Researchers from the Health Sciences Department of the Universidad Católica San Antonio de Murcia (UCAM) in Murcia, Spain found that daily consumption of nutraceutical formulation of lemon verbena (24% verbascoside and 28% total phenylpropanoids) for 90 days led to a significant improvement in the overall sleep quality in the double-blind, randomized study.
"We discovered the positive effects of our lemon verbena on sleep while evaluating its use for joint health in athletes," said Maria Ángeles Gutiérrez, SuanNnutra’s marketing director. "This initial finding spurred the development of RelaxPLX. Since then, we have explored how standardized doses can improve sleep quality, which we believe is a critical component of overall health, mental well-being, and longevity.
"Our first eight-week clinical trial on 40 participants demonstrated RelaxPLX’s capabilities in alleviating occasional stress and sleep difficulties. The current clinical study aimed to confirm and delve deeper into these benefits."
Sleep and stress remedies
Typically, individuals diagnosed with insomnia are treated with pharmacological interventions (e.g., benzodiazepines). Although these approaches improve sleep quality for a short period, they have many side effects including the risk of addiction.
Aloysia citrodora is an herb that exhibits neuroprotective, antioxidant, anticancer, anxiolytic, anesthetic, sedative and antimicrobial activities. These biological activities have been attributed to the presence of high levels of the polyphenol verbascoside.
Some of the mechanisms through which lemon verbena exerts its beneficial activities include: increasing sensitivity to the relaxing GABA-A receptor, enhancing expression of neuroprotective brain-derived neurotrophic factor (BDNF) and enhancing production of serotonin, noradrenaline and dopamine.
Sleep data
The placebo-controlled clinical trial recruited a total of 71 adult participants with poor sleep quality and anxiety scores and randomly assigned them to either an experimental group (33 participants) or a placebo group (38 participants).
Participants in the experimental group received a capsule containing lemon verbena (400 mg) and excipient (150 mg), while those in the placebo group received a capsule containing cellulose microcrystalline and maltodextrin. They were instructed to consume one capsule per day, one hour before sleeping, for 90 consecutive days.
The efficacy of the treatments was assessed at the baseline and after 45 and 90 days of interventions. Sleep quality was measured for 24 hours for three days of the week and one day of the weekend, using a wrist-worn accelerometer.
In the experimental group, significant improvements were noted in all sleep-related variables measured through the Pittsburgh Sleep Quality Index (PSQI) questionnaire, the visual analog scale (VAS) score and actigraphy-based sleep parameters.
Concerning stress-related complaints, the experimental group exhibited improvements based on the Perceived Stress Scale (PSS) and State-Trait Anxiety Inventory (STAI) scores, compared to placebo. Furthermore, a significant increase in nocturnal melatonin levels was observed only in the experimental group. No difference in plasma cortisol levels was found between the study groups.
The study called for further randomized controlled trials with larger cohorts and greater durations to validate the findings.
"Botanical extracts have progressively gained the attention of consumers worldwide who are seeking natural interventions to improve well-being and especially to promote a positive mental outlook and sleep quality," Gutiérrez said. "Our clinical studies endorse its role as an effective holistic solution for improving sleep and quality of life."
Source: Nutrients
doi: doi.org/10.3390/nu16101523
“Dietary Supplementation with an Extract of Aloysia citrodora (Lemon verbena) Improves Sleep Quality in Healthy Subjects: A Randomized Double-Blind Controlled Study”
Authors: Carlos J et al.