A common wild plant may hold hidden brain benefits. Dandelion leaf polyphenols survive digestion and continue targeting pathways associated with Alzheimer’s disease.
Study: Characterisation of Dandelion Polyphenols and Their In Vitro Neuroprotective Effects During Simulated Digestion. Image credit: DUSAN ZIDAR/Shutterstock.com
A recent study in Foods examined the enzyme-targeted neuroprotective potential of polyphenols from dandelion flowers, roots, and leaves during in vitro simulated digestion.
Pathological mechanisms and the limited therapeutics
Neurodegenerative diseases such as Alzheimer’s disease (AD) and Parkinson’s disease represent one of the most pressing challenges in modern medicine. These diseases are characterized by progressive loss of neuronal structure and function, leading to irreversible cognitive and motor decline.
A central mechanism in AD pathogenesis involves the progressive loss of cholinergic neurons and the resulting decline in brain acetylcholine (ACh) levels. This process is accelerated by elevated acetylcholinesterase (AChE) activity, the enzyme that hydrolyzes ACh.
Beyond AChE, lipoxygenase (LOX) and reactive nitrogen species (RNS) are also involved. A dysregulated LOX activity promotes neuroinflammation, while RNS accumulation under oxidative stress can trigger neuronal death.
As global populations age, prevalence rates of neurodegenerative diseases are rising sharply. Despite decades of research, disease-modifying therapies remain difficult to achieve, and current pharmacological approaches largely manage symptoms rather than addressing underlying pathology. This has intensified interest in naturally derived compounds as complementary or preventive strategies.
Polyphenols are among the most biologically active plant metabolites with reported neuroprotective effects. While digestion generally reduces phenolic content, some fractions increase at specific stages and retain post-digestive enzyme-inhibitory activity, such as inhibition of AChE, highlighting their potential functional relevance after digestion and the importance of studying them in food-relevant conditions.
Assessing the neuroprotective functions of dandelion
Dandelion (Taraxacum officinale), widely used in traditional medicine, is a rich source of flavonoids and phenolic acids, making it a compelling subject for neuroprotection research. This study investigates polyphenol content, phenolic composition, and enzyme-targeted neuroprotective activity across different anatomical parts of the dandelion to assess its potential as a neuroprotective functional food ingredient.
The authors harvested and air-dried dandelions from Yuncheng, China, in March 2023. Dried flowers, roots, and leaves were ground and sieved, and polyphenols were extracted using a standard protocol. Total Polyphenol Content (TPC) and Total Flavonoid Content (TFC) were estimated. Researchers also determined and quantified individual polyphenols.
The enzyme-inhibitory and antioxidant-related neuroprotective effects of dandelion polyphenols were assessed in vitro, and a simulated digestion model was used to evaluate their behavior during the oral, gastric, and intestinal phases.
Digestive bioaccessibility of dandelion leaf polyphenols drives superior neuroprotective effect
Dandelion leaves (DL) consistently yielded the richest polyphenol profile, recording the highest total phenolic content (TPC) of 3986.67 mg GAE/100 g (≈39.87 mg/g) and total flavonoid content (TFC) of 3250.00 mg RE/100 g (≈32.50 mg/g) among the three plant parts examined. Dandelion flowers (DF) ranked second, while dandelion roots (DR) contained the lowest levels of both phenolics and flavonoids.
Beyond total polyphenol content, the individual phenolic profiles differed markedly across plant parts. Protocatechuic acid and chicoric acid were most concentrated in DL, whereas rutin and caffeic acid accumulated preferentially in DF.
Ultra-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS) analysis of all three tissue extracts identified 84 compounds across four chemical subclasses, predominantly phenolic acids. In addition, caffeoylquinic acid derivatives and hydroxybenzoic acid derivatives, flavonoids comprising both free aglycones and glycosylated forms, coumarins, and a single tannin completed the profile.
Multivariate analysis using principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and hierarchical clustering heat maps collectively revealed clear tissue-specific differences in dandelion metabolite composition. Overall, flavonoids and phenolic acids together dominated the compound class distribution in near-equal proportions (~46% each), reinforcing their central role in defining the chemical identity of each dandelion tissue.
All three dandelion tissue extracts inhibited AChE in a concentration-dependent manner, with DL consistently outperforming DF and DR, suggesting that dandelion leaf is a promising natural candidate for cholinesterase-targeted strategies in Alzheimer’s disease management. This is likely to involve non-competitive inhibition mechanisms observed with plant polyphenols.
DL showed the strongest LOX inhibitory activity, followed by DF and DR. At low concentrations, DF demonstrated markedly superior RNS scavenging over DL and DR, suggesting its phenolic composition is particularly effective against nitrogen-centred radicals.
TPC increased modestly during oral digestion, declined under gastric acidity, then increased substantially during the intestinal phase, reaching the highest levels across all samples as hydrolases and bile salts released bound phenolics.
Meanwhile, TFC peaked at the oral stage, declined under gastric conditions, and partially recovered during the intestinal phase, with DL maintaining the highest levels throughout. Across all digestion stages, DL consistently released the highest combined quantities of total phenols and flavonoids, followed by DF and DR.
Following simulated digestion, all three tissues retained measurable but generally reduced AChE-inhibitory, LOX-inhibitory, and RNS-scavenging activities. AChE inhibition was highest in the oral phase and declined progressively through gastric and intestinal stages, with reductions partly attributed to structural changes in phenolic compounds under digestive conditions and changes in interactions among phenolic constituents.
LOX inhibition was maintained or, in some cases (notably DR in the intestinal phase), enhanced, reflecting the release or activation of specific phenolics.
RNS scavenging activity remained significant across all tissues, with DF consistently showing the strongest activity, particularly at lower concentrations, while differences between tissues diminished at higher concentrations.
Conclusions
Dandelion leaves were found to be the richest source of phenols and flavonoids, with their polyphenols showing notable inhibition of enzymes involved in neurodegeneration and inflammation.
Together, these findings suggest that dandelion leaves, in particular, hold meaningful potential as a functional food ingredient for supporting neurological health and reducing the risk of conditions such as Alzheimer’s disease. Although these findings are based on in vitro enzyme assays and simulated digestion models, in vivo studies are needed to confirm these outcomes.
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Journal reference:
Guo, C. et al. (2026) Characterisation of Dandelion Polyphenols and Their In Vitro Neuroprotective Effects During Simulated Digestion. Foods. 15(7). DOI: https://doi.org/10.3390/foods15071126. https://www.mdpi.com/2304-8158/15/7/1126