Schizophrenia is a serious mental illness, and its pharmacological treatment consists in the administration of antipsychotics, such as haloperidol. However, treatment with haloperidol often causes extrapyramidal motor disorders such as tardive dyskinesia (TD). TD is a movement disorder characterized by involuntary movements, which can be studied in animals. So far, there is no effective treatment for TD and alternatives have been sought. Thus, the objective was to evaluate the possible protective effect of iso avones against the induction of involuntary movements induced by haloperidol in an animal model. Male Wistars rats were treated with haloperidol (1 mg/ kg/day) and/or iso avones (80 mg/kg) for 28 days. Rats were submitted to behavioral evaluation to quantify vacuous chewing movements (VCM) and the locomotor activity. In addition, the levels of pro-in ammatory cytokines were measured in the striatum. Haloperidol treatment reduced the locomotor activity and increased the number of VCM in rats. Co-treatment with iso avones was able to reverse hypolocomotion and reduce the number of VCM to the levels of the control group. Besides, haloperidol caused signi cant increase in the proin ammatory cytokines (interleukin-1β:IL-1β, tumor necrosis factor-α:TNF-a and IL-6 and the cotreatment with iso avones was able to reduce the levels of IL-1β and TNF-α, but not IL-6. It is believed that the bene cial effect found with this treatment is related to their anti-in ammatory potential and also to the action on estrogen receptors (based on ndings in the scienti c literature). Finally, further studies are needed to elucidate the mechanisms of iso avones in reducing motor disorders induced by antipsychotic.

Schizophrenia is a serious mental illness, and its pharmacological treatment consists in the administration of antipsychotics, such as haloperidol. However, treatment with haloperidol often causes extrapyramidal motor disorders such as tardive dyskinesia (TD). TD is a movement disorder characterized by involuntary movements, which can be studied in animals. So far, there is no effective treatment for TD and alternatives have been sought. Thus, the objective was to evaluate the possible protective effect of isoflavones against the induction of involuntary movements induced by haloperidol in an animal model. Male Wistars rats were treated with haloperidol (1 mg/ kg/day) and/or isoflavones (80 mg/kg) for 28 days. Rats were submitted to behavioral evaluation to quantify vacuous chewing movements (VCM) and the locomotor activity. In addition, the levels of pro-inflammatory cytokines were measured in the striatum. Haloperidol treatment reduced the locomotor activity and increased the number of VCM in rats. Co-treatment with isoflavones was able to reverse hypolocomotion and reduce the number of VCM to the levels of the control group. Besides, haloperidol caused significant increase in the proinflammatory cytokines (interleukin-1β:IL-1β, tumor necrosis factor-α:TNF-a and IL-6 and the co-treatment with isoflavones was able to reduce the levels of IL-1β and TNF-α, but not IL-6. It is believed that the beneficial effect found with this treatment is related to their anti-inflammatory potential and also to the action on estrogen receptors (based on findings in the scientific literature). Finally, further studies are needed to elucidate the mechanisms of isoflavones in reducing motor disorders induced by antipsychotic.