The Anxiolytic Effects of Melissa officinalis L. on Patients Awaiting Surgery: A Randomized Double-Blind Placebo-Controlled Clinical Trial

Preoperative anxiety is prevalent with up to 80% of patients experiencing this unpleasant feeling. Melissa officinalis L. is a famous herb with proposed medicinal activity including anxiolytic effects. Therefore, we aimed to consider the effect of M. officinalis in capsule formulation on preoperative anxiety in this clinical study. The plant material was standardized based on its essential oil content using gas chromatography/mass spectrometry apparatus. Then, 45 patients undergoing general surgery with American society of anesthesiology (ASA) physical status I or II were selected. By randomization, 23 and 22 patients were enrolled in treatment and placebo groups, respectively; to receive 500 mg dried powder of M. officinalis or placebo capsules, every 6 hours for 24 hours in this double-blind clinical study. They also completed the State Trait Anxiety Inventory for the second time and then proceeded to surgery. After the intervention, results showed a significant difference between the drug and placebo groups. The anxiety scores were 4.73 ± 1.17 and 5.81± 1.22 in the drug and placebo groups, respectively (p = 0.01). No adverse event was recorded. The results of this investigation show that M. officinalis capsule decreases preoperative anxiety in the patients who are undergoing general surgery and could be considered as a helpful supplement for these patients.