A comparative study of sedative and anxiolytic effects of the Hypericum perforatumin and diazepam on rats

Background: Hypericum perforatum or St. John’s wort is a plant known as a Raee flower (or Hypericum) in Persian. Hyperisin and Hyperforin are the main constituents of this plant extract that are connected to sigma opioid and GABA receptors. Its various pharmacological effects, such as analgesia, sedation, anti-spasm, anti-convulsion, anti-anxiety, and anti-bacteria have already been known.

Materials and Method: To conduct the study, the authors prepared the hydro alcohol extract taken from the aerial organ of the plant. Then, different groups of female Wistar rats, which were almost equal in age and weight, received doses of 500mg/kg and 250mg/kg of the extract, 1.2mg/kg of diazepam, and di-methyl solphoxid (as placebo) with equal volumes. The intraperitoneal injections were administered 15min before assessing the sedative/hypnotic effects (i.e. duration of the induced sleep by ketamin with a dose of 40mg/kg) and the anxiolytic effects by means of the elevated plus maze.

Results: The results showed a statistically significant increase (p= 0.00) both in the duration of the induced sleep by ketamin and in the time lapsed in the open arms in the experimental groups with high and low doses of the extract.

Conclusion: The findings suggest that the extract of Hypericum perforatum with a dose of 500mg/kg could have sedative, preanaesthetic, and anxiolytic effects.