Biochemical effects of chronic administration of efavirenz on the intracranial auditory relay centers of adult Wistar rats

The biochemical effects of chronic administration of efavirenz, which is commonly used as part of highly active antiretroviral therapy for treatment of human immunodeficiency virus (HIV) type 1, on the intracranial auditory relay centers [i.e., the inferior colliculus (IC) and medial geniculate body (MGB)] of adult Wistar rats were carefully studied. Rats of both sexes (n = 30), with an average weight of 200 g, were randomly assigned into treatment (n = 15) and control (n = 15) groups. Rats in the treatment group each received the recommended daily dose of 600 mg/70 kg (1.71 mg/200 g) of body weight of efavirenz daily for 30 days, while the control group rats received an equal volume of distilled water alone daily for 30 days. The rats were sacrificed after 30 days, and the IC and MGB were carefully removed for further biochemical assays. These analyses indicated that levels of malonyldialdehyde (MDA), a non-enzyme biomarker of oxidative stress, were significantly higher (p < 0.05) whereas levels of superoxide dismutase (SOD) were significantly lower (p < 0.05) in treated tissues than in control tissues. Chronic administration of efavirenz may therefore have an adverse effect on the auditory sensibilities by affecting the IC and MGB of adult Wistar rats.