Involvement of GABA(A)-benzodiazepine receptor in the anxiolytic effect induced by hexanic fraction of Rubus brasiliensis.
To investigate the ability of hexanic ethanolic fraction of Rubus brasiliensis Martius (Roseceae), to induce anxiolytic effect and also the possible involvement of the GABA(A)-benzodiazepine receptor complex, male Wistar rats and Swiss mice behaviour were tested in the elevated plus maze (EPM). All the doses of the extract, 50, 100 and 150 mg/kg, administered per gavage (vo), 30 min before the behavioural evaluation, induced an anxiolytic effect expressed by: increased number of entries in and time spent in the open arms and percentage of open arm entries; and decreased number of entries and time spent in the closed arms. The treatment of mice with flumazenil (Ro 15-1788), 0.5, 1.0 and 1.5 mg/kg, i.p., 15-min before the administration of hexanic fraction, 100 mg/kg, vo, blocked the hexanic fraction-induced anxiolytic effect. The LD50 for the hexanic fraction was 1512 mg/kg. In conclusion, it was shown that the hexanic fraction of R. brasiliensis induced an anxiolytic effect in rats and mice. This effect can be attributed to a liposoluble principle with low toxicity which may be acting as an agonist on GABA(A)-benzodiazepine receptor complex.
Department of Pharmacology, Bioscience Institute, UNESP, Botucatu-SP, Brazil.
E
E
Nogueira
G J
GJ
Rosa
V S
VS
Vassilieff
D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D005106:Exploratory Behavior / Q000187:drug effects; D006586:Hexanes; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology / Q000633:toxicity; D010946:Plants, Medicinal / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000187:drug effects*; D012997:Solvents
D014151:Anti-Anxiety Agents; D006586:Hexanes; D010936:Plant Extracts; D011963:Receptors, GABA-A; D012997:Solvents