Systemic Administration of Curcumin Affect Anxiety-Related Behaviors in a Rat Model of Posttraumatic Stress Disorder via Activation of Serotonergic Systems

Posttraumatic stress disorder (PTSD) is a trauma-induced psychiatric disease characterized by impaired hyperarousal, fear extermination, depression, anxiety, and amnesic symptoms that may include the release of monoamines in the dread circuit. Curcumin (CUR), a major diarylheptanoid and polyphenolic component of Curcuma longa, reportedly possesses several pharmacological features, including antidiabetic, antiatherosclerotic, anticancer, and neuropsychiatric actions. But the anxiolytic-like effects of CUR and its mechanism of action in PTSD are unclear. The current research measured some anxiety-related behavioral responses to examine the effects of CUR on symptoms of anxiety in rats after single prolonged stress (SPS) exposure by reversing the serotonin (5-HT) dysfunction. Rats received CUR (20, 50, or 100 mg/kg, i.p., once daily) for 14 days after SPS exposure. Administration of CUR significantly increased the number of central zone crossings in the open field test and reduced grooming behavior in the elevated plus maze (EPM) test and increased the number of open-arm visits on the EPM test. CUR administration significantly reduced freezing response to contextual fear conditioning. CUR recovered neurochemical abnormalities and SPS-induced decreased 5-HT tissue levels in the hippocampus, amygdala, and striatum. These results suggested that CUR has anxiolytic-like effects on biochemical and behavioral symptoms associated with anxiety. Thus, CUR may be a useful agent to alleviate or treat psychiatric disorders similar to those observed in patients with PTSD.