Memory-Enhancing Effects of Origanum majorana Essential Oil in an Alzheimer’s Amyloid beta1-42 Rat Model: A Molecular and Behavioral Study

Abstract

Origanum L. (Lamiaceae) is an important genus of medicinal and aromatic plants used in traditional medicine since ancient times as culinary herbs and remedies. The aim of the present study was to evaluate the chemical composition, as well as the biochemical and cellular activities of freshly prepared Origanum majorana L. essential oil (OmEO) in an Alzheimer’s disease (AD) amyloid beta1-42 (Aβ1-42) rat model. OmEO (1% and 3%) was inhaled for 21 consecutive days, while Aβ1-42 was administered intracerebroventricularly to induce AD-like symptoms. Our data demonstrate that OmEO increased antioxidant activity and enhanced brain-derived neurotrophic factor (BDNF) expression, which in concert contributed to the improvement of cognitive function of animals. Moreover, OmEO presented beneficial effects on memory performance in Y-maze and radial arm-maze tests in the Aβ1-42 rat AD model.

Ficus erecta Thunb. Leaves Ameliorate Cognitive Deficit and Neuronal Damage in a Mouse Model of Amyloid-β-Induced Alzheimer’s Disease

“…In our previous study, we performed Y-maze test to verify whether the locomotor activity is affected by Aβ infusion (Lim et al, 2018). According to many studies, Y-maze and open field tests are the most commonly used tests for locomotor activity of rodents by counting the number of entries to the maze arms (Yamada et al, 1999;Zhang et al, 2015;Heredia-López et al, 2016;Postu et al, 2020). Our results showed that Aβ-injected group was not differ from any other groups in total entry number of Y-maze test.…”

A behavioral and molecular study; ameliorated anxiety‐like behavior and cognitive dysfunction in a rat model of chronic unpredictable stress treated with oregano extract

“…Likewise, studies have revealed that oregano extract consumption improves learning and memory in normal rats, possibly owing to its antioxidant activity and inhibition of acetylcholinesterase (Ghaderi et al., 2020 ; Sheibani et al., 2011 ). In addition, the essential oil extracted from oregano has been shown to ameliorate cognitive dysfunction in Alzheimer's rats (Postu et al., 2020 ).…”

Pinus halepensis Essential Oil Ameliorates Aβ1-42-Induced Brain Injury by Diminishing Anxiety, Oxidative Stress, and Neuroinflammation in Rats

“…route has been used to establish the amyloid-beta feature of AD. Through stereotaxic surgery, 50 rats received 4 μL of Aβ1-42 suspension (1 mM, Sigma-Aldrich, Darmstadt, Germany) in the third cerebral ventricle via a well-established, previously described protocol [ 66 ]. The remaining 10 rats, corresponding to the sham group, received the same volume of saline following the same protocol.…”

“…The relative quantification of histone-associated DNA fragments was performed by using a cell death detection ELISA kit version 8 (Roche Diagnostics, Mannheim, Germany) as previously described [ 66 ]. The wells were first coated with antibodies directed against DNA and histone, and then the amygdala protein extracts were added.…”