Neuroprotective role of a monoterpene (thymol) on diazepam induced withdrawal symptoms in rats.

Benzodiazepine administration is known to be related to tolerance and a withdrawal syndrome on sudden cessation. Thymol possesses multiple biological properties especially in the pathogenesis of different brain disorders. However, to the best of our knowledge there is no study that relates the use of thymol to benzodiazepine induced withdrawal symptoms. Therefore the aim of the current study was to investigate the usefulness of thymol in the treatment of benzodiazepine withdrawal syndrome in rats. Animals were divided into four groups, thymol (40mg/kg/ml), diazepam (4 mg/kg), thymol + diazepam and vehicle control group. The treatment was given for 14 days and then suddenly ceased. After 24 h animals were tested in different behavioral paradigms such as physical signs for withdrawal, marble burying test, inverted screen test, elevated plus maze, passive avoidance test and open field activity. The results of the present study revealed that co-administration of thymol significantly reduced the withdrawal symptoms induced by diazepam. Our results further suggest that administration of thymol not only ameliorates rebound anxiety associated with diazepam withdrawal but also improves motor and memory impairment in rats.