Author(s): Hayk Harutyunyan, Svetlana Sharoyan, Alvard Antonyan and Sona Mardanyan

Abstract: The aggregates of Aβ(1-40) and Aβ(1-42) peptides are considered as the pathological hallmarks of Alzheimer's disease. The present work examined the ability of several plant preparations to protect the viability of hippocampal cells in the presence of aggregated Aβ peptides. The inhibition of the viability of rat hippocampal cells by the preliminarily aggregated peptides down to 20±2.5% of control was proved. In the presence of aggregated Aβ peptides, the cell viability was saved at 51-114% of control in the medium containing the ethanol extracts from grape and sorrel leaves, rose petals, melilot, phenol glycoside and flavonoid fractions from these extracts. The DNA-comet analysis evidenced the cell integrity conserving by the extracts, but not by the phenol glycoside fraction from rose petals, which significantly protected the cell viability from aggregated Aβ(1-40) and Aβ(1-42) (IC₅₀ = 0.2 ± 0.02 and 2.1 ± 0.7 µg/ml, respectively). Conclusion: the studied plants can be considered as sources for neuroprotecting agents.