Tannoid principles of Emblica officinalis renovate cognitive deficits and attenuate amyloid pathologies against aluminum chloride induced rat model of Alzheimer's disease

Abstract

Background/aims: Emblica officinalis is mentioned as a maharasayana in many Ayurvedic texts and promotes intelligence, memory, freedom from disease, longevity, and strength of the senses. The present study has been designed to explore the memory-enhancing effect of the tannoid principles of E. officinalis (EoT) at the biochemical, anatomical, behavioral, and molecular levels against aluminum chloride (AlCl₃) induced Alzheimer's disease (AD) in rats. Aluminum is reported to have an important role in the etiology, pathogenesis, and development of AD.

Methods: Male Wistar rats were divided into control, AlCl₃ treated, AlCl₃ and EoT (50, 100, and 200 mg/kg bw) co-treated, and EoT (200 mg/kg bw) alone treated groups. In control and experimental rats, behavior tests including water maze and open field test, estimation of aluminum, assay of acetylcholinesterase (AChE) activity, and expression of amyloidogenic proteins were performed.

Results: Intraperitonial injection of AlCl₃ (100 mg/kg bw) for 60 days significantly elevated the concentration of aluminum (Al), activity of AChE and protein expressions of amyloid precursor protein, A-beta₁₋₄₂, beta-, and gamma-secretases as compared to control group in hippocampus and cortex. Co-administration of EoT orally to AlCl₃ rats for 60 days significantly revert back the Al concentration, AChE activity, and A-beta synthesis-related molecules in the studied brain regions. The spatial learning, memory, and locomotor impairments observed in AlCl₃ treated rats were significantly attenuated by EoT.

Conclusion: Therefore, EoT may be a promising therapy in ameliorating neurotoxicity of aluminum, however further studies are warranted to elucidate the exact mechanism of action of EoT.

Keywords:

• Alzheimer's disease
• AlCl₃
• Emblica officinalis
• Tannoid principles
• A-beta peptide
• Memory
• AChE

Acknowledgements

We gratefully acknowledge the Indian Herbs Research & Supply Company, Saharanpur, India for the generous supply of standardized extract of E. officinalis tannoids. Financial assistance in the form of a major research project from the University Grants Commission, New Delhi, is gratefully acknowledged.

Disclaimer statements

Contributors None.

Funding None.

Conflicts of interest None.

Ethics approval This study was approved by the Animal Ethics Committee of the Institute (Reg. No. 160/1999/ CPCSEA, Proposal No. 1016).