Chemical inhibition of acetyl-cholinesterase has been the major strategy for the management of nerve-signaling related diseases like Alzheimer’s disease. Limited treatment options have driven the research into extracts from indigenous plants. In this study, the chemical constituents, anti-cholinesterase and radical scavenging potentials of the essential oil and the decoction water of a Nigerian variety of the medicinal plant, Hyptis suaveolens (L.) Poit were investigated. Essential oil from the leaves of the medicinal plant was obtained through Hydro-distillation and the chemical composition was determined using gas chromatography-mass spectrometry (GC-MS). Radicals scavenging activity potential and acetyl-cholinesterase inhibition activity were carried out using colorimetric method. The GC-MS analysis revealed 24 chemical compounds including ?-Caryophyllene (15.31%), ?-Phellandrene (9.73%), trans-?-Bergamotene (6.94%) and Fenchone (5.79%) as major components. The phytochemicals present in the polar constituent (the decoction water) of the leaves of H. suaveolens were alkaloids, glycosides, flavonoid, tannins, steroids, terpenoids and saponins. Bioactivity assessment revealed significant antioxidant activities in essential oil extracts with values ranging from (DPPH = 38.80 ± 0.04 to 69.33 ± 0.12 %, ABTS = 2.84 ± 0.01 to 11.26 ± 0.26 mg TEAC /g, FRAP = 10.89 ± 0.01 to 15.79 ± 0.33 mg AAE /g and NOx = 26.06 ± 0.03 to 71.87 ± 0.21 %). Higher acetyl-cholinesterase inhibition activity was recorded for the essential oil compared to the polar constituents with values ranging from 10.42 ± 0.12 to 46.50 ± 0.19 %. Findings from this study highlight the antioxidant and anticholinesterase potential of extracts from Hyptis suaveolens (L.) Poit.

Keywords: Essential oil, Bioactivity, ?-Caryophyllene, Decoction Water