The use of flavonoids in central nervous system disorders

Therapeutic potential of berries in age-related neurological disorders

Aging significantly impacts several age-related neurological problems, such as stroke, brain tumors, oxidative stress, neurodegenerative diseases (Alzheimer's, Parkinson's, and dementia), neuroinflammation, and neurotoxicity. Current treatments for these conditions often come with side effects like hallucinations, dyskinesia, nausea, diarrhea, and gastrointestinal distress. Given the widespread availability and cultural acceptance of natural remedies, research is exploring the potential effectiveness of plants in common medicines. The ancient medical system used many botanical drugs and medicinal plants to treat a wide range of diseases, including age-related neurological problems. According to current clinical investigations, berries improve motor and cognitive functions and protect against age-related neurodegenerative diseases. Additionally, berries may influence signaling pathways critical to neurotransmission, cell survival, inflammation regulation, and neuroplasticity. The abundance of phytochemicals in berries is believed to contribute to these potentially neuroprotective effects. This review aimed to explore the potential benefits of berries as a source of natural neuroprotective agents for age-related neurological disorders.

Honey and Alzheimer's Disease-Current Understanding and Future Prospects

Alzheimer's disease (AD), a leading cause of dementia, has been a global concern. AD is associated with the involvement of the central nervous system that causes the characteristic impaired memory, cognitive deficits, and behavioral abnormalities. These abnormalities caused by AD is known to be attributed by extracellular aggregates of amyloid beta plaques and intracellular neurofibrillary tangles. Additionally, genetic factors such as abnormality in the expression of APOE, APP, BACE1, PSEN-1, and PSEN-2 play a role in the disease. As the current treatment aims to treat the symptoms and to slow the disease progression, there has been a continuous search for new nutraceutical agent or medicine to help prevent and cure AD pathology. In this quest, honey has emerged as a powerful nootropic agent. Numerous studies have demonstrated that the high flavonoids and phenolic acids content in honey exerts its antioxidant, anti-inflammatory, and neuroprotective properties. This review summarizes the effect of main flavonoid compounds found in honey on the physiological functioning of the central nervous system, and the effect of honey intake on memory and cognition in various animal model. This review provides a new insight on the potential of honey to prevent AD pathology, as well as to ameliorate the damage in the developed AD.

Potential Benefits of Anthocyanins in Chronic Disorders of the Central Nervous System

Anthocyanins have been shown to be effective in chronic diseases because of their antioxidant and anti-inflammatory effects together with changes in the gut microbiota and modulation of neuropeptides such as insulin-like growth factor-1. This review will examine whether these mechanisms may be effective to moderate the symptoms of disorders of the central nervous system in humans, including schizophrenia, Parkinson's disease, Alzheimer's disease, autism spectrum disorder, depression, anxiety, attention-deficit hyperactivity disorder and epilepsy. Thus, anthocyanins from fruits and berries should be considered as complementary interventions to improve these chronic disorders.

The Neuroprotective Potentiality of Flavonoids on Alzheimer's Disease

Alzheimer's disease (AD), due to its spread, has become a global health priority, and is characterized by senile dementia and progressive disability. The main cause of AD and other neurodegenerations (Huntington, Parkinson, Amyotrophic Lateral Sclerosis) are aggregated protein accumulation and oxidative damage. Recent research on secondary metabolites of plants such as polyphenols demonstrated that they may slow the progression of AD. The flavonoids' mechanism of action in AD involved the inhibition of acetylcholinesterase, butyrylcholinesterase, Tau protein aggregation, β-secretase, oxidative stress, inflammation, and apoptosis through modulation of signaling pathways which are implicated in cognitive and neuroprotective functions, such as ERK, PI3-kinase/Akt, NFKB, MAPKs, and endogenous antioxidant enzymatic systems. This review focuses on flavonoids and their role in AD, in terms of therapeutic potentiality for human health, antioxidant potential, and specific AD molecular targets.

Synaptic Effects of Palmitoylethanolamide in Neurodegenerative Disorders

Increasing evidence strongly supports the key role of neuroinflammation in the pathophysiology of neurodegenerative diseases, such as Alzheimer’s disease, frontotemporal dementia, and amyotrophic lateral sclerosis. Neuroinflammation may alter synaptic transmission contributing to the progression of neurodegeneration, as largely documented in animal models and in patients’ studies. In the last few years, palmitoylethanolamide (PEA), an endogenous lipid mediator, and its new composite, which is a formulation constituted of PEA and the well-recognized antioxidant flavonoid luteolin (Lut) subjected to an ultra-micronization process (co-ultraPEALut), has been identified as a potential therapeutic agent in different disorders by exerting potential beneficial effects on neurodegeneration and neuroinflammation by modulating synaptic transmission. In this review, we will show the potential therapeutic effects of PEA in animal models and in patients affected by neurodegenerative disorders.

Anxiolytic effect of the heartwood of Haematoxylum campechianum L. and sappanchalcone in an in vivo model in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Haematoxylum campechianum L., is a well-known plant in the southeast region of Mexico, where it is named as "palo tinto" or "palo de Campeche", in English there are vernacular names such as "redwood", "bloodwood tree" or "campeachy wood". Traditional medicine refers its use for the treatment of different disorders including depression.

AIM OF THE STUDY

Considering the traditional use of this plant for the alleviation of depression, the aim of this study was the evaluation of the anxiolytic effect of the methanolic and hydroalcoholic extracts from the heartwood of Haematoxylum campechianum L., and the sappanchalchone (Sapp). Additionally, it is presented the characterization of the new compound 4-hydroxyhematoxylol (2) isolated from the hydroalcoholic extract.

MATERIAL AND METHODS

The anxiolytic effect of the extracts and Sapp was evaluated by using the Elevated Plus Maze (EPM) additionally the sedative effect was assessed with the Open Field Test (OFT). The chemical characterization of Sapp and 2 was performing by 1D and 2D NMR experiments.

RESULTS

The EPM test showed that the administration of the plant extracts increased the percentage of time spent in open arms (76.32 ± 6.35 and 66.68 ± 20.64%, respectively for the methanolic and hydroalcoholic extracts), whereas the administration of Sapp increased the percentage of time spent in open arms by 60.07 ± 14.28%, these results are similar to Diazepam (DZP, positive control) which caused an increment of 74.06 ± 23.42%. For the OFT, all of the doses evaluated for both extracts and Sapp diminished the number of rearing (R) and total corssing (TC) behavior in a similar way to the positive control (DZO) and statistically different with respect to the vehicle.

CONCLUSION

The results obtained showed that the polar extracts from the heartwood of Haematoxylum campechianum L. possess both anxiolytic and sedative effect and that the chalcone-type compound Sapp, isolated from the methanolic extract, is partially responsible of these activities.

In Vitro and In Silico Characterization of Kurarinone as a Dopamine D1A Receptor Antagonist and D2L and D4 Receptor Agonist

Alterations in the expression and/or activity of brain G-protein-coupled receptors (GPCRs) such as dopamine D₁R, D_2LR, D₃R, and D₄R, vasopressin V_1AR, and serotonin 5-HT_1AR are noted in various neurodegenerative diseases (NDDs). Since studies have indicated that flavonoids can target brain GPCRs and provide neuroprotection via inhibition of monoamine oxidases (hMAOs), our study explored the functional role of kurarinone, an abundant lavandulated flavonoid in Sophora flavescens, on dopamine receptor subtypes, V_1AR, 5-HT_1AR, and hMAOs. Radioligand binding assays revealed considerable binding of kurarinone on D₁R, D_2LR, and D₄R. Functional GPCR assays unfolded the compound's antagonist behavior on D₁R (IC₅₀ 42.1 ± 0.35 μM) and agonist effect on D_2LR and D₄R (EC₅₀ 22.4 ± 3.46 and 71.3 ± 4.94 μM, respectively). Kurarinone was found to inhibit hMAO isoenzymes in a modest and nonspecific manner. Molecular docking displayed low binding energies during the intermolecular interactions of kurarinone with the key residues of the deep orthosteric binding pocket and the extracellular loops of D₁R, D_2LR, and D₄R, validating substantial binding affinities to these prime targets. With appreciable D_2LR and D₄R agonism and D₁R antagonism, kurarinone might be a potential compound that can alleviate clinical symptoms of Parkinson's disease and other NDDs.

The Protective Effect of Bergamot Polyphenolic Fraction (BPF) on Chemotherapy-Induced Neuropathic Pain

Paclitaxel is a chemotherapeutic drug used for cancer treatment. Chemotherapy-induced peripheral neuropathy (CIPN) is a common major dose-limiting side effect of many chemotherapeutic agents, including paclitaxel. CIPN is accompanied by mechanical and thermal hypersensitivity that resolves within weeks, months, or years after drug termination. To date, there is no available preventive strategy or effective treatment for CIPN due to the fact that its etiology has not been fully explained. It is clear that free radicals are implicated in many neurodegenerative diseases and recent studies have shown the important role of oxidative stress in development of CIPN. Here, we observed how, in rats, the administration of a natural antioxidant such as the bergamot polyphenolic extract (BPF), can play a crucial role in reducing CIPN. Paclitaxel administration induced mechanical allodynia and thermal hyperalgesia, which began to manifest on day seven, and reached its lowest levels on day fifteen. Paclitaxel-induced neuropathic pain was associated with nitration of proteins in the spinal cord including MnSOD, glutamine synthetase, and glutamate transporter GLT-1. This study showed that the use of BPF, probably by inhibiting the nitration of crucial proteins involved in oxidative stress, improved paclitaxel-induced pain behaviors relieving mechanical allodynia, thermal hyperalgesia, thus preventing the development of chemotherapy-induced neuropathic pain.

Behavioral Evaluation of the Effects of Aqueous and Ethanol Extracts of Suaeda vermiculata Forssk on Rats

BACKGROUND

Suaeda vermiculata is one of the widely distributed halophytes in central Saudi Arabia. The plant is used as a remedy for liver diseases, jaundice, and inflammation. S. vermiculata is also used as camels' food by local shepherds.

PURPOSE

The study aims to evaluate the behavioral antidepressant and anxiolytic effects of S. vermiculata aqueous and ethanol extracts.

METHODS

Aqueous and ethanol extracts of S. vermiculata were prepared by the maceration technique. Standard forced swim test cylinder and light/dark chamber device were used to evaluate the antidepressant and anxiolytic activities of the extracts (200 mg/kg) in rats model, respectively.

RESULTS

The aqueous and ethanol extracts of S. vermiculata showed remarkable antidepressant activity with significant increase in the swimming time and reduced immobility in the rats compared to imipramine treated animals (P<0.05). Ethanol extract increased the swimming time by 20% and decreased the immobility time by more than 60% compared to the control group of animals. In contrast, the extracts induced the anxiety behavior in experimental rats compared to vehicle- treated animals. The extracts significantly (P<0.001) reduced the time spent by rats in the light chamber by more than 50% and increased the time spent in dark chamber as compared with the control group and the group receiving diazepam.

CONCLUSION

The medicinally important plant S. vermiculata induced anxiety behavior with antidepressant activity in rats. These effects from our point of view are similar to the effects of some common beverages containing caffeine such as coffee and tea.

GardeninA confers neuroprotection against environmental toxin in a Drosophila model of Parkinson's disease

Parkinson’s disease is an age-associated neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons from the midbrain. Epidemiological studies have implicated exposures to environmental toxins like the herbicide paraquat as major contributors to Parkinson’s disease etiology in both mammalian and invertebrate models. We have employed a paraquat-induced Parkinson’s disease model in Drosophila as an inexpensive in vivo platform to screen therapeutics from natural products. We have identified the polymethoxyflavonoid, GardeninA, with neuroprotective potential against paraquat-induced parkinsonian symptoms involving reduced survival, mobility defects, and loss of dopaminergic neurons. GardeninA-mediated neuroprotection is not solely dependent on its antioxidant activities but also involves modulation of the neuroinflammatory and cellular death responses. Furthermore, we have successfully shown GardeninA bioavailability in the fly heads after oral administration using ultra-performance liquid chromatography and mass spectrometry. Our findings reveal a molecular mechanistic insight into GardeninA-mediated neuroprotection against environmental toxin-induced Parkinson’s disease pathogenesis for novel therapeutic intervention.

Maitra and colleagues identify the neuroprotective properties of GardeninA against environmental toxin-induced neurodegeneration in Drosophila. This study has the potential to influence future research into toxin-induced Parkinson’s disease pathogenesis.

Enteromorpha prolifera Extract Improves Memory in Scopolamine-Treated Mice via Downregulating Amyloid-β Expression and Upregulating BDNF/TrkB Pathway

Enteromorpha prolifera, a green alga, has long been used in food diets as well as traditional remedies in East Asia. Our preliminary study demonstrated that an ethyl acetate extract of Enteromorpha prolifera (EAEP) exhibited the strongest antioxidant activity compared to ethanol or water extracts. Nonetheless, there has been no report on the effect of EAEP on memory impairment due to oxidative damage. This study investigated whether EAEP could attenuate memory deficits in an oxidative stress-induced mouse model. EAEP was orally administered (50 or 100 mg/kg body weight (b.w.)) to mice and then scopolamine was administered. The oral administration of EAEP at 100 mg/kg b.w. significantly restored memory impairments induced by scopolamine, as evaluated by the Morris water maze test, and the passive avoidance test. Further, EAEP upregulated the protein expression of BDNF, p-CREB, p-TrkB, and p-Akt. Moreover, EAEP downregulated the expression of amyloid-β, tau, and APP. The regulation of cholinergic marker enzyme activities and the protection of neuronal cells from oxidative stress-induced cell death in the brain of mice via the downregulation of amyloid-β and the upregulation of the BDNF/TrkB pathway by EAEP suggest its potential as a pharmaceutical candidate to prevent neurodegenerative diseases.

Anti-stress effects of polyphenols: animal models and human trials

Polyphenols, a category of plant compounds that contain multiple phenol structural units, are widely distributed throughout the plant kingdom and have multiple benefits for human health including anti-obesity, anti-hyperglycemic, and anti-hyperlipidemic effects. Additionally, polyphenols have recently gained attention for their anti-stress effects. In this review article, we summarize physiological responses against exposure to stressors and discuss biomarkers for exposure to stressors that are widely used in animal studies and human trials. We also review commonly used animal models for evaluating anti-stress effects. Finally, we discuss recent findings related to the anti-stress effects of polyphenols evaluated in animal models and human trials, and their putative mechanisms. These emerging data require further investigation in scientific studies and human trials to evaluate the anti-stress effects of polyphenols and their potential use for the prevention of stress-related health problems.

Agathisflavone modulates astrocytic responses and increases the population of neurons in an in vitro model of traumatic brain injury

Traumatic brain injury (TBI) is a critical health problem worldwide, with a high incidence rate and potentially severe long-term consequences. Depending on the level of mechanical stress, astrocytes react with complex morphological and functional changes known as reactive astrogliosis. In cases of severe tissue injury, astrocytes proliferate in the area immediately adjacent to the lesion to form the glial scar, which is a major barrier to neuronal regeneration in the central nervous system. The flavonoid agathisflavone has been shown to have neuroprotective, neurogenic, and immunomodulatory effects and could have beneficial effects in situations of TBI. In this study, we investigated the effects of agathisflavone on modulating the responses of astrocytes and neurons to injury, using the in vitro scratch wound model of TBI in primary cultures of rat cerebral cortex. In control conditions, the scratch wound induced an astroglial injury response, characterized by upregulation of glial fibrillary acidic protein (GFAP) and hypertrophy, together with the reduction in proportion of neurons within the lesion site. Treatment with agathisflavone (1 μM) decreased astroglial GFAP expression and hypertrophy and induced an increase in the number of neurons and neurite outgrowth into the lesion site. Agathisflavone also induced increased expression of the neurotrophic factors NGF and GDNF, which are associated with the neuroprotective profile of glial cells. These results demonstrate that in an in vitro model of TBI, the flavonoid agathisflavone modulates the astrocytic injury response and glial scar formation, stimulating neural recomposition.

An Update of Palmitoylethanolamide and Luteolin Effects in Preclinical and Clinical Studies of Neuroinflammatory Events

The inflammation process represents of a dynamic series of phenomena that manifest themselves with an intense vascular reaction. Neuroinflammation is a reply from the central nervous system (CNS) and the peripheral nervous system (PNS) to a changed homeostasis. There are two cell systems that mediate this process: the glia of the CNS and the lymphocites, monocytes, and macrophages of the hematopoietic system. In both the peripheral and central nervous systems, neuroinflammation plays an important role in the pathogenesis of neurodegenerative diseases, such as Parkinson’s and Alzheimer’s diseases, and in neuropsychiatric illnesses, such as depression and autism spectrum disorders. The resolution of neuroinflammation is a process that allows for inflamed tissues to return to homeostasis. In this process the important players are represented by lipid mediators. Among the naturally occurring lipid signaling molecules, a prominent role is played by the N-acylethanolamines, namely N-arachidonoylethanolamine and its congener N-palmitoylethanolamine, which is also named palmitoylethanolamide or PEA. PEA possesses a powerful neuroprotective and anti-inflammatory power but has no antioxidant effects per se. For this reason, its co-ultramicronization with the flavonoid luteolin is more efficacious than either molecule alone. Inhibiting or modulating the enzymatic breakdown of PEA represents a complementary therapeutic approach to treating neuroinflammation. The aim of this review is to discuss the role of ultramicronized PEA and co-ultramicronized PEA with luteolin in several neurological diseases using preclinical and clinical approaches.

A Close Look at Echium amoenum Processing, Neuroactive Components, and Effects on Neuropsychiatric Disorders

Pharmacological researches in the area of herbal medicine have considerably increased over the last two centuries. Echium amoenum (known as Gol-e-Gavzaban in Persian) is a medicinal plant that has been widely used in Iranian folk medicine. In this review, databases including PubMed, Scopus, and Google Scholar were searched up. Data collecting was completed by January 2019 and available scientific reports regarding the processing methods, main chemical constituents, and effects of E. amoenum on different neuropsychiatric disorders are summarized. Thirteen five studies met the inclusion criteria. According to results, the important phytochemicals of the plant was phenolic compounds, fatty acids, rosmarinic acid, anthocyanidins, and flavonoids. Also, experimental and clinical studies demonstrated the effectiveness of E. amoenum in the treatment of several neuropsychiatric disorders such as anxiety, depression, ischemic stroke, seizure, Alzheimer's disease, and pain. Many of these effects are, at least in part, due to its rosmarinic acid or polyphenolic compounds such as flavonoids and natural pigments such as anthocyanins. Also, fatty acids such as gamma-linolenic acid play critical role in neuroactive properties of this herb. Among these effects, only the antidepressant and anxiolytic properties of the plant extract have been examined both experimentally and clinically. There was some controversy over its toxicity effects. It seems that E. amoenum protects neurons via attenuation of oxidative stress and inflammation as well as blocking of apoptosis in the nervous system. However, more studies are necessary for assessing exact mechanisms of action in neuropsychiatric disorders, finding of bioactive ingredients, and processing methods of this plant.

Potential for diet to prevent and remediate cognitive deficits in neurological disorders

The pathophysiology of many neurological disorders involves oxidative stress, neuroinflammation, and mitochondrial dysfunction. There is now substantial evidence that diet can decrease these forms of pathophysiology, and an emerging body of literature relatedly suggests that diet can also prevent or even remediate the cognitive deficits observed in neurological disorders that exhibit such pathology (eg, Alzheimer's disease, multiple sclerosis, age-related cognitive decline, epilepsy). The current review summarizes the emerging evidence in relation to whole diets prominent in the scientific literature-ketogenic, caloric restriction, high polyphenol, and Mediterranean diets-and provides a discussion of the possible underlying neurophysiological mechanisms.

Anticonvulsive and behavior modulating effects of sophoretin and rutoside

INTRODUCTION

Seizures are the hallmarks of most types of epilepsies. Behavioral and cognitive impairments coincide with interictal periods even though it is not clear whether these impairments spring out of the seizure itself or accompanying sociopsychological burden of the disease.

MATERIALS AND METHODS

In this study, we investigated behavioral and cognitive consequences of a single GABA receptor-related seizure in mice, and examined the potential anticonvulsive and behavior-modulating properties of sophoretin (quercetin) and rutoside (rutin).

RESULTS

The study demonstrated that sophoretin and rutoside, common flavonoids of the human diet, delay the seizure onset and reduce the seizure stage. Moreover, they exerted an antidepressant-like effect, which was independent of the seizure. Neither treatments nor seizure altered recognition and spatial memory performances of the mice.

CONCLUSIONS

Behavioral or cognitive disturbances that are evident in epileptic patients did not appear following a single seizure. In addition, we suggest that both sophoretin and rutoside successfully alleviate the seizure severity without interfering in the behavioral stability and cognitive performance. Hence, these flavonoids may be of use as adjuncts to the current treatment options.

Flavonoids Regulate Lipid Droplets Biogenesis in Drosophila melanogaster

Lipid droplets (LDs), cytosolic fat storage organelles, are emerging as major regulators of lipid metabolism, trafficking, and signaling in various cells and tissues. LDs are altered in cardiovascular and neuronal disorders, inflammation, obesity, and cancer. Flavonoids comprise different classes of molecules, characterized by a well-known antioxidant activity and a beneficial effect in several diseases. However, the cellular mechanism by which different classes of flavonoids improve health is poorly understood, in particular as far as LDs biogenesis is concerned. Here we used Drosophila melanogaster as a model system to investigate the effects of a selected group of flavonoids on larval tissues by examining LDs biogenesis. In our study, fruit flies were grown in xanthohumol-, isoquercetin-, and genistein-enriched food and larval tissues were analyzed using a LD marker. Total mRNA expression of two main enzymes (minotaur and midway) responsible for triacylglycerides synthesis was evaluated after treatments. Among the flavonoids analyzed, xanthohumol and isoquercetin resulted to be potent regulators of LDs biogenesis in a tissue-specific manner, inducing fat storage decrease in fat bodies and accumulation of LDs in nerves. Since LDs have been suggested to play a protective role against intracellular stress in nonadipocyte cells, our data support the hypothesis that some phytochemicals could act as strong modulators of LDs biogenesis in vivo. The knowledge of how different flavonoids act on lipid metabolism in different tissues can help to manage the use of phytochemicals with the aim of selectively ameliorating specific neuronal and metabolic diseases’ manifestations.

Association of dietary phytochemical index and mental health in women: a cross-sectional study

Previous studies have shown that unhealthy dietary patterns are among the most important modifiable risk factors in the development of mental health disorders. We examined the association of dietary phytochemical index (DPI) with symptoms of depression, anxiety and psychological distress in Iranian women. In this cross-sectional study, a total of 488 women aged 20–50 years old attending health centres in the south of Tehran in 2018 were included. A validated and reliable FFQ was used for dietary assessment. Symptoms of depression, anxiety and psychological distress were assessed using a validated depression, anxiety, stress scales questionnaires with twenty-one-items. DPI was estimated using the following formula: (daily energy derived from phytochemical-rich foods (kJ)/total daily energy intake (kJ))×100. The mean age of the study participants was 31·9 (sd7·7) years. The prevalence of depressive symptoms, anxiety and psychological distress among study participants was 34·6, 40·6 and 42·4 %, respectively. After controlling for potential confounders, women in the highest tertile of DPI had a lower prevalence of depressive symptoms (OR 0·22; 95 % CI 0·12, 0·38) and anxiety (OR 0·33; 95 % CI 0·20, 0·55), as well as psychological distress (OR 0·30; 95 % CI 0·18, 0·49) compared with those in the lowest tertile. In conclusion, we found a significant association between DPI and mental health in women. Prospective studies are needed to confirm these findings.

Flavonoids as Therapeutic Agents in Alzheimer's and Parkinson's Diseases: A Systematic Review of Preclinical Evidences

Alzheimer's and Parkinson's diseases are considered the most common neurodegenerative disorders, representing a major focus of neuroscience research to understanding the cellular alterations and pathophysiological mechanisms involved. Several natural products, including flavonoids, are considered able to cross the blood-brain barrier and are known for their central nervous system-related activity. Therefore, studies are being conducted with these chemical constituents to analyze their activities in slowing down the progression of neurodegenerative diseases. The present systematic review summarizes the pharmacological effects of flavonoids in animal models for Alzheimer's and Parkinson's diseases. A PRISMA model for systematic review was utilized for this search. The research was conducted in the following databases: PubMed, Web of Science, BIREME, and Science Direct. Based on the inclusion criteria, 31 articles were selected and discussed in this review. The studies listed revealed that the main targets of action for Alzheimer's disease therapy were reduction of reactive oxygen species and amyloid beta-protein production, while for Parkinson's disease reduction of the cellular oxidative potential and the activation of mechanisms of neuronal death. Results showed that a variety of flavonoids is being studied and can be promising for the development of new drugs to treat neurodegenerative diseases. Moreover, it was possible to verify that there is a lack of translational research and clinical evidence of these promising compounds.

Dietary Polyphenol Intake and Depression: Results from the Mediterranean Healthy Eating, Lifestyle and Aging (MEAL) Study

Background: The epidemiological evidence for a relation between dietary polyphenol intake and depression is limited. Therefore, the aim of this study was to assess the association between habitual dietary intake of total polyphenols, their classes, subclasses and individual compounds and depressive symptoms among the participants of the Mediterranean healthy Eating, Lifestyle and Aging (MEAL) study. Methods: Demographic and dietary characteristics of 1572 adults living in southern Italy were analyzed. Food frequency questionnaires and Phenol-Explorer were used to calculate habitual dietary intakes of polyphenols. The Center for Epidemiologic Studies Depression Scale (CES-D-10) was used as screening tool for depressive symptoms. Multivariate logistic regression analyses were used to test associations and were expressed as odds ratio (OR) and 95% confidence intervals (CI). Results: A total of 509 individuals reported having depressive symptoms. Based on multivariate logistic regression analyses, total polyphenol intake was not associated with depressive symptoms. After adjustment for potential confounding factors, dietary intake of phenolic acid (OR = 0.64, 95% CI: 0.44, 0.93), flavanones (OR = 0.54, 95% CI: 0.32, 0.91), and anthocyanins (OR = 0.61, 95% CI: 0.42, 0.89) showed significant inverse association with depressive symptoms, when comparing the highest with the lowest quartile. Moreover, flavanones and anthocyanins, were associated with depressive symptoms in a dose-response manner. Among individual compounds, inverse association was observed for quercetin (OR = 0.53, 95% CI: 0.32, 0.86) and naringenin (OR = 0.51, 95% CI: 0.30, 0.85), for the highest versus lowest quartile of intake. When taking into consideration the major sources of the polyphenols, only citrus fruits and wine consumption was inversely associated with depressive symptoms (Q4 vs. Q1: OR= 0.51, 95% CI: 0.35, 0.75; Q4 vs. Q1: OR = 0.53, 95% CI: 0.38, 0.74, respectively). Conclusions: Higher dietary intake of flavonoid may be inversely associated with depressive symptoms. Further studies are needed to definitively confirm these observed associations.

In vitro multimodal-effect of Trichilia catigua A. Juss. (Meliaceae) bark aqueous extract in CNS targets

ETHNOPHARMACOLOGICAL RELEVANCE

The bark of Trichilia catigua A. Juss. (Meliaceae), popularly known as "big catuaba", is traditionally used in Brazilian folk medicine for its neuroactive potential as memory stimulant, and antinociceptive and antidepressant effects.

AIM OF THE STUDY

To study the aqueous extract of T. catigua bark as dual inhibitor of monoamine oxidase A (MAO-A) and acetylcholinesterase (AChE). To explore its antioxidant potential through interaction with xanthine/xanthine oxidase (X/XO) pathway, and to attempt a relationship between its phenolic profile and effects displayed.

MATERIALS AND METHODS

Phenolic profiling was achieved by HPLC-DAD-ESI/MSⁿ and UPLC-ESI-QTOF-MS analyses. The capacity to inhibit hMAO-A was assessed in vitro, as was that for AChE, evaluated in rat brain homogenates. The direct inhibition of the X/XO pathway and the scavenging of superoxide anion radical were the selected in vitro models to explore the antioxidant potential. The cytotoxic effects were assayed in the human neuronal SH-SY5Y cells by MTT reduction, after direct exposure (24h).

RESULTS

Twenty-six compounds were identified and quantified (551.02 ± 37.61mg/g of lyophilized extract). The phenylpropanoid substituted flavan-3-ols were the most representative compounds (~81% of quantified mass). The extract inhibited hMAO activity in a concentration-dependent manner (IC₅₀ = 121.06 ± 2.13μg/mL). A mixed model of inhibition of AChE activity was observed, reflected by the pronounced increase of Km values and a more discreet effect over the Vmax parameters, calculated from Michaelis-Menten fitted equations. In addition, it was demonstrated that the extract directly inhibits the X/XO pathway (IC₅₀ = 121.06 ± 2.13μg/mL) and also imbalances the oxidative stress acting as superoxide anion radical scavenger (EC₅₀ = 104.42 ± 10.67μg/mL), an oxidative by-product of this reaction. All these neuroprotective and neurotrophic effects were displayed within the non-toxic range of concentrations (0.063-0.500μg/mL) in SH-SY5Y cells.

CONCLUSIONS

Our results validate the traditional use of T. catigua bark for its neuroactive and neuroprotective potential. A novel approach upon its application towards the management of neurodegenerative and related symptomatology was likewise demonstrated.

Protective effects of fisetin and other berry flavonoids in Parkinson's disease

Parkinson's disease (PD) is an age-associated degenerative disease of the midbrain that results from the loss of dopaminergic neurons in the substantia nigra. It initially presents as a movement disorder with cognitive and other behavioral problems appearing later in the progression of the disease. Current therapies for PD only delay the onset or reduce the motor symptoms. There are no treatments to stop the nerve cell death or to cure the disease. It is becoming increasingly clear that neurological diseases such as PD are multi-factorial involving disruptions in multiple cellular systems. Thus, it is unlikely that modulating only a single factor will be effective at either preventing disease development or slowing disease progression. A better approach is to identify small molecules that have multiple biological activities relevant to the maintenance of brain function. Flavonoids are polyphenolic compounds that are widely distributed in fruits and vegetables and therefore regularly consumed in the human diet. While flavonoids were historically characterized on the basis of their antioxidant and free radical scavenging effects, more recent studies have shown that flavonoids have a wide range of activities that could make them particularly effective as agents for the treatment of PD. In this article, the multiple physiological benefits of flavonoids in the context of PD are first reviewed. Then, the evidence for the beneficial effects of the flavonol fisetin in models of PD are discussed. These results, coupled with the known actions of fisetin, suggest that it could reduce the impact of PD on brain function.

A protocol for a randomised double-blind placebo-controlled feasibility study to determine whether the daily consumption of flavonoid-rich pure cocoa has the potential to reduce fatigue in people with relapsing and remitting multiple sclerosis (RRMS)

Background

Dietary interventions including consumption of flavonoids, plant compounds found in certain foods, may have the ability to improve fatigue. However, to date, no well-designed intervention studies assessing the role of flavonoid consumption for fatigue management in people with MS (pwMS) have been performed. The hypothesis is that the consumption of a flavonoid-rich pure cocoa beverage will reduce fatigue in pwMS. The aim of this study is to determine the feasibility and potential outcome of running a trial to evaluate this hypothesis.

Methods

Using a randomised (1:1) double-blind placebo-controlled feasibility study, 40 men and women (20 in each trial arm) with a recent diagnosis (< 10 years) of relapsing and remitting MS (RRMS) and who are over 18 years of age will be recruited from neurology clinics and throughout the Thames Valley community. During a 6-week nutrition intervention period, participants will consume the cocoa beverage, high flavonoid or low flavonoid content, at breakfast daily. At baseline, demographic factors and disease-related factors will be assessed. Fatigue, activity and quality of life, in addition to other measures, will be taken at three visits (baseline, week 3 and week 6) in a university setting by a researcher blinded to group membership. Feasibility and fidelity will be assessed through recruitment and retention, adherence and a quantitative process evaluation at the end of the trial.

We will describe demographic factors (age, gender, level of education) as well as disease-related factors (disease burden scores, length of time diagnosed with MS) and cognitive assessment, depression and quality of life and general physical activity in order to characterise participants and determine possible mediators to identify the processes by which the intervention may bring about change. Feasibility (recruitment, safety, feasibility of implementation of the intervention and evaluation, protocol adherence and data completion) and potential for benefit (estimates of effect size and variability) will be determined to inform future planned studies. Results will be presented using point estimates, 95% confidence intervals and p values. Primary statistical analysis will be on an intention-to-treat basis and will use the complete case data set.

Discussion

We propose that a flavonoid-enriched cocoa beverage for the management of fatigue will be well received by participants. Further, if it is implemented early in the disease course of people diagnosed with RRMS, it will improve mobility and functioning by modifying fatigue.

Trial registration

Registered with ISRCTN Registry. Trial registration No: ISRCTN69897291; Date April 2016

Beneficial Effects of Silibinin Against Kainic Acid-induced Neurotoxicity in the Hippocampus in vivo

Silibinin, an active constituent of silymarin extracted from milk thistle, has been previously reported to confer protection to the adult brain against neurodegeneration. However, its effects against epileptic seizures have not been examined yet. In order to investigate the effects of silibinin against epileptic seizures, we used a relevant mouse model in which seizures are manifested as status epilepticus, induced by kainic acid (KA) treatment. Silibinin was injected intraperitoneally, starting 1 day before an intrahippocampal KA injection and continued daily until analysis of each experiment. Our results indicated that silibinin-treatment could reduce seizure susceptibility and frequency of spontaneous recurrent seizures (SRS) induced by KA administration, and attenuate granule cell dispersion (GCD), a morphological alteration characteristic of the dentate gyrus (DG) in temporal lobe epilepsy (TLE). Moreover, its treatment significantly reduced the aberrant levels of apoptotic, autophagic and pro-inflammatory molecules induced by KA administration, resulting in neuroprotection in the hippocampus. Thus, these results suggest that silibinin may be a beneficial natural compound for preventing epileptic events.

Cyclodextrins improving the physicochemical and pharmacological properties of antidepressant drugs: a patent review

INTRODUCTION

Depression is a serious mood disorder and is one of the most common mental illnesses. Despite the availability of several classes of antidepressants, a substantial percentage of patients are unresponsive to these drugs, which have a slow onset of action in addition to producing undesirable side effects. Some scientific evidence suggests that cyclodextrins (CDs) can improve the physicochemical and pharmacological profile of antidepressant drugs (ADDs). The purpose of this paper is to disclose current data technology prospects involving antidepressant drugs and cyclodextrins.

AREAS COVERED

We conducted a patent review to evaluate the antidepressive activity of the compounds complexed in CDs, and we analyzed whether these complexes improved their physicochemical properties and pharmacological action. The present review used 8 specialized patent databases for patent research, using the term 'cyclodextrin' combined with 'antidepressive agents' and its related terms. We found 608 patents. In the end, considering the inclusion criteria, 27 patents reporting the benefits of complexation of ADDs with CDs were included.

EXPERT OPINION

The use of CDs can be considered an important tool for the optimization of physicochemical and pharmacological properties of ADDs, such as stability, solubility and bioavailability.

Homoisoflavonoids and Chalcones Isolated from Haematoxylum campechianum L., with Spasmolytic Activity

Haematoxylum campechianum is a medicinal plant employed as an astringent to purify the blood and to treat stomach problems such as diarrhea and dysentery. A bio-guided chemical fractionation of the methanolic extract obtained from this plant allowed for the isolation of five compounds: two chalcones known as sappanchalcone (1); 3-deoxysappanchalcone (2); three homoisoflavonoids known as hematoxylol A (3); 4-O-methylhematoxylol (4); and, hematoxin (5). The spasmolytic activity was determined in an in vitro model (electrically induced contractions of guinea pig ileum), and allowed to demonstrate that the methanolic extract (EC₅₀ = 62.11 ± 3.23) fractions HcF7 (EC₅₀ = 61.75 ± 3.55) and HcF9 (EC₅₀ = 125.5 ± 10.65) and compounds 1 (EC₅₀ = 16.06 ± 2.15) and 2 (EC₅₀ = 25.37 ± 3.47) of Haematoxylum campechianum present significant relaxing activity as compared to papaverine (EC₅₀ = 20.08 ± 2.0) as a positive control.

Medicinal species as MTDLs: Turnera diffusa Willd. Ex Schult inhibits CNS enzymes and delays glutamate excitotoxicity in SH-SY5Y cells via oxidative damage

One of the most promising approaches to confront the complexity of central nervous system disorders are new multi-target directed ligands (MTDLs). Five medicinal species (Cereus grandiflorus (L.) Mill., Hyssopus officinalis L., Acorus calamus L., Silybum marianum L. Gaertn. and Turnera diffusa Willd. Ex Schult), selected for their ethnopharmacological relevance, were object for in vitro screening. The aqueous extract of T. diffusa revealed the strongest neuroactive potential, inhibiting monoamine oxidase-A (IC₅₀ = 129.80 ± 11.97 μg/mL), and acetyl- and butyrylcholinesterase (IC₂₅ = 0.352 ± 0.011 and 0.370 ± 0.036 mg/mL, respectively). Its phenolic profile was established for the first time by HPLC-DAD-ESI/MSⁿ. Twenty-six out of thirty-seven compounds were newly identified in this species. The pre-treatment with this flavonoid-rich extract promoted a rightward shift of the glutamate concentration neuronal cell (SH-SY5Y) death response curve. Furthermore, it significantly reduced the early phase formation of intracellular reactive species after glutamate and t-BHP exposure, suggesting that neuroprotection in SH-SY5Y cells was, in part, mediated by antioxidant mechanisms.

Luteolin Inhibits Fibrillary β-Amyloid1-40-Induced Inflammation in a Human Blood-Brain Barrier Model by Suppressing the p38 MAPK-Mediated NF-κB Signaling Pathways

Amyloid-β peptides (Aβ) exist in several forms and are known as key modulators of Alzheimer's disease (AD). Fibrillary Aβ (fAβ) has been found to disrupt the blood-brain barrier (BBB) by triggering and promoting inflammation. In this study, luteolin, a naturally occurring flavonoid that has shown beneficial properties in the central nervous system, was evaluated as a potential agent to preserve barrier function and inhibit inflammatory responses at the BBB that was injured by fAβ_1-40. We established an in vitro BBB model by co-culturing human brain microvascular endothelial cells (hBMECs) and human astrocytes (hAs) under fAβ_1-40-damaged conditions and investigated the effect of luteolin by analyzing cellular toxicity, barrier function, cytokine production and inflammation-related intracellular signaling pathways. Our results demonstrated that, in cells injured by fAβ_1-40, luteolin increased cell viability of hBMECs and hAs. The cytoprotection of the co-culture against the damage induced by fAβ_1-40 was also increased at both the apical and basolateral sides. Luteolin protected the barrier function by preserving transendothelial electrical resistance and relieving aggravated permeability in the human BBB model after being exposed to fAβ_1-40. Moreover, in both the apical and basolateral sides of the co-culture, luteolin reduced fAβ_1-40-induced inflammatory mediator and cytokine production, including cyclooxygenase-2 (COX-2), tumor necrosis factor α (TNF-α), interleukin 1 β (IL-1β), interleukin 6 (IL-6), and interleukin 8 (IL-8), however it did not show sufficient effects on scavenging intracellular reactive oxygen species (ROS) in hBMECs and hAs. The mechanism of BBB protection against fAβ_1-40-induced injury may be related to the regulation of inflammatory signal transduction, which involves inhibition of p38 mitogen-activated protein kinase (MAPK) activation, downregulation of phosphorylated inhibitory κB kinase (phosphor-IKK) levels, relief of inhibitory κB α (IκBα) degradation, blockage of nuclear factor κB (NF-κB) p65 nuclear translocation, and reduction of the release of inflammatory cytokines. Moreover, the employment of p38 MAPK and NF-κB inhibitors reversed luteolin-mediated barrier function and cytokine release. Taken together, luteolin may serve as a potential therapeutic agent for BBB protection by inhibiting inflammation following fAβ_1-40-induced injury.

Citrus bergamia Juice Extract Attenuates β-Amyloid-Induced Pro-Inflammatory Activation of THP-1 Cells Through MAPK and AP-1 Pathways

Flavonoids have been shown to be effective in protecting against age-related cognitive and motor decline in both in vitro and in vivo models. Recently, a flavonoid-rich extract of Citrus bergamia juice (BJe) has been shown to display anti-oxidant and anti-inflammatory properties against LPS-induced activation of human THP-1 monocytes. In the light of these observations, we wondered whether BJe may be beneficial against neuroinflammatory processes, such as those observed in Alzheimer’s disease. To this aim we used THP-1 monocytes to investigate the mechanisms underlying the beneficial potential of BJe against amyloid-beta_1–42 (Aβ₁₋₄₂) -mediated inflammation. Exposure of THP-1 cells to Aβ₁₋₄₂ significantly induced the expression and secretion of IL-6 and IL-1β in THP-1 cells and increased the phosphorylation of ERK 1/2 as well as p46 and p54 members of JNK family. Moreover, Aβ₁₋₄₂ raises AP-1 DNA binding activity in THP-1-treated cells. Interestingly, all these effects were reduced in the presence of BJe. Our data indicate that BJe may effectively counteract the pro-inflammatory activation of monocytes/microglial cells exposed to amyloid fibrils, suggesting a promising role as a natural drug against neuroinflammatory processes.

Passiflora actinia hydroalcoholic extract and its major constituent, isovitexin, are neuroprotective against glutamate-induced cell damage in mice hippocampal slices

OBJECTIVES

To investigate whether Passiflora actinia hydroalcoholic extract and its major constituent, isovitexin, protect mice hippocampal brain slices from glutamate-induced neurotoxicity.

METHODS

Neuroprotective effect of the extract against glutamate-induced excitotoxicity (10 mm) was evaluated through cell viability of hippocampal slices. The extract or its flavonoids were directly applied to hippocampal slices and then subjected to glutamate-induced toxicity. Alternatively, hippocampal slices from extract-treated mice were also subjected to the same toxicity protocol.

KEY FINDINGS

Mice supplementation with the extract protected hippocampal slices from in-vitro neurotoxicity. When directly applied to hippocampal slices, the extract showed a higher neuroprotective potential than a commercial dry extract of Passiflora incarnata, which was related to P. actinia extract which had higher isovitexin and total flavonoid content expressed as isovitexin. Isovitexin, but not apigenin, induced a similar neuroprotective response when applied alone, at a concentration equivalent to that found in the extract.

CONCLUSIONS

This study highlights new neuropharmacological activity of the Passiflora genus, suggesting that it can act as modulator of the glutamatergic system. The search for improved pharmacotherapies with novel mechanisms of action has been shown of great importance for the treatment of resistant neurological and psychiatric disorders.

Protective effect of naringin on 3-nitropropionic acid-induced neurodegeneration through the modulation of matrix metalloproteinases and glial fibrillary acidic protein

Naringin (4',5,7-trihydroxy-flavonone-7-rhamnoglucoside), a flavonone present in grapefruit, has recently been reported to protect against neurodegeration, induced with 3-nitropropionic acid (3-NP), through its antioxidant, anti-inflammatory, and antiapoptotic properties. This study used a rat model of 3-NP-induced neurodegeneration to investigate the neuroprotective effects of naringin exerted by modulating the expression of matrix metalloproteinases and glial fibrillary acidic protein. Neurodegeneration was induced with 3-NP (10 mg/kg body mass, by intraperitoneal injection) once a day for 2 weeks, and induced rats were treated with naringin (80 mg/kg body mass, by oral gavage, once a day for 2 weeks). Naringin ameliorated the motor abnormalities caused by 3-NP, and reduced blood-brain barrier dysfunction by decreasing the expression of matrix metalloproteinases 2 and 9, along with increasing the expression of the tissue inhibitors of metalloproteinases 1 and 2 in 3-NP-induced rats. Further, naringin reduced 3-NP-induced neuroinflammation by decreasing the expression of nuclear factor-kappa B and glial fibrillary acidic protein. Thus, naringin exerts protective effects against 3-NP-induced neurodegeneration by ameliorating the expressions of matrix metalloproteinases and glial fibrillary acidic protein.

Phytochemical analysis of hydroethanolic extract of Turnera diffusa Willd and evaluation of its effects on astrocyte cell death

OBJECTIVE

To evaluate the phytochemical composition of hydroethanolic extracts from powdered aerial parts of Turnera diffusa Willd (Turneraceae; T. diffusa), as well as its toxicity in astrocytes.

METHODS

Chemical analyses of hydroethanolic extract from powdered aerial parts ofT. diffusa were carried out using HPLC-DAD-ESI-MS/MS.In vitro assays using astrocytes culture were performed to evaluate cell death.

RESULTS

Flavone-C, O-diglycosides, such as, luteolin-8-C-[6-deoxy-2-O-rhamnosyl]-xylo-hexos-3-uloside, apigenin-8-C-[6-deoxy-2-O-rhamnosyl]-xylo-hexos-3-uloside and apigenin-7-O-6"-p-coumaroylglucoside were the main compounds found in this hydroethanolic extract. Concentration time-effect demonstrated the toxicity of this extract at a concentration of 1,000µg/mL in astrocyte culture, after 6 and 24 hours of incubation.

CONCLUSION

In phytochemical analyses, important antioxidants (mainly flavonoids) were observed. T. diffusa extracts presented cytotoxic effect in high concentrations, leading to increased cell death in astrocyte culture.

Co-ultramicronized Palmitoylethanolamide/Luteolin Promotes the Maturation of Oligodendrocyte Precursor Cells

Oligodendrocytes have limited ability to repair the damage to themselves or to other nerve cells, as seen in demyelinating diseases like multiple sclerosis. An important strategy may be to replace the lost oligodendrocytes and/or promote the maturation of undifferentiated oligodendrocyte precursor cells (OPCs). Recent studies show that a composite of co-ultramicronized N-palmitoylethanolamine (PEA) and luteolin (co-ultramicronized PEA/luteolin, 10:1 by mass) is efficacious in improving outcome in experimental models of spinal cord and traumatic brain injuries. Here, we examined the ability of co-ultramicronized PEA/luteolin to promote progression of OPCs into a more differentiated phenotype. OPCs derived from newborn rat cortex were placed in culture and treated the following day with 10 μM co-ultramicronized PEA/luteolin. Cells were collected 1, 4 and 8 days later and analyzed for expression of myelin basic protein (MBP). qPCR and Western blot analyses revealed a time-dependent increase in expression of both mRNA for MBP and MBP content, along with an increased expression of genes involved in lipid biogenesis. Ultramicronized PEA or luteolin, either singly or in simple combination, were ineffective. Further, co-ultramicronized PEA/luteolin promoted morphological development of OPCs and total protein content without affecting proliferation. Co-ultramicronized PEA/luteolin may represent a novel pharmacological strategy to promote OPC maturation.

Mast cells in meningiomas and brain inflammation

Background

Research focus in neuro-oncology has shifted in the last decades towards the exploration of tumor infiltration by a variety of immune cells and their products. T cells, macrophages, B cells, and mast cells (MCs) have been identified.

Methods

A systematic review of the literature was conducted by searching PubMed, EMBASE, Google Scholar, and Turning Research into Practice (TRIP) for the presence of MCs in meningiomas using the terms meningioma, inflammation and mast cells.

Results

MCs have been detected in various tumors of the central nervous system (CNS), such as gliomas, including glioblastoma multiforme, hemangioblastomas, and meningiomas as well as metastatic brain tumors. MCs were present in as many as 90 % of all high-grade meningiomas mainly found in the perivascular areas of the tumor. A correlation between peritumoral edema and MCs was found.

Interpretation

Accumulation of MCs in meningiomas could contribute to the aggressiveness of tumors and to brain inflammation that may be involved in the pathogenesis of additional disorders.