Neuropharmacological effects of d-pinitol and its possible mechanisms of action.

Abstract

The aim was to evaluate the diuretic and neuropharmacological actions of d-pinitol and describe a possible mechanism of action. The diuretic effects of d-pinitol were evaluated using mice placed in metabolic cages. The sedative, anxiolytic-like, antidepressant-like, and anticonvulsant effects of 1-100mg/kg d-pinitol were assessed. The possible mechanisms of action of the anxiolytic-like, antidepressant-like, and anticonvulsant effects of d-pinitol were evaluated using inhibitors. d-pinitol lacked diuretic effects. However, d-pinitol showed the highest anxiolytic-like actions (ED50 =70mg/kg p.o. in mice) in the cylinder exploratory test and the highest antidepressant-like activity in the forced swimming test (ED50 =26mg/kg p.o. in mice). d-pinitol (100mg/kg) exerted anticonvulsant actions in the pentylenetetrazole-induced seizures test. The pre-treatment with 2mg/kg flumazenil reverted the anxiolytic-like actions and the anticonvulsant effects of d-pinitol, whereas the pre-treatment with 1mg/kg yohimbine and 0.05mg/kg prazosin abolished the antidepressant effects of d-pinitol. PRACTICAL APPLICATIONS: d-pinitol (3-O-methyl-d-chiro-inositol) is a polyol found in many fruits, as well as in many members of the Leguminosae and Fabaceae families. The results propose that this compound could contribute in the treatment of anxiety, depression, and convulsions. The findings suggest the possible participation of the GABAergic system in the anxiolytic-like and anticonvulsant actions of d-pinitol, whereas the noradrenergic system is probably involved in the antidepressant effects of d-pinitol. This study provides new information about other pharmacological uses for d-pinitol.