# The Therapeutic Potential of Dalbergia pinnata (Lour.) Prain Essential Oil in Alzheimer’s Disease: EEG Signal Analysis In Vivo, SH-SY5Y Cell Model In Vitro, and Network Pharmacology

## TL;DR

This study explores how Dalbergia pinnata essential oil may help with Alzheimer’s by improving brain waves and reducing harmful proteins in cells.

## Contribution

The study is the first to combine EEG, cell models, and network pharmacology to evaluate Dalbergia pinnata essential oil for Alzheimer’s.

## Key findings

- DPEO inhalation increased brainwave power in frontal and parietal lobes, suggesting reduced anxiety and improved cognition.
- DPEO reduced Aβ, P-Tau, and inflammatory markers in an Alzheimer’s cell model.
- Network pharmacology linked DPEO to the JAK-STAT pathway as a potential mechanism.

## Abstract

Simple Summary: Plant essential oils are currently gaining increasing attention for their roles in mood regulation and neuroprotection. Dalbergia pinnata (Lour.) Prain (DP) is a traditional aromatic medicinal plant in China, primarily containing elemicin and methyl eugenol. Despite limited research, the potential neurological effects of aromatherapy are acknowledged, particularly in Alzheimer’s Disease. The pathogenesis of AD involves amyloid-beta (Aβ) deposition and Tau protein hyperphosphorylation, leading to neuronal dysfunction and inflammation. This study aims to document changes in brainwave power in male and female subjects following inhalation of DP essential oil (DPEO) and to investigate its impact on mood and brain function across genders. Additionally, the study examines the efficacy of DPEO in mitigating Aβ1–42-induced neurotoxicity using an in vitro Alzheimer’s Disease neural cell model.

Alzheimer’s disease (AD) is a neurodegenerative disorder that is projected by the WHO to affect over 100 million people by 2050. Clinically, AD patients undergoing long-term antipsychotic treatment often experience severe anxiety or depression in later stages. Furthermore, early-stage AD manifests with weakened α waves in the brain, progressing to diminished α and β waves in late-stage disease, reflecting changes in emotional states and disease progression. In this study, EEG signal analysis revealed that inhalation of Dalbergia pinnata (Lour.) Prain essential oil (DPEO) enhanced δ, θ, α and β wave powers in the frontal and parietal lobes, with a rising trend in the β/α ratio in the temporal lobe. These findings suggest an alleviation of anxiety and an enhancement of cognitive functions. Treatment of the AD SH-SY5Y (human neuroblastoma cells) cell model with DPEO resulted in decreased intracellular levels of Aβ, GSK-3β, P-Tau, IL-1β, TNF-α, IL-6, COX-2, OFR, and HFR, alongside reduced AchE and BchE activities and increased SOD activity. Network pharmacology analysis indicated a potential pharmacological mechanism involving the JAK-STAT pathway. Our study provides evidence supporting DPEO’s role in modulating anxiety and slowing AD pathological progression.