The inulin-type oligosaccharides extract from morinda officinalis, a traditional Chinese herb, ameliorated behavioral deficits in an animal model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a severe psychiatric condition. The allopregnanolone biosynthesis has been implicated as one of the possible contributors to PTSD. Inulin-type oligosaccharides of morinda officinalis (IOMO) had been shown to be effective in the therapy of depression. However, few studies concern the anti-PTSD-like effects of IOMO. To evaluate this, the single prolonged stress (SPS) model was used in the present study. It had been shown that the behavioral deficits of SPS-treated rats were reversed by IOMO (25.0 and 50.0 mg/kg, i.p.), which reversed the increased freezing time in contextual fear paradigm (CFP) and the decreased time and entries in open arms in the elevated plus maze (EPM) test without affecting the locomotor activity in the open field (OF) test. In addition, the decreased allopregnanolone in the prefrontal cortex, hippocampus, and amygdala was reversed by IOMO (25.0 and 50.0 mg/kg, i.p.), respectively. In summary, the present study indicated that the IOMO exert anti-PTSD-like behaviors, which maybe associated with the brain allopregnanolone biosynthesis.