Effect of ethanolic leaf extract of Ocimum sanctum on haloperidol-induced catalepsy in albino mice

Neuroleptic drugs used in the treatment of schizophrenia and other affective disorders are known to produce extrapyramidal side effects. Catalepsy induced by these drugs in animals has been used as a model for the extrapyramidal side effects associated with antipsychotic agents in human beings. In the present study, we have attempted to evaluate the protective effect of the ethanolic leaf extractof Ocimum sanctum (OS) on haloperidol (1.0 mg/kg, intraperitoneal administration)-induced catalepsy in mice by employing the standard bar test. Mice were allocated to seven groups, each group containing six animals. The effects of the test drug OS (at 1.75, 4.25 and 8.5 mg/kg doses) and the standard drugs, scopolamine (1.0 mg/kg) and ondansetron (0.5 and 1.0 mg/kg doses) were assessed after single and repeat dose administration for seven days, 30 minutes prior to the haloperidol. The results suggest that OS has a protective effect against haloperidol-induced catalepsy, which is comparable to the standard drugs used for the same purpose. Our study indicates that OS could be used to prevent drug-induced extrapyramidal side effects.