Psidium guajava Ameliorates Pathological Alterations in the Hippocampus of ScopolamineInduced Alzheimers Disease Rats
Abstract
Alzheimer’s disease is one of the neurodegenerative diseases characterised by accumulation of hyperphosphorylated tau and amyloid ? in the brain pathologically and dementia as its manifestation. These pathological hallmarks lead to other histological alteration in the brain tissues. This study evaluated the ameliorative potential of Psidium guajava leaf methanol extract in the hippocampus of scopolamine-induced Alzheimer’s disease Wistar rats. P. guajava leaves were obtained from a garden in Agada1, Abua, prepared and extracted with N- hexane, methanol, and hydro-methanol. The phytochemical analysis indicated the presence of flavonoid, alkaloid, saponin, tannin, anthraquinone, glycoside and phlobatannin. These antioxidants were found to by higher in the methanol extract hence, was used for the administration. 80 male Wistar rats of weight 100 -120 g were divided into two phases with five groups in each (n = 8). Phase one lasted for 14 days while phase two took 84 days. Group 1 served as normal control and received distilled water (2 mL), group 2 (Alzheimer’s control) received 1 mg/kg bw scopolamine + 2 mL of distilled water, group 3 received 1 mg/kg scopolamine + 100 mg/kg of P. guajava leaf extract, group 4 received 1 mg/kg scopolamine + 300 mg/kg of P. guajava leaf extract and group 5 received 1 mg/kg scopolamine + 5 mg/kg of donepezil. The histological demonstration by H&E indicated marked pathological changes such as neuronal loss, pyknotic nuclei, neuroinflammation and distorted pyramidal cell layer in the CA3 region of the hippocampus of group 2 which worsened at the end of phase two of the study. Conversely, these pathological alterations were ameliorated by the two doses of the P. guajava leaf extract. P. guajava leaf may be a candidate for the treatment of AD as evident in the histological results.
Keywords
Alzheimer’s diseasePsidium guajavascopolamine
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