Evaluación de la actividad inhibitoria del extracto alcaloidal de Phaedranassa glauciflora sobre acetilcolinesterasa y butirilcolinesterasa.

Abstract

The present investigation aims to determine the inhibitory activity of the alkaloidal extract of Phaedranassa glauciflora on the cholinesterase enzymes AChE and BuChE. The vegetal species of study belongs to the Amaryllidaceae family. A maceration process with methanol was performed to obtain the crude extract of the dry bulb, obtaining a percentage of alkaloid yield of 0.3% and the extraction of them was carried out by means of an extraction protocol based on pH changes and use of organic solvents. To identify the alkaloids present in the bulb of Phaedranassa glauciflora, Gas Chromatography coupled to Mass Spectrometry was performed, which allowed to determine the percentages of each one. The evaluation of the inhibitory activity was developed based on the modified methodology of Ellman et al., having as a reference compound galantamine. GC-MS showed a total of 10 identified alkaloids, being those of significant abundance liquorine (75.01%) and sternbergine (8.66%); in addition 3 alkaloids not yet identified were found (m/z 228*a;[M=33]*b,m/z228*a; [M=289]*b y m/z125*a). The alkaloid extract of Phaedranassa glauciflora showed an inhibitory activity on AChE expressed as IC50 from 39,94 ± 5,09 ug/mL, and the galantamine reference compound for the same enzyme presented an IC50 from 0,30 ± 0,01 ug/mL. With respect to the inhibitory activity on BuChE, the alkaloidal extract presented an IC50 of 323,62 ± 3,51 ug/mL, while galantamine exhibited an IC50 of 5,67 ± 0,08 ug/mL. In both cases, the alkaloidal extract of the species does not exceed the inhibitory activity of the galantamine referential compound, but it can be observed that there is a greater affinity for the AChE enzyme. It is recommended to carry out more studies of the species belonging to the genus Phaedranassa since the metabolite profile that it shows has interesting pharmacological activities.