Abstract:
BACKGROUND : Natural products, including those derived from higher plants have, over the years, contributed greatly
to the development of modern therapeutic drugs. Due to the medicinal importance in traditional practice and the
diversified biology and chemistry of the constituents from Artemisia spp., the genus has been receiving growing
attention. The aim of this study was to investigate the ability of the ethanol extract, four fractions (F1–F4) and five
compounds namely artemisinin (1), scopoletin (2), chrysosplenetin (3), eupatin (4) and 3-O-β-d-glucopyranoside of
sitosterol (5) isolated from A. annua to modulate the activity of anticholinesterase (AchE) and the production of nitric
oxide (NO) in LPS-activated RAW 264.7 macrophages.
RESULTS : At the lowest concentration tested (6.25 μg/mL), the crude extract and fraction F2 had the highest NO
inhibitory activity (72.39 and 71.00 % inhibition respectively) without significant toxicity on the viability of macrophage
cells (93.86 and 79.87 % of cell viability respectively). The crude extract inhibited AchE activity by 71.83 % (at
1 mg/mL) with an IC50 value of 87.43 μg/mL while F2 and F4 were the most active fractions (IC50 values of 36.75 and
28.82 μg/mL). Artemisinin (1) and chrysosplenetin (3) had the highest AChE activity with 71.67 and 80.00 % inhibition
(at 0.1 mg/mL) and IC50 values of 29.34 and 27.14 μg/mL, respectively.
CONCLUSION : Our results validate the traditional use of A. annua and could help to support the usefulness of this plant
in the treatment of inflammatory and neurological disorders especially where nitric oxide and a cholinesterase are
involved.
