Natural essential oils derived from herbal medicines: A promising therapy strategy for treating cognitive impairment

Abstract

Cognitive impairment (CI), mainly Alzheimer’s disease (AD), continues to increase in prevalence and is emerging as one of the major health problems in society. However, until now, there are no first-line therapeutic agents for the allopathic treatment or reversal of the disease course. Therefore, the development of therapeutic modalities or drugs that are effective, easy to use, and suitable for long-term administration is important for the treatment of CI such as AD. Essential oils (EOs) extracted from natural herbs have a wide range of pharmacological components, low toxicity, and wide sources, In this review, we list the history of using volatile oils against cognitive disorders in several countries, summarize EOs and monomeric components with cognitive improvement effects, and find that they mainly act by attenuating the neurotoxicity of amyloid beta, anti-oxidative stress, modulating the central cholinergic system, and improving microglia-mediated neuroinflammation. And combined with aromatherapy, the unique advantages and potential of natural EOs in the treatment of AD and other disorders were discussed. This review hopes to provide scientific basis and new ideas for the development and application of natural medicine EOs in the treatment of CI.

Enhancing Sleep Quality through Aromatherapy: Updating the Therapeutic Benefits of Essential Oils

“…These oils, known for their aromatic properties, have a long history of use in treating cognitive and mental disorders across various cultures. Modern research corroborates their effectiveness in improving cognition and mitigating symptoms of cognitive impairment [1].…”

Essential Oil Constituents as Anti-Inflammatory and Neuroprotective Agents: An Insight through Microglia Modulation

“…Essential oils (EOs) and their constituents are recognised for their potential cognitiveenhancing effects, which involve attenuating the neurotoxicity of Aβ, reducing oxidative stress by scavenging reactive oxygen species (ROS), modulating the central cholinergic system, and regulating microglia-mediated neuroinflammation [35]. Demonstrating antiinflammatory properties, EOs can reduce microglial activation and proinflammatory responses, thereby mitigating the detrimental effects of inflammation on neuronal cells [36].…”

“…The Nrf2 pathway mediated the effect of linalool in cultured BV2 microglia cells exposed to LPS, thus producing noticeable concentration-dependent anti-inflammatory action [87]. More precisely, linalool causes the translocation of Nrf2 to the nucleus, leading to the increased production of HO-1 and, consequently, to a decrease in inflammatory mediator (TNF-α, IL-1β, NO, and PGE2) production through the inhibition of gene expression [35]. Additionally, linalool decreases NF-kB signalling pathway activation by reducing chromatin-bound active p50 and p65 [37].…”

“…Additionally, linalool decreases NF-kB signalling pathway activation by reducing chromatin-bound active p50 and p65 [37]. Second, linalool decreases ROS production by directly influencing free radical generation, increasing enzymatic antioxidant capacities (e.g., glutathione peroxidase) or through its scavenging properties [35,88]. Finally, linalool, as the main constituent of the Coriandrum sativum (70%), was found to be potentially associated with delayed cerebral amyloidosis including the accumulation of amyloid deposits and β-amyloid peptides in the hippocampal tissue of ageing triple transgenic state mutation mice through the reduction in ROS and a decrease in IL-1β, iNOS, and COX-2 [35].…”