Polygonatum sibiricum Rhizome Extract Helps Improve Mild Insomnia

by | Aug 7, 2019 | 2019, Botanicals, Sleep

Written by Angeline A. De Leon, Staff Writer. Compared to control, a four‐week daily administration of 500 mg of Polygonatum sibiricum rhizome significantly improved subjective and objective sleep in the forty participating subjects by possibly increasing cerebral perfusion in brain areas associated with insomnia.

sleepWithin the general population, insomnia is a prevalent health condition, associated not only with lower quality of life and higher rates of transportation-related accidents 1, but also other health disturbances, such as higher risk of cardiovascular disease and cognitive impairment 2. Standardized treatment for insomnia relies on the use of sedative hypnotics such as benzodiazepines 3, however, such pharmacological medications involve undesirable side-effects such as memory loss, poor daytime alertness, and even addiction 4. The growing trend towards self-help strategies among individuals with insomnia has given rise to the use of herbal remedies such as the flowering plant Polygonatum sibiricum (PS). A perennial plant commonly used to treat sleep disturbance, the rhizome of PS has been shown to effectively mitigate symptoms of insomnia in animals without adverse effect 5. The primary active component of the PS rhizome, glyceryl-1-monolinoleate, is thought to reduce sleep latency and promote general sleep duration through its activation of benzodiazepine receptors 6. In a recent study 7 published in Nutrients (2019), researchers in Korea tested whether PS rhizome extract could improve sleep quality in subjects with mild insomnia, specifically looking at the effects of supplementation on cerebral blood flow within the default mode network (DMN), a network of brain regions associated with insomnia 8.

A total of 80 individuals (aged 20 to 65 years) with mild insomnia (experiencing at least once a week difficulty falling asleep, staying asleep, or going back to sleep and/or feeling restless in the morning without impairment in daytime activities) were enrolled in a randomized, double-blind, placebo-controlled trial. Subjects were randomly assigned to ingest either 500 mg PS rhizome extract or identical placebo about half an hour before bed daily for four weeks. At baseline, sleep quality was assessed using the Athens Insomnia Scale (AIS), along with actigraphy (an accelerometer worn on the wrist to measure total sleep time, sleep efficacy, and frequency of waking). Subjects underwent Magnetic Resonance Imaging (MRI) scans, and perfusion imaging was performed to quantify regional cerebral blood perfusion throughout brain regions of interest associated with the DMN (bilateral medial prefrontal cortex, mPFC; precuneus; posterior cingulate cortex, PCC; interior parietal lobule, IPL).

Results indicated that over the course of 4 weeks, the PS group experienced a significant reduction in total AIS score, compared to placebo (p for group x visit interaction = 0.035). Actigraphy data revealed a significant group x visit interaction in changes in total sleep time (p = 0.046) over the 4-week period, and a significant group x visit interaction was also observed in changes in cerebral perfusion within the mPFC of the DMN, with perfusion levels increasing for the PS group but diminishing for the placebo group (p = 0.001).

Based on findings, researchers conclude that short-term supplementation with PS rhizome extract is associated with both subjective and objective measures of improvement in mild insomnia. In comparison to placebo, PS rhizome extract was seen to specifically improve AIS score and total sleep time based on actigraphy. Moreover, as the first study to employ cerebral perfusion neuroimaging to evaluate the efficacy of PS rhizome, the current trial showed that supplementation with PS rhizome was linked to increased cerebral perfusion within the mPFC of the DMN, a finding in line with prior research reporting lower regional cerebral metabolism in the DMN of insomnia patients (along with a specific pathophysiological role of the mPFC in insomnia) 8. For future studies, it would be valuable to replicate findings using a longer treatment period, a longer follow-up period, and/or a clinical population experiencing more severe forms of insomnia. To further promote the use of nutraceuticals for the treatment of sleep disorders, it would also be beneficial to examine the biological mechanisms responsible for PS rhizome’s sleep-promoting effects.

Source: Ha E, Hong H, Kim TD, et al. Efficacy of Polygonatum sibiricum on mild insomnia: A randomized placebo-controlled trial. Nutrients. 2019; 11: 1719. DOI: 10.3390/nu11081719.

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

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Posted August 7, 2019.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

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