EYVOR | Are essential oils effective on the fundamental units of the brain? (PART-01)

Individuals have put their trust in the healing properties of essential oils for more than 2000 years now. This is because of the psychological and pharmacological benefits that essential oils provide. With the various known uses, these outstanding oils have been used to prevent and cure illnesses in various parts of Asia and Persia for centuries.

 Over time, studies have proven the various pharmacological effects of essential oils, including antioxidant properties, antibacterial effects, etc. However, given the increasing prevalence of mental illnesses like depression and anxiety in recent years, researchers have begun to explore the calming, anxiolytic, and analgesic effects of essential oils on the nervous system.

Conventional Therapy vs Essential Oils:

For mental illnesses, such as panic disorder and anxiety, conventional methods of treatment include both pharmacotherapy (drug use) and psychotherapy (counseling). The drugs usually given to such patients include SSRIs and SNRIs to increase serotonin levels in the body. These drugs work by inhibiting the reuptake of serotonin and norepinephrine, increasing their concentration throughout the body’s systems. Although these drugs show good results, they’re often avoided because of the mountains of side effects they are associated with.

Psychostimulant essential oils, on the other hand, interact with the neurotransmitter systems like serotonergic, and adrenergic systems that are involved in the alert waking state. They also showcase neuroprotective effects because of their free radical scavenging and antioxidant properties. Such effects help in improving cognitive function and preventing brain damage.

For these reasons, there is an increasing demand and interest in essential oils as alternative treatment strategies for depression and anxiety with reduced or no side effects.

Lemongrass Essential Oil:

Lemongrass essential oil is extracted from the leaves of Cymbopogon citratus. The major compound of this essential oil is citral and other compounds such as limonene, which have great anxiolytic and antidepressant properties. In an experiment dedicated to discovering the effects of this oil, subjects were put in an anxious state using a video-monitored version of SCWT and were divided into two groups, namely Control (those given no therapy) and Test (those given aromatherapy). After exposure to the aroma (3-6 drops of Lemon Grass essential oils), the Test group exhibited a significant reduction of anxiety and subjective tension compared to the Control group. This was assessed by special questionnaires. The proposed mechanism of action of lemongrass essential oil is its interaction with the GABAnergic system, the main neurotransmitter system responsible for producing a calming and sedative effect on the body. This is how it potentiates its effect and acts as an anxiolytic agent.

Sweet Orange Essential Oil:

Sweet orange essential oil is extracted from the leaves of Citrus sinensis. The major active compounds responsible for the CNS action of this essential oil are d-limonene, α-pinene, linalool, geranial, and neral. Geranial and neral are the same compounds responsible for the

formation of citral, which is the primary active component of lemongrass.

Studying sweet orange essential oil using infrared spectroscopy showed a significant decrease in oxyhemoglobin concentration in the right prefrontal cortex of the brain, as well as induced feelings of comfort and relaxation in the volunteers on whom the study was performed. Another human trial performed confirmed the strong anxiolytic effects of the drug due to its action on the HPA axis.

Conclusion:

The increased focus on the research of essential oils for more knowledge of their pharmacological activity during the last 15 years has revealed a diverse range of therapeutic effects, especially on neural pathways. This has allowed a more comprehensive understanding of their psychological and central nervous system effects. This includes their influence on the HPA axis, interaction with the sympathetic nervous system, and effects on neurotransmitter systems like serotonergic, adrenergic, and GABAergic systems. Clinical trials have shown evidence for a range of physiological and psychological responses to aromatherapy which can be further used as an alternative treatment for mental illnesses with a better risk-benefit balance, as it has none to only a few unharmful potential side effects. However, due to the scarce availability of clinical data, greater research must be done, especially in clinical research to promote the development and acceptance of essential oil-based drugs.