Résumé:
Earlier studies have reported that oxidative damages play an important role in
development of neurodegenerative diseases like vascular dementia, stroke and Alzheimer’s
disease (AD).This later is the most neurodegenerative disorder affecting people in the world
due to the formation of β-amyloid plaques, which are probably formed by cholinesterase
enzymes; acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). AChE is known as
specific cholinesterase and it is usually present in the brain, while BChE is known as
pseudocholinesterase and it is present in the peripheral. However, inhibitors of AChE and
BChE increase the levels of acetylcholine in the brain and are used as therapeutic molecules
for AD. This work aimed to study the chemical composition, cholinesterase inhibitory activity
of the essential oil from leaves Lawsonia inermis Linn commonly known as “henna” recolted
from Algerian Sahara. The essential oil (EO) was obtained through steam distillation. The
chemical composition of the essential oil was evaluated by gas chromatography, coupled to
mass spectrometry (GC–MS) and the inhibition of cholinsterase was evaluated by the capacity
of the inhibition of the two enzymes involved the Alzheimer diseases acetylcholinesterase
(AChE) and butyrylcholinesterase (BuChE).The analyses led to the identification of essential
oil compounds which obtained with a yield of 0.2%. Leaves essential oil showed interesting
selective inhibitory activity against both enzymes AChE (25.2 ± 0.01µg/mL) and BuChE
(29.8 ± 0.02µg/mL). By contrast, the EO of the leaves showed moderate mean inhibitory
activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), with IC50
values of 21.2 ± 0.15µg/mL and 37.4 ± 0.11 µg/mL, respectively. The results of this present
study support the uses of Lawsonia inermis in traditional medicine and enhance the use of its
essential oil in phytomedicines
