The effect of Coriandrum sativum seed extract on the learning of newborn mice by electric shock: interaction with caffeine and diazepam

Coriander has been recommended for the relief of pain, anxiety, flatulence, and loss of appetite. In traditional medicine, it is believed that coriander can induce some degree of amnesia in a child when his/her mother uses coriander during the pregnancy. We evaluated the effect of Coriandrum sativum seed extract on learning in second-generation mice. Ethanolic extract (2%) of coriander (100 mg/kg intraperitoneal) was dissolved in sunflower oil (oil) as a vehicle and injected into the control group mother mice during breastfeeding for 25 days at 5-day intervals. After feeding the newborn mice, their learning was evaluated using a step-through passive avoidance task with 0.4 mA electric shock for 2 or 4 seconds. While coriander extract showed a negative effect in the short term (1 hour) after the training session, it potentiated the mice's learning in later assessments (24 hours post-training [P = 0.022] and 1 week post-training [P = 0.002] by a 4-second shock). Low-dose caffeine (25 mg/kg ip after training) improved the learning after 1 hour (P = 0.024); while diazepam (1 mg/kg ip) suppressed learning at all time points after the 4-second shock training (1 hour, P = 0.022; 24 hours, P = 0.002; and 1 week, P = 0.008). No modification in the pain threshold was elicited by electric stimuli both in coriander and control groups. In conclusion, coriander does not improve learning within a short period of time after training; however, learning after coriander administration can be improved in the long term.