Smokeless Tobacco Induces Astrocyte Activation in The Hippocampus of Male Wistar Rat
Obot, Joseph Ime *
University of Port Harcourt, Port Harcourt, Rivers State, Nigeria.
Okoseimiema, Sonny Clement
University of Port Harcourt, Port Harcourt, Rivers State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Smokeless tobacco has been used widely in our villages and rural communities, most especially to ease stress and improve the mood of the users. Its use has been established by literature to elicit several health outcomes. Despite the negative health effects associated with smokeless tobacco, grasping its usage and effects is complicated due to the broad range of products and user-specific habits. This variety renders it incorrect to generalise about these products as a single entity across different regions and countries. Few researches have already been done to establish or refute its cognitive ability in different parts of the world, bearing in mind its wide variability. Its neurodegenerative tendencies have also been mentioned in pockets of literature. These neurodegenerative tendencies can be explained further using an immunohistochemical assay of hippocampal tissue. This research evaluated the immunohistochemistry of the CA1 region of the hippocampus of adult male Wistar rats following the consumption of smokeless tobacco.
24 adult male Wistar rats were randomly assigned to four groups: groups I, II, III, and IV. Group I received only distilled water, group II received 20 mg/kg, group III received 30 mg/kg, and group IV received 40 mg/kg of the aqueous extract of smokeless tobacco orally through oral gavage. The duration of the administration lasted for 33 days. On days 3 and 33, the rats were sacrificed to extract the brain tissue for glial fibrillary acidic protein (GFAP) immunohistochemical assay.
Reactive astrocytes exhibit extensive synthesis of GFAP, implying that increased GFAP expression and upregulation are strong markers for reactive astrogliosis. GFAP upregulation was observed in the micrograph of CA1 region of the hippocampus for groups III and IV. The observed astrocytes in those micrographs were enlarged with longer processes as compared to those in the group I micrograph. The observed features in the group III and IV micrograph suggest possible dose-dependent reactive astrogliosis.
Keywords: Astrocyte, glial fibriliary acidic protein, hippocampus, smokeless tobacco, neurodegeneration