Abstract
Origanum spp. are used both for culinary purposes and for their biological activities. In
this study, commercial Origanum majorana, Origanum minutiflorum, Origanum vulgare,
and Origanum onites essential oils and their prominent constituent carvacrol were evaluated for their
in vitro and in silico angiotensin-converting enzyme 2 and
lipoxygenase enzyme inhibitory potentials. The essential oils were analysed by gas
chromatography-flame ionisation detection and gas chromatography-mass spectrometry,
where carvacrol was
identified as the major component (62 – 81%), confirming the quality. In vitro enzyme inhibition assays were conducted both with the essential oils (20 µg/mL) and
with carvacrol
(5 µg/mL). The comparative values of angiotensin-converting enzyme 2 percent inhibition
for O. majorana, O. minutiflorum, O. vulgare, and O. onites essential oils were
determined as 85.5, 79.1, 74.3, and 42.8%, respectively. As a result of the enzyme
assays, carvacrol showed 90.7% in vitro angiotensin-converting enzyme 2 inhibitory activity. The
in vitro lipoxygenase inhibition of the essential oils (in the same order) was 89.4, 78.9,
81.1, and 73.5%, respectively, where carvacrol showed 74.8% inhibition. In addition,
protein–ligand docking and interaction profiling was used to gain structural and mechanistic
insights into the angiotensin-converting enzyme 2 and lipoxygenase inhibitory potentials
of major
Origanum essential oil constituents. The in silico findings agreed with the significant enzyme inhibition activity observed in vitro. Further in vivo studies are
suggested to confirm the safety and efficacy of the oils.
Key words
Lamiaceae -
Origanum spp. - essential oil - ACE2 - LOX - carvacrol
