Pharmacological basis for sedative and hypnotic like effects of Pyrus pashia using in vivo experimental models.

OBJECTIVE

Pyrus pashia has traditionally been used as a therapeutic agent including sedative. In this regard, hydroethanolic extract of Pyrus pashia (HEPP) was screened for phytochemical investigation, acute toxicity, and sedative-hypnotic activity to provide a scientific rationale to its ethno-medicinal uses.

METHODS

Mice were used in acute toxicity test; sedative potential was observed in open field test while thiopental-induced sleeping time and barbiturate-induced sleeping time tests were used for the assessment of hypnotic like effects of HEPP. Various phytochemical groups were detected in preliminary phytochemical tests.

RESULTS

In acute toxicity study, the extract was found safe up to 1g/kg while the extract caused 50% death at 1500 mg/kg. In all animal models, the extract had shown sedative and hypnotic effects but the most significant effect observed at increased dose in comparison with standard diazepam-treated group. In open field test, the extract at doses of 200 and 400 mg/kg, there is mild decrease in number of lines crossed by tested animals (mice) while significant reduction shown at 600 mg/kg compared with diazepam-treated group at dose 0.5 mg/kg. In phytochemical investigation HEPP subjected to different phytochemical tests. From the thoroughly study, it is revealed that these constituents mainly participating in sedation and hypnosis.

CONCLUSIONS

The results of the present study showed significant sedative-hypnotic effects of the HEPP in mice and that the central benzodiazepine receptors are involved in the sedative-hypnotic effects of this plant.