Effects of chronic administration of efavirenz on DNA of the intracranial visual relay centers of adult Wistar rats

The effects of chronic administration of efavirenz commonly used as part of Highly Active Antiretroviral Therapy (HAART) for the treatment of Human Immunodeficiency Virus (HIV) type-1 therapy on the DNA of the intracranial visual relay centre namely the superior colliculus and lateral geniculate body of adult Wistar rats were carefully studied. The rats of both sexes (n=20), with an average weight of 200g were randomly assigned into treatment (n=10) and control (n=10) groups. The rats in the treatment group received 600mg/70kg bogy weight of efavirenz dissolved in distilled water daily for 30 days through the orogastric tube. The control group received equal volume of distilled water daily for 30 days through the same route. The rats were fed with grower’s mash obtained from Edo Feeds and Flour Mill Limited, Ewu, Edo State, Nigeria and given water liberally. The rats were sacrificed by cervical dislocation method on the thirty-first day of the experiment. The superior colliculus and lateral geniculate body were carefully dissected out and quickly fixed in 10% formal saline for histochemical study. The histochemical findings indicated that the treatment sections of the superior colliculus and lateral geniculate body showed less intense staining and appeared pachychromatic. The stained neurons and glia cells were few as compared to the control sections. There were observations of neuronal enlargement in the superior colliculus and lateral geniculate body of the treated sections. The superior colliculus of the treated rats showed evidence of hypertrophy and microcytic changes in the darkly stained DNA positive granules, while the treated section of the lateral geniculate body showed positively stained DNA granules of various sizes and shapes, with an indication of hypertrophy and microcytic changes as compared to the control group. Chronic administration of efavirenz may therefore have an adverse effect on the DNA of the superior colliculus and lateral geniculate body of adult Wistar rats. It is recommended that further studies aimed at corroborating these observations be carried out.