essp04

EPSA Students' Science Publication
Studies regarding the protective
effects exerted by some anti-Alzheimer
molecules on endothelial cells
Alexandra Cătălina Bogzeanu coordinated by PhD. Denisa Margină,
Biochemistry Department, Faculty of Pharmacy, University of Medicine and Pharmacy,
Bucharest, Romania
Alzheimer’s disease (AD) is one of the most frequent neurodegenerative
disorders. Cholinesterase inhibitors (AChE) such as rivastigmin and donepezil
and the partial NMDA receptor antagonist (memantine) are currently used as
treatment for AD. In the synaptic gap between the affected neurons there is
a constant hypersecretion of glutamate which leads to an excessive calcium
uptake in the existing channels of NMDARs. The postsynaptic membrane is
always depolarized and has an impaired function.
Recent studies suggest that effects of AChE inhibitors are not limited to
their cholinergic activity; other mechanisms including inhibition of glutamate
excitotoxicity, thereby reducing inflammatory processes, have been proposed
as ways of action. Prolonged and sustained inflammation may have cytotoxic
effects. MCPs (produced during inflammation) are associated to neuronal
death.
The aim of this study was to reveal the effect induced by donepezil, rivastigmine
and memantine on the LDH activity (indicating the membrane damage), on
the susceptibility of membrane cells to lipid peroxidation and on the MCP-1
synthesis, using EaHy96 endothelial cells as study model.
Cells were treated with rivastigmine, memantine and donepezil using 10 µM,
20 µM and 50 µM concentrations. The LDH assay was performed based on
the kinetic UV evaluation of NADH transformation (in the process of oxidizing
lactate to pyruvate).
For the assessment of the lipid susceptibility to peroxidation DPPP was used, a
probe that lacks fluorescence but has high affinity for lipids. DPPP labelled cells
were treated with CuOOH to induce DPPP-oxide formation (highly fluorescent
compound). The process was assayed by performing a fluorescence emission
spectrum. The ELISA method was used for detecting the MCP-1 synthesis.
Results: The three substances do not significantly reduce the LDH activity,
having a protective effect on the mitochondrial metabolism. The three tested
substances do not influence the susceptibility to lipid peroxidation which
means the three substances do not modify the redox equilibrium and thereby
do not act as antioxidants. Also, the study demonstrated that they have the
ability to reduce MCP-1 synthesis, memantine being the one with the most
powerful effect and reduction was seen with all tested concentrations.
Conclusion: The three tested drugs have a protective effect and do not induce
cellular death. This effect can be interpreted in correlation with the cardiovascular
disease, which appears especially at elderly.
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