Effects of curcumin on pentylenetetrazole-induced anxiety-like behaviors and associated changes in cognition and monoamine levels

ABSTRACT

The purpose of the present study was to estimate the protective effects of curcumin against anxiety and memory impairment, which are often comorbid in patients with anxiety disorders who are on standard anxiolytic therapy. The effects of curcumin on brain monoamine levels were also determined. We used the elevated plus maze (EPM), a standard animal model of anxiety, to determine the effects of subacute administration (14 days) of curcumin at doses of 5 and 10 mg/kg (p.o.) against pentylenetetrazole (PTZ; 20 mg/kg, i.p.)-induced anxiety-like behavior, followed by an evaluation of the effects of curcumin on cognitive deficits induced by PTZ using the passive avoidance retention task. Rats were exposed to the passive avoidance learning task before the initiation of treatment, and the effects on memory retention were studied 24 h after the EPM trial. A marked increase in the time spent in the open arms, an index of anxiety, and an increase in the step-down latency, an index of memory retention, were observed in curcumin-treated rats. Curcumin increased the levels of serotonin, norepinephrine, and dopamine in various regions of the rat brain. These results confirm the anxiolytic and memory-retentive effects of curcumin, and alterations in brain monoamine levels may have contributed to the present findings: