Could lemon balm help Alzheimer's patients?
Lemon balm Melissa officinalis may be potentially useful for people with Alzheimer's disease, related neurological diseases, or at risk for those diseases.
The reasons include its interaction with nervous system biochemistry including
binding to nicotinic and muscarinic cholinergic receptors in human brain tissue,
acetylcholinesterase (AChE) inhibition,
inhibition of GABA transaminase in rats,
reduction of both tauopathy and beta amyloid pathology,
and both antioxidant and anti-inflammatory properties among others.
In addition, both the regular extracts and essential oil extracts have shown anti-anxiety and calming effects, and memory improvements in normal people.
Furthermore, these effects and benefits have been found without significant side effects at this time, as well as having an excellent safety record for human usage for over two thousand years at an extremely low cost.
An early study with 42 men and women over age 65 with mild to moderate Alzheimer's tested them with a placebo or a lemon balm Melissa officinalis extract for four months.
The patients receiving lemon balm showed significant improvements in cognition and reduced agitation and the researchers concluded that lemon balm is a valuable adjunct for treatment (Akhondzadeh S et al: Melissa officinalis extract in the treatment of patients with mild to moderate Alzheimer's disease: a double blind, randomised, placebo controlled trial, J Neurol Neurosurg Psychiatry July 2003, p863-6).
Other studies have examined agitation in patients with dementia symptoms similar to Alzheimer's symptoms.
A study in the United Kingdom tested lemon balm (Melissa officinalis) essential oil against a placebo oil with 72 resident patients with severe dementia and agitation.
The lemon balm oil or placebo was added to a skin lotion and applied daily during the four week study.
60% of the lemon balm oil group showed a 30% improvement in agitation scores compared to 14% improvement in the placebo group, a highly significant result.
Quality of life scores and time spent in constructive activities also showed significant improvements in the lemon balm group.
There were no significant side effects and the researchers found that the application of lemon balm essential oil was both safe and effective for agitation in dementia patients, with recommendations for additional studies (Ballard CG et al: Aromatherapy as a safe and effective treatment for the management of agitation in severe dementia: the results of a double-blind, placebo-controlled trial with Melissa, J Clin Psychiatry July 2002, p553-8).
Another study compared lemon balm essential oil aromatherapy with donepezil (an AChE inhibitor) and a placebo in 114 Alzheimer's disease patients with significant agitation over a 12 week program.
The researchers noted that there were improvements in all three groups, but all three groups, including placebo interaction showed approximately the same amount of improvement leading this study to suggest that drug-free non-specific touch or interaction may be as effective as prescription drugs or aromatherapy with lemon balm essential oil (Burns A et al: A double-blind placebo-controlled randomized trial of Melissa officinalis oil and donepezil for the treatment of agitation in Alzheimer's disease, Dement Geriatr Cogn Disord 2011, p158-64).
In 20 young healthy adults, researchers tested a placebo and an extract of lemon balm Melissa officinalis in a double-blind, crossover study.
They used three dosage levels of lemon balm, testing the cognitive memory performances of the participants prior to dosing and 1 hour, 2.5 hours, 4 hours, and 6 hours afterwards.
The study results showed sustained memory improvement with accuracy of attention with the 600 mg. dose, improved calmness with lowest dose, and reduced alertness with highest dose (Kennedy DO et al: Modulation of mood and cognitive performance following acute administration of Melissa officinalis (lemon balm), Pharmacol Biochem Behav July 2002, p953-64).
This experiment was revisited with 20 new people using higher doses of encapsulated dried LB leaf with results showing improved memory and increased calmness for at least 6 hours after the highest 1600 mg dose.
This study had some opposite results based on dosage compared to the 2002 study which may indicate a U shaped response pattern (Kennedy DO et al: Modulation of mood and cognitive performance following acute administration of single doses of Melissa officinalis (Lemon balm) with human CNS nicotinic and muscarinic receptor-binding properties, Neuropsychopharmacology October 2003, p1871-81.).
In a meta-analysis review of several lemon balm studies, results confirmed that lemon balm showed improvements in cognition and improved calming or sedative effects with no reported side effects (Dos Santos-Neto LL et al: The use of herbal medicine in Alzheimer's disease-a systematic review, Evid Based Complement Alternat Med December 2006, p441-5).
The presence of beta amyloid plaque and related biochemical entities in the brain have been characteristically found in the brain of patients who were diagnosed with Alzheimer's disease.
A cell study in 2017 found that the acidic fraction of Melissa officinalis protected cerebellar granule neurons from beta amyloid induced oxidative stress and cell death.
In this study, the protection by lemon balm Melissa officinalis was primarily due to antioxidant and other cellular anti-apoptosis activity which did not involve nicotinic receptors (Soodi M et al: Melissa officinalis acidic fraction protects cultured cerebellar granule neurons against beta amyloid-induced apoptosis and oxidative stress, Cell J Winter 2017, p556-564).
Researchers used a cell study to test the protective effects of lemon balm extracts during beta amyloid induced toxicity.
They used three extracts of lemon balm: an ethanolic extract, an acidic extract, and a non-acidic extract, and found that the ethanolic and the acidic extracts of lemon balm protected against oxidative damage and cell death when used as a pretreatment, with the acidic extract being the more potent (Sepand MR et al: Comparison of neuroprotective effects of Melissa officinalis total extract and its acidic and non-acidic fractions against A ß-induced toxicity, Iran J Pharm Res Spring 2013, p415-23).
Another primary finding in Alzheimer's disease is reduced synthesis of acetylcholine and the loss of cholinergic synapses in the brain, leading to the loss of information transmission for memory or behavior control.
Since the enzyme acetylcholinesterase created in the body, degrades existing acetylcholine, research and prescription drug approaches have focused on inhibiting the action of acetylcholinesterase in the hopes of maintaining normal acetylcholine function.
This research includes
identifying compounds that can connect (bind) to cholinergic receptors, especially in the hippocampus and neocortex,
identifying compounds that inhibit the activities of acetylcholinesterase,
identifying compounds that protect cholinergic neurons in the brain directly possibly with antioxidant or anti-inflammatory actions, among others.
An early study confirmed that lemon balm and some other herbs could bind to cholinergic receptors (Wake G et al: CNS acetylcholine receptor activity in European medicinal plants traditionally used to improve failing memory, J Ethnopharmacol February 2000, p105-14).
Other studies have confirmed lemon balm Melissa species as source of AChE agents (Orhan I and Aslan M: Appraisal of scopolamine-induced antiamnesic effect in mice and in vitro antiacetylcholinesterase and antioxidant activities of some traditionally used Lamiaceae plants, J Ethnopharmacol March 2009, p327-32, and Russo P et al: From traditional European medicine to discovery of new drug candidates for the treatment of dementia and Alzheimer's disease: acetylcholinesterase inhibitors, Curr Med Chem 2013, p976-83).
Lemon balm extract was tested for inhibition of acetylcholinesterase and was found to inhibit acetylcholinesterase in a dose and time dependent manner with the rosmarinic acid fractions showing the greatest potency (Dastmalchi K et al: Acetylcholinesterase inhibitory guided fractionation of Melissa officinalis L, Bioorg Med Chem January 2009, p867-71).
For more lemon balm Alzheimer's studies including effectiveness of the essential oil, cerebrovascular and nervous system protection, and the benefits of rosmarinic acid (a primary chemical in Melissa officinalis lemon balm) for Alzheimer's disease, please see my new book listed below:
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