Plants, Plants, and More Plants: Plant-Derived Nutrients and Their Protective Roles in Cognitive Function, Alzheimer’s Disease, and Other Dementias

Pharmacognostic evaluation and antimicrobial activity of Pteridium aquilinum (L.) Kuhn leaves (Onocleaceae) via in vitro and in silico perspectives

BACKGROUND AND OBJECTIVE

Traditionally, Pteridium aquilinum L. has been utilized as medicine for ages, however, it is not listed in the Nigerian herbal pharmacopeia, and there is no information regarding its standardization and antimicrobial activity. Therefore, the purpose of this study was to examine the pharmacognostic parameters and antimicrobial activity of Pteridium aquilinum leaf.

METHODS

Macroscopy, chemo-microscopy, fluorescence, and microscopic analyses of the leaf were investigated using standard methods. Qualitative and quantitative phytochemical screening, thin layer chromatography (TLC), GC-MS, and FTIR were also determined using standard procedures. Antioxidants were evaluated using DPPH. The antimicrobial activities of methanol extract and fractions were evaluated using Agar well diffusion method against Candida albicans, Aspergillus niger, Staphylococcus aureus, Salmonella Typhimurium, Escherichia coli, and Pseudomonas aeruginosa. The macroscopic features of P. aquilinum leaf include a bi-pinnate leaflet and alternate pinna arrangement. The GC-MS-identified compounds in the most active (DCM fraction) were docked against Candida albicans Sterol 14-alpha demethylase (5TZ1) and Escherichia coli DNA gyrase subunit B (6YD9).

RESULTS

The macroscopic features and microscopic features such as anomocytic stomata, numerous stomata in the abaxial layer, and absence of stomata in the adaxial layer were observed. Chemomicroscopy of the powdered leaves shows that the leaf contains tannins, starch, and lignin. GC-MS detected eighteen compounds. The antimicrobial test revealed that the dichloromethane fraction of P. aquilinum leaf was most active on all the test strains (bacteria and fungi) at 25 mg/mL to 100 mg/mL concentrations. Through in silico research, the binding of 1,2-benzenedicarboxylic acid, (4-hydroxybenzoyl) hydrazine, octadecadienoyl chloride, and 11,14-Eicosadienoic acid, detected in the DCM fraction by GC-MS analysis, to the active sites of 5TZ1 and 6YD9 was stable.

CONCLUSION

This research gave scientific credence to the traditional medical practice of treating infections with P. aquilinum leaves.

Neuroprotective Properties of Clove (Syzygium aromaticum): State of the Art and Future Pharmaceutical Applications for Alzheimer's Disease

This study explores the neuropharmacological potential of various molecular and amino acid components derived from Syzygium aromaticum (clove), an aromatic spice with a long history of culinary and medicinal use. Key bioactive compounds such as eugenol, α-humulene, β-caryophyllene, gallic acid, quercetin, and luteolin demonstrate antioxidant, anti-inflammatory, and neuroprotective properties by scavenging free radicals, modulating calcium channels, and reducing neuroinflammation and oxidative stress. Moreover, gallic acid and asiatic acid may exhibit protective effects, including neuronal apoptosis inhibition, while other useful properties of clove phytocompounds include NF-κB pathway inhibition, membrane stabilization, and suppression of pro-inflammatory pathways, possibly in neurons or other relevant cell types, further contributing to neuroprotection and cognitive enhancement. Amino acid analysis revealed essential and non-essential amino acids such as aspartic acid, serine, glutamic acid, glycine, histidine, and arginine in various clove parts (buds, fruits, branches, and leaves). These amino acids play crucial roles in neurotransmitter synthesis, immune modulation, antioxidant defense, and metabolic regulation. Collectively, these bioactive molecules and amino acids contribute to clove's antioxidant, anti-inflammatory, neurotrophic, and neurotransmitter-modulating effects, highlighting its potential as a preventive and therapeutic candidate for neurodegenerative disorders. While preliminary preclinical studies support these neuroprotective properties, further research, including clinical trials, is needed to validate the efficacy and safety of clove-based interventions in neuroprotection.

Exploring Plant-Based Nutrition for Patients with Substance Use Disorders: A Scoping Review of Dietary Intake and Potential Applications

BACKGROUND

Substance use disorders (SUDs) represent a significant global public health challenge, with affected individuals often exhibiting poor dietary habits, nutritional deficiencies, and compromised mental and physical health. This scoping review evaluates existing literature on dietary intake in individuals with SUDs, focusing on the potential benefits of plant-based dietary interventions for improving nutritional status and supporting recovery.

METHODS

A scoping review was conducted following PRISMA guidelines. Four databases were searched using PICO-based terms, targeting studies assessing dietary intake in patients with SUD, particularly plant-based interventions. Inclusion criteria were studies reporting macro- and micronutrient intake among patients with SUD, while studies lacking direct dietary intake data were excluded. Study quality was appraised using the STROBE checklist.

RESULTS

The search yielded 1142 potential articles, with 6 meeting inclusion criteria (4 from the United States and 2 from Iran). Patients with SUD exhibited significant deficiencies in iron (-16.8%, P = .04), folate (-15.0%, P = .04), and vitamins E and A, alongside diets high in simple carbohydrates and unhealthy processed foods. Plant-based dietary interventions were associated with improved Healthy Eating Index scores (P < .001), increased resilience (+31%, P = .031), and enhanced self-esteem (P = .043). High energy intake and low multivitamin use were reported among methadone-treated patients, emphasizing the need for dietary interventions to address nutrient gaps and support recovery.

CONCLUSION

Plant-based dietary interventions may offer a promising strategy to address nutrient deficiencies and improve mental health outcomes in patients with SUD. However, studies are limited, with small sample sizes and variability in dietary assessments. Future research, including randomized controlled trials, is needed to establish the efficacy and feasibility of integrating plant-based nutrition into SUD treatment programs. Addressing barriers such as socioeconomic challenges and food access is also crucial for implementing effective dietary interventions.

The association between dietary dark green vegetable intake and cognitive function in US older adults

Dark green vegetables include dark green leafy vegetables and broccoli. They are sources of many essential nutrients, including vitamins A, B and C, folate, fibre, carotenoids and flavonoids. This study aimed to explore the association between dietary dark green vegetable intake and cognitive function in US older adults. We included 2344 older adults (≥60 years old) from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 cycles. Dark green vegetable consumption was assessed using a continuous variable (cups/day) and two categorical variables. The first categorical variable classified participants into non-consumers and consumers based on whether they consumed dark green vegetables. The second categorical variable grouped participants into four levels of dark green vegetable consumption (non-consumers, consumers with low intakes, consumers with moderate intakes and consumers with high intakes). We used five continuous variables with non-normal distribution to assess cognitive function, including a composite z-score and the standardised scores of four individual cognitive tests. The four cognitive tests included the Immediate Recall Test (IRT), the Delayed Recall Test (DRT), the Animal Mobility Test (AFT) and the Digit Symbol Substitution Test (DSST). The standardised scores of the four cognitive tests were calculated using the mean and standard deviation of each cognitive test score. The composite z-score was calculated by averaging the standardised scores of four cognitive tests to evaluate global cognition. We used multiple linear regression models to examine the association between dietary dark green vegetable intake and cognitive function. Our findings indicated that dark green vegetable intake was positively associated with global cognition (β [95% CI]: 0.17 [0.04, 0.30]; p = 0.016) and IRT (β [95% CI]: 0.26 [0.08, 0.43]; p = 0.009) and DRT (β [95% CI]: 0.21 [0.05, 0.36]; p = 0.012) standardised scores. Individuals with high intake of dark green vegetables showed notably better global cognition (β [95% CI]: 0.16 [0.05, 0.28]; p = 0.010) and showed higher IRT (β [95% CI]: 0.22 [0.07, 0.38]; p = 0.010) and DRT standardised scores (β [95% CI]: 0.21 [0.07, 0.36]; p = 0.007) compared with the non-consumers. Blood neutrophil counts mediated the cognitive benefits of dark green vegetables (Proportion: 9.5%, p = 0.006). In conclusion, our findings suggest that dark green vegetable consumption may have favourable effects on cognitive function in US older adults, especially on immediate and delayed learning abilities. The underlying mechanisms include the ability of dark green vegetables to reduce blood neutrophil levels, an indicator of decreased systemic inflammation. Increasing dietary intake of dark green vegetables may be a beneficial intervention to improve cognitive health in the older US population.

Causal association between plant foods intake and Alzheimer's disease: a Mendelian randomization study

BACKGROUND

Alzheimer's disease (AD) is a degenerative disease of the nervous system. Observational studies have found an association between plant food intake and AD. However, it is unclear whether this association is influenced by confounding factors. We aimed to explore the causal relationship between plant-based diet and the risk of AD using two-sample Mendelian randomization.

MATERIALS AND METHODS

We obtained datasets of exposure from the IEU Open GWAS project, including dried fruit intake, fresh fruit intake, raw vegetable intake, cooked vegetable intake, and cereal intake. The summary data for AD were obtained from a large GWAS meta-analysis containing 71,880 cases and 383,378 controls.

RESULTS

Increased intake of dried fruits was associated with a reduced risk of AD (IVW: OR = 0.88, 95CI = 0.82-0.95). No causal association was found between the intake of other foods and AD.

CONCLUSION

This MR study suggests that genetically predicted increased intake of dried fruits is a causal protective factor for AD.

Mushroom-derived bioactive components with definite structures in alleviating the pathogenesis of Alzheimer's disease

Alzheimer's disease (AD) is a complicated neurodegenerative condition with two forms: familial and sporadic. The familial presentation is marked by autosomal dominance, typically occurring early in individuals under 65 years of age, while the sporadic presentation is late-onset, occurring in individuals over the age of 65. The majority of AD cases are characterized by late-onset and sporadic. Despite extensive research conducted over several decades, there is a scarcity of effective therapies and strategies. Considering the lack of a cure for AD, it is essential to explore alternative natural substances with higher efficacy and fewer side effects for AD treatment. Bioactive compounds derived from mushrooms have demonstrated significant potential in AD prevention and treatment by different mechanisms such as targeting amyloid formation, tau, cholinesterase dysfunction, oxidative stress, neuroinflammation, neuronal apoptosis, neurotrophic factors, ER stress, excitotoxicity, and mitochondrial dysfunction. These compounds have garnered considerable interest from the academic community owing to their advantages of multi-channel, multi-target, high safety and low toxicity. This review focuses on the various mechanisms involved in the development and progression of AD, presents the regulatory effects of bioactive components with definite structure from mushroom on AD in recent years, highlights the possible intervention pathways of mushroom bioactive components targeting different mechanisms, and discusses the clinical studies, limitations, and future perspectives of mushroom bioactive components in AD prevention and treatment.

Special Issue "Commemorative Issue Celebrating the 20th Anniversary of the Alzheimer's Foundation of America: Understanding and Treating Alzheimer's Disease"

Alzheimer's disease (AD) is the most common form of dementia in older persons [...].

Current perspectives on prevention of vascular cognitive impairment and promotion of vascular brain health

INTRODUCTION

The true global burden of vascular cognitive impairment (VCI) is unknown. Reducing risk factors for stroke and cardiovascular disease would inevitably curtail VCI.

AREAS COVERED

The authors review current diagnosis, epidemiology, and risk factors for VCI. VCI increases in older age and by inheritance of known genetic traits. They emphasize modifiable risk factors identified by the 2020 Lancet Dementia Commission. The most profound risks for VCI also include lower education, cardiometabolic factors, and compromised cognitive reserve. Finally, they discuss pharmacological and non-pharmacological interventions.

EXPERT OPINION

By virtue of the high frequencies of stroke and cardiovascular disease the global prevalence of VCI is expectedly higher than prevalent neurodegenerative disorders causing dementia. Since ~ 90% of the global burden of stroke can be attributed to modifiable risk factors, a formidable opportunity arises to reduce the burden of not only stroke but VCI outcomes including progression from mild to the major in form of vascular dementia. Strict control of vascular risk factors and secondary prevention of cerebrovascular disease via pharmacological interventions will impact on burden of VCI. Non-pharmacological measures by adopting healthy diets and encouraging physical and cognitive activities and urging multidomain approaches are important for prevention of VCI and preservation of vascular brain health.

Composition of healthy diets for older persons

PURPOSE OF REVIEW

This study aims to review recent evidence (2022-2023) on the role of diet in promoting healthy aging in older adults.

RECENT FINDINGS

Current evidence of diet and healthy aging is limited to epidemiological studies. A healthy diet is beneficial for individual domains of intrinsic capacity, that is, cognition, locomotion, vitality, psychological, and/or sensory functions, with sex-specific differences reported. Only a few studies used the multidimensional concept of intrinsic capacity as an outcome. This review supports that a healthy diet for older adults consists of plenty of plant-based foods, adequate protein-rich foods, and healthy fats. Next to quantity, improving the quality and variety within food groups play a role in optimizing health. Data on the associations between adherence to national food-based dietary guidelines and intrinsic capacity are scarce.

SUMMARY

A healthy diet, centered on plant-based foods, adequate protein-rich foods and healthy fats, potentially promotes healthy aging. Future studies may evaluate the association between adherence to healthy dietary patterns (particularly national food-based dietary guidelines) and the multidimensional concept of intrinsic capacity, with consideration of sex-specific differences. Clinical trials are warranted to inform the causal effects of diet and outcomes related to intrinsic capacity.

Abelmoschus eculentus Seed Extract Exhibits In Vitro and In Vivo Anti-Alzheimer's Potential Supported by Metabolomic and Computational Investigation

Abelmoschus esculentus Linn. (okra, F. Malvaceae) is a fruit widely consumed all over the world. In our study, the anti-Alzheimer's potential of A. esculentus was evaluated. An in vitro DPPH free radical assay on A. esculentus seed's total extract and AChE inhibition potential screening indicated a significant anti-Alzheimer's activity of the extract, which was confirmed through an in vivo study in an aluminum-intoxicated rat model. Additionally, in vivo results demonstrated significant improvement in Alzheimer's rats, which was confirmed by improving T-maze, beam balance tests, lower serum levels of AChE, norepinephrine, glycated end products, IL-6, and MDA. The levels of dopamine, BDNF, GSH, and TAC returned to normal values during the study. Moreover, histological investigations of brain tissue revealed that the destruction in collagen fiber nearly returns back to the normal pattern. Metabolomic analysis of the ethanolic extract of A. esculentus seeds via LC-HR-ESI-MS dereplicated ten compounds. A network pharmacology study displayed the relation between identified compounds and 136 genes, among which 84 genes related to Alzheimer's disorders, and focused on AChE, APP, BACE1, MAPT and TNF genes with interactions to all Alzheimer's disorders. Consequently, the results revealed in our study grant potential dietary elements for the management of Alzheimer's disorders.

Gut microbiota, pathogenic proteins and neurodegenerative diseases

As the world's population ages, neurodegenerative diseases (NDs) have brought a great burden to the world. However, effective treatment measures have not been found to alleviate the occurrence and development of NDs. Abnormal accumulation of pathogenic proteins is an important cause of NDs. Therefore, effective inhibition of the accumulation of pathogenic proteins has become a priority. As the second brain of human, the gut plays an important role in regulate emotion and cognition functions. Recent studies have reported that the disturbance of gut microbiota (GM) is closely related to accumulation of pathogenic proteins in NDs. On the one hand, pathogenic proteins directly produced by GM are transmitted from the gut to the central center via vagus nerve. On the other hand, The harmful substances produced by GM enter the peripheral circulation through intestinal barrier and cause inflammation, or cross the blood-brain barrier into the central center to cause inflammation, and cytokines produced by the central center cause the production of pathogenic proteins. These pathogenic proteins can produced by the above two aspects can cause the activation of central microglia and further lead to NDs development. In addition, certain GM and metabolites have been shown to have neuroprotective effects. Therefore, modulating GM may be a potential clinical therapeutic approach for NDs. In this review, we summarized the possible mechanism of NDs caused by abnormal accumulation of pathogenic proteins mediated by GM to induce the activation of central microglia, cause central inflammation and explore the therapeutic potential of dietary therapy and fecal microbiota transplantation (FMT) in NDs.