Assessment of aqueous extract of Lemon verbena on anxiety‑like behavior in rats

Abstract

Aim: The purpose of the present study was to evaluate the anxiolytic effects of the
aqueous extract of Lemon verbena on rats. Materials and Methods: In this study, aqueous
extract of Lemon verbena leaves was prepared, and then male Wistar rats (200‑230 g)
were divided randomly into six experimental groups. Each group received a single
intraperitoneal (IP) injection of saline, aqueous extract of Lemon verbena (10 mg/kg,
100 mg/kg, 500 mg/kg, 1,000 mg/kg)or diazepam, respectively. The level of anxiety was
asserted by an elevated plus maze (EPM) 20 min after treatment. Statistical Analysis
Used: Results were analyzed by one‑way analysis of variance (ANOVA) and Tukey’s
post‑hoc test. The results were expressed as mean ± standard error of mean (SEM).
The differences were considered significant at P < 0.05. Results: The results of this
study showed that there was a significant difference in the number of entrances into
the open arms, spent time in the open arms and number of total entrances into the
open and closed arms of the EPM between control, diazepam and extract‑receiving
groups (10 mg/kg, 100 mg/kg, 500 mg/kg, 1,000 mg/kg) and control. The numbers
of entrances into the open arms, spent time in the open arms in extract receiving groups
were significantly less than control group. Conclusion: These results indicated that
acute administration of aqueous extract of Lemon verbena (≥10 mg/kg) increased
anxiety‑like behavior in rats in the EPM.