Abstract
Kola nut (from Cola nitida) is popular in Nigeria and West Africa and is commonly consumed by pregnant women during the first trimester to alleviate morning sickness and dizziness. There is, however, a dearth of information on its effects on the developing brain. This study, therefore, investigated the potential effects of kola nut on the structure of the developing neonatal and juvenile cerebellum in the rat. Pregnant Wistar rats were administered water (as control) or crude (aqueous) kola nut extract at 400, 600, and 800 mg/kg body weight orally, from pregnancy to day 21 after birth. On postnatal days 1, 7, 14, 21 and 28, the pups were weighed, anaesthetised, sacrificed and perfused with neutral buffered formalin. Their brains were dissected out, weighed and the cerebellum preserved in 10% buffered formalin. Paraffin sections of the cerebellum were stained with haematoxylin and eosin for cerebellar cytoarchitecture, cresyl violet stain for Purkinje cell count, Glial Fibrillary Acidic Protein (GFAP) immunohistochemistry (IHC) for estimation of gliosis, and B-cell lymphoma 2 (Bcl-2) IHC for apoptosis induction. The kola nut-treated rats exhibited initial reduction in body and brain weights, persistent external granular layer, increased molecular layer thickness, and loss of Bergmann glia. Their Purkinje cells showed reduction in density, loss of dendrites and multiple layering, and their white matter showed neurodegeneration (spongiosis) and GFAP and Bcl-2 over-expression, with evidence of reactive astrogliosis. This study, therefore, demonstrates that kola nut, administered repeatedly at certain doses to pregnant dams, could disrupt normal postnatal cerebellar development in their pups. The findings suggest potential deleterious effects of excessive kola nut consumption on human brain and thus warrant further studies to understand the wider implications for human brain development.
Highlights
While we found the effects of kola nut to be widespread in the brain, we investigated the cerebellum, as it is an important model for brain development and evolution and has a key role in sensory-motor processing, providing us an opportunity to demonstrate a proof of concept
There was evidence of impairment of motor control and posture in kola nut-treated dams, as they showed some difficulty in walking on the grid and flared their hind limbs when picked by the tails
Kola nut administration was for a total of 6 weeks, starting at mating, continuing through the 3 weeks of pregnancy, and ending 3 weeks after the pups were born (post-natal day (PND) 21), which was when the pups were weaned
Summary
Ethical approval for this project was obtained from the Institutional Animal Care and Use Committee, University of Ibadan, Nigeria (UI-ACUREC/APP/2015/009), and the use of animals in the study was consistent with internationally accepted standards for the welfare of, and. Sections were differentiated in 1% acid alcohol for thirty seconds, placed in Scott’s tap water for 1 min for bluing, counterstained with eosin for a minute, rinsed briefly in tap water and transferred to ascending grades of alcohol (70%, 95%) for two minutes each and into two changes of absolute alcohol for a minute each They were cleared in xylene and mounted in Dibutylphthalate Polystyrene Xylene (DPX) with cover slips in their wet state, at what stage they were ready for microscopic examination. Sections were counterstained with Haematoxylin solution for at least 2 min and blued briefly (1 min) by immersion in Scott’s tap water until the stain was intensified in the target nuclei They were dehydrated in alcohol, cleared in xylene and mounted in DPX.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
