Ferulic acid is a nutraceutical β-secretase modulator that improves behavioral impairment and alzheimer-like pathology in transgenic mice

Ferulic acid amide derivatives with varying inhibition of amyloid-β oligomerization and fibrillization

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized, in part, by the misfolding, oligomerization and fibrillization of amyloid-β (Aβ). Evidence suggests that the mechanisms underpinning Aβ oligomerization and subsequent fibrillization are distinct, and may therefore require equally distinct therapeutic approaches. Prior studies have suggested that amide derivatives of ferulic acid, a natural polyphenol, may combat multiple AD pathologies, though its impact on Aβ aggregation is controversial. We designed and synthesized a systematic library of amide derivatives of ferulic acid and evaluated their anti-oligomeric and anti-fibrillary capacities independently. Azetidine tethered, triphenyl derivatives were the most potent anti-oligomeric agents (compound 2i: IC₅₀ = 1.8 µM ± 0.73 µM); notably these were only modest anti-fibrillary agents (20.57% inhibition of fibrillization), and exemplify the poor correlation between anti-oligomeric/fibrillary activities. These data were subsequently codified in an in silico QSAR model, which yielded a strong predictive model of anti-Aβ oligomeric activity (κ = 0.919 for test set; κ = 0.737 for validation set).

Rice bran, an off-shoot to newer therapeutics in neurological disorders

Normal brain functioning involves the interaction of interconnected molecular and cellular activities, which appear to alter normal to abnormal brain functioning when worsened, contributing to the emergence of neurological disorders. There are currently millions of people who are living with brain disorders globally and this will rise if suitable prevention strategies are not explored. Nutraceutical intended to treat numerous health goals with little adverse effect possible together can be more beneficial than pharmaceutical monotherapy for fostering balanced brain functioning. Nutraceutical provides a specific composition of effective macronutrients and micronutrients that are difficult to synthesize in the laboratory. Numerous elements of rice fibers in rice bran are characterized as natural anti-oxidant and having potential anti-inflammatory activity. The rice bran captures interest among the researchers as it is widespread, affordable, and rich in nutrients including protein, fat, carbohydrates, bioactive components, and dietary fiber. This review covers the neuroprotective multiplicity of rice bran and its constituents to deter pathological conditions of the brain and to facilitate balanced brain functioning at the same time.

Downregulation of CD73/A2AR-Mediated Adenosine Signaling as a Potential Mechanism of Neuroprotective Effects of Theta-Burst Transcranial Magnetic Stimulation in Acute Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is a chronic neurodegenerative disease caused by autoimmune-mediated inflammation in the central nervous system. Purinergic signaling is critically involved in MS-associated neuroinflammation and its most widely applied animal model—experimental autoimmune encephalomyelitis (EAE). A promising but poorly understood approach in the treatment of MS is repetitive transcranial magnetic stimulation. In the present study, we aimed to investigate the effect of continuous theta-burst stimulation (CTBS), applied over frontal cranial bone, on the adenosine-mediated signaling system in EAE, particularly on CD73/A_2AR/A₁R in the context of neuroinflammatory activation of glial cells. EAE was induced in two-month-old female DA rats and in the disease peak treated with CTBS protocol for ten consecutive days. Lumbosacral spinal cord was analyzed immunohistochemically for adenosine-mediated signaling components and pro- and anti-inflammatory factors. We found downregulated IL-1β and NF- κB-ir and upregulated IL-10 pointing towards a reduction in the neuroinflammatory process in EAE animals after CTBS treatment. Furthermore, CTBS attenuated EAE-induced glial eN/CD73 expression and activity, while inducing a shift in A_2AR expression from glia to neurons, contrary to EAE, where tight coupling of eN/CD73 and A_2AR on glial cells is observed. Finally, increased glial A₁R expression following CTBS supports anti-inflammatory adenosine actions and potentially contributes to the overall neuroprotective effect observed in EAE animals after CTBS treatment.

Ferulic Acid Ameliorates Alzheimer's Disease-like Pathology and Repairs Cognitive Decline by Preventing Capillary Hypofunction in APP/PS1 Mice

Brain capillaries are crucial for cognitive functions by supplying oxygen and other nutrients to and removing metabolic wastes from the brain. Recent studies have demonstrated that constriction of brain capillaries is triggered by beta-amyloid (Aβ) oligomers via endothelin-1 (ET1)-mediated action on the ET1 receptor A (ETRA), potentially exacerbating Aβ plaque deposition, the primary pathophysiology of Alzheimer's disease (AD). However, direct evidence is still lacking whether changes in brain capillaries are causally involved in the pathophysiology of AD. Using APP/PS1 mouse model of AD (AD mice) relative to age-matched negative littermates, we identified that reductions of density and diameter of hippocampal capillaries occurred from 4 to 7 months old while Aβ plaque deposition and spatial memory deficit developed at 7 months old. Notably, the injection of ET1 into the hippocampus induced early Aβ plaque deposition at 5 months old in AD mice. Conversely, treatment of ferulic acid against the ETRA to counteract the ET1-mediated vasoconstriction for 30 days prevented reductions of density and diameter of hippocampal capillaries as well as ameliorated Aβ plaque deposition and spatial memory deficit at 7 months old in AD mice. Thus, these data suggest that reductions of density and diameter of hippocampal capillaries are crucial for initiating Aβ plaque deposition and spatial memory deficit at the early stages, implicating the development of new therapies for halting or curing memory decline in AD.

Natural products as pharmacological modulators of mitochondrial dysfunctions for the treatments of Alzheimer's disease: A comprehensive review

Alzheimer's disease (AD) is the most common progressive neurodegenerative disorder characterized by neuronal loss and cognitive impairment that harshly affect the elderly individuals. Currently, the available anti-AD pharmacological approaches are purely symptomatic to alleviate AD symptoms, and the curative effects of novel anti-AD drugs focused on Aβ target are disappointing. Hence, there is a tremendous need to adjust AD therapeutic targets and discover novel anti-AD agents. In AD, mitochondrial dysfunction gradually triggers neuronal death from different aspects and worsens the occurrence and progress of AD. Consequently, it has been proposed that the intervention of impaired mitochondria represents an attractive breakthrough point for AD treatments. Due to chemical diversity, poly-pharmacological activities, few adverse effects and multiple targeting, natural products (NPs) have been identified as a valuable treasure for drug discovery and development. Multiple lines of studies have scientifically proven that NPs display ameliorative benefits in AD treatment in relation to mitochondrial dysfunction. This review surveys the complicated implications for mitochondrial dysregulation and AD, and then summarizes the potentials of NPs and their underlying molecular mechanisms against AD via reducing or improving mitochondrial dysfunction. It is expected that this work may open the window to speed up the development of innovative anti-AD drugs originated from NPs and improve upcoming AD therapeutics.

Comparison of memory, affective behavior, and neuropathology in APPNLGF knock-in mice to 5xFAD and APP/PS1 mice

Transgenic mouse models of Aβ amyloidosis generated by knock-in of a humanized Aβ sequence can offer some advantages over the transgenic models that overexpress amyloid precursor protein (APP). However, systematic comparison of memory, behavioral, and neuropathological phenotypes between these models has not been well documented. In this study, we compared memory and affective behavior in APP^NLGF mice, an APP knock-in model, to two widely used mouse models of Alzheimer's disease, 5xFAD and APP/PS1 mice, at 10 months of age. We found that, despite similar deficits in working memory, object recognition, and social recognition memory, APP^NLGF and 5xFAD mice but not APP/PS1 mice show compelling anxiety- and depressive-like behavior, and exhibited a marked impairment of social interaction. We quantified corticolimbic Aβ plaques, which were lowest in APP^NLGF, intermediate in APP/PS1, and highest in 5xFAD mice. Interestingly, analysis of plaque size revealed that plaques were largest in APP/PS1 mice, intermediate in 5xFAD mice, and smallest in APP^NLGF mice. Finally, we observed a significantly higher percentage of the area occupied by plaques in both 5xFAD and APP/PS1 relative to APP^NLGF mice. Overall, our findings suggest that the severity of Aβ neuropathology is not directly correlated with memory and affective behavior impairments between these three transgenic mouse models. Additionally, APP^NLGF may represent a valid mouse model for studying AD comorbid with anxiety and depression.

A Review on Potential Footprints of Ferulic Acid for Treatment of Neurological Disorders

Ferulic acid is being screened in preclinical settings to combat various neurological disorders. It is a naturally occurring dietary flavonoid commonly found in grains, fruits, and vegetables such as rice, wheat, oats, tomatoes, sweet corn etc., which exhibits protective effects against a number of neurological diseases such as epilepsy, depression, ischemia-reperfusion injury, Alzheimer's disease, and Parkinson's disease. Ferulic acid prevents and treats different neurological diseases pertaining to its potent anti-oxidative and anti-inflammatory effects, beside modulating unique neuro-signaling pathways. It stays in the bloodstream for longer periods than other dietary polyphenols and antioxidants and easily crosses blood brain barrier. The use of novel drug delivery systems such as solid-lipid nanoparticles (SLNs) or its salt forms (sodium ferulate, ethyl ferulate, and isopentyl ferulate) further enhance its bioavailability and cerebral penetration. Based on reported studies, ferulic acid appears to be a promising molecule for treatment of neurological disorders; however, more preclinical (in vitro and in vivo) mechanism-based studies should be planned and conceived followed by its testing in clinical settings.

Rapid determination of rosmarinic acid and its two bioactive metabolites in the plasma of rats by LC-MS/MS and application to a pharmacokinetics study

Rosmarinic acid (RA), an ester compound of caffeic acid (CA) and 3,4-dihydroxyphenyllacic acid, is widely distributed in the herbs of the Lamiaceae family and has shown a wide spectrum of pharmacological properties. CA and FA (ferulic acid) are two bioactive metabolites in vivo after oral administration of RA; however, a rapid and robust analytical approach that can enable the quantitative assay of RA and two bioactive metabolites is still lacking. A liquid chromatography/tandem mass spectrometry method was established that was capable of the quantitative determination of RA, CA and FA by negative-mode multiple reaction monitoring within 7 min using a Zorbax SB-C18 column and an isocratic elution. This assay method was validated as linear over the investigated ranges with correlation coefficients (r) > 0.9950. The intra- and inter-day precision was <10.65%, and the accuracies (relative error, %) <-6.41%. The validated approach was applied to a pharmacokinetics study of RA and its two metabolites in rats after oral and intravenous administration. RA was rapidly metabolized in both administration modes, whilst the metabolites CA and FA were only detectable by oral administration. The absolute availability of RA was calculated to be 4.13%.

Protective Effect of Ferulic Acid against Hydrogen Peroxide Induced Apoptosis in PC12 Cells

Ferulic Acid (FA) is a highly abundant phenolic phytochemical which is present in plant tissues. FA has biological effects on physiological and pathological processes due to its anti-apoptotic and anti-oxidative properties, however, the detailed mechanism(s) of function is poorly understood. We have identified FA as a molecule that inhibits apoptosis induced by hydrogen peroxide (H₂O₂) or actinomycin D (ActD) in rat pheochromocytoma, PC12 cell. We also found that FA reduces H₂O₂-induced reactive oxygen species (ROS) production in PC12 cell, thereby acting as an anti-oxidant. Then, we analyzed FA-mediated signaling responses in rat pheochromocytoma, PC12 cells using antibody arrays for phosphokinase and apoptosis related proteins. This FA signaling pathway in PC12 cells includes inactivation of pro-apoptotic proteins, SMAC/Diablo and Bad. In addition, FA attenuates the cell injury by H₂O₂ through the inhibition of phosphorylation of the extracellular signal-regulated kinase (ERK). Importantly, we find that FA restores expression levels of brain-derived neurotrophic factor (BDNF), a key neuroprotective effector, in H₂O₂-treated PC12 cells. As a possible mechanism, FA increases BDNF by regulating microRNA-10b expression following H₂O₂ stimulation. Taken together, FA has broad biological effects as a neuroprotective modulator to regulate the expression of phosphokinases, apoptosis-related proteins and microRNAs against oxidative stress in PC12 cells.

Can We Treat Neuroinflammation in Alzheimer's Disease?

Alzheimer's disease (AD), considered the most common type of dementia, is characterized by a progressive loss of memory, visuospatial, language and complex cognitive abilities. In addition, patients often show comorbid depression and aggressiveness. Aging is the major factor contributing to AD; however, the initial cause that triggers the disease is yet unknown. Scientific evidence demonstrates that AD, especially the late onset of AD, is not the result of a single event, but rather it appears because of a combination of risk elements with the lack of protective ones. A major risk factor underlying the disease is neuroinflammation, which can be activated by different situations, including chronic pathogenic infections, prolonged stress and metabolic syndrome. Consequently, many therapeutic strategies against AD have been designed to reduce neuro-inflammation, with very promising results improving cognitive function in preclinical models of the disease. The literature is massive; thus, in this review we will revise the translational evidence of these early strategies focusing in anti-diabetic and anti-inflammatory molecules and discuss their therapeutic application in humans. Furthermore, we review the preclinical and clinical data of nutraceutical application against AD symptoms. Finally, we introduce new players underlying neuroinflammation in AD: the activity of the endocannabinoid system and the intestinal microbiota as neuroprotectors. This review highlights the importance of a broad multimodal approach to treat successfully the neuroinflammation underlying AD.

Nanotechnology to improve the Alzheimer's disease therapy with natural compounds

Alzheimer's disease (AD) is a form of dementia with high impact worldwide, accounting with more than 46 million cases. It is estimated that the number of patients will be four times higher in 2050. The initial symptoms of AD are almost imperceptible and typically involve lapses of memory in recent events. However, the available medicines still focus on controlling the symptoms and do not cure the disease. Regarding the advances in the discovery of new treatments for this devastating disease, natural compounds are gaining increasing relevance in the treatment of AD. Nevertheless, they present some limiting characteristics such as the low bioavailability and the low ability to cross the blood-brain barrier (BBB) that hinder the development of effective therapies. To overcome these issues, the delivery of natural products by targeting nanocarriers has aroused a great interest, improving the therapeutic activity of these molecules. In this article, a review of the research progress on drug delivery systems (DDS) to improve the therapeutic activity of natural compounds with neuroprotective effects for AD is presented. Graphical abstract.

Clinical Benefits of Antioxidative Supplement Twendee X for Mild Cognitive Impairment: A Multicenter, Randomized, Double-Blind, and Placebo-Controlled Prospective Interventional Study

Oxidative stress is part of the entire pathological process that underlies the development of Alzheimer's disease (AD), including the mild cognitive impairment (MCI) stage. Twendee X (TwX) is a supplement containing a strong antioxidative mix of eight antioxidants, which has been shown to have a clinical and therapeutic benefit in AD model mice. Here, we conducted a multicenter, randomized, double-blind, and placebo-controlled prospective interventional study to evaluate the efficacy of TwX in mitigating MCI. The primary outcomes were differences in Mini-Mental State Examination (MMSE) and Hasegawa Dementia Scale-revised (HDS-R) scores between baseline and six months for placebo and TwX groups. Seventy-eight subjects with MCI were randomized into placebo (n = 37) and TwX (n = 41) groups. MMSE scores at six months differed significantly between the TwX and placebo groups (p = 0.018), and HDS-R scores for the TwX group exhibited a significant improvement at six months relative to baseline (p = 0.025). The TwX group did not show any change in affective or activities of daily living scores at six months. The present study indicates that strong antioxidative supplement TwX is clinical beneficial for cognitive function in subjects with MCI.

Ferulic acid delayed amyloid β-induced pathological symptoms by autophagy pathway via a fasting-like effect in Caenorhabditis elegans

The amyloid β (Aβ) generation or aggregation plays a crucial role in Alzheimer's disease (AD). Autophagy agonists, which function as the clearance of Aβ, could be the potential drug candidates against AD. In staple food crops, ferulic acid (FA) is an enormously copious and almost ubiquitous phenolic antioxidant. In the present study, FA significantly inhibited Aβ-induced pathological symptoms of paralysis and hypersensitivity to exogenous serotonin, meanwhile restrained Aβ monomers, oligomers, and deposits in AD C. elegans. FA increased the expression of autophagy reporter LGG-1 and enhanced autophagy flux. However, the autophagy inhibitors abolished the restrictive action of FA on the worm paralysis phenotype. According to these results, FA triggered autophagy and ameliorated Aβ-induced pathological symptoms by the autophagy pathway. Moreover, FA activated the HLH-30 transcription factor to nuclear localization, which acts upstream of autophagy in fasted animals, reduced the level of lipids, but affected nor the growth of E. coli OP50, neither animal food intake behavior. These suggest that FA induced a fasting-like effect to activate the autophagy pathway. Additionally, FA ameliorated poly Q aggregations in Huntington's disease worm. Thus, FA could not only affect AD, broadly but also neurodegenerative diseases characterized by misfolded or aggregated proteins.

Nanocarriers for effective nutraceutical delivery to the brain

Neurodegenerative disorders are common among aging populations around the globe. Most are characterized by loss of neurons, protein aggregates, oxidative stress, mitochondrial damage, neuroinflammation among others. Although symptomatic treatment using conventional pharmacotherapy has been widely employed, their therapeutic success is limited due to varied reasons. In the need to identify an alternative approach, researchers successfully demonstrated the therapeutic utility of plant-derived nutraceuticals in cell and animal models of neurodegenerative conditions. However, most nutraceuticals failed during clinical trials in humans owing to their poor bioavailability in vivo and limited permeability across the blood brain barrier (BBB). The current emphasis is therefore on the improved delivery of nutraceuticals to the brain. In this regard, development of nanoparticle conjugated nutraceuticals to enhance bioavailability and therapeutic efficacy in the brain has gained attention. Here, we review the research advances in nanoparticles conjugated nutraceuticals applied in neurodegenerative disorders and discuss their advantages and limitations, clinical trials and toxicity concerns.

Effects of Ferulic Acid and Angelica archangelica Extract (Feru-guard ®) on Mild Cognitive Impairment: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Prospective Trial

We conducted a multicenter, randomized, double-blind, placebo-controlled prospective trial examining a supplement containing ferulic acid and Angelica archangelica extract (Feru-guard ^®) for mild cognitive impairment (MCI). In the intention-to-treat population, Mini-Mental State Examination (MMSE) scores were significantly better at 24 weeks (p = 0.041) in the active group. In the per protocol population, MMSE was significantly better in the active group at 24 weeks (p = 0.008), and mixed effect models for repeated measures (MMRM) showed significant difference (p = 0.016). ADAS-Jcog was significantly better at 24 (p = 0.035) and 48 weeks (p = 0.015) in the active group, and MMRM was significant (p = 0.031). Thus, Feru-guard ^® may be useful for MCI.

Gallic acid is a dual α/β-secretase modulator that reverses cognitive impairment and remediates pathology in Alzheimer mice

Several plant-derived compounds have demonstrated efficacy in pre-clinical Alzheimer's disease (AD) rodent models. Each of these compounds share a gallic acid (GA) moiety, and initial assays on this isolated molecule indicated that it might be responsible for the therapeutic benefits observed. To test this hypothesis in a more physiologically relevant setting, we investigated the effect of GA in the mutant human amyloid β-protein precursor/presenilin 1 (APP/PS1) transgenic AD mouse model. Beginning at 12 months, we orally administered GA (20 mg/kg) or vehicle once daily for 6 months to APP/PS1 mice that have accelerated Alzheimer-like pathology. At 18 months of age, GA therapy reversed impaired learning and memory as compared with vehicle, and did not alter behavior in nontransgenic littermates. GA-treated APP/PS1 mice had mitigated cerebral amyloidosis, including brain parenchymal and cerebral vascular β-amyloid deposits, and decreased cerebral amyloid β-proteins. Beneficial effects co-occurred with reduced amyloidogenic and elevated nonamyloidogenic APP processing. Furthermore, brain inflammation, gliosis, and oxidative stress were alleviated. We show that GA simultaneously elevates α- and reduces β-secretase activity, inhibits neuroinflammation, and stabilizes brain oxidative stress in a pre-clinical mouse model of AD. We further demonstrate that GA increases abundance of a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10, Adam10) proprotein convertase furin and activates ADAM10, directly inhibits β-site APP cleaving enzyme 1 (BACE1, Bace1) activity but does not alter Adam10 or Bace1 transcription. Thus, our data reveal novel post-translational mechanisms for GA. We suggest further examination of GA supplementation in humans will shed light on the exciting therapeutic potential of this molecule.

Effect of Feru-guard 100M on amyloid-beta deposition in individuals with mild cognitive impairment

AIM

Many researchers argue that Alzheimer's disease is at least partly caused by deposition of amyloid beta (Aβ) in the brain. Ferulic acid (FA) and Angelica archangelica (AA) are candidate agents for reducing Aβ and improving cognitive function. Feru-guard 100M is a supplement containing FA and AA extract. Using this supplement, we planned to assess the effect of FA and AA on Aβ deposition in the human brain.

METHODS

This was an open-label, interventional multi-institutional joint study of Kobe University and the Institute of Biomedical Research and Innovation (Kobe, Japan). Seventeen subjects diagnosed with mild cognitive impairment were divided into two groups: the intervention group (n = 10) and the control group (n = 7). The subjects in the intervention group used Feru-guard 100M every day for 48 weeks, whereas the subjects in the control group did not use the supplement. We assessed the differences between the two groups by examining Aβ deposition and brain atrophy at 48 weeks and cognitive function every 24 weeks. We used carbon-11-labelled Pittsburgh compound B (PiB) positron emission tomography to evaluate Aβ deposition.

RESULTS

There were no significant differences in Aβ deposition, brain atrophy, and cognitive function between the two groups. Specifically, differences in Aβ deposition change in seven regions of interest examined with PiB positron emission tomography, brain atrophy change in four indicators of voxel-based morphometry, and cognitive impairment measured by five psychological tests were not significantly between the two groups.

CONCLUSION

Treatment with Feru-guard 100M, a supplement containing FA and AA extract, for 48 weeks did not reduce cortical PiB retention, which reflects Aβ deposition. It also did not suppress the aggravation of brain atrophy or decline in cognitive function.

Exploring the multimodal role of phytochemicals in the modulation of cellular signaling pathways to combat age-related neurodegeneration

Neurodegeneration is the progressive loss of neuronal structures and functions that lead to copious disorders like Alzheimer's (AD), Parkinson's (PD), Huntington's (HD), amyotrophic lateral sclerosis (ALS), and other less recurring diseases. Aging is the prime culprit for most neurodegenerative events. Moreover, the shared pathogenic factors of many neurodegenerative processes are inflammatory responses and oxidative stress (OS). Unfortunately, it is very complicated to treat neurodegeneration and there is no effective remedy. The rapid progression of the neurodegenerative diseases that exacerbate the burden and the concurrent absence of effective treatment strategies force the researchers to investigate more therapeutic approaches that ultimately target the causative factors of the neurodegeneration. Phytochemicals have great potential to exert their neuroprotective effects by targeting various mechanisms, such as OS, neuroinflammation, abnormal protein aggregation, neurotrophic factor deficiency, disruption in mitochondrial function, and apoptosis. Therefore, this review represents the molecular mechanisms of neuroprotection by multifunctional phytochemicals to combat age-linked neurodegenerative disorders.

Health promoting microbial metabolites produced by gut microbiota after prebiotics metabolism

Human gut microbiota (HGM) is a microbial complex where dynamic mutualistic interactions related to digestion and absorption of dietary components take place. The consumption of specific food ingredients, such as prebiotics and dietary fibers, constituted mainly by carbohydrates polymers, can modulate the HGM composition and metabolism serving as a fermentable substrate to produce bacterial metabolites with beneficial effects on host health. Especially, bacterial short-chain fatty acids, tryptophan and organic acids have shown positive effects on pathogenic bacteria control, mineral absorption, weight control and obesity, immune response homeostasis, gut barrier improvement, brain modulation and anticancer activity. Despite the fact that these effects vary between individuals due to personal HGM richness, the information presented in this review contributes to understanding the effects of prebiotics and dietary fibers consumption on the generation of HGM metabolites and the mechanisms by which these metabolites interact with host cells improving host health.

Oral administration of ferulic acid or ethyl ferulate attenuates retinal damage in sodium iodate-induced retinal degeneration mice

Epidemiological studies indicate that the daily intake of antioxidants from a traditional Asian diet reduces the risk of developing age-related macular degeneration. Many of the phytochemicals that are abundant in whole grains exhibit a wide variety of biological activity such as antioxidant, anti-inflammatory, and neuroprotective effects. Ferulic acid (FA) is a phenolic acid found in vegetables and grains that has therapeutic potential for diabetes mellitus, Alzheimer's disease, and other diseases. We investigated the retinal protective effect of FA in a sodium iodate (NaIO₃)-induced model of retinal degeneration. In a human retinal pigment epithelial cell line, FA attenuated H₂O₂-induced injury and lipopolysaccharide- or 7-ketocholesterol-induced inflammation. In mice, the oral administration of FA or its analog, ethyl ferulate, attenuated the morphological and functional features of NaIO₃-induced retinal degeneration according to optical coherence tomography and electroretinography. Our results demonstrate that the oral administration of FA provides protective effects to the retina, suggesting that the intake of FA as a daily supplement or daily healthy diet containing rich vegetables and whole grains may prevent age-related macular degeneration.

Effects of Exercise and Ferulic Acid on Alpha Synuclein and Neuroprotective Heat Shock Protein 70 in An Experimental Model of Parkinsonism Disease

BACKGROUND & OBJECTIVE

This study investigated the effects of ferulic acid (FR), muscle exercise (Ex) and combination of them on rotenone (Rot)-induced Parkinson disease (PD) in mice as well as their underlying mechanisms.

METHOD

56 male C57BL/6 mice were allocated into 8 equal groups, 1) Normal control (CTL), 2) FR (mice received FR at 20 mg/kg/day), 3) Ex (mice received swimming Ex) and 4) Ex + FR (mice received FR and Ex), 5) Rot (mice received Rot 3 mg/Kg i.p. for 70 days), 6) ROT+ FR (mice received Rot + FR at 20 mg/kg/day), 7) ROT+ Ex (mice received Rot + swimming Ex) and 8) ROT+ Ex + FR (mice received Rot + FR and Ex). ROT group showed significant impairment in motor performance and significant reduction in tyrosine hydroxylase (TH) density and Hsp70 expression (p< 0.05) with Lewy bodies (alpha synuclein) aggregates in corpus striatum. Also, ROT+FR, ROT+EX and ROT + Ex+ FR groups showed significant improvement in behavioral and biochemical changes, however the effect of FR alone was more potent than Ex alone (p< 0.05) and addition of Ex to FR caused no more significant improvement than FR alone.

CONCLUSION

We concluded that, FR and Ex improved the motor performance in rotenone-induced PD rodent model which might be due to increased Hsp70 expression and TH density in corpus striatum and combination of both did not offer more protection than FR alone.

The Additive Effects of Low Dose Intake of Ferulic Acid, Phosphatidylserine and Curcumin, Not Alone, Improve Cognitive Function in APPswe/PS1dE9 Transgenic Mice

Alzheimer's disease (AD) is the most common form of dementia and its prevention and treatment is a worldwide issue. Many natural components considered to be effective against AD have been identified. However, almost all clinical trials of these components for AD reported inconclusive results. We thought that multiple factors such as amyloid β (Aβ) and tau progressed the pathology of AD and that a therapeutic effect would be obtained by using multiple active ingredients with different effects. Thus, in this study, we treated ferulic acid (FA), phosphatidylserine (PS) and curcumin (Cur) in combination or alone to APPswe/PS1dE9 transgenic mice and evaluated cognitive function by Y-maze test. Consequently, only the three-ingredient group exhibited a significant improvement in cognitive function compared to the control group. In addition, we determined the amounts of Aβ, brain-derived neurotrophic factor (BDNF), interleukin (IL)-1β, acetylcholine and phosphorylated tau in the mouse brains after the treatment. In the two-ingredient (FA and PS) group, a significant decrease in IL-1β and an increasing trend in acetylcholine were observed. In the Cur group, significant decreases in Aβ and phosphorylated tau and an increasing trend in BDNF were observed. In the three-ingredient group, all of them were observed. These results indicate that the intake of multiple active ingredients with different mechanisms of action for the prevention and treatment of AD.

Hydroxycinnamic acids and human health: recent advances

There is an urgent need to improve human diet globally. Compelling evidence gathered over the past several decades suggests that a suboptimal diet is associated with many chronic diseases and may be responsible for more deaths than any other risks worldwide. The main components in our diet that need higher intake are whole grains, fruit and vegetables, and nuts and seeds; all of these are important sources of dietary fiber and polyphenols. The health benefits of dietary fiber and polyphenols are also supported by several decades of valuable research. However, the conclusions drawn from interventional human trials are not straightforward and the action mechanisms in improving human health are not fully understood. Moreover, there is a great inter-individual variation caused by different individual capabilities of processing, absorbing and using these compounds effectively. Data on the bioavailability and bioefficacy of hydroxycinnamic acids (HCAs) are limited when compared to other classes of polyphenols (e.g. anthocyanins). This review aims to summarize the latest research advances related to HCA bioavailability and their biological effects revealed by epidemiological data, pre-clinical and clinical studies. Moreover, we aim to review the effects of HCAs on gut microbiota diversity and function and its respective influence on host health. © 2019 Society of Chemical Industry.

Current Status of Drug Targets and Emerging Therapeutic Strategies in the Management of Alzheimer's Disease

Alzheimer's disease (AD) is a chronic neurodegenerative disease affecting the elderly. AD is associated with a progressive decline in memory and cognitive abilities, drastic changes in behavioural patterns and other psychiatric manifestations. It leads to a significant decline in the quality of life at personal, household as well as national level. Although AD was described about hundred years back and multiple theories have been proposed, its exact pathophysiology is unknown. There is no cure for AD and the life expectancy of AD patients remains low at 3-9 years. An accurate understanding of the molecular mechanism(s) involved in the pathogenesis of AD is imperative to devise a successful treatment strategy. This review explains and summarises the current understanding of different therapeutic strategies based on various molecular pathways known to date. Different strategies based on anti-amyloid pathology, glutamatergic pathway, anti-tau, neuroprotection through neurotrophic factors and cholinergic neurotransmission have been discussed. Further, the use of anti-inflammatory drugs, nutraceuticals, and dietary interventions has also been explained in the management of AD. It further describes different pharmacological and dietary interventions being used in treating and/or managing AD. Additionally, this article provides a thorough review of the literature for improving the therapeutic paradigm of AD.

Neurotoxicity of green- synthesized magnetic iron oxide nanoparticles in different brain areas of wistar rats

AIMS

The aim of the present study was to evaluate the toxicity of magnetic iron oxide nanoparticles (MIONs) which were synthesized using carob leaf extract on various brain areas of Wistar rats.

MAIN METHODS

Carob leaf synthesized-MIONs were characterized using different techniques: Dynamic Light Scattering (DLS), Transmission Electron Microscope (TEM), UV-vis spectrophotometer, Fourier Transform infrared (FTIR), X-Ray Diffraction (XRD) and Atomic Force Microscope (AFM). The toxicity of MIONs in vivo was evaluated by: monitoring rat's body weight, measuring iron content in different brain areas, evaluating some oxidative stress parameters, estimating acetylcholinesterase (AChE) in addition to histopathological investigations.

KEY FINDINGS

The present study demonstrated no body weight changes of MIONs- treated rats. According to the conditions of the present study, the hippocampus and striatum were the most affected areas and demonstrated neuronal degeneration due to MIONs exposure. MIONs treatment of Wistar rats, also affected the iron homeostasis in both striatum and midbrain by decreasing iron content in these areas. The least affected areas were thalamus and cerebellum. The histopathological examination of brain areas demonstrated moderate neuronal degeneration in hippocampus and striatum, mild neuronal degeneration in cortex and slight degeneration in hypothalamus and pons-medulla areas were detected.

SIGNIFICANCE

The results suggested that MIONs have a toxic impact on different brain areas and the effect varies according to the brain area.

Astrocyte-Targeted Transporter-Utilizing Derivatives of Ferulic Acid Can Have Multifunctional Effects Ameliorating Inflammation and Oxidative Stress in the Brain

Ferulic acid (FA) is a natural phenolic antioxidant, which can exert also several other beneficial effects to combat neuroinflammation and neurodegenerative diseases, such as Alzheimer's disease. One of these properties is the inhibition of several enzymes and factors, such as β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), cyclooxygenases (COXs), lipoxygenases (LOXs), mammalian (or mechanistic) target for rapamycin (mTOR), and transcription factor NF-κB. We have previously synthesized three L-type amino acid transporter 1- (LAT1-) utilizing FA-derivatives with the aim to develop brain-targeted prodrugs of FA. In the present study, the cellular uptake and bioavailability of these FA-derivatives were evaluated in mouse primary astrocytic cell cultures together with their inhibitory effects towards BACE1, COX/LOX, mTOR, NF-κB, acetylcholinesterase (AChE), and oxidative stress. According to the results, all three FA-derivatives were taken up 200–600 times more effectively at 10 μM concentration into the astrocytes than FA, with one derivative having a high intracellular bioavailability (K_p,uu), particularly at low concentrations. Moreover, all of the derivatives were able to inhibit BACE1, COX/LOX, AChE, and oxidative stress measured as decreased cellular lipid peroxidation. Furthermore, one of the derivatives modified the total mTOR amount. Therefore, these derivatives have the potential to act as multifunctional compounds preventing β-amyloid accumulation as well as combating inflammation and reducing oxidative stress in the brain. Thus, this study shows that converting a parent drug into a transporter-utilizing derivative not only may increase its brain and cellular uptake, and bioavailability but can also broaden the spectrum of pharmacological effects elicited by the derivative.

7-O-Esters of taxifolin with pronounced and overadditive effects in neuroprotection, anti-neuroinflammation, and amelioration of short-term memory impairment in vivo

Alzheimer's disease (AD) is a multifactorial disease and the most common form of dementia. There are no treatments to cure, prevent or slow down the progression of the disease. Natural products hold considerable interest for the development of preventive neuroprotectants to treat neurodegenerative disorders like AD, due to their low toxicity and general beneficial effects on human health with their anti-inflammatory and antioxidant features. In this work we describe regioselective synthesis of 7-O-ester hybrids of the flavonoid taxifolin with the phenolic acids cinnamic and ferulic acid, namely 7-O-cinnamoyltaxifolin and 7-O-feruloyltaxifolin. The compounds show pronounced overadditive neuroprotective effects against oxytosis, ferroptosis and ATP depletion in the murine hippocampal neuron HT22 cell model. Furthermore, 7-O-cinnamoyltaxifolin and 7-O-feruloyltaxifolin reduced LPS-induced neuroinflammation in BV-2 microglia cells as assessed by effects on the levels of NO, IL6 and TNFα. In all in vitro assays the 7-O-esters of taxifolin and ferulic or cinnamic acid showed strong overadditive activity, significantly exceeding the effects of the individual components and the equimolar mixtures thereof, which were almost inactive in all of the assays at the tested concentrations. In vivo studies confirmed this overadditive effect. Treatment of an AD mouse model based on the injection of oligomerized Aβ_25-35 peptide into the brain to cause neurotoxicity and subsequently memory deficits with 7-O-cinnamoyltaxifolin or 7-O-feruloyltaxifolin resulted in improved performance in an assay for short-term memory as compared to vehicle and mice treated with the respective equimolar mixtures. These results highlight the benefits of natural product hybrids as a novel compound class with potential use for drug discovery in neurodegenerative diseases due to their pharmacological profile that is distinct from the individual natural components.

L-Type Amino Acid Transporter 1 (LAT1/Lat1)-Utilizing Prodrugs Can Improve the Delivery of Drugs into Neurons, Astrocytes and Microglia

l-Type Amino Acid Transporter 1 (LAT1/Lat1) is responsible for carrying large, neutral l-amino acids as well as several drugs and prodrugs across the blood-brain barrier (BBB). However, the BBB is not the only barrier that hinders drugs acting effectively within the brain; the brain parenchymal cell membranes represent a secondary barrier for the drugs with intracellular target sites. In this study, expression and function of Lat1 was quantified in mouse primary neuron, astrocyte and immortalized microglia (BV2) cultures. Moreover, ability of Lat1 to carry prodrugs inside these brain cells was evaluated. The results showed that Lat1 was localized at the similar level in all studied cells (3.07 ± 0.92–3.77 ± 0.91 fmol/µg protein). The transporter was also functional in all three cell types, astrocytes having the highest transport capacity and affinity for the LAT1/Lat1-substrate, [¹⁴C]-l-leucine, followed by neurons and microglia. The designed prodrugs (1-6) were able to utilize Lat1 for their cellular uptake and it was mainly much higher than the one of their parent drugs. Interestingly, improved cellular uptake was also achieved in cells representing Alzheimer’s Disease phenotype. Therefore, improved delivery and intra-brain targeting of drugs can be attained by utilizing LAT1/Lat1 and prodrug approach.

Porcine placental extract facilitates memory and learning in aged mice

Aging induces a decline in both memory and learning ability without predisposing an individual to diseases of the central nervous system, such as dementia. This decline can have a variety of adverse effects on daily life, and it can also gradually affect the individual and the people they are surrounded by. Since recent evidence indicated that placental extract has effects on brain function such as memory, we hypothesized that placental extract could ameliorate the age-associated reduction in cognitive function in aging. Here, we investigated the effect of new modified porcine placental extract (SD-F) on memory ability in aged mice at both the behavioral and molecular levels. Our results revealed that SD-F significantly enhanced memory ability in the object recognition and object location tasks in a dose-dependent manner in aged mice relative to controls. The numbers of Nissl-positive cells in the hippocampal cornu ammonis 3 (CA3) and dentate gyrus (DG) regions were increased in SD-F-treated aged mice relative to controls. RNA-seq analysis of the hippocampus of aged mice identified 542 differentially expressed genes, of which 216 were up-regulated and 326 were down-regulated in SD-F-treated mice relative to controls. Of the 216 up-regulated genes, we identified four characteristic genes directly related to memory, including early growth response protein 1 (Egr1), growth arrest and DNA-damage-inducible, beta (Gadd45b), NGFI-A binding protein 2 (Nab2), and vascular endothelial growth factor a (Vegfa). These results suggest that the efficacy of SD-F involves upregulation of these genes.

Inhibition of the Self-Assembly of Aβ and of Tau by Polyphenols: Mechanistic Studies

The amyloid-β (Aβ) peptide and tau protein are thought to play key neuropathogenic roles in Alzheimer's disease (AD). Both Aβ and tau self-assemble to form the two major pathological hallmarks of AD: amyloid plaques and neurofibrillary tangles, respectively. In this review, we show that naturally occurring polyphenols abundant in fruits, vegetables, red wine, and tea possess the ability to target pathways associated with the formation of assemblies of Aβ and tau. Polyphenols modulate the enzymatic processing of the amyloid-β precursor protein and inhibit toxic Aβ oligomerization by enhancing the clearance of Aβ42 monomer, modulating monomer-monomer interactions and remodeling oligomers to non-toxic forms. Additionally, polyphenols modulate tau hyperphosphorylation and inhibit tau β-sheet formation. The anti-Aβ-self-assembly and anti-tau-self-assembly effects of polyphenols increase their potential as preventive or therapeutic agents against AD, a complex disease that involves many pathological mechanisms.

Ferulic acid improves self-renewal and differentiation of human tendon-derived stem cells by upregulating early growth response 1 through hypoxia

We aimed to investigate the potential beneficial effect of ferulic acid (FA) on stemness of human tendon-derived stem cells (hTSCs) in vitro and to elucidate the underlying molecular mechanism. The self-renewal ability of hTSCs was evaluated by colony formation and cell proliferation was determined by CCK-8 kit. Adipogenesis, osteogenesis, and chondrogenesis were determined by Oil Red O, Alizarin Red, and Alcian Blue stainings, respectively. Relative mRNA levels of PPARγ, Col2A1, Acan, Runx2, HIF1α, and EGR1 were measured with real-time PCR. Protein levels of HIF1α and EGR1 were detected by western blot. Direct binding of HIF1α with EGR1 promoter was analyzed by ChIP assay. Hypoxia-induced expression of EGR1 was interrogated by luciferase reporter assay. We demonstrated that FA treatment improved both self-renewal ability and multi-differentiation potential of hTSCs. FA induced hypoxia which in turn upregulated EGR1 expression via direct association with its hypoxia response element consensus sequence. Furthermore, we showed that both HIF1α and EGR1 were required for the enhancing effects of FA on hTSC self-renewal and differentiation. We hereby characterize the beneficial effect of FA on the stemness of hTSCs and highlight the critical role of HIF1α-EGR1 axis in this process.

Natural Compounds for Alzheimer's Disease Therapy: A Systematic Review of Preclinical and Clinical Studies

Alzheimer's Disease (AD) is a neurodegenerative disorder related with the increase of age and it is the main cause of dementia in the world. AD affects cognitive functions, such as memory, with an intensity that leads to several functional losses. The continuous increase of AD incidence demands for an urgent development of effective therapeutic strategies. Despite the extensive research on this disease, only a few drugs able to delay the progression of the disease are currently available. In the last years, several compounds with pharmacological activities isolated from plants, animals and microorganisms, revealed to have beneficial effects for the treatment of AD, targeting different pathological mechanisms. Thus, a wide range of natural compounds may play a relevant role in the prevention of AD and have proven to be efficient in different preclinical and clinical studies. This work aims to review the natural compounds that until this date were described as having significant benefits for this neurological disease, focusing on studies that present clinical trials.

A novel synbiotic delays Alzheimer's disease onset via combinatorial gut-brain-axis signaling in Drosophila melanogaster

The gut-brain-axis (GBA) describing the bidirectional communication between the gut microbiota and brain was recently implicated in Alzheimer’s disease (AD). The current study describes a novel synbiotic containing three metabolically active probiotics and a novel polyphenol-rich prebiotic which has beneficial impacts on the onset and progression of AD. In a transgenic humanized Drosophila melanogaster model of AD, the synbiotic increased survivability and motility and rescued amyloid beta deposition and acetylcholinesterase activity. Such drastic effects were due to the synbiotic’s combinatorial action on GBA signaling pathways including metabolic stability, immune signaling, oxidative and mitochondrial stress possibly through pathways implicating PPARγ. Overall, this study shows that the therapeutic potential of GBA signaling is best harnessed in a synbiotic that simultaneously targets multiple risk factors of AD.

Neuroprotection of multifunctional phytochemicals as novel therapeutic strategy for neurodegenerative disorders: antiapoptotic and antiamyloidogenic activities by modulation of cellular signal pathways

In neurodegenerative disorders, including Alzheimer's and Parkinson's disease, neuroprotection by diet and natural bioactive compounds has been proposed to prevent the onset and progress of neurodegeneration by modification of pathogenic factors. Plant food-derived phytochemicals protect neurons via targeting oxidative stress, mitochondrial dysfunction, neurotrophic factor deficit, apoptosis and abnormal protein accumulation. This review presents the molecular mechanism of neuroprotection by phytochemicals: direct regulation of mitochondrial apoptotic machinery, modification of cellular signal pathways, induction of antiapoptotic Bcl-2 protein family and prosurvival neurotrophic factors, such as brain- and glial cell line-derived neurotrophic factor, and prevention of protein aggregation. Multitargeted neuroprotective agents are under development based on the structure of blood–brain barrier-permeable phytochemicals to ameliorate brain dysfunction and prevent neurodegeneration.

Combined treatment with the phenolics (-)-epigallocatechin-3-gallate and ferulic acid improves cognition and reduces Alzheimer-like pathology in mice

"Nutraceuticals" are well-tolerated natural dietary compounds with drug-like properties that make them attractive as Alzheimer's disease (AD) therapeutics. Combination therapy for AD has garnered attention following a recent National Institute on Aging mandate, but this approach has not yet been fully validated. In this report, we combined the two most promising nutraceuticals with complementary anti-amyloidogenic properties: the plant-derived phenolics (-)-epigallocatechin-3-gallate (EGCG, an α-secretase activator) and ferulic acid (FA, a β-secretase modulator). We used transgenic mice expressing mutant human amyloid β-protein precursor and presenilin 1 (APP/PS1) to model cerebral amyloidosis. At 12 months of age, we orally administered EGCG and/or FA (30 mg/kg each) or vehicle once daily for 3 months. At 15 months, combined EGCG-FA treatment reversed cognitive impairment in most tests of learning and memory, including novel object recognition and maze tasks. Moreover, EGCG- and FA-treated APP/PS1 mice exhibited amelioration of brain parenchymal and cerebral vascular β-amyloid deposits and decreased abundance of amyloid β-proteins compared with either EGCG or FA single treatment. Combined treatment elevated nonamyloidogenic soluble APP-α and α-secretase candidate and down-regulated amyloidogenic soluble APP-β, β-C-terminal APP fragment, and β-secretase protein expression, providing evidence for a shift toward nonamyloidogenic APP processing. Additional beneficial co-treatment effects included amelioration of neuroinflammation, oxidative stress, and synaptotoxicity. Our findings offer preclinical evidence that combined treatment with EGCG and FA is a promising AD therapeutic approach.

Ferulic Acid exerts concentration-dependent anti-apoptotic and neuronal differentiation-inducing effects in PC12 and mouse neural stem cells

Ferulic Acid (FA) is a phenolic compound with anti-apoptotic and anti-oxidative properties. There are reports regarding its neuro-protective, neuro-proliferative and neuro-differentiative effects. However, effect of FA on neuronal differentiation and its effective neuro-protective and neuro-differentiative concentrations are unknown. Also the role of sirtuin molecules in neuroprotective effects of FA were not reported. We used PC12 and mouse neural stem cells (mNSCs) in our experiments. Intact and apoptotic (H₂O₂-exposed) cells were treated with different concentrations of FA, and then they were evaluated by MTT, quantitative real-time RT-PCR and immunostaining assays. FA treatment at low concentrations (50 µg/ml) significantly reduced apoptosis in H₂O₂-treated PC12 cells. Real-time RT-PCR and western blot assays confirmed that FA induced this effect through stabilization and degradation of P53 by increasing the expression rate of SIRT1, SIRT7 and MDM2 but down-regulation of USP7. Beside this anti-apoptotic effect, treatments of PC12 cells and mNSCs with higher concentrations of FA (250-800 µg/ml on PC12 cells and 100-500 µg/ml on mNSCs) increased the rate of neuronal differentiation. Immunocytochemical staining for β-tubulin III and Map2 verified the presence of mature neurons, and western blot assay showed that FA-treated PC12 cells had a stepwise rise of phosphorylated-ERK1/2 with increasing concentrations of FA. Our findings showed that FA at low concentrations has neuroprotective effect through up-regulation of SIRT1, SIRT7 and MDM2, and at higher concentrations can promote neural differentiation and neurite outgrowth.

Effect and Safety of Huannao Yicong Formula () in Patients with Mild-to-Moderate Alzheimer's Disease: A Randomized, Double-Blinded, Donepezil-Controlled Trial

OBJECTIVE

To assess the effect and safety of Huannao Yicong Formula (, HYF) in the treatment of patients with mild-to-moderate Alzheimer's disease (AD).

METHODS

Sixty patients with mild-tomoderate AD were evenly randomized into HYF group and donepezil group with the random number method. Patients in the HYF group took 5 g of HYF granules twice daily and 5 mg placebo of donepezil once daily. Patients in the donepezil group took 5 mg donepezil once daily and 5 g placebo of HYF granules twice daily. The intervention lasted for 6 months. Clinical researchers, participants and statisticians were blinded to the treatment assignment throughout the study. The primary outcomes were scores of Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) and Chinese Medicine Symptom Scale (CM-SS). The secondary outcomes were scores of Montreal Cognitive Assessment (MoCA) test and Mini-Mental State Exam (MMSE). The serum levels of acetylcholinesterase (AchE) and amyloid-β protein 42 (Aβ₄₂) were detected with enzymelinked immunosorbent assay kits. The scale assessments were conducted at baseline, the 3rd and 6th months of treatment, respectively. Biochemistry tests were conducted at baseline and the 6th month of treatment.

RESULTS

A total of 52 patients completed the trial, 28 in HYF group and 24 in donepezil group. Compared with the baseline, HYF and donepezil signifificantly decreased the total scores of ADAS-Cog and CM-SS, and signifificantly increased the scores of MoCA and MMSE after 6-month treatment (all P<0.01). Both treatments remarkably reduced the serum levels of AchE and Aβ₄₂ (both P<0.05). The CM-SS total effective rate of HYF was signifificantly higher than donepezil [75.00% (21/28) vs. 54.17% (13/24), P<0.05]. No severe adverse events were observed in both groups.

CONCLUSION

HYF is effective and safe for improving the cognitive function in mildto-moderate AD patients. [Trial registration: Chinese Clinical Trial Registry (Reg No. ChiCTR-IOR-17011746)].

Effects of alcoholic beverage treatment on spatial learning and fear memory in mice

Although chronic ethanol treatment is known to impair learning and memory, humans commonly consume a range of alcoholic beverages. However, the specific effects of some alcoholic beverages on behavioral performance are largely unknown. The present study compared the effects of a range of alcoholic beverages (plain ethanol solution, red wine, sake and whiskey; with a matched alcohol concentration of 10%) on learning and memory. 6-week-old C57BL6J mice were orally administered alcohol for 7 weeks. The results revealed that red wine treatment exhibited a trend toward improvement of spatial memory and advanced extinction of fear memory. Additionally, red wine treatment significantly increased mRNA levels of brain-derived neurotrophic factor (BDNF) and N-methyl-D-aspartate (NMDA) receptors in mice hippocampus. These results support previous reports that red wine has beneficial effects.

Ferulic Acid Rescues LPS-Induced Neurotoxicity via Modulation of the TLR4 Receptor in the Mouse Hippocampus

Microglia play a crucial role in the inflammatory brain response to infection. However, overactivation of microglia is neurotoxic. Toll-like receptor 4 (TLR4) is involved in microglial activation via lipopolysaccharide (LPS), which triggers a variety of cytotoxic pro-inflammatory markers that produce deleterious effects on neuronal cells. Ferulic acid (FA) is a phenolic compound that exerts antioxidant and anti-inflammatory effects in neurodegenerative disease. However, the manner in which FA inhibits neuroinflammation-induced neurodegeneration is poorly understood. Therefore, we investigated the anti-inflammatory effects of FA against LPS-induced neuroinflammation in the mouse brain. First, we provide evidence that FA interferes with TLR4 interaction sites, which are required for the activation of microglia-induced neuroinflammation, and further examined the potential mechanism of its neuroprotective effects in the mouse hippocampus using molecular docking simulation and immunoblot analysis. Our results indicated that FA treatment inhibited glial cell activation, p-JNK, p-NF_KB, and downstream signaling molecules, such as iNOS, COX-2, TNF-α, and IL-1β, in the mouse hippocampus and BV2 microglial cells. FA treatment strongly inhibited mitochondrial apoptotic signaling molecules, such as Bax, cytochrome C, caspase-3, and PARP-1, and reversed deregulated synaptic proteins, including PSD-95, synaptophysin, SNAP-25, and SNAP-23, and synaptic dysfunction in LPS-treated mice. These findings demonstrated that FA treatment interfered with the TLR4/MD2 complex binding site, which is crucial for evoking neuroinflammation via microglia activation and inhibited NF_KB likely via a JNK-dependent mechanism, which suggests a therapeutic implication for neuroinflammation-induced neurodegeneration.

Dissociation of β-Sheet Stacking of Amyloid β Fibrils by Irradiation of Intense, Short-Pulsed Mid-infrared Laser

Structure of amyloid β (Aβ) fibrils is rigidly stacked by β-sheet conformation, and the fibril state of Aβ is profoundly related to pathogenesis of Alzheimer's disease (AD). Although mid-infrared light has been used for various biological researches, it has not yet been known whether the infrared light changes the fibril structure of Aβ. In this study, we tested the effect of irradiation of intense mid-infrared light from a free-electron laser (FEL) targeting the amide bond on the reduction of β-sheet content in Aβ fibrils. The FEL reduced entire contents of proteins exhibiting β-sheet structure in brain sections from AD model mice, as shown by synchrotron-radiation infrared microscopy analysis. Since Aβ1-42 fibril absorbed a considerable FEL energy at amide I band (6.17 μm), we irradiated the FEL at 6.17 μm and found that β-sheet content of naked Aβ1-42 fibril was decreased using infrared microscopic analysis. Consistent with the decrease in the β-sheet content, Congo-red signal is decreased after the irradiation to Aβ1-42 fibril. Furthermore, electron microscopy analysis revealed that morphologies of the fibril and proto-fibril were largely changed after the irradiation. Thus, mid-infrared light dissociates β-sheet structure of Aβ fibrils, which justifies exploration of possible laser-based therapy for AD.

Scutellarin Mitigates Aβ-Induced Neurotoxicity and Improves Behavior Impairments in AD Mice

Alzheimer’s disease (AD) is pathologically characterized by excessive accumulation of amyloid-beta (Aβ) within extracellular spaces of the brain. Aggregation of Aβ has been shown to trigger oxidative stress, inflammation, and neurotoxicity resulting in cognitive dysfunction. In this study, we use models of cerebral Aβ amyloidosis to investigate anti-amyloidogenic effects of scutellarin in vitro and in vivo. Our results show that scutellarin, through binding to Aβ42, efficiently inhibits oligomerization as well as fibril formation and reduces Aβ oligomer-induced neuronal toxicity in cell line SH-SY5Y. After nine months of treatment in APP/PS1 double-transgenic mice, scutellarin significantly improves behavior, reduces soluble and insoluble Aβ levels in the brain and plasma, decreases Aβ plaque associated gliosis and levels of proinflammatory cytokines TNF-α and IL-6, attenuates neuroinflammation, displays anti-amyloidogenic effects, and highlights the beneficial effects of intervention on development or progression of AD-like neuropathology.

Highly water pressurized brown rice improves cognitive dysfunction in senescence-accelerated mouse prone 8 and reduces amyloid beta in the brain

Background

Alzheimer’s disease (AD) is the most common form of dementia and the number of AD patients continues to increase worldwide. Components of the germ layer and bran of Brown rice (BR) help maintain good health and prevent AD. Because the germ layer and bran absorb little water and are very hard and difficult to cook, they are often removed during processing. To solve these problems, in this study, we tried to use a high-pressure (HP) technique.

Methods

We produced the highly water pressurized brown rice (HPBR) by pressurizing BR at 600 MPa, and then we fed it to an AD mouse model, senescence-accelerated mouse prone 8, to investigate the therapeutic effects of HPBR on cognitive dysfunction by Y-maze spatial memory test.

Results

HP treatment increased the water absorbency of BR without nutrient loss. HPBR ameliorated cognitive dysfunction and reduced the levels of amyloid-β, which is a major protein responsible for AD, in the brain.

Conclusions

These results suggest that HPBR is effective for preventing AD.

Inhibition of mitochondrial fragmentation protects against Alzheimer's disease in rodent model

Mitochondrial dysfunction is an early prominent feature in susceptible neurons in the brain of patients with Alzheimer's disease, which likely plays a critical role in the pathogenesis of disease. Increasing evidence suggests abnormal mitochondrial dynamics as important underlying mechanisms. In this study, we characterized marked mitochondrial fragmentation and abnormal mitochondrial distribution in the pyramidal neurons along with mitochondrial dysfunction in the brain of Alzheimer's disease mouse model CRND8 as early as 3 months of age before the accumulation of amyloid pathology. To establish the pathogenic significance of these abnormalities, we inhibited mitochondrial fragmentation by the treatment of mitochondrial division inhibitor 1 (mdivi-1), a mitochondrial fission inhibitor. Mdivi-1 treatment could rescue both mitochondrial fragmentation and distribution deficits and improve mitochondrial function in the CRND8 neurons both in vitro and in vivo. More importantly, the amelioration of mitochondrial dynamic deficits by mdivi-1 treatment markedly decreased extracellular amyloid deposition and Aβ1-42/Aβ1-40 ratio, prevented the development of cognitive deficits in Y-maze test and improved synaptic parameters. Our findings support the notion that abnormal mitochondrial dynamics plays an early and causal role in mitochondrial dysfunction and Alzheimer's disease-related pathological and cognitive impairments in vivo and indicate the potential value of restoration of mitochondrial dynamics as an innovative therapeutic strategy for Alzheimer's disease.

Protective roles of intestinal microbiota derived short chain fatty acids in Alzheimer's disease-type beta-amyloid neuropathological mechanisms

BACKGROUND

Dietary fibers are metabolized by gastrointestinal (GI) bacteria into short-chain fatty acids (SCFAs). We investigated the potential role of these SCFAs in β-amyloid (Aβ) mediated pathological processes that play key roles in Alzheimer's disease (AD) pathogenesis.

RESEARCH DESIGN AND METHODS

Multiple complementary assays were used to investigate individual SCFAs for their dose-responsive effects in interfering with the assembly of Aβß1-40 and Aβ1-42 peptides into soluble neurotoxic Aβ aggregates.

RESULTS

We found that several select SCFAs are capable of potently inhibiting Aβ aggregations, in vitro.

CONCLUSION

Our studies support the hypothesis that intestinal microbiota may help protect against AD, in part, by supporting the generation of select SCFAs, which interfere with the formation of toxic soluble Aβ aggregates.

Microbiome, probiotics and neurodegenerative diseases: deciphering the gut brain axis

The gut microbiota is essential to health and has recently become a target for live bacterial cell biotherapies for various chronic diseases including metabolic syndrome, diabetes, obesity and neurodegenerative disease. Probiotic biotherapies are known to create a healthy gut environment by balancing bacterial populations and promoting their favorable metabolic action. The microbiota and its respective metabolites communicate to the host through a series of biochemical and functional links thereby affecting host homeostasis and health. In particular, the gastrointestinal tract communicates with the central nervous system through the gut-brain axis to support neuronal development and maintenance while gut dysbiosis manifests in neurological disease. There are three basic mechanisms that mediate the communication between the gut and the brain: direct neuronal communication, endocrine signaling mediators and the immune system. Together, these systems create a highly integrated molecular communication network that link systemic imbalances with the development of neurodegeneration including insulin regulation, fat metabolism, oxidative markers and immune signaling. Age is a common factor in the development of neurodegenerative disease and probiotics prevent many harmful effects of aging such as decreased neurotransmitter levels, chronic inflammation, oxidative stress and apoptosis-all factors that are proven aggravators of neurodegenerative disease. Indeed patients with Parkinson's and Alzheimer's diseases have a high rate of gastrointestinal comorbidities and it has be proposed by some the management of the gut microbiota may prevent or alleviate the symptoms of these chronic diseases.