Determinación de la actividad inhibitoria de acetilcolinesterasa y butirilcolinesterasa del extracto de alcaloides de Hippeastrum sp.

Abstract

The objective was to determine the inhibitory activity of acetylcholinesterase and butyrylcholinesterase from the alkaloidal extract of Hippeastrum sp., a plant species that belongs to the Amaryllidaceae family. The alkaloids were extracted by the process of maceration with organic solvents and pH changes with an extraction yield of 0.95%. To identify the alkaloids present in the bulb of Hippeastrum sp. Gas Chromatography coupled to Mass Spectrometry was performed. For the determination of the inhibitory activity of acetylcholinesterase and butyrylcholinesterase, the colorimetric method of Ellman et al. (1961), modified by Ortiz et al. (2016) was used, the reference compound being galantamine. The inhibitory activities were evaluated by varying the concentration of the cosolvent. Three consecutive repetitions were performed to obtain the enzyme inhibition curve with which equation of the line, the mean maximum inhibitory concentration (IC50) was calculated. In the gas chromatography coupled to mass spectrometry (GC-MS) 4 alkaloids were identified, the most representative being montanin with 22.7540 (ug gal/100 mg PS), followed by tazetine with 14.8693 (ug gal/100 mg PS), and in smaller quantity crinina and licorina with 10.99440 and 10.2120 (ug gal/100mg PS), respectively. The alkaloidal extract of Hippeastrum sp., showed a high inhibitory activity against acetylcholinesterase with an IC50 value of 7.25 ± 0.11 ug/ml, in relation to the reference compound galantamine with IC50 of 0.37 ± 0.03 ug/ml. The inhibitory activity against butyrylcholinesterase was moderately high with an IC50 of 105.06 ± 2.14 ug/ml, compared to galantamine that presented IC50 of 16.03 ± 0.77 ug/ml. It is observed that there is greater affinity for the acetylcholinesterase enzyme. Further studies on the species Hippeastrum sp. is recommended.