Histological effects of chronic administration of efavirenz on lateral geniculate body of adult Wistar rats

HIV Non-Nucleoside Reverse Transcriptase Inhibitor Efavirenz Reduces Neural Stem Cell Proliferation in Vitro and in Vivo

The prevalence of HIV-associated neurocognitive disorders (HAND) remains high despite combination antiretroviral therapy (cART). There is evidence that neural stem cells (NSCs) can migrate to sites of brain injury such as those caused by inflammation and oxidative stress, which are pathological features of HAND. Thus, reductions in NSCs may contribute to HAND pathogenesis. Since the HIV non-nucleoside reverse transcriptase inhibitor efavirenz (EFV) has previously been associated with cognitive deficits and promotion of oxidative stress pathways, we examined its effect on NSCs in vitro as well as in C57BL/6J mice. Here we report that EFV induced a decrease in NSC proliferation in vitro as indicated by MTT assay, as well as BrdU and nestin immunocytochemistry. In addition, EFV decreased intracellular NSC adenosine triphosphate (ATP) stores and NSC mitochondrial membrane potential (MMP). Further, we found that EFV promoted increased lactate dehydrogenase (LDH) release, activation of p38 mitogen-activated protein kinase (MAPK), and increased Bax expression in cultured NSCs. Moreover, EFV reduced the quantity of proliferating NSCs in the subventricular zone (SVZ) of C57BL/6J mice as suggested by BrdU, and increased apoptosis as measured by active caspase-3 immunohistochemistry. If these in vitro and in vivo models translate to the clinical syndrome, then a pharmacological or cell-based therapy aimed at opposing EFV-mediated reductions in NSC proliferation may be beneficial to prevent or treat HAND in patients receiving EFV.

Histological effects of long term consumption of nutmeg on the medial geniculate body of adult Wistar rats

Background:

Nutmeg is commonly used as a spice in various dishes, as components of teas and soft drinks or mixed in milk and alcohol. The effect of chronic consumption of nutmeg on the medial geniculate body of adult Wistar rats was carefully studied.

Aim:

The objective is to observe any possible histological changes.

Materials and Methods:

Rats of both sexes (n = 24), with average weight of 200g were equally and randomly assigned into two treatment groups [A] and [B]; and untreated Control group [C] of (n = 8) per group. The rats in the treatment groups [A] and [B] were respectively given 1g and 2g of nutmeg thoroughly mixed with the feeds on a daily basis for thirty-two days. The control group received equal amount of feeds daily without nutmeg added for the thirty-two days period. All rats were fed with grower's mash and given water liberally. The rats were sacrificed by cervical dislocation method on day thirty-three of the experiment, medial geniculate body was carefully dissected out from the brain and quickly fixed in 10% formol-saline for histological study.

Results:

The findings indicate that rats in the treated groups (A & B) showed some cellular degenerative changes like hypertrophy, sparse cellular population, pyknotic nuclei with some microcystic changes, and vacuolation in the stroma of the treated medial geniculate body relative to those in the control group.

Conclusion:

Long term consumption of nutmeg may have adverse effect on microanatomy of medial geniculate body, which could negatively impact on the auditory sensibilities. Further research, including human observational studies, aimed at corroborating these observations is recommended.