Safety and efficacy of Melissa officinalis extract containing rosmarinic acid in the prevention of Alzheimer\u2019s disease progression

Moeko Noguchi-Shinohara,Toshitada Nagai,Junji Komatsu,Shoko Kobayashi,Kenjiro Ono,Tsuyoshi Hamaguchi,Kunihiko Yokoyama,Masahito Yamada,Kazuo Iwasa,Miharu Samuraki-Yokohama,Hiroyuki Nakamura

doi:10.1038/s41598-020-73729-2

Abstract

We conducted a randomized placebo-controlled double-blind 24-week trial using Melissa officinalis (M. officinalis) extract richly containing rosmarinic acid (RA) on patients with mild dementia due to Alzheimer’s disease (AD) with the aim to examine the safety and tolerability (primary endpoint) of RA (500 mg daily) and its clinical effects and disease-related biomarker changes (secondary endpoints). Patients (n = 23) diagnosed with mild dementia due to probable AD were randomized to either the placebo or M. officinalis extract group. No differences in vital signs or physical and neurologic examination results were detected between the M. officinalis and placebo groups. No serious adverse events occurred. There were no significant differences in cognitive measures; however, the mean Neuropsychiatric Inventory Questionnaire (NPI-Q) score improved by 0.5 points in the M. officinalis group and worsened by 0.7 points in the placebo group between the baseline and 24-week visit, indicating a significant difference (P = 0.012). No significant differences were apparent in disease-related biomarkers between the groups. M. officinalis extract containing 500 mg of RA taken daily was safe and well-tolerated by patients with mild dementia due to AD. Our results suggest that RA may help prevent the worsening of AD-related neuropsychiatric symptoms.Trial registration: The registration number for this clinical trial is UMIN000007734 (16/04/2012).

Highlights

We conducted a randomized placebo-controlled double-blind 24-week trial using Melissa officinalis (M. officinalis) extract richly containing rosmarinic acid (RA) on patients with mild dementia due to Alzheimer’s disease (AD) with the aim to examine the safety and tolerability of RA (500 mg daily) and its clinical effects and disease-related biomarker changes
Three patients withdrew from the study between the baseline and 24-week follow-up visit; two patients withdrew because they had to be admitted into a nursing home, and another patient from the M. officinalis group withdrew because caregivers lost interest in the trial
In the 24-week double-blind placebo-controlled study, with a 24-week extension, we examined the safety and tolerability of M. officinalis extract containing RA (500 mg daily dose) in patients with mild dementia due to AD as a primary endpoint and demonstrated that supplementation with this dose was tolerable for 48 weeks and did not raise any safety concerns that manifested clinically or through routine blood tests

Summary

Introduction

We conducted a randomized placebo-controlled double-blind 24-week trial using Melissa officinalis (M. officinalis) extract richly containing rosmarinic acid (RA) on patients with mild dementia due to Alzheimer’s disease (AD) with the aim to examine the safety and tolerability (primary endpoint) of RA (500 mg daily) and its clinical effects and disease-related biomarker changes (secondary endpoints). Because the deposition of Aβ aggregates in the brain occurs approximately 25 years before the appearance of clinical symptoms, it has been proposed that treatments targeting Aβ aggregation, including formation of neurotoxic Aβ oligomers, should be implemented early in the disease process[2]. RA appeared to be the most attractive molecule for preventing AD, because it inhibited both the oligomerization and deposition of Aβ8. We recently demonstrated that monoamine suppresses Aβ aggregation[9], suggesting that an RA-triggered increase in monoamine secretion in the brain is beneficial for the treatment of AD

Methods

Results

Conclusion