INVESTIGADORES
MINAHK Carlos Javier
congresos y reuniones científicas
Título:
Enriched polyphenol extracts derived from grape pomace exert differential inhibition on membrane-bound and soluble acetylcholinesterase activity
Autor/es:
SALAZAR PB; FANZONE M; DUPUY F; RODRIGUEZ VAQUERO MJ; MINAHK C
Lugar:
Lima
Reunión:
Congreso; Revisiting the Central Dogma of Molecular Biology at the Single-Molecule Level. Biophysical Society Thematic Meetings; 2019
Institución organizadora:
Biophysical Society
Resumen:
In this work, the possible inhibition of acetylcholinesterase by phenolic compounds present in methanolic extracts of grape pomace was studied. For that purpose, the human erythrocyte acetylcholinesterase (AChE-E), a membrane-bound variant, was chosen as the model enzyme.The phenolic compounds were significantly less effective in inhibiting AChE-E in its soluble form. To gain a better understanding of the molecular interactions between phenolics with membrane lipids, several biophysical measurements were performed, such as quenching of octadecyl rhodamine B (R18) fluorescence by increasing concentrations of phenolic compounds. The quenching of R18 allowed us to assess the interaction of phenolic compounds with the interfacial region of the membrane. Besides, changes in osmotic resistance of erythrocytes in the presence of polyphenols were also tested. This analysis was complemented with the study of the protective effect of the bilayer to micelle detergent-mediated transition of liposomes. The interaction of each phenolic compound with the lipid moieties of membranes was assessed byinfrared spectroscopy, using lipids purified from erythrocyte ghosts and synthetic lipids. To sum up, it was shown that these flavonoids may bind to the red blood cell membrane, which in turn may improve the interaction between polyphenols and AChE. Actually, the differential inhibition of the membrane-bound and the soluble AChE variants by the pomace polyphenols could be explained as either a direct and differential interaction of the phenolic compounds with these isoforms or as the consequence of an indirect effect. In the latter scenario, the enzyme may be inhibited upon alteration of the lipid phase. Even though we cannot rule out a direct interaction of phenolic compounds with AChE, our results allow us to conclude that the polyphenols tested did interact with lipids and this could explain, at least partially, the inhibition of the AChE activity