Schinus molle L. (Anacardiaceae) has been traditionally used for conditions related to the nervous system and emotional well-being, often through aromatic preparations. However, its cognition-specific Show more
Schinus molle L. (Anacardiaceae) has been traditionally used for conditions related to the nervous system and emotional well-being, often through aromatic preparations. However, its cognition-specific effects have not yet been investigated. To assess the cognitive effects of the fruit-derived essential oil of Schinus molle L. (SMEO), administered via oral and inhalation routes, in a rat model of scopolamine-induced amnesia. SMEO was obtained by hydrodistillation and characterised by GC-MS/GC-FID. Amnesic rats received SMEO for 14 days by inhalation (1% or 3%) or oral gavage (100 or 200 mg/kg). Cognition was assessed by Morris water maze (MWM), passive avoidance (PA), and novel object recognition (NOR) tests; locomotion was measured by activity-meter. Hippocampal BDNF and GFAP immunoreactivity were assessed by immunohistochemistry. SMEO was dominated by α-phellandrene (48.7%). Scopolamine impaired cognition, whereas SMEO attenuated deficits with efficacy comparable to piracetam. Key behavioural and immunohistochemical findings (main omnibus statistical effects) were as follows: In the MWM, treatment and time effects on escape latency were significant (both p < 0.001), and probe performance improved (p < 0.001). PA retention was restored (p < 0.001) and the NOR index improved (p < 0.001), without locomotor changes (all p > 0.05). Scopolamine reduced hippocampal BDNF immunoreactivity in CA1 and DG (p < 0.01) and CA3 (p < 0.001), which was restored by SMEO via both routes. GFAP immunoreactivity was reduced in CA1/CA3/DG (all p < 0.001) and was rescued selectively after inhalation. These findings provide preclinical evidence consistent with an ethnopharmacological rationale for SMEO and support further translational work to clarify its relevance beyond this experimental paradigm. Show less