Emerging role of polyphenolic compounds in the treatment of neurodegenerative diseases: a review of their intracellular targets

Recent Advances in the Inhibition of Membrane Lipid Peroxidation by Food-Borne Plant Polyphenols via the Nrf2/GPx4 Pathway

Lipid peroxidation (LP) leads to changes in the fluidity and permeability of cell membranes, affecting normal cellular function and potentially triggering apoptosis or necrosis. This process is closely correlated with the onset of many diseases. Evidence suggests that the phenolic hydroxyl groups in food-borne plant polyphenols (FPPs) make them effective antioxidants capable of preventing diseases triggered by cell membrane LP. Proper dietary intake of FPPs can attenuate cellular oxidative stress, especially damage to cell membrane phospholipids, by activating the Nrf2/GPx4 pathway. Nuclear factor E2-related factor 2 (Nrf2) is an oxidative stress antagonist. The signaling pathway regulated by Nrf2 is a defense transduction pathway of the organism against external stimuli such as reactive oxygen species and exogenous chemicals. Glutathione peroxidase 4 (GPx4), under the regulation of Nrf2, is the only enzyme that reduces cell membrane lipid peroxides with specificity, thus playing a pivotal role in regulating cellular ferroptosis and counteracting oxidative stress. This study explored the Nrf2/GPx4 pathway mechanism, antioxidant activity of FPPs, and mechanism of LP. It also highlighted the bioprotective properties of FPPs against LP and its associated mechanisms, including (i) activation of the Nrf2/GPx4 pathway, with GPx4 potentially serving as a central target protein, (ii) regulation of antioxidant enzyme activities, leading to a reduction in the production of ROS and other peroxides, and (iii) antioxidant effects on LP and downstream phospholipid structure. In conclusion, FPPs play a crucial role as natural antioxidants in preventing LP. However, further in-depth analysis of FPPs coregulation of multiple signaling pathways is required, and the combined effects of these mechanisms need further evaluation in experimental models. Human trials could provide valuable insights into new directions for research and application.

Ginkgo biloba extract mitigates the neurotoxicity of AlCl3 in alzheimer rat's model: role of apolipoprotein E4 and clusterin genes in stimulating ROS generation and apoptosis

PURPOSE

Alzheimer's disease (AD) appears as a result of an increase in the accumulation of amyloid beta peptide (Aβ) and a decrease in neurotransmitters (acetylcholine) within the brain cells which may be due to increase in acetylcholinesterase (AchE) activity and change in expression of Apolipoprotein E4 (ApoE4) and Clusterin (Clu) genes. The aim of the present study was using natural products such as Ginkgo biloba (G. biloba) extract that has the potential to reduce Aβ formation and increase AchE inhibition with its ability to save neuronal DNA from damage.

METHODS

Sixty male aged rats were divided into six experimental groups exposed to AlCl3 to induce AD model and were treated with G. biloba extract. Collected brain tissues were used to assess the apoptosis rate, reactive oxygen species (ROS) generation, AchE inhibitory activity, expression alteration in ApoE4 and Clu genes, DNA fragmentations and gutathione peroxidase (GPx) activity.Results: The results exhibited that rats exposed to AlCl3 increased significantly rate of apoptosis, ROS formation, DNA fragmentation, up-regulation of ApoE4 and Clu genes as well as decrease of AchE inhibitory activity and GPx activity compared with those in control rats. However, treatment of AlCl3-rats with G. biloba extract improved the above neurotoxicity results induced by AlCl3 exposure.

CONCLUSIONS

It is therefore likely that G. biloba extract's protective properties against AD are due to its ability to activate the response against oxidative stress.

Chemical Characterization and Biological Properties of Leguminous Honey

Honey can beneficially act against different human diseases, helping our body to improve its health. The aim of the present study was first to increase knowledge of some biochemical characteristics (amount and composition of polyphenols and volatile organic compounds, vitamin C content) of five Italian legume honeys (alfalfa, astragalus, carob, indigo, and sainfoin). Furthermore, we evaluated their potential health properties by studying their antioxidant and in vitro anti-inflammatory activities and in vitro inhibitory effects on three enzymes involved in neurodegenerative diseases (acetylcholinesterase, butyrylcholinesterase, and tyrosinase). Alfalfa honey showed the highest total polyphenol content (TPC) (408 μg g-1 of product). Indigo honey showed the lowest TPC (110 μg g-1 of product). The antioxidant activity was noteworthy, especially in the case of sainfoin honey (IC50 = 6.08 mg), which also exhibited excellent inhibitory action against butyrylcholinesterase (74%). Finally, the correlation between the biochemical and functional results allowed us to identify classes of molecules, or even single molecules, present in these five honeys, which are capable of influencing the properties indicated above.

Structure-activity relationship and docking analysis of nature flavonoids as inhibitors of human and rat gonadal 3β-hydroxysteroid dehydrogenases for therapeutic purposes

The potential inhibitory effects of flavonoids on gonadal steroid biosynthesis have gained attention due to their widespread presence in natural plant sources. Specifically, our study focused on evaluating the inhibitory efficacy of these compounds on human 3β-hydroxysteroid dehydrogenase 2 (h3β-HSD2) and rat homolog r3β-HSD1, enzymes responsible for the conversion of pregnenolone to progesterone. Through our investigations, we observed that the potency of flavonoids was silymarin (IC50, 1.31 μM) > luteolin (4.63 μM) > tectorigenin > (5.86 μM), and rutin (44.12 μM) in inhibiting human KGN cell microsomal h3β-HSD2. Similarly, the potency of flavonoids was silymarin (9.50 μM) > luteolin (11.49 μM) > tectorigenin (14.06 μM), and rutin (145.71 μM) in inhibiting rat testicular r3β-HSD1. Silymarin, luteolin, and tectorigenin acted as mixed inhibitors of both human and rat 3β-HSDs. Luteolin and tectorigenin were able to penetrate human KGN cells to inhibit progesterone secretion. Furthermore, docking analysis and structure-activity relationship analysis highlighted the importance of hydrogen bond formation for the inhibitory efficacy of these compounds against h3β-HSD2 and r3β-HSD1. Overall, this study demonstrates that silymarin exhibits the most potent inhibition of human and rat gonadal 3β-HSDs, and significant SAR differences exist among the tested compounds.

Screening of Active Substances Regulating Alzheimer's Disease in Ginger and Visualization of the Effectiveness on 6-Gingerol Pathway Targets

Ginger has been reported to potentially treat Alzheimer's disease (AD), but the specific compounds responsible for this biological function and their mechanisms are still unknown. In this study, a combination of network pharmacology, molecular docking, and dynamic simulation technology was used to screen active substances that regulate AD and explore their mechanisms. The TCMSP, GeneCards, OMIM, and DisGeNET databases were utilized to obtain 95 cross-targets related to ginger's active ingredients and AD as key targets. A functional enrichment analysis revealed that the pathways in which ginger's active substances may be involved in regulating AD include response to exogenous stimuli, response to oxidative stress, response to toxic substances, and lipid metabolism, among others. Furthermore, a drug-active ingredient-key target interaction network diagram was constructed, highlighting that 6-Gingerol is associated with 16 key targets. Additionally, a protein-protein interaction (PPI) network was mapped for the key targets, and HUB genes (ALB, ACTB, GAPDH, CASP3, and CAT) were identified. Based on the results of network pharmacology and cell experiments, 6-Gingerol was selected as the active ingredient for further investigation. Molecular docking was performed between 6-Gingerol and its 16 key targets, and the top three proteins with the strongest binding affinities (ACHE, MMP2, and PTGS2) were chosen for molecular dynamics analysis together with the CASP3 protein as the HUB gene. The findings indicate that 6-Gingerol exhibits strong binding ability to these disease targets, suggesting its potential role in regulating AD at the molecular level, as well as in abnormal cholinesterase metabolism and cell apoptosis, among other related regulatory pathways. These results provide a solid theoretical foundation for future in vitro experiments using actual cells and animal experiments to further investigate the application of 6-Gingerol.

Lonicerae Japonicae Caulis: a review of its research progress of active metabolites and pharmacological effects

Lonicerae Japonicae Caulis is the aboveground stem part of the Lonicera Japonica Thunb, which belongs to the medicine food homology species in China. It has the effects of clearing away heat, toxic material, dredging wind and unblocking collaterals. Modern research shows that it contains various active metabolites and a wide range of pharmacological effects, which is of great research and clinical application value. It mainly contains organic acids, volatile oils, flavonoids, triterpenes, triterpene saponins and other active metabolites. Its pharmacological effects mainly include anti-inflammatory, antibacterial, antitumor, antioxidant, and repairing bone and soft tissue. Based on the literature reports in recent years, the active metabolites, pharmacological effects and mechanisms of Lonicerae Japonicae Caulis were sorted out and summarized. It lays a foundation for explaining the efficacy material basis and application value of Lonicerae Japonicae Caulis. It aims to provide a reference for the in-depth research, development and utilization of Lonicerae Japonicae Caulis.

Cardiometabolic Risk: Characteristics of the Intestinal Microbiome and the Role of Polyphenols

Cardiometabolic diseases like hypertension, type 2 diabetes mellitus, atherosclerosis, and obesity have been associated with changes in the gut microbiota structure, or dysbiosis. The beneficial effect of polyphenols on reducing the incidence of this chronic disease has been confirmed by numerous studies. Polyphenols are primarily known for their anti-inflammatory and antioxidant properties, but they can also modify the gut microbiota. According to recent research, polyphenols positively influence the gut microbiota, which regulates metabolic responses and reduces systemic inflammation. This review emphasizes the prebiotic role of polyphenols and their impact on specific gut microbiota components in patients at cardiometabolic risk. It also analyzes the most recent research on the positive effects of polyphenols on cardiometabolic health. While numerous in vitro and in vivo studies have shown the interaction involving polyphenols and gut microbiota, additional clinical investigations are required to assess this effect in people.

The Phenolic Composition and Antioxidant Properties of Figs (Ficus carica L.) Grown in the Black Sea Region

This study compared the phenolic composition and antioxidant properties of three varieties of fig fruits (Ficus carica L) from the Eastern Black Sea region of Türkiye. Total polyphenol content (TPC), total flavonoid content (TFC), and phenolic compositions were analyzed in green, purple, and dark purple species. The mean TPC value was 42.10 ± 5.71 mg GAE/100 g FW, ranging from 35.98 to 47.30 mg GAE/100 g FW, and was highest in the dark purple species. The mean TFC value was 1.27 ± 0.93 mg QUE/100 FW g, ranging between 0.35 and 2.21 mg QUE/100 FW g, and was highest in the purple species. The samples' total antioxidant capacity was measured based on ferric reducing/antioxidant power (FRAP), the values ranging from 151.98 to 372.97 μmol FeSO4.7H2O/100 g FW, with an average value of 239.64 μmol FeSO4.7H2O/100 g FW, being highest in the dark purple species. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the fruits was expressed as SC50 (mg/mL), and the values ranged from 10.04 to 42.42 mg/mL, being highest in the purple species. The phenolic composition was analyzed using HPLC-PDA according to the method in which 25 phenolic standards were used. Chlorogenic acid and t-cinnamic acid were the most common phenolic compounds, with rutin, chrysin, apigenin, and luteolin being detected at different amounts. In conclusion, the purple species contained the highest flavonoid content, was rich in apigenin, luteolin, and chrysin, and possessed the highest DPPH radical scavenging activity.

A chemical probe unravels the reactive proteome of health-associated catechols

Catechol-containing natural products are common constituents of foods, drinks, and drugs. Natural products carrying this motif are often associated with beneficial biological effects such as anticancer activity and neuroprotection. However, the molecular mode of action behind these properties is poorly understood. Here, we apply a mass spectrometry-based competitive chemical proteomics approach to elucidate the target scope of catechol-containing bioactive molecules from diverse foods and drugs. Inspired by the protein reactivity of catecholamine neurotransmitters, we designed and synthesised a broadly reactive minimalist catechol chemical probe based on dopamine. Initial labelling experiments in live human cells demonstrated broad protein binding by the probe, which was largely outcompeted by its parent compound dopamine. Next, we investigated the competition profile of a selection of biologically relevant catechol-containing substances. With this approach, we characterised the protein reactivity and the target scope of dopamine and ten biologically relevant catechols. Strikingly, proteins associated with the endoplasmic reticulum (ER) were among the main targets. ER stress assays in the presence of reactive catechols revealed an activation of the unfolded protein response (UPR). The UPR is highly relevant in oncology and cellular resilience, which may provide an explanation of the health-promoting effects attributed to many catechol-containing natural products.

Protective Effects of Polyphenol-Rich Extracts against Neurotoxicity Elicited by Paraquat or Rotenone in Cellular Models of Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disorder involving motor symptoms caused by a loss of dopaminergic neurons in the substantia nigra region of the brain. Epidemiological evidence suggests that anthocyanin (ANC) intake is associated with a low risk of PD. Previously, we reported that extracts enriched with ANC and proanthocyanidins (PAC) suppressed dopaminergic neuron death elicited by the PD-related toxin rotenone in a primary midbrain culture model. Here, we characterized botanical extracts enriched with a mixed profile of polyphenols, as well as a set of purified polyphenolic standards, in terms of their ability to mitigate dopaminergic cell death in midbrain cultures exposed to another PD-related toxicant, paraquat (PQ), and we examined underlying neuroprotective mechanisms. Extracts prepared from blueberries, black currants, grape seeds, grape skin, mulberries, and plums, as well as several ANC, were found to rescue dopaminergic neuron loss in PQ-treated cultures. Comparison of a subset of ANC-rich extracts for the ability to mitigate neurotoxicity elicited by PQ versus rotenone revealed that a hibiscus or plum extract was only neuroprotective in cultures exposed to rotenone or PQ, respectively. Several extracts or compounds with the ability to protect against PQ neurotoxicity increased the activity of the antioxidant transcription factor Nrf2 in cultured astrocytes, and PQ-induced dopaminergic cell death was attenuated in Nrf2-expressing midbrain cultures. In other studies, we found that extracts prepared from hibiscus, grape skin, or purple basil (but not plums) rescued defects in O₂ consumption in neuronal cells treated with rotenone. Collectively, these findings suggest that extracts enriched with certain combinations of ANC, PAC, stilbenes, and other polyphenols could potentially slow neurodegeneration in the brains of individuals exposed to PQ or rotenone by activating cellular antioxidant mechanisms and/or alleviating mitochondrial dysfunction.

Biochemical Evaluation of Some Fruit Characteristics of Blueberry Progenies Obtained from 'Simultan × Duke'

The popularity of Vaccinium corymbosum blueberry cv. has increased over time because its fruits are highly valued for their taste, aroma, and multiple ways of use. A field trial with two genotypes and their hybrids was organized during 2021-2022 at the Research Institute for Fruit Growing Pitesti-Maracineni, Romania. This paper proposes a comparative analysis of the quality of berries in 17 hybrids of the 'Simultan' and 'Duke' cultivars, selected by the size and the soluble solid content, in agreement with the objectives of the blueberry breeding program. The genotype influence on berry weight, total soluble solids, pH, vitamin C, total polyphenols, total flavonoids, total anthocyanins, lycopene, β-carotene, and antioxidant activity was determined considering the climatic factors. The results showed that fruit weight varied between 1.22 and 2.47 g, total soluble solids reached a maximum of 19.22 °Brix, and the pH oscillated between 3.14 and 3.89. Vitamin C content varied from 9.52 to 18.69 mg in 100 g fresh weight, with an average of 14.35 mg/100 g. Total polyphenol, flavonoid, and anthocyanin contents averaged 709.92 mg gallic acid equivalent in 100 g fresh weight, 165.48 mg catechin equivalent in 100 g fresh weight, and 81.88 mg cyanidin-3-O-glucoside equivalent in 100 g fresh weight, respectively. Results show that the strategy of growers to produce blueberries with a large diameter, visually attractive for traders and consumers, is not sufficient for repeat sales. Our study proves that large fruits do not have the highest content of bioactive compounds. Smaller berries had higher polyphenol, lycopene, and β-carotene contents. It is recommended that the selection of the hybrid in the breeding program also takes into account the content of bioactive compounds.

Protective effects of polyphenol-rich extracts against neurotoxicity elicited by paraquat or rotenone in cellular models of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder involving motor symptoms caused by a loss of dopaminergic neurons in the substantia nigra region of the brain. Epidemiological evidence suggests that anthocyanin (ANC) intake is associated with a low risk of PD. Previously, we reported that extracts enriched with ANC and proanthocyanidins (PAC) suppressed dopaminergic neuron death elicited by the PD-related toxin rotenone in a primary midbrain culture model. Here, we characterized botanical extracts enriched with a mixed profile of polyphenols, as well as a set of purified polyphenolic standards, in terms of their ability to mitigate dopaminergic cell death in midbrain cultures exposed to another PD-related toxicant, paraquat (PQ), and we examined underlying neuroprotective mechanisms. Extracts prepared from blueberries, black currants, grape seeds, grape skin, mulberries, and plums, as well as several ANC, were found to rescue dopaminergic neuron loss in PQ-treated cultures. Comparison of a subset of ANC-rich extracts for the ability to mitigate neurotoxicity elicited by PQ versus rotenone revealed that a hibiscus or plum extract was only neuroprotective in cultures exposed to rotenone or PQ, respectively. Several extracts or compounds with the ability to protect against PQ neurotoxicity increased the activity of the antioxidant transcription factor Nrf2 in cultured astrocytes, and PQ-induced dopaminergic cell death was attenuated in Nrf2-expressing midbrain cultures. In other studies, we found that extracts prepared from hibiscus, grape skin, or purple basil (but not plums) rescued defects in O ₂ consumption in neuronal cells treated with rotenone. Collectively, these findings suggest that extracts enriched with certain combinations of ANC, PAC, stilbenes, and other polyphenols could potentially slow neurodegeneration in the brains of individuals exposed to PQ or rotenone by activating cellular antioxidant mechanisms and/or alleviating mitochondrial dysfunction.

Adsorption of Tannic Acid onto Gold Surfaces

Thin film coatings are widely applicable in materials for consumer products, electronics, optical coatings, and even biomedical applications. Wet coating can be an effective method to obtain thin films of functional materials, and this technique has recently been studied in depth for the formation of bioinspired polyphenolic films. Naturally occurring polyphenols such as tannic acid (TA) have garnered interest due to their roles in biological processes and their applicability as antioxidants, antibacterial agents, and corrosion inhibitors. Understanding the adsorption of polyphenols to surfaces is a core aspect in the fabrication processes of thin films of these materials. In this work, the adsorption of TA to gold surfaces is measured using a quartz crystal microbalance with dissipation monitoring (QCMD) and surface plasmon resonance (SPR) for a wide range of TA concentrations. The adsorption kinetics, aggregation, and stability of TA solutions in physiological-like conditions are studied. Unexpectedly, it is found that the adsorption rates depend only weakly on concentration because of the presence of TA aggregates that do not adsorb. The mechanism of layer formation is also investigated, finding that TA monolayers readily adsorb onto gold with flat or edge-on molecular orientations dependent on the solution concentration. A mix of orientations in the intermediate case leads to slow multilayer adsorption.

Latent Potential of Multifunctional Selenium Nanoparticles in Neurological Diseases and Altered Gut Microbiota

Neurological diseases remain a major concern due to the high world mortality rate and the absence of appropriate therapies to cross the blood-brain barrier (BBB). Therefore, the major focus is on the development of such strategies that not only enhance the efficacy of drugs but also increase their permeability in the BBB. Currently, nano-scale materials seem to be an appropriate approach to treating neurological diseases based on their drug-loading capacity, reduced toxicity, targeted delivery, and enhanced therapeutic effect. Selenium (Se) is an essential micronutrient and has been of remarkable interest owing to its essential role in the physiological activity of the nervous system, i.e., signal transmission, memory, coordination, and locomotor activity. A deficiency of Se leads to various neurological diseases such as Parkinson's disease, epilepsy, and Alzheimer's disease. Therefore, owing to the neuroprotective role of Se (selenium) nanoparticles (SeNPs) are of particular interest to treat neurological diseases. To date, many studies investigate the role of altered microbiota with neurological diseases; thus, the current review focused not only on the recent advancement in the field of nanotechnology, considering SeNPs to cure neurological diseases, but also on investigating the potential role of SeNPs in altered microbiota.

Protective Effects of Currants (Vitis vinifera) on Corticolimbic Serotoninergic Alterations and Anxiety-like Comorbidity in a Rat Model of Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of nigral dopaminergic neurons. Increasing evidence supports that PD is not simply a motor disorder but a systemic disease leading to motor and non-motor symptoms, including memory loss and neuropsychiatric conditions, with poor management of the non-motor deficits by the existing dopaminergic medication. Oxidative stress is considered a contributing factor for nigrostriatal degeneration, while antioxidant/anti-inflammatory properties of natural phyto-polyphenols have been suggested to have beneficial effects. The present study aimed to determine the contribution of monoaminergic neurotransmission on the anxiety-like phenotype in a rat rotenone PD model and evaluate the possible neuroprotective effects of black Corinthian currant, Vitis vinifera, consisting of antioxidant polyphenols. Rotenone-treated rats showed anxiety-like behavior and exploratory deficits, accompanied by changes in 5-HT, SERT and β₂-ARs expression in the prefrontal cortices, hippocampus and basolateral amygdala. Importantly, the motor and non-motor behavior, as well as 5-HT, SERT and β₂-ARs expression patterns of the PD-like phenotype were partially recovered by a supplementary diet with currants. Overall, our results suggest that the neuroprotective effects of Corinthian currants in rotenone-induced anxiety-like behavior may be mediated via corticolimbic serotonergic transmission.

Possible Utilization of Two-Phase Olive Pomace (TPOP) to Formulate Potential Functional Beverages: A Preliminary Study

The demand for functional beverages is expanding over the world. In this work, a rapid, easy and low-cost procedure was followed to prepare a functional beverage (FB) by directly using two-phase olive pomace (TPOP). Liquid ingredients (water and 6% citric acid), extraction systems (heat and ultrasonic treatment), treatment time (30, 60, 90 min) and drying techniques (freeze and air-dried) were studied. Experimented TPOP had a total phenol content of 7.5 mg/g CAE (caffeic acid equivalent), composed majorly of o-diphenols. Air drying of TPOP caused a 50% depletion of total phenols compared to freeze drying. Conversely, no substantial differences were found in the FB, neither for liquid ingredients nor treatment/time adopted. Both 6% citric acid and water were revealed to be profitable liquid ingredients. A 30-min heating treatment was enough to produce a satisfactory beverage, whereas ultrasound treatment caused a loss of total phenols, especially in the water FB. All FBs appeared just limpid after a simple filtration; the citric acid beverage showed reddish color, while water ones were brownish. Finally, the prepared FBs had an average total phenol of about 600 mg/L CAE (by using 300 g/L fresh pomace), with hydroxytyrosol and related compounds being well represented, which confirmed their potential functionality.

Trans-Resveratrol Decreases Membrane Water Permeability: A Study of Cholesterol-Dependent Interactions

Resveratrol (RSV), a biologically active plant phenol, has been extensively investigated for cancer prevention and treatment due to its ability to regulate intracellular targets and signaling pathways which affect cell growth and metastasis. The non-specific interactions between RSV and cell membranes can modulate physical properties of membranes, which in turn can affect the conformation of proteins and perturb membrane-hosted biological functions. This study examines non-specific interactions of RSV with model membranes having varying concentrations of cholesterol (Chol), mimicking normal and cancerous cells. The perturbation of the model membrane by RSV is sensed by changes in water permeability parameters, using Droplet Interface Bilayer (DIB) models, thermotropic properties from Differential Scanning Calorimetry, and structural properties from confocal Raman spectroscopy, all of which are techniques not complicated by the use of probes which may themselves perturb the membrane. The nature and extent of interactions greatly depend on the presence and absence of Chol as well as the concentration of RSV. Our results indicate that the presence of RSV decreases water permeability of lipid membranes composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), indicating a capability for RSV in stiffening fluidic membranes. When Chol is present, however, (at 4:1 and 2:1 mol ratio DOPC to cholesterol), the addition of RSV has no significant effect upon the water permeability. DSC thermograms show that RSV interacts with DOPC and DOPC/Chol bilayers and influences their thermotropic phase behavior in a concentration-dependent manner, by decreasing the main phase transition temperature and enthalpy, with a phase separation shown at the higher concentrations of RSV. Raman spectroscopic studies indicate an ordering effect of RSV on DOPC supported bilayer, with a lesser extent of ordering in the presence of Chol. Combined results from these investigations highlight a differential effect of RSV on Chol-free and Chol-enriched membranes, respectively, which results constitute a bellwether for increased understanding and effective use of resveratrol in disease therapy including cancer.

Traversing through half a century research timeline on Ginkgo biloba, in transforming a botanical rarity into an active functional food ingredient

Neurodegenerative diseases and various other chronic ailments have gradually transformed into public-health issues. Neurodegenerative disorders are a range of progressive neural abnormalities characterized by cellular dysfunctions, neuronal structure, and function loss. Among many chronic disorders, oxidative stress, inflammation, mitochondrial dysregulation, and cellular alterations in the human body are considered the most prevalent diagnostic symptoms. They have a profound impact on patients' health and wellbeing. The disease's poor curability, high healthcare costs, and lethality are the principal reasons for approaching and exploring the conventional treatment's phytotherapeutic alternatives. Ginkgo biloba (Maidenhair tree) is a well-known and widely used herbal plant in the Ginkgoaceae family. Its phytochemical constituents, Flavonoids, and terpenes, have been identified as the primary ingredients of Ginkgo biloba leaf extracts. It has been widely used due to its therapeutic properties, including its neuroprotective, anti-dementia, antioxidant, anti-inflammatory, vasoactive, anti-psychotic, anti-neoplastic, and anti-platelet activity. In recent decades, plenty of Ginkgo-derived substances has been researched and elucidated to have significant therapeutic effects in numerous disease models. This review aims to provide a thorough understanding of the botanical basis for Ginkgo biloba, its usage as herbal medicine, and its pivotal role in functional foods. Additionally, the clinical significance of Ginkgo biloba, as observed in various research works and clinical investigations, is also emphasized, facilitating a better understanding of their molecular basis and application in many chronic diseases.

Unraveling the Phytochemistry, Traditional Uses, and Biological and Pharmacological Activities of Thymus algeriensis Boiss. & Reut

Growing concern for public health has increased the need to change the paradigm towards a healthcare system that advocates holistic practices while reducing adverse effects. Herbal therapy is becoming an integral part of the therapeutic arsenal, and several successful plant-derived compounds/molecules are being introduced into the market. The medicinal plants belonging to the genus Thymus are among the most important species within the Lamiaceae family. One of them is Thymus algeriensis which is mainly distributed in the Mediterranean region. For a long time, this species has been used in traditional medicine to treat several disorders and diseases including inflammation, diabetes, rheumatism, digestive, and respiratory affections. This review describes the traditional uses, phytochemical composition, and biological and pharmacological activities of T. algeriensis extracts. Data were obtained using electronic databases such as SciFindern, ScienceDirect, Scopus, and Web of Science. Several plant-based extracts and a broad spectrum of identified secondary metabolites were highlighted and discussed with respective activities and modes of action. T. algeriensis represents a promising natural resource for the pharmaceutical industry mainly for antioxidant, anti-inflammatory, antimicrobial, and anticancer activities. Considering these findings, more research is needed to transmute the conventional uses of T. algeriensis into scientifically sound information. Moreover, extensive preclinical, clinical, toxicological, and pharmacokinetic trials on this species and its derivatives compounds are required to underpin the mechanisms of action and ensure its biosafety and efficiency. This comprehensive review provides a scientific basis for future investigations on the use of T. algeriensis and derived compounds in health maintenance and promotion and disease prevention.

Introducing melatonin to the horticultural industry: physiological roles, potential applications, and challenges

Melatonin (N-acetyl-5-methoxytryptamine) is an emerging biomolecule that influences horticultural crop growth, flowering, fruit ripening, postharvest preservation, and stress protection. It functions as a plant growth regulator, preservative and antimicrobial agent to promote seed germination, regulate root system architecture, influence flowering and pollen germination, promote fruit production, ensure postharvest preservation, and increase resistance to abiotic and biotic stresses. Here, we highlight the potential applications of melatonin in multiple aspects of horticulture, including molecular breeding, vegetative reproduction, production of virus-free plants, food safety, and horticultural crop processing. We also discuss its effects on parthenocarpy, autophagy, and arbuscular mycorrhizal symbiosis. Together, these many features contribute to the promise of melatonin for improving horticultural crop production and food safety. Effective translation of melatonin to the horticultural industry requires an understanding of the challenges associated with its uses, including the development of economically viable sources.

Peanut (Arachis hypogaea) sprout prevents high-fat diet-induced cognitive impairment by improving mitochondrial function

This study was performed to evaluate the improvement effect of the ethyl acetate fraction from peanut (Arachis hypogaea) sprout (EFPS) on high-fat diet (HFD)-induced cognitive deficits in C57BL/6 mice. Mice were randomly divided four groups (n = 13) as control (normal chow), HFD, EFPS 20 (20 mg/kg of body weight; intragastric administration) and EFPS 50 (50 mg/kg of body weight; intragastric administration) groups. HFD was provide for 15 weeks excepting control group. EFPS ameliorated cognitive dysfunction in Y-maze, passive avoidance test and Morris water maze test. EFPS significantly improved glucose tolerance and serum lipid profile, and reduced body weight. EFPS ameliorated oxidative stress by regulating MDA levels and SOD activity in liver and brain tissues. In addition, EFPS restored brain mitochondrial dysfunction related to energy metabolism. Moreover, the bioactive compounds of EFPS were identified as di-caffeic acid, caffeic acid, dihydrokaempferol-hexoside, di-p-coumaroyl tartaric acid isomer and group B soyasaponins using ultra-performance liquid chromatography-quadrupole-time-of-flight (UPLC-Q-TOF) mass spectrometry. These results show that EFPS can improve cognitive functions in HFD-induced diabetic mice.

Plant-Derived Nanoscale-Encapsulated Antioxidants for Oral and Topical Uses: A Brief Review

Several plant-based nanoscale-encapsulated antioxidant compounds (rutin, myricetin, β-carotene, fisetin, lycopene, quercetin, genkwanin, lutein, resveratrol, eucalyptol, kaempferol, glabridin, pinene, and whole-plant bio-active compounds) are briefly introduced in this paper, along with their characteristics. Antioxidants’ bioavailability has become one of the main research topics in bio-nanomedicine. Two low patient compliance drug delivery pathways (namely, the oral and topical delivery routes), are described in detail in this paper, for nanoscale colloidal systems and gel formulations. Both routes and/or formulations seek to improve bioavailability and maximize the drug agents’ efficiency. Some well-known compounds have been robustly studied, but many remain elusive. The objective of this review is to discuss recent studies and advantages of nanoscale formulations of plant-derived antioxidant compounds.

Modulating Boronic Ester Stability in Block Copolymer Micelles via the Neighbor Effect of Copolymerized Tertiary Amines for Controlled Release of Polyphenolic Drugs

The traceless and pH-sensitive properties of boronic esters are attractive for the synthesis of polymer-drug conjugates, but current platforms suffer from both low stability under physiologically relevant conditions and synthetically demanding optimization to tune drug release profiles. We hypothesized that the high catechol affinity and stability of Wulff-type boronic acids could be mimicked by copolymerization of phenyl boronic acid with a tertiary amine and subsequent micellization. This strategy yielded a versatile platform for the preparation of reversible polymer-drug conjugates, which more than doubled the oxidative stability of encapsulated polyphenolic drug cargo at physiologically relevant pH and enabled simple and incremental tuning of drug release kinetics. Moreover, we validated, with ¹⁹F NMR, that these copolymers exhibit uniquely high catechol affinity that could not be replicated by combinations of similarly functionalized small molecules. Overall, this report demonstrates that copolymerization of boronic acid and tertiary amine monomers is a powerful and modular approach to improving boronic ester chemistry for drug delivery applications.

Ginkgo biloba in the Aging Process: A Narrative Review

Neurodegenerative diseases, cardiovascular disease (CVD), hypertension, insulin resistance, cancer, and other degenerative processes commonly appear with aging. Ginkgo biloba (GB) is associated with several health benefits, including memory and cognitive improvement, in Alzheimer's disease (AD), Parkinson's disease (PD), and cancer. Its antiapoptotic, antioxidant, and anti-inflammatory actions have effects on cognition and other conditions associated with aging-related processes, such as insulin resistance, hypertension, and cardiovascular conditions. The aim of this study was to perform a narrative review of the effects of GB in some age-related conditions, such as neurodegenerative diseases, CVD, and cancer. PubMed, Cochrane, and Embase databases were searched, and the PRISMA guidelines were applied. Fourteen clinical trials were selected; the studies showed that GB can improve memory, cognition, memory scores, psychopathology, and the quality of life of patients. Moreover, it can improve cerebral blood flow supply, executive function, attention/concentration, non-verbal memory, and mood, and decrease stress, fasting serum glucose, glycated hemoglobin, insulin levels, body mass index, waist circumference, biomarkers of oxidative stress, the stability and progression of atherosclerotic plaques, and inflammation. Therefore, it is possible to conclude that the use of GB can provide benefits in the prevention and treatment of aging-related conditions.

Dietary Antioxidants and Risk of Parkinson's Disease: A Systematic Review and Dose-Response Meta-analysis of Observational Studies

The aim of the current review was to explore the association between various dietary antioxidants and the risk of developing Parkinson's disease (PD). PubMed, Scopus, Web of Science, and Google Scholar were searched up to March 2021. Prospective, observational cohort studies, nested case-control, and case-control designs that investigated the association between antioxidants and PD risk were included. A random-effects model was used to pool the RRs. The certainty of the evidence was rated using the GRADE (Grading of Recommendations Assessment, Development, and Evaluations) scoring system. In addition, a dose-response relation was examined between antioxidant intake and PD risk. Six prospective cohort studies and 2 nested case-control (total n = 448,737 with 4654 cases), as well as 6 case-control (1948 controls, 1273 cases) studies were eligible. The pooled RR was significantly lower for the highest compared with the lowest intake categories of vitamin E (n = 7; 0.84; 95% CI: 0.71, 0.99) and anthocyanins (n = 2; 0.76; 95% CI: 0.61, 0.96) in cohort studies. Conversely, a significantly higher risk of PD was observed for higher lutein intake (n = 3; 1.86; 95% CI: 1.20, 2.88) among case-control studies. Dose-response meta-analyses indicated a significant association between a 50-mg/d increase in vitamin C (n = 6; RR: 0.94; 95% CI: 0.88, 0.99), a 5-mg/d increment in vitamin E (n = 7; RR: 0.84; 95% CI: 0.70, 0.99), a 2-mg/d increment in β-carotene (n = 6; RR: 0.94, 95% CI: 0.89, 0.99), and a 1-mg/d increment in zinc (n = 1; OR: 0.65; 95% CI: 0.49, 0.86) and a reduced risk of PD. Overall, higher intake of antioxidant-rich foods may be associated with a lower risk of PD. Future well-designed prospective studies are needed to validate the present findings. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (https://www.crd.york.ac.uk/PROSPERO, CRD42021242511).

Role of Phenolic Compounds in Human Disease: Current Knowledge and Future Prospects

Inflammation is a natural protective mechanism that occurs when the body's tissue homeostatic mechanisms are disrupted by biotic, physical, or chemical agents. The immune response generates pro-inflammatory mediators, but excessive output, such as chronic inflammation, contributes to many persistent diseases. Some phenolic compounds work in tandem with nonsteroidal anti-inflammatory drugs (NSAIDs) to inhibit pro-inflammatory mediators' activity or gene expression, including cyclooxygenase (COX). Various phenolic compounds can also act on transcription factors, such as nuclear factor-κB (NF-κB) or nuclear factor-erythroid factor 2-related factor 2 (Nrf-2), to up-or downregulate elements within the antioxidant response pathways. Phenolic compounds can inhibit enzymes associated with the development of human diseases and have been used to treat various common human ailments, including hypertension, metabolic problems, incendiary infections, and neurodegenerative diseases. The inhibition of the angiotensin-converting enzyme (ACE) by phenolic compounds has been used to treat hypertension. The inhibition of carbohydrate hydrolyzing enzyme represents a type 2 diabetes mellitus therapy, and cholinesterase inhibition has been applied to treat Alzheimer's disease (AD). Phenolic compounds have also demonstrated anti-inflammatory properties to treat skin diseases, rheumatoid arthritis, and inflammatory bowel disease. Plant extracts and phenolic compounds exert protective effects against oxidative stress and inflammation caused by airborne particulate matter, in addition to a range of anti-inflammatory, anticancer, anti-aging, antibacterial, and antiviral activities. Dietary polyphenols have been used to prevent and treat allergy-related diseases. The chemical and biological contributions of phenolic compounds to cardiovascular disease have also been described. This review summarizes the recent progress delineating the multifunctional roles of phenolic compounds, including their anti-inflammatory properties and the molecular pathways through which they exert anti-inflammatory effects on metabolic disorders. This study also discusses current issues and potential prospects for the therapeutic application of phenolic compounds to various human diseases.

Multitarget 2'-hydroxychalcones as potential drugs for the treatment of neurodegenerative disorders and their comorbidities

The complex nature of neurodegenerative diseases (NDDs), such as Alzheimer's disease (AD) and Parkinson's disease (PD) calls for multidirectional treatment. Restoring neurotransmitter levels by combined inhibition of cholinesterases (ChEs) and monoamine oxidases (MAOs, MAO-A and MAO-B), in conjunction with strategies to counteract amyloid β (Aβ) aggregation, may constitute a therapeutically strong multi-target approach for the treatment of NDDs. Chalcones are a subgroup of flavonoids with a broad spectrum of biological activity. We report here the synthesis of 2'-hydroxychalcones as MAO-A and MAO-B inhibitors. Compounds 5c (IC50 = 0.031 ± 0.001 μM), 5a (IC50 = 0.084 ± 0.003 μM), 2c (IC50 = 0.095 ± 0.019 μM) and 2a (IC50 = 0.111 ± 0.006 μM) were the most potent, selective and reversible inhibitors of human (h)MAO-B isoform. hMAO-B inhibitors 1a, 2a and 5a also inhibited murine MAO-B in vivo in mouse brain homogenates. Molecular modelling rationalised the binding mode of 2'-hydroxychalcones in the active site of hMAO-B. Additionally, several derivatives inhibited murine acetylcholinesterase (mAChE) (IC50 values from 4.37 ± 0.83 μM to 15.17 ± 6.03 μM) and reduced the aggregation propensity of Aβ. Moreover, some derivatives bound to the benzodiazepine binding site (BDZ-bs) of the γ-aminobutyric acid A (GABAA) receptors (1a and 2a with Ki = 4.9 ± 1.1 μM and 5.0 ± 1.1 μM, respectively), and exerted sedative and/or anxiolytic like effects on mice. The biological results reported here on 2'-hydroxychalcones provide an extension to previous studies on chalcone scaffold and show them as a potential treatment strategy for NDDs and their associated comorbidities.

The direct and indirect effects of bioactive compounds against coronavirus

Emerging viruses are known to pose a threat to humans in the world. COVID‐19, a newly emerging viral respiratory disease, can spread quickly from people to people via respiratory droplets, cough, sneeze, or exhale. Up to now, there are no specific therapies found for the treatment of COVID‐19. In this sense, the rising demand for effective antiviral drugs is stressed. The main goal of the present study is to cover the current literature about bioactive compounds (e.g., polyphenols, glucosinolates, carotenoids, minerals, vitamins, oligosaccharides, bioactive peptides, essential oils, and probiotics) with potential efficiency against COVID‐19, showing antiviral activities via the inhibition of coronavirus entry into the host cell, coronavirus enzymes, as well as the virus replication in human cells. In turn, these compounds can boost the immune system, helping fight against COVID‐19. Overall, it can be concluded that bioactives and the functional foods containing these compounds can be natural alternatives for boosting the immune system and defeating coronavirus.

Neuroprotective Potential of Tamarillo (Cyphomandra betacea) Epicarp Extracts Obtained by Sustainable Extraction Process

Tamarillo (Cyphomandra betacea (Cav.) Sendt.), or tree tomato, is a tropical fruit from the Andean region of South America; it is highly rich in vitamins, minerals, and polyphenolic compounds. In this study, extracts from tamarillo epicarp (TE) were obtained by pressurized liquid extraction (PLE), and their in-vitro neuroprotective potential was assessed. A central composite design with response surface methodology was performed to optimize PLE as a function of solvent composition and temperature. Selected response variables were extraction yield, total phenolic content (TPC), total flavonoid content (TFC), total carotenoid content (TCC), antioxidant (ABTS), and anti-inflammatory (LOX) activities, and anti-acetylcholinesterase (AChE) inhibitory capacity. According to the desirability function, the optimal conditions were 100% ethanol and 180°C with a 0.87 desirability value. Next, the anti-butyrylcholinesterase enzyme (BChE), reactive oxygen species (ROS), and reactive nitrogen species (RNS) inhibition as well as cytotoxicity in HK-2, THP-1 monocytes, and SH-5YSY neuroblastoma cell lines were studied for the TE extract obtained under optimized conditions. The optimum TE extract provided the following results: extraction yield (36.25%), TPC (92.09 mg GAE/g extract), TFC (4.4 mg QE/g extract), TCC (107.15 mg CE/g extract), antioxidant capacity (ABTS, IC₅₀ = 6.33 mg/ml extract), LOX (IC₅₀ = 48.3 mg/ml extract), and AChE (IC₅₀ = 97.46 mg/ml extract), and showed no toxicity at concentration up to 120 μg/ml extract for all the tested cell lines. Finally, chemical characterization by liquid chromatography-tandem mass spectrometry (UHPLC-q-TOF-MS/MS) of the optimum TE extract exhibited an important presence of hydroxycinnamic acid derivatives and other phenolic acids as well as quercetin hexoside and rutin, as main metabolites responsible for the observed biological properties. All these results suggested that TE, which represents between 8 and 15% of the total fruit, could become a promising natural by-product with a potential "multitarget" activity against Alzheimer's disease.

Therapeutic Potential and Main Methods of Obtaining Selenium Nanoparticles

This review presents the latest data on the importance of selenium nanoparticles in human health, their use in medicine, and the main known methods of their production by various methods. In recent years, a multifaceted study of nanoscale complexes in medicine, including selenium nanoparticles, has become very important in view of a number of positive features that make it possible to create new drugs based on them or significantly improve the properties of existing drugs. It is known that selenium is an essential trace element that is part of key antioxidant enzymes. In mammals, there are 25 selenoproteins, in which selenium is a key component of the active site. The important role of selenium in human health has been repeatedly proven by several hundred works in the past few decades; in recent years, the study of selenium nanocomplexes has become the focus of researchers. A large amount of accumulated data requires generalization and systematization in order to improve understanding of the key mechanisms and prospects for the use of selenium nanoparticles in medicine, which is the purpose of this review.

Structure, synthesis, biosynthesis, and activity of the characteristic compounds from Ginkgo biloba L

Covering: 1928-2021Ginkgo biloba L. is one of the most distinctive plants to have emerged on earth and has no close living relatives. Owing to its phylogenetic divergence from other plants, G. biloba contains many compounds with unique structures that have served to broaden the chemical diversity of herbal medicine. Examples of such compounds include terpene trilactones (ginkgolides), acylated flavonol glycosides (ginkgoghrelins), biflavones (ginkgetin), ginkgotides and ginkgolic acids. The extract of G. biloba leaf is used to prevent and/or treat cardiovascular diseases, while many ginkgo-derived compounds are currently at various stages of preclinical and clinical trials worldwide. The global annual sales of G. biloba products are estimated to total US$10 billion. However, the content and purity of the active compounds isolated by traditional methods are usually low and subject to varying environmental factors, making it difficult to meet the huge demand of the international market. This highlights the need to develop new strategies for the preparation of these characteristic compounds from G. biloba. In this review, we provide a detailed description of the structures and bioactivities of these compounds and summarize the recent research on the development of strategies for the synthesis, biosynthesis, and biotechnological production of the characteristic terpenoids, flavonoids, and alkylphenols/alkylphenolic acids of G. biloba. Our aim is to provide an important point of reference for all scientists who research ginkgo-related compounds for medicinal or other purposes.

Multifunctional Therapeutic Potential of Phytocomplexes and Natural Extracts for Antimicrobial Properties

Natural products have been known for their antimicrobial factors since time immemorial. Infectious diseases are a worldwide burden that have been deteriorating because of the improvement of species impervious to various anti-infection agents. Hence, the distinguishing proof of antimicrobial specialists with high-power dynamic against MDR microorganisms is central to conquer this issue. Successful treatment of infection involves the improvement of new drugs or some common source of novel medications. Numerous naturally occurring antimicrobial agents can be of plant origin, animal origin, microbial origin, etc. Many plant and animal products have antimicrobial activities due to various active principles, secondary metabolites, or phytochemicals like alkaloids, tannins, terpenoids, essential oils, flavonoids, lectins, phagocytic cells, and many other organic constituents. Phytocomplexes' antimicrobial movement frequently results from a few particles acting in cooperative energy, and the clinical impacts might be because of the direct effects against microorganisms. The restorative plants that may furnish novel medication lead the antimicrobial movement. The purpose of this study is to investigate the antimicrobial properties of the phytocomplexes and natural extracts of the plants that are ordinarily being utilized as conventional medications and then recommended the chance of utilizing them in drugs for the treatment of multiple drug-resistant disease.

HIV-1-RT inhibition activity of Satureja spicigera (C.KOCH) BOISS. Aqueous extract and docking studies of phenolic compounds identified by RP-HPLC-DAD

AIDS is a global disease caused by HIV, affecting millions of people and causing death. The current limitations of antiretroviral therapy used in the therapy of HIV/AIDS have led to the need to search for new and effective drugs from natural products, especially plants. Herewith, using the present study, the detection of HIV-1-RT inhibition of aqueous extract of Satureja spicigera (C.KOCH) BOISS. was performed for the first time. Besides, total phenolic content (TPC), analysis of phenolic constituents by RP-HPLC-DAD and antioxidant capacity by DPPH and Ferric reducing antioxidant power (FRAP) methods were determined for the first time. In addition, molecular docking studies were carried out between HIV-1-RT and phenolic substances, the presence of which was determined in the aqueous extract, for the determination of the phenolics that may be responsible for HIV-1-RT activity. HIV-1-RT inhibition was defined as IC₅₀ : 22.83 μg/ml. Benzoic acid, vanillin, rutin, and chlorogenic acid were present as main phenolics in quantities of 621.96, 505.87, 349.33, and 323.23 µg phenolic/g extract, respectively. Further, TPC, DPPH, and FRAP were calculated as in the order of 151.69 mg GAE/g extract, 23.77 µg/ml, and 445.7 µmol TE/g extract. Chlorogenic acid (-8.48 kcal/mol) was found to be the most effective ligand in docking studies, with a value close to positive standard nevirapine (-9.35 kcal/mol). Hereby, although the aqueous extract of S. spicigera can be used as a natural antioxidant, the crude extract or its phenolics have the potential to be used in the treatment of AIDS due to its high HIV-1-RT activity. PRACTICAL APPLICATIONS: In this study, anti-HIV-1-RT and antioxidant activity and total phenolic content of Satureja spicigera aqueous extract were determined. In addition, HPLC analysis of some phytochemicals and the activities of these phytochemicals against HIV-1-RT enzyme was determined by molecular docking studies. The results showed that the aqueous extract of S. spicigera and some of the phytochemicals it contains have the potential to be used as a natural product against HIV infection or in the treatment of AIDS.

Pharmacophore modeling and 3D-QSAR study for the design of novel α-synuclein aggregation inhibitors

Alpha-synuclein (α-syn), as a highly soluble presynaptic protein expressed in the brain, plays an important role in recycling synaptic vesicles and regulating the synthesis, storage, and release of neurotransmitters. Accumulation of α-syn in Lewy bodies and Lewy neurites is the pathological hallmark of Parkinson's disease (PD), so inhibition of α-syn aggregation may provide a novel approach for treating PD. In this study, the 3D structure of α-syn was downloaded from Protein Data Bank (PDB ID: 2N0A). A ligand-based pharmacophore model was conducted on a set of 43 diverse α-syn ligands, and the results suggested that two hydrogen-bond acceptors, one hydrophobic group, and two aromatic rings were significant to the inhibition of α-syn aggregation. A ligand-based 3D-QSAR model was also established with good statistical significance (R² = 0.920) and excellent predictive ability (Q² = 0.752). Novel indolinone derivatives were designed and synthesized based on the pharmacophore model. Subsequently, the 3D-QSAR model was used to predict the inhibitory activities towards α-syn aggregation, and the actual inhibitory activities were evaluated by thioflavin-T assay in vitro with the best inhibitory activity reaching 45.08%. The fitting results indicated that the built pharmacophore and 3D-QSAR models provided better reliability and accuracy for compound modification and prediction of the activity thereof. A ligand-based pharmacophore modeling and 3D-QSAR study have been performed on a set of 43 diverse ligands for α-synuclein for the first time. Based on the best pharmacophore modeling, novel indolinone derivatives were designed and synthesized, and the inhibitory activities for α-synuclein aggregation were evaluated by thioflavin-T assay in vitro, which preliminary indicated that five pharmacophore sites (two hydrogen bond acceptors (A), a hydrophobic group (H), and two aromatic rings (R)) in compounds contribute to the inhibitory activities. In the study, the built pharmacophore modeling and 3D-QSAR provided better reliability and accuracy for compound modification and prediction of the activity thereof.

Corilagin and 1,3,6-Tri-O-galloy-β-D-glucose: potential inhibitors of SARS-CoV-2 variants

The COVID-19 disease caused by the virus SARS-CoV-2, first detected in December 2019, is still emerging through virus mutations. Although almost under control in some countries due to effective vaccines that are mitigating the worldwide pandemic, the urgency to develop additional vaccines and therapeutic treatments is imperative. In this work, the natural polyphenols corilagin and 1,3,6-tri-O-galloy-β-d-glucose (TGG) are investigated to determine the structural basis of inhibitor interactions as potential candidates to inhibit SARS-CoV-2 viral entry into target cells. First, the therapeutic potential of the ligands are assessed on the ACE2/wild-type RBD. We first use molecular docking followed by molecular dynamics, to take into account the conformational flexibility that plays a significant role in ligand binding and that cannot be captured using only docking, and then analyze more precisely the affinity of these ligands using MMPBSA binding free energy. We show that both ligands bind to the ACE2/wild-type RBD interface with good affinities which might prevent the ACE2/RBD association. Second, we confirm the potency of these ligands to block the ACE2/RBD association using a combination of surface plasmon resonance and biochemical inhibition assays. These experiments confirm that TGG and, to a lesser extent, corilagin, inhibit the binding of RBD to ACE2. Both experiments and simulations show that the ligands interact preferentially with RBD, while weak binding is observed with ACE2, hence, avoiding potential physiological side-effects induced by the inhibition of ACE2. In addition to the wild-type RBD, we also study numerically three RBD mutations (E484K, N501Y and E484K/N501Y) found in the main SARS-CoV-2 variants of concerns. We find that corilagin could be as effective for RBD/E484K but less effective for the RBD/N501Y and RBD/E484K-N501Y mutants, while TGG strongly binds at relevant locations to all three mutants, demonstrating the significant interest of these molecules as potential inhibitors for variants of SARS-CoV-2.

Plant Polyphenols: Natural and Potent UV-Protective Agents for the Prevention and Treatment of Skin Disorders

Nowadays, destructive and immunosuppressive effects from long-term exposure to UV radiation have been fully investigated and documented in the literature. UV radiation is known as the main cause of skin aging and carcinogenesis. Hence, skin protection against anti-oxidative and immunosuppressive processes is highly in demand. Now, plant polyphenols have been found as a versatile and natural tool for the prevention and treatment of various skin diseases. The presence of a large number of hydroxyl groups in the cyclic structure of polyphenols has induced valuable biological activities. Among them, their UV protective activity has attracted lots of attention due to promising efficacy and simple instruction to use.

Review of Functional and Pharmacological Activities of Berries

Functional plant-based foods (such as fruits, vegetables, and berries) can improve health, have a preventive effect, and diminish the risk of different chronic diseases during in vivo and in vitro studies. Berries contain many phytochemicals, fibers, vitamins, and minerals. The primary phytochemicals in berry fruits are phenolic compounds including flavonoids (anthocyanins, flavonols, flavones, flavanols, flavanones, and isoflavonoids), tannins, and phenolic acids. Since berries have a high concentration of polyphenols, it is possible to use them for treating various diseases pharmacologically by acting on oxidative stress and inflammation, which are often the leading causes of diabetes, neurological, cardiovascular diseases, and cancer. This review examines commonly consumed berries: blackberries, blackcurrants, blueberries, cranberries, raspberries, black raspberries, and strawberries and their polyphenols as potential medicinal foods (due to the presence of pharmacologically active compounds) in the treatment of diabetes, cardiovascular problems, and other diseases. Moreover, much attention is paid to the bioavailability of active berry components. Hence, this comprehensive review shows that berries and their bioactive compounds possess medicinal properties and have therapeutic potential. Nevertheless, future clinical trials are required to study and improve the bioavailability of berries' phenolic compounds and extend the evidence that the active compounds of berries can be used as medicinal foods against various diseases.

Vaccinium Species (Ericaceae): From Chemical Composition to Bio-Functional Activities

The genus Vaccinium L. (Ericaceae) includes more than 450 species, which mainly grow in cooler areas of the northern hemisphere. Vaccinium species have been used in traditional medicine of different cultures and the berries are widely consumed as food. Indeed, Vaccinium supplement-based herbal medicine and functional food, mainly from V. myrtillus and V. macrocarpon, are used in Europe and North America. Biological studies support traditional uses since, for many Vaccinium components, important biological functions have been described, including antioxidant, antitumor, anti-inflammatory, antidiabetic and endothelium protective activities. Vaccinium components, such as polyphenols, anthocyanins and flavonoids, are widely recognized as modulators of cellular pathways involved in pathological conditions, thus indicating that Vaccinium may be an important source of bioactive molecules. This review aims to better describe the bioactivity of Vaccinium species, focusing on anti-inflammatory and endothelial protective cellular pathways, modulated by their components, to better understand their importance for public health.

Natural Phytochemicals as Novel Therapeutic Strategies to Prevent and Treat Parkinson's Disease: Current Knowledge and Future Perspectives

Parkinson's disease (PD) is the second-most common neurodegenerative chronic disease affecting both cognitive performance and motor functions in aged people. Yet despite the prevalence of this disease, the current therapeutic options for the management of PD can only alleviate motor symptoms. Research has explored novel substances for naturally derived antioxidant phytochemicals with potential therapeutic benefits for PD patients through their neuroprotective mechanism, targeting oxidative stress, neuroinflammation, abnormal protein accumulation, mitochondrial dysfunction, endoplasmic reticulum stress, neurotrophic factor deficit, and apoptosis. The aim of the present study is to perform a comprehensive evaluation of naturally derived antioxidant phytochemicals with neuroprotective or therapeutic activities in PD, focusing on their neuropharmacological mechanisms, including modulation of antioxidant and anti-inflammatory activity, growth factor induction, neurotransmitter activity, direct regulation of mitochondrial apoptotic machinery, prevention of protein aggregation via modulation of protein folding, modification of cell signaling pathways, enhanced systemic immunity, autophagy, and proteasome activity. In addition, we provide data showing the relationship between nuclear factor E2-related factor 2 (Nrf2) and PD is supported by studies demonstrating that antiparkinsonian phytochemicals can activate the Nrf2/antioxidant response element (ARE) signaling pathway and Nrf2-dependent protein expression, preventing cellular oxidative damage and PD. Furthermore, we explore several experimental models that evaluated the potential neuroprotective efficacy of antioxidant phytochemical derivatives for their inhibitory effects on oxidative stress and neuroinflammation in the brain. Finally, we highlight recent developments in the nanodelivery of antioxidant phytochemicals and its neuroprotective application against pathological conditions associated with oxidative stress. In conclusion, naturally derived antioxidant phytochemicals can be considered as future pharmaceutical drug candidates to potentially alleviate symptoms or slow the progression of PD. However, further well-designed clinical studies are required to evaluate the protective and therapeutic benefits of phytochemicals as promising drugs in the management of PD.

Effects of daily consumption of wild blueberry on cognition and urinary metabolites in school-aged children: a pilot study

Purpose

Acute intervention with wild blueberry (WBB) has previously revealed positive cognitive and mood effects in typically developing children; however, it is unclear whether effects persist after daily supplementation. In addition, no data have been published exploring the metabolite profiles of children following berry consumption, to our knowledge. A study of this kind could provide insight into a mechanism of action for the cognitive and mood improvements observed previously in children. The aim of this pilot study was to assess cognitive performance and urinary metabolite concentrations in healthy 7–10-year-old children across a 4 week daily WBB drink intervention.

Methods

This pilot study examined the effects of daily WBB consumption for 4 weeks (766 mg total polyphenols; 253 mg anthocyanins; equivalent to 240 g fresh blueberries per day) on cognition and mood in 15 healthy 7–10-year-old children. Polyphenol metabolites were measured in 24 h urine before and after the 4 week intervention.

Results

Chronic WBB-related benefits were seen on cognitively demanding trials on the modified attention network task, a task measuring executive functioning. Specifically, the WBB group maintained significantly higher accuracy on incongruent trials (96%; SE 0.03) compared with placebo participants (85%; SE 0.03; p = 0.038) after the 4 week intervention, suggesting WBB was of most benefit on the more difficult aspects of the task. No significant WBB-related effects were observed on the auditory verbal learning task or the child’s version of the positive and negative affect schedule. Urinary metabolite analyses indicated significant increases in different metabolites in WBB and placebo groups after 4 week consumption.

Conclusion

The research demonstrates 24 h WBB bioavailability in a child cohort for the first time with increases in urinary hippuric acid excretion during 2 week daily WBB consumption. This study highlights the importance of conducting a larger study in children investigating the mechanism of action behind cognitive effects using bioavailability data.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02588-y.

Dependence of the Ripeness Stage on the Antioxidant and Antimicrobial Properties of Walnut (Juglans regia L.) Green Husk Extracts from Industrial By-Products

Walnut green husk (WGH) is a waste generated by the walnut (Juglans regia L.) harvest industry. It represents a natural source of polyphenols, compounds with antioxidant and antimicrobial activities, but their activity could be dependent on the ripeness stage of the raw material. In this study, the effect of the different ripeness stages-open (OH) and closed (CH) husks-on the antioxidant and antimicrobial properties of WGH extracts were analyzed, emphasizing the influence of the extracts in inhibiting Escherichia coli growth. The ripeness stage of WGH significantly affected the antioxidant activity of the extracts. This was attributed to the different polyphenol profiles related to the mechanical stress when the husk opened compared to the closed sample. The antimicrobial activity showed inhibition of E. coli growth. OH-extracts at 96 µg/mL caused the lowest specific growth rate (µ_max = 0.003 h^-1) and the greatest inhibition percentage (I = 93%) compared to CH-extract (µ_max = 0.01 h^-1; I = 69%). The obtained results showed the potential of the walnut green husk, principally open husk, as an economical source of antioxidant and antimicrobial agents with potential use in the food industry.

Phytochemicals as Regulators of Genes Involved in Synucleinopathies

Synucleinopathies are a group of neurodegenerative diseases characterized by the accumulation of α-synuclein aggregates in neurons, nerve fibers or glial cells. Three main types of diseases belong to the synucleinopathies: Parkinson’s disease, dementia with Lewy bodies, and multiple system atrophy. All of them develop as a result of an interplay of genetic and environmental factors. Emerging evidence suggests that epigenetic mechanisms play an essential role in the development of synucleinopathies. Since there is no disease-modifying treatment for these disorders at this time, interest is growing in plant-derived chemicals as a potential treatment option. Phytochemicals are substances of plant origin that possess biological activity, which might have effects on human health. Phytochemicals with neuroprotective activity target different elements in pathogenic pathways due to their antioxidants, anti-inflammatory, and antiapoptotic properties, and ability to reduce cellular stress. Multiple recent studies demonstrate that the beneficial effects of phytochemicals may be explained by their ability to modulate the expression of genes implicated in synucleinopathies and other diseases. These substances may regulate transcription directly via transcription factors (TFs) or play the role of epigenetic regulators through their effect on histone modification, DNA methylation, and RNA-based mechanisms. Here, we summarize new data about the impact of phytochemicals on the pathogenesis of synucleinopathies through regulation of gene expression.