Investigating the Therapeutic Potential of Plants and Plant-Based Medicines: Relevance to Antioxidant and Neuroprotective Effects

Assessing the effect of anthocyanins through diet and supplementation on cognitive function in older adults at risk for dementia: protocol for a randomised controlled trial

INTRODUCTION

Promising evidence is emerging for the procognitive, anti-inflammatory and neuroprotective properties of dietary flavonoids, particularly anthocyanins that provide red, purple and blue plant pigments.

METHODS AND ANALYSIS

The 'Food for Thought' study is a multicentre, 6-month randomised, parallel 3-arm clinical trial. Its primary aim is to investigate whether anthocyanin consumption, either through diet or supplementation, can prevent memory loss progression and improve inflammatory and cardiovascular health in older adults at risk for dementia. Eligible participants will include those aged 60-85 years with a diagnosis of amnestic mild cognitive impairment or with a self-referral of memory concerns and scoring ≤13 on the Memory Index Score within the Telephone Montreal Cognitive Assessment screening test. Participants will be randomised to one of three arms: High anthocyanin ('purple foods') diet (aiming for a target of 250 mg anthocyanins/day); freeze-dried product derived from blackcurrants (250 mg anthocyanins/day); or control (coloured maltose powder). The primary outcome is auditory anterograde memory functioning assessed by the Buschke and Grober Free and Cued Selective Reminding Test-Immediate Recall. Secondary outcomes are additional cognitive functions including processing speed, working memory, aspects of executive functioning (attentional shifting and word generativity) and premorbid estimate as well as subjective memory problems and self-reported depression symptoms. Additional secondary outcomes are blood pressure, inflammatory biomarkers, brain-derived neurotrophic factor, fatty acid profile, apolipoprotein E and polyphenol metabolites, gut microbiota composition and function and vascular and microvascular endothelial function tests. Repeated measures analysis of variance and/or mixed linear modelling will evaluate changes over time, with the inclusion of covariates.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Greater Western Human Research Ethics Committee (2021/ETH12083). A Consumer Advisory Group was established to guide and review the protocol and dissemination strategy. The results of this trial are intended to be published in a peer-reviewed journal.

TRIAL SPONSOR

National Health and Medical Research Centre Dementia Collaborative Research Centre.Start date of clinical trial: 02 September 2022.Expected end date: 11 October 2024.

TRIAL REGISTRATION NUMBER

ACTRN12622000065796.

Effects of Strawberry Tree Water Leaf Extract and Arbutin on Biochemical Markers and DNA Integrity in Brain Cells of Lewis Rats

There is growing evidence that arbutin and plant extracts rich in arbutin, such as extracts of the strawberry tree (Arbutus unedo L.), exert a range of beneficial effects, including cyto- and genoprotective properties. This study evaluated the effects of strawberry tree water leaf extract (STE) and arbutin in the brain tissue of Lewis rats. STE or arbutin were administered per os to male and female rats at a dose of 200 mg/kg body weight/day for 14 or 28 days. Treatment outcomes were evaluated using biochemical markers (lipid peroxidation and the activities of the antioxidative enzymes catalase and superoxide dismutase). The effects of the tested substances on DNA integrity in brain cells were evaluated using the alkaline comet assay. The results suggest a high biocompatibility of both tested substances with rat brain tissue. No significant harmful disturbances were observed in the oxidative/antioxidative status or impairments of DNA integrity in the rat brain cells. Nearly all post-treatment values were within tolerable limits as compared to the matched control rats. Such encouraging findings support further research using other subtle biomarkers to clarify the safety aspects of arbutin and STE prior to the development of specific nutraceutical products.

Genus Sambucus: Exploring Its Potential as a Functional Food Ingredient with Neuroprotective Properties Mediated by Antioxidant and Anti-Inflammatory Mechanisms

The genus Sambucus, mainly Sambucus nigra, has emerged as a valuable source of bioactive compounds with potential neuroprotective properties. This review explores the antioxidant, anti-inflammatory, and neuroregenerative effects of Sambucus-derived compounds and their implications for brain health and cognitive function. In vitro studies have demonstrated the ability of Sambucus extracts to mitigate oxidative stress, modulate inflammatory responses, and promote neural stem cell proliferation and differentiation. In vivo studies using animal models of neurodegenerative diseases, such as Alzheimer's and Parkinson's, have shown that Sambucus compounds can improve cognitive function, motor performance, and neuronal survival while attenuating neuroinflammation and oxidative damage. The neuroprotective effects of Sambucus are primarily attributed to its rich content of polyphenols, particularly anthocyanins, which exert their benefits through multiple mechanisms, including the modulation of signaling pathways involved in inflammation, apoptosis, mitochondrial function, and oxidative stress. Furthermore, the potential of Sambucus as a functional food ingredient is discussed, highlighting its application in various food products and the challenges associated with the stability and bioavailability of its bioactive compounds. This review provides a comprehensive overview of the current state of research on the neuroprotective potential of Sambucus and its derivatives, offering valuable insights for the development of dietary strategies to promote brain health and prevent age-related cognitive decline.

The Different Phytochemical Profiles of Salvia officinalis Dietary Supplements Labelled for Menopause Symptoms

Phytochemical screening of four commercial products containing Salvia officinalis was carried out. Total phenolic content was estimated spectrophotometrically through the use of the Folin-Ciocalteau method, flavonoid content was measured through the use of aluminum chloride and 2,4-dinitrophenylhydrazine colorimetric assays, and isoflavones and α/β-thujones were analyzed through the use of high-performance liquid chromatograph (HPLC) and the gas chromatographic method. The analyses revealed the absence of thujones and isoflavones (i.e., genistin, genistein, and daidzein) in all four different extracts. The content of polyphenolic compounds varied among the samples, with the extract T being richer in both polyphenols and flavonoids than the other products by 1.8-3.2 and 1.4-4.0 times, respectively (p-value < 0.05). These results highlight the importance of quality control in salvia-based products since a thujone-free extract rich in polyphenols and flavonoids could be a good candidate for further preclinical and clinical studies to identify an effective herbal approach suitable for the long-term therapy of menopausal symptoms.