Effects of Chronic Administration of Antipsychotic Drug (Olanzapine) on the Anterior Pituitary Gland of Adult Male Albino Rats and the Potential Protective Role of Hypericum Perforatum

Introduction: Olanzapine (OLZ) is an atypical antipsychotic drug, has been used as approved therapy for schizophrenia and
bipolar disorder. Hypericum perforatum (HP) is a herbaceous plant, has been described as a neuroprotective agent with potent
antioxidant and anti-inflammatory effects.
Objectives: To evaluate the effects of chronic use of olanzapine on the anterior pituitary gland and the possible protective role
of hypericum perforatum
Material and method: Fifty six adult male albino rats were divided into 4 groups, received treatment orally for 8 weeks;
(I) control group, (II) HP supplemented group (80 mg/kg/day), (III) OLZ treated group (10 mg/kg/day), (IV) OLZ and HP
group (10 mg of OLZ and80 mg of HP/kg/day) . Finally, rats were weighted, anesthetized and sacrificed. Blood samples were
collected for biochemical study. Pituitary gland were dissected out and processed for histological study.
Results: Olanzapine treated rats exhibited a high significant increase in rat`s body weight. Plasma levels of luteinizing hormone
(LH) and follicle stimulating hormone (FSH) were significantly decreased but thyroid stimulating hormone (TSH) and prolactin
hormone were increased. OLZ induced degeneration of pars distalis cells. Where, cells had small dark nuclei and cytoplasmic
vacuolization. Eosinophilic material deposition and congestion of blood sinusoid were noticed. Most chromophiles contained
degenerated mitochondria and dilated rough endoplasmic reticulum. Furthermore, there was a high significant increase in the
number of positive caspase-3 immune-stained cells. Hypericum perforatum co-administration induced improvement of these
changes occurred by OLZ.
Conclusion: Olanzapine induced morphological and biochemical changes in the anterior pituitary gland. Hypericum
perforatum could ameliorate these changes.