Neurocognitive investigation of Morinda tinctoria against amyloid beta-induced oxidative insult and cognitive impairment in albino mice: A phytotherapeutic approach

Background: Alzheimer's is a progressive neurodegenerative disorder characterized by cognitive declination associated with several clinicopathological changes. Due to consistent drawback in the conventional therapy, now the attentions toward herbal therapeutics have been increased in recent times. Morinda tinctoria Roxb (MT) is a novel medicinal herb reported with versatile therapeutic activity. Still now, there is no proper scientific data available to confirm its efficacy against neurodegeneration. Objectives: The objective of the present research is to investigate the neurocognitive enhancing potential of MT against amyloid beta (Aβ) (25–35)-induced memory dysfunction in mice. Materials and Methods: Animals were pretreated with ethanol extract of MT (EEMT) and standard donepezil followed by single intracerebro ventricular injection of Aβ25–35. Estimation of antioxidant enzymes, metabolic enzymes, and neurotransmitters was performed along with quantification of inflammatory cytokines using quantitative polymerase chain reaction method. Results: The outcome of the study clearly indicates that treatment with EEMT (200 and 400 mg/kg) and donepezil (5 mg/kg) had significantly ameliorated the cognitive stress induced by Aβ25–35, which was evident from the data obtained from memory and learning task. There was a sequential decrease in pro-inflammatory cytokines such as interleukin (IL)-6, tumor necrosis factor, IL-1, and nuclear factor-κ level in EEMT and donepezil treated groups. Histological finding of the samples belonging to EEMT and donepezil treated groups reveals the presence of dense network of pyramidal cell in CA layers with increased number of granular cells aligned on the dentate gyrus zone of the hippocampi. Conclusion: Neurotherapeutics from the herbal origin advocates the potential therapeutic efficacy against Alzheimer's and may become novel entity in the clinical management of neurodegenerative diseases.