four groups (n = 10 /group): control (0.9% saline), the three doses of turmerone (1.25, 2.5, 5.0 mg/kg) for one-week treatment. To assess the effect of turmerone on locomotor activity, mice were evaluated in the open-field paradigm. Forced swimming test (FST) and Tail suspension test (TST) were used to take as a measure of antidepressant activity. The probable mechanisms of action of the anti-depressive effect of turmerone was also investigated by measuring the activity of monoamine oxidase-A and corticosterone levels in the blood and the levels of monoamines in the cortex, striatum, hippocampus and hypothalamus of the mice.

Results: Turmerone (2.5, 5.0 mg/kg, p.o.) significantly reduced the immobility time of mice in both the FST and TST, but it did not significantly affect the ambulatory and total movements of mice. However, hyperactivity might explain the results. In addition, turmerone decreased the corticosterone level in the blood while it increased the levels of 5-HT in cortex, striatum, hippocampus, and hypothalamus, the level of NE in striatum and hippocampus, the levels of MHPG and DOPAC in hypothalamus, the level of 5-HIAA in striatum, and the level of DA in striatum, hippocampus, and hypothalamus. Turmerone (2.5, 5.0 mg/kg) decreased the activity of MAO-A in the frontal cortex and hippocampus of mouse brain.

Conclusions: After one-week administration, turmerone produced antidepressant-like effects. The mechanisms of action of anti-depressive effect of turmerone seemed to involve an increase of the monoamines level decreasing the MAO-A activity and the stress of mice.

Figure 1

The effect of turmerone (1.25-5.0 mg/kg, p.o.), or fluoxetine (FLU, 10 mg/kg, p.o.) on the immobility time in the forced swimming (A) and tail suspension (B) tests after one week of administration. The values are mean ± SEM for each group (n = 10). ***p < 0.001 as compared with control group (One-way ANOVA followed by Scheffe’s multiple range test).

Figure 2

The effects of one week of turmerone administration on: (A) total movements, (B) total distance, and (C) total ambulatory move time in the locomotion tests. The values are mean ± SEM for each group (n = 10).

Figure 3

The effects of turmerone (2.5-5.0 mg/kg) for one week’ administration on serum corticosterone levels in the mouse FST. Data are expressed as mean ± SEM (n = 6/group). For statistical significance, ^#p < 0.05 compared to vehicle-treated control group, ^***p < 0.001 compared to vehicle-treated FST group.