Determinación de la actividad inhibitoria de acetilcolinesterasa y butirilcolinesterasa del extracto de alcaloides de Crinum x amabile.

Abstract

The present research aimed to determine the inhibitory activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) of the alkaloids extract of the plant species Crinum x amabile, belonging to the family Amaryllidaceae. From the crude extract obtained by maceration in methanol of the dried and crushed bulb, it was used an alkaloid extraction protocol based on changes in pH nd use of organic solvents. The purified extract was analyzed by Gas Chromatography coupled to Mass Spectrometry (GC-MS). The inhibitory activity of AChE and BuChE was determined by the modified method of Ellman, in which the necessary conditions to carry out the analysis were established. In total, 18 alkaloids of Amaryllidaceae were identified, being lycorine the most abundant with a percentage of 44.01%, followed by assoanine with 11.63%; in addition, the presence of galanthamine type alkaloids; and 3 unidentified alkaloids (m/z 287, m/z 315, m/z 280). The enzyme inhibition results of the alkaloid extract were expressed as IC50 values, showing a significant acetylcholinesterase inhibitory activity (IC50 2.24 ± 0.01 μg/mL), a result close to the reference compound galanthamine (IC50 0.27 ± 0.03 μg mL). On the other hand, a weak inhibition of butyrylcholinesterase (IC50 116.59 ± 2.85 μg/mL) was showed, observing less activity than the reference compound (IC50 4.88 ± 0.17 μg/mL). This result evidences a low selectivity of the alkaloids of the extract towards this enzyme. This plant species is considered as a possible candidate for the search for new selective inhibitors of AChE, with a potential use for the treatment of Alzheimer's disease. For this reason, it is recommended to carry out more phytochemical and pharmacological studies of Crinum x amabile.