Effects of Oxytocin on Parkinson’s like symptoms Induced by Haloperidol in Mice

Abstract

Antipsychotic drugs are mainly used for treatment of psychosis; they are more prone to produce extrapyramidal symptoms due
to their higher affinity to dopamine (D2) receptor, and they act as antagonists. Haloperidol as a high-affinity dopamine antagonist
predisposed toward a higher risk of extrapyramidal side effects. These adverse neurologic responses include catalepsy,
ptosis, akinesia and tremor. Oxytocin is a peptide hormone of the posterior pituitary gland; several studies had suggested
that oxytocin has broader effects on the central nervous system. Oxytocin regulates social behaviors, pain perception, anti
inflammatory responses, stress reduction and blood pressure modulation. It acts as a hormone in the peripheral circulation
and a neurotransmitter in the central nervous system. Recent research suggests that oxytocin may alter the progression of
neurodegenerative diseases due to its anti-inflammatory and antioxidant properties. Oxytocin may provide neuroprotection as a
potential therapy for neurodegenerative diseases. Therefore, this work aimed to find out the effects of oxytocin on Parkinson’s
like symptoms induced by haloperidol in mice. Mice were divided into six groups (n=6 each). Group 1, the control group
received 1% Tween 80 solution; group 2 treated with haloperidol at a dose of 2 mg/kg; group 3 received oxytocin at dose of 1iu/
kg; group 4 received oxytocin at dose of 10 iu/kg; group 5 received combination of oxytocin (1 iu/kg) and haloperidol (2 mg/kg)
and group 6 received combination of oxytocin (10 iu/kg) and haloperidol (2 mg/kg). Intraperitoneal sub-acute administration
was applied in three doses on 24, 5 hrs. and 1 hr. before scoring. Parameters scored were catalepsy, ptosis, tremor, akinesia and
righting reflex. Oxytocin at a dose of 10 iu/kg antagonized ptosis, akinesia and catalepsy induced by haloperidol; while loss of
righting reflex and tremor were not observed.