Involvement of GABAergic system in regulation of the anxiolytic- and antidepressant-like effects of Scrophularia striata extract in rats.
BACKGROUND
Neuropsychiatric disorders, like anxiety and depression, are global problems for clinical researchers in neurology. Recently, some authors have shown neuroprotective and anti-inflammatory effects of Scrophularia striata Boiss (Scrophulariaceae) extract in rodents.


OBJECTIVE
The purpose of the current study was to investigate the effects of S. striata extract on anxiety and depressant-like behaviors and find a possible mechanism for these impacts.


METHODS
In this study, the elevated plus-maze (EPM) and forced swimming test (FST), which are useful models for selective identification of anxiolytic and antidepressant drug effects in rodents, were used. We investigated the effects of S. striata ethanol extract at different doses (20, 50, 100, 160 and 220 mg/kg) on anxiety and depression behaviors in the EPM and FST, and then we assessed the role of γ-aminobutyric acid (GABA)A receptor in modulation of the effects of S. striata extract in the brain.


RESULTS
Our results showed that effective doses of S. striata (100 and 160 mg/kg) increased the percentages of open arm time and entries in the EPM and decreased immobility time in the FST in comparison with control group, indicating anxiolytic and antidepressant effects, respectively. Moreover, intracerebroventricular administration of GABAA receptor agonist (muscimol; 1 µg/rat) enhanced the impact of S. striata, and GABAA receptor antagonist (bicuculline; 1 µg/rat) blocked these effects in rats, indicating that significant interactions existed between S. striata and the GABAergic system in the brain.


CONCLUSIONS
Findings of this study suggest that anxiolytic and antidepressant effects of S. striata may be modulated via the GABAergic system.
Laboratory of Plant Biotechnology, Hayyan Research Institute, University of Tabriz, Tabriz, Iran.
Morteza
M
Kosari-Nasab
Shirin
S
Babri
Laleh
L
Fatehi-Gharehlar
Mohammad-Hossein
MH
Doosti
Sara
S
Pakzad
D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D001007:Anxiety / Q000188:drug therapy / Q000503:physiopathology; D001640:Bicuculline / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D003863:Depression / Q000188:drug therapy / Q000503:physiopathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D007276:Injections, Intraventricular; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D009118:Muscimol / Q000494:pharmacology; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism; D032266:Scrophularia / Q000737:chemistry*; D013550:Swimming / Q000523:psychology
D014151:Anti-Anxiety Agents; D000928:Antidepressive Agents; D010936:Plant Extracts; D011963:Receptors, GABA-A; D009118:Muscimol; D001640:Bicuculline