Inositol reduces depressive-like behaviors in two different animal models of depression

Rationale: Myo-inositol is an isomer of glucose that is a precursor in the phosphatidylinositol (PIP) cycle, a source of two second messengers: diacyl glycerol (DAG) and inositol triphosphate (IP3). Clinical studies have repor ted that inositol is effective in relieving symptoms of depression. Objecti ve: The present study examined the effects of inositol on two animal models of depression: the Porsolt forced swim test, a behaviorally based model; a nd the reserpine-induced immobility model, a pharmacologically based model. Methods and results: Chronic inositol injections (daily for 14 days) of 1. 2 g/kg (but not at lower doses) reduced immobility time and increased strug gle time in the Porsolt test compared with control animals. The same dose a nd treatment schedule also reduced complete immobility time but did not aff ect ambulatory activity in the reserpine test compared with controls. Chron ic oral treatment with inositol (10% in food for 14 days) had effects simil ar to IP inositol in the Porsolt test. Conclusions: The effect of inositol in animal models of depression supports its possible importance as a new tr eatment for the disorder, and permits research on its mechanisms of action.