Effects of paroxetine on PTSD-like symptoms in mice.

RATIONALE: After exposure to a severe traumatic event, avoidance, fear sensitization, and increased anxiety are among features that can persist over time in people developing posttraumatic stress disorder (PTSD). Basic research on treatment interfering with these symptoms can provide insights to improve PTSD treatment. OBJECTIVES: The purposes of the present study were to induce these behavioral changes in mice and examine whether paroxetine would interfere with their expression. METHODS: Mice were submitted to avoidance training with a low (0.4 mA) or high (1.5 mA) foot-shock intensity, as mild and severe stressors, respectively, and posttraining avoidance was evaluated 1 and 12 days later. Fear sensitization, measured as increased freezing to a neutral tone, and enhanced contextual fear, measured as increased freezing to a conditioned context (wherein all mice received a 0.4-mA foot-shock), were assessed during this time window. An elevated plus maze test was also used to assess mouse anxiety-like behavior. RESULTS: Persistent avoidance, persistent fear sensitization, and long-term enhancement of contextual fear and increased anxiety-like behavior were established only in mice that received the 1.5-mA foot-shock during avoidance training. Paroxetine (at 8 mg/kg/day), injected from day 5 to day 11 after avoidance training, suppressed all of these behavioral changes. CONCLUSIONS: These data provide additional evidence for the role of paroxetine against expression of PTSD-like behaviors in mice.

Evaluation of the developmental toxicity of the aqueous extract from Trigonella foenum-graecum (L.) in mice.

AIM OF THE STUDY: The use of medicinal plant products to treat various ailments is a common practice in many developing countries. However, a lack of information on the adverse effects of these plants raises questions on their safety and possible adverse side effects. This study was undertaken to evaluate the potential toxic effects of fenugreek seeds on pregnant mice and foetal development. MATERIALS AND METHODS: Lyophilized aqueous extract from fenugreek seeds (LAE-FS) was administered to mated female mice during the entire period of pregnancy, at doses of 500 and 1000 mg/kg/day. Females were examined for standard parameters of reproductive performance. Foetuses were weighed and examined for externally visible malformations. RESULTS: In pregnant females, there were no obvious symptoms of toxicity, LAE-FS-related deaths or macroscopic abnormalities. Developmental toxicity in offspring included an increase in the foetal death rate, a decrease in the litter size, and a reduction in the foetal body weight. In addition there was an increase in the incidence of morphological abnormalities. CONCLUSIONS: Based on these results, it was concluded that fenugreek seeds extract may have deleterious toxic effects on reproductive performance and potential teratogenic effects in foetuses.