Dada, M. M.; ADELODUN, S. T.; AWOLUSI, O. E.

Parkinson disease is a progressive neurodegenerative disorder contributing to cognitive decline and memory impairment beyond its characteristic motor deficits. Rotenone, a mitochondrial complex I inhibitor, reliably reproduces both the motor and non-motor features of Parkinson disease in experimental models. Tiger nut (Cyperus esculentus) is a commonly consumed plant known for its antioxidant and anti-inflammatory properties; however, its neuroprotective efficacy against rotenone-induced hippocampal damage is not yet fully elucidated. This study, therefore, evaluated the neuroprotective efficacy of tiger nut-infused diet on the hippocampus in a rotenone-induced Parkinson disease model using male Wistar rats. Thirty-two male Wistar rats weighing between 100 g to 150 g were obtained from the Animal Holding facility of Babcock University, Ilishan-Remo, Ogun State. The rats were randomly assigned into four groups (A, B, C and D) (n = 8). Group A served as the control and received normal rat chow and sunflower oil. Group B received tiger nut-infused diet only. Group C received rotenone (2 mg/kg) intraperitoneally. Group D received rotenone (2 mg/kg) concurrently with tiger nut-infused diet for 28 days. Neurobehavioral assessments were conducted using the open field test and Y-maze tests. Oxidative stress biomarkers, including malondialdehyde, catalase, and glutathione, were assayed from hippocampal homogenates, and gamma-aminobutyric acid was measured as a neurotransmitter parameter. Histological evaluation was performed using hematoxylin and eosin for general cytoarchitecture, Cresyl Fast Violet for Nissl substance integrity, and Luxol Fast Blue for myelin visualization. Data were analyzed using One-way ANOVA followed by the Student Newman-Keuls post-hoc test on GraphPad Prism 9.0, with significance set at p [≤] 0.05. Rotenone administration produced significant impairments in locomotor activity and spatial working memory, reduced catalase activity, and caused marked histopathological alterations in the hippocampus, including neuronal vacuolation, chromatolysis, and myelin disruption. Tiger nut-infused diet partially attenuated these effects, most notably by enhancing catalase activity and preserving hippocampal cytoarchitecture compared to the rotenone-only group. This study concludes that tiger nut-infused diet demonstrates partial neuroprotective potential against rotenone-induced hippocampal neurotoxicity, with implications for dietary intervention in Parkinson-like disease-related cognitive decline. Further studies involving phytochemical screening of the tiger nut-infused diet are recommended to identify and isolate the specific active ingredient responsible for its neuroprotective effects, enabling investigation of its mechanisms of action at the molecular level.