Chronic stress-induced neurodegenerative changes in Wistar rats: Hippocampal evidence and the mitigating effects of Allium Sativum

Abstract

Objective: Stress triggers a biological response perceiving a threat, chemicals and hormones surge throughout the body, after long-term exposure, stress accelerates cell ageing, immune senescence, and some age-related diseases such as neurodegenerative disorders and osteoporosis. This study finds possible effects of Allium sativum ethanolic extract on the hippocampus of chronic stress-induced neurodegenerative changes in male Wistar rats. Methods: Forty Wistar rats were grouped into eight of five (n=5). Group A - control group (no stress and treatment), Group B - 100mg/kg of Allium sativum (No stress), Group C - 250mg/kg of Allium sativum (No stress), Group D - 500 mg/kg Allium sativum (No stress), Group E - Stress alone + No treatment, Group F - 100mg/kg of Allium sativum (Stressed), Group G - 250mg/kg of Allium sativum (Stressed) and Group H - 500mg/kg of Allium sativum (Stressed), all for 14 days. Animals were euthanized humanely and the hippocampus was excised and fixed in 10% formalin solution for histological processing while the part used for biochemical assay was homogenized in phosphate buffer before centrifugation. Results: Chronic exposure of rats to stress elicited reduced body and brain weights, altered neurotransmitter levels and overall neurobehavioural functions, while also resulting in marked histomorphological distortions in the hippocampus. Interestingly, supplementation with Allium sativum significantly (p<0.05) mitigated biochemical, neurobehavioural, and hippocampal aberrations. Conclusion: Notably, data obtained from this study showed that Allium sativum may be a very effective adaptogen in curtailing the deleterious neurodegenerative changes associated with chronic stress.