Multi-Component Xinjiang Basil Essential Oil Mitigates Alzheimer’s Disease-like Pathology Through Amyloid and Neuroinflammatory Modulation

Background: Basil (Ocimum basilicum L.) is a herbaceous plant belonging to the family Lamiaceae. It is not only edible, but it also has nutritional value and can be used for medicinal purposes. Previous studies suggest that basil-derived extracts may protect neurons from injury. Objectives: Our research aimed to investigate whether basil essential oil (BEO) from Xinjiang has a neuroprotective effect in Alzheimer’s disease (AD)-like pathological mouse model and to elucidate the mechanism underlying this effect. Methods: The essential oil was extracted using steam distillation. UHPLC–MS/MS technology was used to identify constituents detected in brain tissue following intranasal administration. In the experiment, BEO was administered intranasally to APP/PS1 mice for 4 weeks, and its therapeutic effects on AD-like pathological features were evaluated through behavioral and biochemical assessments. Results: The results showed that there were 787 compounds in the BEO, of which 30 putatively annotated compounds were detected in brain tissue after intranasal administration. Most of these were prenol lipids (36%). BEO markedly enhanced spatial learning and cognitive abilities in APP/PS1 mice, while also reducing neurodegeneration within the hippocampus and decreasing Aβ1–40 and Aβ1–42 levels. BEO additionally lowered the levels of IL-1β, IL-6, and TNF-α and inhibited the activation of astrocytes and microglia. BEO exerted its neuroprotective effects by reducing the activation of the IκB-α/NF-κB pathway. Conclusions: BEO exerted neuroprotective-like effects in this AD mouse model accompanied by anti-inflammatory activity and suppression of amyloid-β (Aβ) accumulation, and BEO treatment was associated with reduced IκB-α/NF-κB pathway activation. This research demonstrated that BEO might serve as a natural treatment against AD.