With the application and promotion of aromatherapy, as well as the establishment of its theoretical system, research on targeted improvement of insomnia has also made significant progress. At present, the main research on aromatherapy plants with sedative and hypnotic effects includes lavender, valerian, citrus, etc. Through their study, it has been found that factors such as medication route and environment can lead to different sedative and hypnotic effects. Therefore, researchers further explored the mechanism of the sedative and hypnotic effects of aromatherapy, among which aromatherapy transdermal absorption and aromatherapy inhalation therapy have been confirmed。

For a long time, people have hoped to achieve safer and less adverse effects through natural plants for treatment purposes. Replacing current chemically synthesized drugs with natural sleeping pills has become an anticipated goal. Aromatherapy plants demonstrate sedative and hypnotic effects through aromatherapy, allowing people toSeeing its advantages, research results in recent years have shown that many aromatherapy plants have good sedative and hypnotic effects with few adverse reactions, and are worthy of further development and research.

Overview of Aromatherapy

Aromatherapy, as the name suggests, is the use of aromatherapy scents to improve diseases. Specifically, it is a branch of the entire field of plant medicine that uses volatile compounds from aromatherapy plants to improve physical and mental illnesses. The effectiveness of aromatherapy has been confirmed through various methods, such as brain signals, heart rate, blood pressure, and model digital calculations.

French chemist and spice manufacturerGattefoss é first proposed the concept of aromatherapy based on previous research in the 1930s. After French physician Jean Valnet published the book "Aromatherapy" in 1964, aromatherapy became popular as a treatment in Europe. China has a medical history of using spice plants to drive away epidemics and avoid pollution as early as 5000 years ago. In the "Compendium of Materia Medica," the Ming Dynasty physician Li Shizhen also listed various aromatic plants that can clear heat, kill bacteria, and relieve pain. There are generally five types of classical aromatherapy methods: wearing fragrance, smelling fragrance, drinking fragrance, burning fragrance, and bathing fragrance, but nowadays the forms of aromatherapy have not changed much.

insomniaThe harm of the disease and the current treatment status

With the development of science and the progress of society, sleep disorders have become increasingly prominent.A study by WHO shows that approximately 27% of people worldwide suffer from sleep disorders. Multiple epidemiological surveys have shown that approximately 35.2% of people in Western countries suffer from varying degrees of insomnia, while the insomnia rate in China is as high as 10% to 20%. According to experts' estimates, there will be over 700 million insomniacs worldwide by 2020. Lack of sleep can seriously affect people's physical and mental health, and reduce their work efficiency.

At present, the drugs used to treat insomnia in clinical practice mainly include benzodiazepines and barbiturates, but these drugs often have varying degrees of adverse reactions and are prone to drug dependence. The ideal anti insomnia medication should haveQuick onset, able to maintain sufficient sleep, does not affect sleep structure, has no daytime hangover symptoms, and has no resistance or rebound after discontinuation. To this day, there is no such ideal sedative hypnotic drug.

Research on Sedative and Hypnotic Aromatherapy Plants

LavenderMost studies support the sedative and hypnotic effects of lavender. A randomized single blind crossover study found that lavender is effective in treating insomnia. But the sample size of this experiment is relatively small, with only 5 males and 5 females. Another experiment using lavender aromatherapy to treat 42 female college students with insomnia has shown good results. There are also experiments showing that lavender can increase slow wave sleep, and it is believed that lavender can be used as a new and mild sedative. Even studies have shown that lavender oil aromatherapy can help reduce the dosage of opioid sedatives used by patients during laparoscopic gastric volume reduction surgery. As one of the main components of lavender, linalool has been found by foreign scholars to have sedative effects, and compared with psychotropic sedatives, it has almost no damage to the motor ability of mice. 32 cases of insomnia were treated with acupuncture combined with lavender aromatherapy in China, and satisfactory therapeutic effects were achieved.

ValerianThere are reports indicating that valerian inhalants have sedative and hypnotic effects. Experiments have shown that valerian inhalants significantly prolong pentobarbital induced sleep time in rats, and the author believes that the sedative and hypnotic effects of valerian inhalants may be achieved by reducing the activity of aminobutyric acid transaminase and increasing aminobutyric acid. There are many studies on the chemical pharmacology of European valerian, but so far, there is still significant controversy over its sedative and hypnotic active ingredients and their mechanisms. The research report on the sedative and hypnotic effects of domestically produced valerian in China shows that it can reduce the spontaneous activity of mice and prolong the sleep time induced by pentobarbital sodium, making it a good medicinal herb for sedative and hypnotic adjuvant therapy. Some studies have also found that extracts of Valerian have no significant effect on treating sleep disorders in arthritis patients.

citrusThere are experiments showing that citrus can be used as a sedative therapy. Researchers have extracted a volatile aromatic compound called limonene from citrus peel and found that limonene can directly bind to adenosine A receptors. The experiment suggests that citrus may exert a sedative effect through this pathway.

camomileChamomile is an ancient medicinal herb, and its dried flowers contain various terpenoids and flavonoids, making it valuable for medical purposes. Chamomile's medicinal properties can be used for sedation and hypnosis. A study has shown that using polysomnography to observe the effects of chamomile extract on sleep in rats can effectively shorten sleep latency, suggesting that chamomile has a similar effect to benzodiazepine hypnotic drugs.

BergamotBergamot essential oil is widely used for its ability to alleviate anxiety caused by stress, alleviate mild mood disorders, and alleviate pain caused by cancer. Studies have shown that bergamot may exert sedative and anti anxiety effects through the hypothalamic pituitary adrenal axis, reducing cortisol production to alleviate stress responses and achieve sedative and anti anxiety effects.

There are other aromatherapy plants that have also been used by scholars for aromatherapy to calm and hypnotize(Like roses). Multiple studies on rose essential oil have shown its anti anxiety effect, and its hypnotic effect is weaker than that of valerian, but its mechanism of action has not been truly understood. Snake hemp grass has a therapeutic effect on primary insomnia, and recent studies have shown that snake hemp seed extract can improve sleep, but more careful research design is still needed to fully confirm its effect. Research has shown that essential oil extracted from the rhizome of Ligusticum chuanxiong can quickly exert analgesic and sedative effects after nasal administration. Experimental observations have shown that Ligusticum chuanxiong essential oil can quickly shorten sleep latency and prolong total sleep time. It is a very effective hypnotic drug that takes effect quickly, lasts for a long time, and rarely leaves hangovers the next morning after taking it again. Studies have shown that kava, when applied to rats, can prolong sleep time and improve sleep quality through polysomnography observation. However, there have been reports that Kava has severe liver cell toxicity and has been banned from use. But there is also a randomized, double-blind, controlled trial that suggests Kava may not have sedative hypnotic effects. Honeybee flowers belong to traditional medicine and are auxiliary drugs for improving sleep, anti anxiety, treating migraines, and mental illnesses.

Although there are many studies on the use of aromatherapy to treat insomnia, there is still controversy over the sedative and hypnotic effects of aromatherapy. The inconsistent conclusions are due to differences in medication routes, drug formulations, drug dosages, subject age, gender, and environment, and may even be related to different genetic backgrounds. This requires future researchers to pay attention to the rigor of methods, the selection of samples and sample sizes, and the selection of appropriate control groups when conducting related research, in order to obtain stable data to effectively demonstrate the sedative and hypnotic effects of aromatherapy plants.

The pathways and mechanisms of aromatherapy

The efficacy of aromatherapy plants is closely related to their pathways of action. The most widely used and researched methods currently are aromatherapy inhalation therapy and aromatherapy transdermal absorption therapy.

Aromatherapy transdermal absorption refers to the use of massage methods to allow aromatherapy substances to enter the bloodstream through the skin in a short period of time(Cells and tissues such as nerves, bones, and muscles can all be affected by it) to achieve the goal of preventing and treating diseases. A study has found that even short-term aromatherapy can slow down endothelial dysfunction caused by night shift work, indicating that aromatherapy can act on blood vessels and exert its therapeutic effects. Aromatherapy inhalation therapy refers to the treatment of diseases by acting on the central nervous system through the olfactory pathway. Aromatherapy molecules specifically bind to G-protein coupled receptors on olfactory sensory neurons, triggering olfactory receptor potentials that are transmitted from olfactory sensory neurons to the olfactory bulb. The olfactory bulb then projects the signal through the olfactory tract to the primary olfactory cortex, which in turn projects it to secondary cortical centers such as the cortex, orbitofrontal cortex, dorsal medial nucleus of thalamus, hypothalamus, and basolateral amygdala. This complex pathway may be an important basis for olfactory effects on brain function and a possible mechanism by which aromatherapy acts on sleep.

At present, there are two theories to explain the possible mechanism of action of aromatherapy

① The theory of brainstem reticular structure: Smell regulates the activity level of the central nervous system by stimulating the reticular structure. Due to the rapid response of brainstem reticular structure to olfactory stimuli, aromatherapy works quickly and can improve sleep, regulate tension, concentration and attention in a short period of time.

② The theory of the limbic system of the brain: The limbic system of the brain has the function of regulating emotions and is related to various emotional responses in humans. Aromatherapy can regulate the functions of the somatic motor nerves, autonomic nerves, and cerebral cortex through the limbic system of the brain, thereby exerting a sedative and sleep promoting effect.

After years of research on the sedative and hypnotic effects of aromatherapy plants, some achievements have been made. However, there are also many doubts facing researchers, which require more rigorous, scientific, and cautious experimental results to answer these questions. Research on the Mechanism of Sedation and Hypnosis in AromatherapyMore diverse and in-depth exploration is needed.