Background: Alzheimer disease is a neurological disease related to age which is characteristic
of excess of oxidative stress and deficit level of acetylcholine in the brain. Centella asiatica (Linn.)
have several beneficial pharmacological activities such as antioxidant, anti-inflammatory and memory
Objective: To evaluate the phenolic contents, antioxidant and AChE inhibitory activities of different
fractions of Centella asiatica grown in Vietnam.
Methods: The leaves of Centella asiatica were extracted with ethanol 96% and fractionated with nhexane,
ethyl acetate and butanol solvents. These fractions were investigated the antioxidant activity by
DPPH assay and acetylcholinesterase (AChE) inhibitory activity by Ellman's colorimetric method.
Results: Our results showed that the total phenolic content of BuOH fraction was the highest, being
equivalent to 68.4 ± 2.4 mg quercetin/g of fraction. Our data also demonstrated that BuOH fraction had
the strongest antioxidant activity with IC50 of 7.76 ± 0.74 µg/mL and AChE inhibitory activity with an IC50
value of 36.31 ± 2.45 µg/mL in a concentration-dependent manner, followed by EtOAc fraction and nhexane
fraction with the weakest activity. Kinetic inhibition analysis indicated BuOH fraction of mixed
inhibition type with Ki (representing the affinity of the enzyme and inhibitor) of 34.36 ± 2.34 µg/mL.
Conclusion: Our data suggest that the BuOH fraction of Centella asiatica may be a promising source of
AChE inhibitors for Alzheimer's disease.