In Vitro Acetylcholinesterase Inhibitory and Antioxidant Activity of Alphonsea tonkinensis A.DC

Abstract

Knowledge of the bioactivity of Alphonsea tonkinensis A.DC is limited. We have investigated the in vitro acetylcholinesterase inhibitory and antioxidant activities of extracts and pure compounds isolated from stems and leaves of this species collected from Dakrong district, Quang Tri Province, Vietnam. Extracts and isolated compounds were obtained by using an in-house extraction and chromatographic technique. The in vitro acetylcholinesterase inhibitory and antioxidant activities were evaluated using an Ellman test and 2,2-diphenyl-1-picryl-hydrazyl test, respectively. The total MeOH and CH2Cl2 extracts, the MeOH portion of the CH2Cl2 extract, pseudocolumbamine, and pseudopalmatine showed potential inhibitory activity against acetylcholinesterase with IC50 values of 22.7, 32.9, 14.6, 18.9, and 8.6 μM, respectively. The aqueous phase (pH 9), MeOH portion of the CH2Cl2 extract, and N-trans-feruloyltyramin exhibited significant antioxidant activities with IC50 values of 24.5, 72.1, and 61.2 µM, respectively. This is the first study showing such bioactivities of various extracts obtained from A. tonkinensis.