Antistress effect of Mentha piperita in rats and the role of brain serotonin and dopamine

Tahira Parveen, Naila Amin, Darakhshan Saleem,Faiza Razi, Saida Haider ,Darakhshan Jabeen Haleem

Abstract
Objective: Stress is the emotional and tangible exertion caused by our response to pressure from the outside world. Common stress reactions include tension, irritability, inability to concentrate and a variety of physical symptoms that include headache and a fast heart beat. The present study investigates stress relieving effects of an herbal extract Mentha piperita in rats.
Methods: Animals are divided into test and control group. Peppermint extract (0.1gm/kg) given to test animals. Control animals were received an equal volume of water. A group of test and control animals were restraint for 2 hours. 24 hours following the restraint stress different behaviors were monitored. After monitoring the behaviors rats were decapitated. Neurochemical estimation were performed by High Performance Liquid Chromatography using EC detector.
Results: Exposure to 2h restraint stress increased circulating levels of plasma corticosterone. Brain Serotonin and Dopamine metabolism also increased. Prior administration of Mentha piperita leave extract for 5 week reversed the effect of stress on plasma corticosterone levels, brain Serotonin and Dopamine metabolism. Decrease in stress induced anxiety levels also observed in mint treated animals.
Conclusion: The results are consistent with antistress effect of Mentha piperita and suggest a role of brain Serotonin and Dopamine in antistress effect.

Key words: Stress, Mentha piperita, Corticosterone, 5-HT