Anxiolytic effects of Echium amoenum on the elevated plus-maze model of anxiety in mice
Introduction
Anxiety disorders are the most common mental illness in the world and became a very important area of research interest in psychopharmacology. Interest in alternative medicine and plant-derived medications that affect the ‘mind’ is growing.
Self administration of herbal medicines was the most popular alternative therapies to the official medicine. The use of herbal medications by physicians in Europe and Asia is becoming very common and researchers are exploring the traditional remedies to find a suitable cure for these ‘mind affecting diseases’.
Moreover, Iranian climate and favored geographical location have contributed to the diversity of medicinal plants. In Iran, four species of Echium, which belongs to the Boraginaceae family, are available [1]. Echium amoenum Fisch. et Mey. is a biennial herb indigenous to a narrow zone of northern part of Iran and Caucasus where it grows at an altitude up to 2200 m [2]. The decoct of dried violet-blue petal of E. amoenum has long been known to have tranquillizing effects among the Iranian people [3].
Despite the widespread use of E. amoenum as an anxiolytic, there are no pharmacological data to support such effects. The aim of the present study was to evaluate the effect of the ethanolic extract of E. amoenum on CNS in rats.
Section snippets
Plant material
Flowers of E. amoenum were collected from the north of Iran and identified by Dr M.R. Rahiminejhad. A voucher specimen 1147 was deposited in the herbarium of Faculty of Pharmacy, Isfahan University of Medical Sciences, Isfahan, Iran.
Extraction
Air-dried and powdered flowers of E. amoenum (200 g) were macerated in 600 ml of 80% aqueous EtOH for 48 h. The extract, filtered and evaporated under vacuo gave a residue (5.5 g). The residue was dissolved in normal saline for final suitable concentrations.
Animals
Male TO
Effect of E. amoenum extract on the elevated plus-maze
In the elevated plus-maze, the behavior observed confirmed the anxiolytic activity of diazepam as reported previously [10]. The ethanolic extract of E. amoenum flowers at a dose of 50 mg/kg increased the percentage of time spent and percentage of arm entries in the open arms (P<0.05, Fig. 1a,b) and decreased the percentage of time spent and percentage of arm entries in the closed arms (P<0.05, Fig. 2a,b). The extract at 25 mg/kg had no significant effects on any of the measured parameters
Discussion and conclusions
The aim of the present study was to evaluate the anxiolytic effect of ethanolic extract of E. amoenum flowers. Various doses of the plant extract were tested on the EPM. Only at 50 mg/kg, the plant extract produced anxiolytic effect with a mild sedative action, at doses lower than 50 mg/kg, there was no significant changes in the behavior parameter that was measured on the EPM. Doses higher than 50 mg/kg produce severe sedative effects (data not shown) and were not considered suitable for
Acknowledgements
This work was supported by Research Department of Isfahan University of Medical Sciences.
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