Abstract

Morinda lucida was found common in recipes given by Traditional Medical Practitioners in South Western Nigeria either as memory enhancer or anti-ageing. The oven dried leaves were extracted with 80% methanol and screened for both acetyl (AChE) and buteryl (BuChE) cholinesterase inhibitory activities. Fractionation of the crude extracts, followed by ethyl acetate bulk extraction, precipitation studies, phytochemical screening and anti-cholinesterase activity of the extracts and fractions are hereby reported. Both the precipitate and supernatant showed different coloured spots with vanillin in H₂SO₄ and were positive for terpenoids, anthraquinones and flavonoids while negative for alkaloids. The methanolic extract inhibited both AChE (40.15% ± 2.5) and BuChE (34.09% ± 1.93), and the activity resided more in the supernatant of the ethyl acetate fraction (82.35% AChE). This correlates with ethno medical claims and thus provides for the first time, the pharmacological basis for the folkloric use of M. lucida in the management of memory dysfunction in South Western Nigeria.

Key words: Morinda lucida, cholinesterase, acetyl (AChE), buteryl (BuChE).