SCREENING OF ACETYLCHOLINESTERASE INHIBITORY ACTIVITY IN ESSENTIAL OIL FROM MYRTACEAE

Objective: This research was to investigate acetylcholinesterase inhibitory activity of the essential oil from Myrtaceae and its components. Methods: The essential oils were extracted from fresh leave of Myrtaceae plants: Eucalyptus globulus Labill (Eucalyptus), Melaleuca cajuputi Powell (Samed-Khao), Melaleuca citrina (Curtis) Dum. Cours (Bottle brush tree), Psidium guajava Linn. (Gauva), Syzygium cumini (L.) Skeel (Wha) and Syzygium samarangense (Blume) Merr&L.M.Perry (Chompoo Nam Dok Mai) by hydrodistillation and analyzed chemical constituent by gas chromatography. The acetylcholinesterase inhibition was determined based on Ellman’s method. Results: The essential oil from M. citrina presented the greatest inhibitory activity (71.77%) and followed by E. globulus (47.65%), P. guajava (24.96%), M. cajuputi (21.18%), S. cumini (19.97%) and S. samarangense (13.78%) respectively. α-Pinene was found in the essential oil of 6 species.  1,8-Cineole was the main compound of the essential oil from M. citrina and act as an active constituent on AChEI. The essential oil from M. cajuputi , S. cumini and S. samarangense contained a small amount of α-pinene and without 1,8-cineole, then they were less potency on AChEI. Conclusion: The essential oil containing higher amount of 1,8-cineole presented strong activity to inhibit the acetylcholinesterase. Moreover, there are also other constituents in the essential oils that may affect the acetylcholinesterase inhibitor activity and also present synergistic effect for acetylcholinesterase inhibitor.