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Research seeds: Sage, rosemary and lemon balm

  • Dr Melanie-Jayne Howes
    Dr Melanie-Jayne Howes

    Dr Melanie-Jayne Howes is the Senior Research Leader in Biological Chemistry, Royal Botanic Gardens, Kew

    She currently lead Kew’s Science Strategy Initiative ‘Biointeractions and Bioactive Molecules’ (Priority 2) which aims to explore biological interactions and bioactive molecules to unlock the useful properties in plants and fungi.

    Her own research is focused on investigating the chemistry and bioactive constituents of plants and fungi to understand the scientific basis for their uses, especially as medicines including for drug discovery.

    Her research also includes scientific studies on edible plants to explore their uses as food and to understand how they may benefit human health, for example, their potential role in reducing dementia risk.

    She uses techniques in natural product and analytical chemistry (including liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry) to chemically characterise plants and fungi. This includes the comparative analysis of specimens in Kew’s extensive living and preserved collections to provide new insights into the chemical diversity of plants and fungi and further understanding of their potential sustainable uses.

  • 2:10 reading time (ish)
  • Research Seeds

In this article, we discuss the paperA randomised double-blind placebo-controlled pilot trial of a combined extract of sage, rosemary and melissa, traditional herbal medicines, on the enhancement of memory in normal healthy subjects, including influence of age

Plant name and species

Rosemary (Rosmarinus officinalis), sage (salvia officinalis) and lemon balm (melissa officinalis)

Aim of study

To evaluate the combination of sage, rosemary and lemon balm on verbal recall and memory in healthy subjects.

Study method

44 healthy subjects participated in this study which was a double-blind, randomised, placebo-controlled trial. The groups were split into an active group (with SRL extract) and placebo group. Immediate and delayed word recall were used to assess memory after taking SRM or placebo. The groups were also divided into younger and older subgroups.

Herbal preparation

An ethanol extract of SRL was used that was chemically characterised using high resolution LC-UV-MS/MS analysis.

Sample size

There were 44 participants overall split into the following group sizes; (≀ 62 years mean age n = 26: SRL n = 10, Placebo n = 16; ≄ 63 years n = 19: SRL n = 13, Placebo n = 6).

Results of study

Overall there was no significant differences between treatment and the placebo group from baseline for immediate or delayed word recall, however in the treatment group who were under 63 years old there was significant improvements. There were no adverse effects.


This pilot study shows encouraging indications that sage, rosemary and lemon balm can be valuable for supporting memory and brain health which is in alignment with their traditional uses. This is likely to be due to anticholinesterase actions of these species, as acetylcholine is a key component for forming memories. Other contributing factors include anti-inflammatory, anti-amyloid, antioxidative and neuroprotective actions due to compounds such as pinenes, geraniol, apigenin, terpenoids and phenolics. 

You can also read “An interview with medicinal plant scientist Dr Howes on plants for neurodegeneration“.


This study shows that the SRL extract is more effective than placebo for verbal episodic memory tests in healthy subjects under 63 years of age. Short and long term supplementation with SRL should be further investigated as an adjunctive treatment for patients with Alzheimer’s disease and the general ageing population.

Dr Melanie-Jayne Howes

Dr Melanie-Jayne Howes is the Senior Research Leader in Biological Chemistry, Royal Botanic Gardens, Kew She currently lead Kew’s Science Strategy Initiative ‘Biointeractions and Bioactive... Read more

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