Fraccionamiento bio-guiado de Chaptalia nutans (L.) Pol. (Asteraceae) y su efecto inhibidor de acetilcolinesterasa

ROBLEDO ALMONACID, J.E; DÍAZ BRAVO MJ; BUSAJM D; CARLINI, V.P; VALLEJO, M.G.

San Juan

Jornada; XLI Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2023

Sociedad de Biología de Cuyo

Chaptalia nutans (L.) Pol. (Asteraceae) is a species used in Guarani folk medicine (Argentina) to ameliorate centra cognitive functions, mainly as an antidepressant. Bearing in mind the relationship between depression and memory, the aim of the present work is to explore the potential nootropic, or memory and learning enhancing effects, of C. nutans secondary metabolites. To achieve this goal, the inhibitory effect on acetylcholinesterase (AChE), an enzyme targeted in cognitive decline, was evaluated. Whole parts of C. nutans, dried and ground (116 g), were extracted by decoction, according to FA 7th Ed. Polysaccharides present in the aqueous extract were separated by precipitation using 5% EtOH and filtration to obtain the working fraction (Cn, 3.12 g). Cn purification was carried out by means of a silica-gel chromatographic column, using a gradient of increasing polarity solvents (hexane, ethyl acetate and methanol). Six fractions (from CnFr-A to CnFr-F) were obtained and their AChE inhibitory effects evaluated using the Ellman’s method, at initial time (t=0) and 30 minutes later (t=30). For the active fractions, the IC50 was determined by using the concentration range: 0.1- 50 µg/mL. Phytochemical profile of the fractions was analyzed by UPLC-MS/MS in which the presence of nutanocoumarins were found in each fraction, except in the last one. It was determined that CnFr-A fraction was the only one that exerted a potent inhibitory action (IC50: 4.07 μg/mL, t=0 and 7.76 μg/mL, t=30) which makes it an interesting candidate to be studied deeply its chemical composition, in order to find a potential drug with nootropicactivity.