Oral flavonoids delay recovery from experimental autoimmune encephalomyelitis in SJL mice

Immunomodulatory Effects of Anadenanthera colubrina Bark Extract in Experimental Autoimmune Encephalomyelitis

This study aimed to evaluate the efficacy of the ethanolic extract of Anadenanthera colubrina in modulating the immune response in the Experimental Autoimmune Encephalomyelitis (EAE) model. The ethanolic extract of the dried bark was analyzed by ESI (+) Orbitrap-MS to obtain a metabolite profile, demonstrating a wide variety of polyphenols, such as flavonoids and phenolic acids. Various parameters were evaluated, such as clinical signs, cytokines, cellular profile, and histopathology in the central nervous system (CNS). The ethanolic extract of A. colubrina demonstrated significant positive effects attenuating the clinical signs and pathological processes associated with EAE. The beneficial effects of the extract treatment were evidenced by reduced levels of pro-inflammatory cytokines, such as IL1β, IL-6, IL-12, TNF, IFN-γ, and a notable decrease in several cell profiles, including CD8+, CD4+, CD4+IFN-γ, CD4+IL-17+, CD11c+MHC-II+, CD11+CD80+, and CD11+CD86+ in the CNS. In addition, histological analysis revealed fewer inflammatory infiltrates and demyelination sites in the spinal cord of mice treated with the extract compared to the control model group. These results showed, for the first time, that the ethanolic extract of A. colubrina exerts a modulatory effect on inflammatory processes, improving clinical signs in EAE, in the acute phase of the disease, which could be further explored as a possible therapeutic alternative.

Neuroprotective effects of rutin against cuprizone-induced multiple sclerosis in mice

Multiple sclerosis (MS) is a chronic inflammatory neurodegenerative disease of the central nervous system that injures the myelin sheath, provoking progressive axonal degeneration and functional impairments. No efficient therapy is available at present to combat such insults, and hence, novel safe and effective alternatives for MS therapy are extremely required. Rutin (RUT) is a flavonoid that exhibits antioxidant, anti-inflammatory, and neuroprotective effects in several brain injuries. The present study evaluated the potential beneficial effects of two doses of RUT in a model of pattern-III lesion of MS, in comparison to the conventional standard drug; dimethyl fumarate (DMF). Demyelination was induced in in male adult C57BL/6 mice by dietary 0.2% (w/w) cuprizone (CPZ) feeding for 6 consecutive weeks. Treated groups received either oral RUT (50 or 100 mg/kg) or DMF (15 mg/kg), along with CPZ feeding, for 6 consecutive weeks. Mice were then tested for behavioral changes, followed by biochemical analyses and histological examinations of the corpus callosum (CC). Results revealed that CPZ caused motor dysfunction, demyelination, and glial activation in demyelinated lesions, as well as significant oxidative stress, and proinflammatory cytokine elevation. Six weeks of RUT treatment significantly improved locomotor activity and motor coordination. Moreover, RUT considerably improved remyelination in the CC of CPZ + RUT-treated mice, as revealed by luxol fast blue staining and transmission electron microscopy. Rutin also significantly attenuated CPZ-induced oxidative stress and inflammation in the CC of tested animals. The effect of RUT100 was obviously more marked than either that of DMF, regarding most of the tested parameters, or even its smaller tested dose. In silico docking revealed that RUT binds tightly within NF-κB at the binding site of the protein-DNA complex, with a good negative score of -6.79 kcal/mol. Also, RUT-Kelch-like ECH-associated protein 1 (Keap1) model clarifies the possible inhibition of Keap1-Nrf2 protein-protein interaction. Findings of the current study provide evidence for the protective effect of RUT in CPZ-induced demyelination and behavioral dysfunction in mice, possibly by modulating NF-κB and Nrf2 signaling pathways. The present study may be one of the first to indicate a pro-remyelinating effect for RUT, which might represent a potential additive benefit in treating MS.

Increased activity of IRE1 improves the clinical presentation of EAE

Activation of the endoplasmic reticulum (ER) stress sensor inositol-requiring enzyme-1α (IRE1α) contributes to neuronal development and is known to induce neuronal remodeling in vitro and in vivo. On the contrary, excessive IRE1 activity is often detrimental and may contribute to neurodegeneration. To determine the consequences of increased activation of IRE1α, we used a mouse model expressing a C148S variant of IRE1α with increased and sustained activation. Surprisingly, the mutation did not affect the differentiation of highly secretory antibody-producing cells but exhibited a beneficial effect in a mouse model of experimental autoimmune encephalomyelitis (EAE). Although mechanical allodynia was unaffected, significant improvement in motor function was found in IRE1C148S mice with EAE relative to wild type (WT) mice. Coincident with this improvement, there was reduced microgliosis in the spinal cord of IRE1C148S mice, with reduced expression of proinflammatory cytokine genes. This was accompanied by reduced axonal degeneration and enhanced 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) levels, suggesting improved myelin integrity. Interestingly, while the IRE1C148S mutation is expressed in all cells, the reduction in proinflammatory cytokines and in the microglial activation marker ionized calcium-binding adapter molecule (IBA1), along with preservation of phagocytic gene expression, all point to microglia as the cell type contributing to the clinical improvement in IRE1C148S animals. Our data suggest that sustained increase in IRE1α activity can be beneficial in vivo, and that this protection is cell type and context dependent. Considering the overwhelming but conflicting evidence for the role of ER stress in neurological diseases, a better understanding of the function of ER stress sensors in physiological contexts is clearly needed.

Targeting gut microbiota: new therapeutic opportunities in multiple sclerosis

Multiple sclerosis (MS) causes long-lasting, multifocal damage to the central nervous system. The complex background of MS is associated with autoimmune inflammation and neurodegeneration processes, and is potentially affected by many contributing factors, including altered composition and function of the gut microbiota. In this review, current experimental and clinical evidence is presented for the characteristics of gut dysbiosis found in MS, as well as for its relevant links with the course of the disease and the dysregulated immune response and metabolic pathways involved in MS pathology. Furthermore, therapeutic implications of these investigations are discussed, with a range of pharmacological, dietary and other interventions targeted at the gut microbiome and thus intended to have beneficial effects on the course of MS.

Methyl-CpG-Binding Protein 2 Emerges as a Central Player in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders

MECP2 and its product methyl-CpG binding protein 2 (MeCP2) are associated with multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), which are inflammatory, autoimmune, and demyelinating disorders of the central nervous system (CNS). However, the mechanisms and pathways regulated by MeCP2 in immune activation in favor of MS and NMOSD are not fully understood. We summarize findings that use the binding properties of MeCP2 to identify its targets, particularly the genes recognized by MeCP2 and associated with several neurological disorders. MeCP2 regulates gene expression in neurons, immune cells and during development by modulating various mechanisms and pathways. Dysregulation of the MeCP2 signaling pathway has been associated with several disorders, including neurological and autoimmune diseases. A thorough understanding of the molecular mechanisms underlying MeCP2 function can provide new therapeutic strategies for these conditions. The nervous system is the primary system affected in MeCP2-associated disorders, and other systems may also contribute to MeCP2 action through its target genes. MeCP2 signaling pathways provide promise as potential therapeutic targets in progressive MS and NMOSD. MeCP2 not only increases susceptibility and induces anti-inflammatory responses in immune sites but also leads to a chronic increase in pro-inflammatory cytokines gene expression (IFN-γ, TNF-α, and IL-1β) and downregulates the genes involved in immune regulation (IL-10, FoxP3, and CX3CR1). MeCP2 may modulate similar mechanisms in different pathologies and suggest that treatments for MS and NMOSD disorders may be effective in treating related disorders. MeCP2 regulates gene expression in MS and NMOSD. However, dysregulation of the MeCP2 signaling pathway is implicated in these disorders. MeCP2 plays a role as a therapeutic target for MS and NMOSD and provides pathways and mechanisms that are modulated by MeCP2 in the regulation of gene expression.

Increased activity of IRE1 improves the clinical presentation of EAE

Activation of the ER stress sensor IRE1α contributes to neuronal development and is known to induce neuronal remodeling in vitro and in vivo. On the other hand, excessive IRE1 activity is often detrimental and may contribute to neurodegeneration. To determine the consequences of increased activation of IRE1α, we used a mouse model expressing a C148S variant of IRE1α with increased and sustained activation. Surprisingly, the mutation did not affect the differentiation of highly secretory antibody-producing cells, but exhibited a strong protective effect in a mouse model of experimental autoimmune encephalomyelitis (EAE). Significant improvement in motor function was found in IRE1C148S mice with EAE relative to WT mice. Coincident with this improvement, there was reduced microgliosis in the spinal cord of IRE1C148S mice, with reduced expression of pro-inflammatory cytokine genes. This was accompanied by reduced axonal degeneration and enhanced CNPase levels, suggestiing improved myelin integrity. Interestingly, while the IRE1C148S mutation is expressed in all cells, the reduction in proinflammatory cytokines and in the activation of microglial activation marker IBA1, along with preservation of phagocytic gene expression, all point to microglia as the cell type contributing to the clinical improvement in IRE1C148S animals. Our data suggest that sustained increase in IRE1α activity can be protective in vivo, and that this protection is cell type and context dependent. Considering the overwhelming but conflicting evidence for the role of the ER stress in neurological diseases, a better understanding of the function of ER stress sensors in physiological contexts is clearly needed.

Dietary Polyphenols, Microbiome, and Multiple Sclerosis: From Molecular Anti-Inflammatory and Neuroprotective Mechanisms to Clinical Evidence

Multiple sclerosis (MS) is a multifactorial, immune-mediated disease caused by complex gene-environment interactions. Dietary factors modulating the inflammatory status through the control of the metabolic and inflammatory pathways and the composition of commensal gut microbiota, are among the main environmental factors involved in the pathogenesis of MS. There is no etiological therapy for MS and the drugs currently used, often accompanied by major side effects, are represented by immunomodulatory substances capable of modifying the course of the disease. For this reason, nowadays, more attention is paid to alternative therapies with natural substances with anti-inflammatory and antioxidant effects, as adjuvants of classical therapies. Among natural substances with beneficial effects on human health, polyphenols are assuming an increasing interest due to their powerful antioxidant, anti-inflammatory, and neuroprotective effects. Beneficial properties of polyphenols on the CNS are achieved through direct effects depending on their ability to cross the blood-brain barrier and indirect effects exerted in part via interaction with the microbiota. The aim of this review is to examine the literature about the molecular mechanism underlying the protective effects of polyphenols in MS achieved by experiments conducted in vitro and in animal models of the disease. Significant data have been accumulated for resveratrol, curcumin, luteolin, quercetin, and hydroxytyrosol, and therefore we will focus on the results obtained with these polyphenols. Clinical evidence for the use of polyphenols as adjuvant therapy in MS is restricted to a smaller number of substances, mainly curcumin and epigallocatechin gallate. In the last part of the review, a clinical trial studying the effects of these polyphenols in MS patients will also be revised.

Stem Cells and Natural Agents in the Management of Neurodegenerative Diseases: A New Approach

Neurodegenerative diseases refer to a group of neurological disorders as a consequence of various destructive illnesses, that predominantly impact neurons in the central nervous system, resulting in impairments in certain brain functions. Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, and other neurodegenerative disorders represent a major risk to human health. In order to optimize structural and functional recovery, reconstructive methods integrate many approaches now, to address the complex and multivariate pathophysiology of neurodegenerative disorders. Stem cells, with their unique property of regeneration, offer new possibilities in regenerative and reconstructive medicine. Concurrently, there is an important role for natural products in controlling many health sufferings and they can delay or even prevent the onset of various diseases. In addition, due to their therapeutic properties, they have been used as neuroprotective agents to treat neurodegenerative disorders. After decades of intensive research, scientists made advances in treating these disorders so far, but current therapies are still not capable of preventing the illnesses from progressing. Therefore, in this review, we focused on a new perspective combining stem cells and natural products as an innovative therapy option in the management of neurodegenerative diseases.

Curcumin β-D-Glucuronide Modulates an Autoimmune Model of Multiple Sclerosis with Altered Gut Microbiota in the Ileum and Feces

We developed a prodrug type of curcumin, curcumin monoglucuronide (CMG), whose intravenous/intraperitoneal injection achieves a high serum concentration of free-form curcumin. Although curcumin has been reported to alter the gut microbiota and immune responses, it is unclear whether the altered microbiota could be associated with inflammation in immune-mediated diseases, such as multiple sclerosis (MS). We aimed to determine whether CMG administration could affect the gut microbiota at three anatomical sites (feces, ileal contents, and the ileal mucosa), leading to suppression of inflammation in the central nervous system (CNS) in an autoimmune model for MS, experimental autoimmune encephalomyelitis (EAE). We injected EAE mice with CMG, harvested the brains and spinal cords for histological analyses, and conducted microbiome analyses using 16S rRNA sequencing. CMG administration modulated EAE clinically and histologically, and altered overall microbiota compositions in feces and ileal contents, but not the ileal mucosa. Principal component analysis (PCA) of the microbiome showed that principal component (PC) 1 values in ileal contents, but not in feces, correlated with the clinical and histological EAE scores. On the other hand, when we analyzed the individual bacteria of the microbiota, the EAE scores correlated with significant increases in the relative abundance of two bacterial species at each anatomical site: Ruminococcus bromii and Blautia (Ruminococcus) gnavus in feces, Turicibacter sp. and Alistipes finegoldii in ileal contents, and Burkholderia spp. and Azoarcus spp. in the ileal mucosa. Therefore, CMG administration could alter the gut microbiota at the three different sites differentially in not only the overall gut microbiome compositions but also the abundance of individual bacteria, each of which was associated with modulation of neuroinflammation.

Luteolin alleviates non-alcoholic fatty liver disease in rats via restoration of intestinal mucosal barrier damage and microbiota imbalance involving in gut-liver axis

Nonalcoholic fatty liver disease (NAFLD) is demonstrated to be closely related to the disorder of gut microbiota and the intestinal mucosal barrier. Luteolin is a natural flavonoid with various activities. We aimed to investigate whether Luteolin can alleviate NAFLD and its possible mechanism involving the gut-liver axis. A rat NAFLD model was established by feeding a high-fat diet (HFD), and Luteolin was administered intragastrically. The effects of Luteolin on liver biochemical parameters, intestinal histopathology and integrity, gut microbiota, lipopolysaccharides (LPS), inflammatory cytokines, and the Toll-like receptor 4 (TLR4) signaling pathway were evaluated. We found that Luteolin restored the expression of the tight junction proteins in the intestine and ameliorated the increase permeability of the intestinal mucosa to Fluorescein isothiocyanate-dextran (FD4) caused by a high-fat diet, thus enhancing the function of the intestinal barrier. In addition, Luteolin inhibited the TLR4 signaling pathway in the liver, thereby reducing the secretion of pro-inflammatory factors and alleviating NAFLD. 16S rRNA gene sequencing revealed that Luteolin intervention significantly altered the composition of the gut microbiota in NAFLD rats and increased the richness of gut microbiota. Luteolin alleviates NAFLD in rats via restoration and repair of the damaged intestinal mucosal barrier and microbiota imbalance.

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.

Benefits of hesperidin in central nervous system disorders: a review

Citrus species contain significant amounts of flavonoids that possess antioxidant activities; furthermore, dietary citrus is not associated with adverse effects or cytotoxicity in healthy individuals. Hesperidin, which is an abundant flavanone glycoside in the peel of citrus fruits, possesses a variety of biological capabilities that include antioxidant and anti-inflammatory actions. Over the last few decades, many studies have been investigated the biological actions of hesperidin and its aglycone, hesperetin, as well as their underlying mechanisms. Due to the antioxidant effects of hesperidin and its derivatives, the cardioprotective and anti-cancer effects of these compounds have been widely reviewed. Although the biological activities of hesperidin in neurodegenerative diseases have been evaluated, its potential involvement in a variety of central nervous system (CNS) disorders, including autoimmune demyelinating disease, requires further investigation in terms of the underlying mechanisms. Thus, the present review will focus on the potential role of hesperidin in diverse models of CNS neuroinflammation, including experimental autoimmune encephalomyelitis, with special consideration given to its antioxidant and anti-inflammatory effects in neurodegenerative disease models. Additionally, current evidence provides information regarding the nutraceutical use of hesperidin to prevent various CNS disorders.

Apigenin inhibits fibroblast proliferation and reduces epidural fibrosis by regulating Wnt3a/β-catenin signaling pathway

BACKGROUND

Failed back surgery syndrome (FBSS) is a common complication after the laminectomy. Epidural fibrosis is the major cause of lower back pain and other complications. Numerous studies have shown that apigenin (API) could treat various fibrotic diseases by regulating various signaling pathways, whereas no study has discussed whether API can inhibit fibroblast proliferation and reduce epidural fibrosis after the laminectomy by regulating Wnt3a/β-catenin signaling pathway.

METHODS

Human fibroblasts were cultured and treated with API in different concentrations for 24 h. CCK-8 detection and EdU incorporation assay were performed to detect cell viability and cell proliferation. Western blotting analysis was applied to detect expressions of proliferative proteins, Wnt3a, and its downstream proteins. Moreover, the Wnt3a gene was overexpressed in fibroblasts to define the relationship between Wnt3a/β-catenin signaling pathway and fibroblast proliferation. Wnt3a overexpressed fibroblasts were treated with API to verify if it could reverse the effects of API treatment. Twenty-four Sprague-Dawley rats were randomly divided into four groups. Laminectomy was performed and the rats were gavaged with different doses of API or 5% sodium carboxyl methyl cellulose (CMC-Na) solution for 1 month. The abilities of API to inhibit fibroblast proliferation and to reduce epidural fibrosis were evaluated using histological and immunohistochemical analysis.

RESULTS

CCK-8 detection and EdU incorporation assay demonstrated that API could inhibit the viability and proliferation rate of fibroblasts in a concentration-dependent manner. The Western blotting analysis revealed that API could inhibit the expressions of PCNA, cyclinD1, Wnt3a, and its downstream proteins. The overexpression of Wnt3a in fibroblasts could upregulate the expressions of proliferative proteins such as PCNA and cyclinD1. The inhibitory effect of API on PCNA, Wnt3a, and its downstream proteins was partially reversed by overexpression of Wnt3a. Moreover, the results of the histological and immunohistochemical analysis revealed that API could reduce the epidural fibrosis in rats by inhibiting fibroblast proliferation in a dose-dependent manner.

CONCLUSIONS

API can inhibit fibroblast proliferation and reduce epidural fibrosis by suppressing Wnt3a/β-catenin signaling pathway, which can be adopted as a new option to prevent epidural fibrosis after the laminectomy.

Impact of Flavonoids on Cellular and Molecular Mechanisms Underlying Age-Related Cognitive Decline and Neurodegeneration

Purpose of Review

This review summarises the most recent evidence regarding the effects of dietary flavonoids on age-related cognitive decline and neurodegenerative diseases.

Recent Findings

Recent evidence indicates that plant-derived flavonoids may exert powerful actions on mammalian cognition and protect against the development of age-related cognitive decline and pathological neurodegeneration. The neuroprotective effects of flavonoids have been suggested to be due to interactions with the cellular and molecular architecture of brain regions responsible for memory.

Summary

Mechanisms for the beneficial effects of flavonoids on age-related cognitive decline and dementia are discussed, including modulating signalling pathways critical in controlling synaptic plasticity, reducing neuroinflammation, promoting vascular effects capable of stimulating new nerve cell growth in the hippocampus, bidirectional interactions with gut microbiota and attenuating the extracellular accumulation of pathological proteins. These processes are known to be important in maintaining optimal neuronal function and preventing age-related cognitive decline and neurodegeneration.

The significant impact of apigenin on different aspects of autoimmune disease

Autoimmune diseases are among the highest diseases to diagnose and treat. The current "gold standard" of care for these diseases is immunosuppressive drugs which interfere with overall immune responses; their long-term high-dose treatments would expose the patient to opportunistic, life-threatening and long-term malignant infections. Considering the side effects and toxicity of these drug and also the beneficial effects of herbal compounds among their consumers, the professional investigation on the exact mechanism of the plant's major element has grown much attention in the last years. Apigenin as an extracting compound of plants, such as parsley and celery, which has a variety of biological effects, such as anti-inflammatory, anti-cancer and antioxidant effects. This review is intended to summarize the various effects of Apigenin on several autoimmune diseases which have been worked on so far. The pluralization of the obtained results has revealed Apigenin's effects on pro-inflammatory cytokines such as IL-1β, chemokines such as ICAM-1, immune cells proliferation such as T cells, apoptosis, and various signaling pathways. According to these preclinical findings, we recommend that further robust unbiased studies should be done to use Apigenin as a supplementary or therapeutic element in autoimmune disease.

Stem Cells as Potential Targets of Polyphenols in Multiple Sclerosis and Alzheimer's Disease

Alzheimer's disease (AD) and multiple sclerosis are major neurodegenerative diseases, which are characterized by the accumulation of abnormal pathogenic proteins due to oxidative stress, mitochondrial dysfunction, impaired autophagy, and pathogens, leading to neurodegeneration and behavioral deficits. Herein, we reviewed the utility of plant polyphenols in regulating proliferation and differentiation of stem cells for inducing brain self-repair in AD and multiple sclerosis. Firstly, we discussed the genetic, physiological, and environmental factors involved in the pathophysiology of both the disorders. Next, we reviewed various stem cell therapies available and how they have proved useful in animal models of AD and multiple sclerosis. Lastly, we discussed how polyphenols utilize the potential of stem cells, either complementing their therapeutic effects or stimulating endogenous and exogenous neurogenesis, against these diseases. We suggest that polyphenols could be a potential candidate for stem cell therapy against neurodegenerative disorders.

Lipoic acid in secondary progressive MS: A randomized controlled pilot trial

Objective:

To determine whether lipoic acid (LA), an endogenously produced antioxidant, slowed the whole-brain atrophy rate and was safe in secondary progressive MS (SPMS).

Methods:

Patients with SPMS aged 40–70 years enrolled in a single center, 2-year, double-blind, randomized trial of daily oral 1,200 mg LA vs placebo. Primary outcome was change in annualized percent change brain volume (PCBV). Secondary outcomes were changes in rates of atrophy of segmented brain, spinal cord, and retinal substructures, disability, quality of life, and safety. Intention-to-treat analysis used linear mixed models.

Results:

Participation occurred between May 2, 2011, and August 14, 2015. Study arms of LA (n = 27) and placebo (n = 24) were matched with mean age of 58.5 (SD 5.9) years, 61% women, mean disease duration of 29.6 (SD 9.5) years, and median Expanded Disability Status Score of 6.0 (interquartile range 1.75). After 2 years, the annualized PCBV was significantly less in the LA arm compared with placebo (−0.21 [standard error of the coefficient estimate (SEE) 0.14] vs −0.65 [SEE 0.10], 95% confidence interval [CI] 0.157–0.727, p = 0.002). Improved Timed 25-Foot Walk was almost but not significantly better in the LA than in the control group (−0.535 [SEE 0.358] vs 0.137 [SEE 0.247], 95% CI −1.37 to 0.03, p = 0.06). Significantly more gastrointestinal upset and fewer falls occurred in LA patients. Unexpected renal failure (n = 1) and glomerulonephritis (n = 1) occurred in the LA cohort. Compliance, measured by pill counts, was 87%.

Conclusions:

LA demonstrated a 68% reduction in annualized PCBV and suggested a clinical benefit in SPMS while maintaining favorable safety, tolerability, and compliance over 2 years.

ClinicalTrials.gov identifier:

NCT01188811.

Classification of evidence:

This study provides Class I evidence that for patients with SPMS, LA reduces the rate of brain atrophy.

Modulating inflammation and neuroprotection in multiple sclerosis

Multiple sclerosis (MS) is a neurological disorder of the central nervous system with a presentation and disease course that is largely unpredictable. MS can cause loss of balance, impaired vision or speech, weakness and paralysis, fatigue, depression, and cognitive impairment. Immunomodulation is a major target given the appearance of focal demyelinating lesions in myelin-rich white matter, yet progression and an increasing appreciation for gray matter involvement, even during the earliest phases of the disease, highlights the need to afford neuroprotection and limit neurodegenerative processes that correlate with disability. This review summarizes key aspects of MS pathophysiology and histopathology with a focus on neuroimmune interactions in MS, which may facilitate neurodegeneration through both direct and indirect mechanisms. There is a focus on processes thought to influence disease progression and the role of oxidative stress and mitochondrial dysfunction in MS. The goals and efficacy of current disease-modifying therapies and those in the pipeline are discussed, highlighting recent advances in our understanding of pathways mediating disease progression to identify and translate both immunomodulatory and neuroprotective therapeutics from the bench to the clinic.

Bio-effectiveness of the main flavonoids of Achillea millefolium in the pathophysiology of neurodegenerative disorders- a review

The Achillea millefolium L. (Yarrow) is a common herb which is widely being used, worldwide. Achillea is being used for treatment of many disorders since centuries. It is considered safe for supplemental use and flavonoids such as kaempferol, luteolin and apigenin are of main constituents present in Achillea. Most of both antioxidant and anti-inflammatory properties of this herb have been attributed to its flavonoid content. Oxidative and inflammatory processes play important roles in pathogenesis of neurodegenerative diseases. Present review was aimed to review the latest literature evidences regarding application of Achillea and/or its three main flavonoid constituents on epilepsy, Alzheimer's disease, multiple sclerosis, Parkinson's disease and stroke.

Nutritional control of IL-23/Th17-mediated autoimmune disease through HO-1/STAT3 activation

The nutritional curcumin (CUR) is beneficial in cell-mediated autoimmune diseases. The molecular mechanisms underlying this food-mediated silencing of inflammatory immune responses are poorly understood. By investigating antigen-specific immune responses we found that dietary CUR impairs the differentiation of Th1/Th17 cells in vivo during encephalomyelitis and instead promoted Th2 cells. In contrast, feeding CUR had no inhibitory effect on ovalbumin-induced airway inflammation. Mechanistically, we found that CUR induces an anti-inflammatory phenotype in dendritic cells (DC) with enhanced STAT3 phosphorylation and suppressed expression of Il12b and Il23a. On the molecular level CUR readily induced NRF2-sensitive heme oxygenase 1 (HO-1) mRNA and protein in LPS-activated DC. HO-1 enhanced STAT3 phosphorylation, which enriched to Il12b and Il23a loci and negatively regulated their transcription. These findings demonstrate the underlying mechanism through which a nutritional can interfere with the immune response. CUR silences IL-23/Th17-mediated pathology by enhancing HO-1/STAT3 interaction in DC.

Pharmacogenomic Characterization and Isobologram Analysis of the Combination of Ascorbic Acid and Curcumin-Two Main Metabolites of Curcuma longa-in Cancer Cells

Curcuma longa has long been used in China and India as anti-inflammatory agent to treat a wide variety of conditions and also as a spice for varied curry preparations. The chemoprofile of the Curcuma species exhibits the presence of varied phytochemicals with curcumin being present in all three species but AA only being shown in C. longa. This study explored the effect of a curcumin/AA combination on human cancer cell lines. The curcumin/AA combination was assessed by isobologram analysis using the Loewe additivity drug interaction model. The drug combination showed additive cytotoxicity toward CCRF-CEM and CEM/ADR5000 leukemia cell lines and HCT116p53^+/+ and HCT116p53^−/− colon cancer cell line, while the glioblastoma cell lines U87MG and U87MG.ΔEGFR showed additive to supra-additive cytotoxicity. Gene expression profiles predicting sensitivity and resistance of tumor cells to induction by curcumin and AA were determined by microarray-based mRNA expressions, COMPARE, and hierarchical cluster analyses. Numerous genes involved in transcription (TFAM, TCERG1, RGS13, C11orf31), apoptosis-regulation (CRADD, CDK7, CDK19, CD81, TOM1) signal transduction (NR1D2, HMGN1, ABCA1, DE4ND4B, TRIM27) DNA repair (TOPBP1, RPA2), mRNA metabolism (RBBP4, HNRNPR, SRSF4, NR2F2, PDK1, TGM2), and transporter genes (ABCA1) correlated with cellular responsiveness to curcumin and ascorbic acid. In conclusion, this study shows the effect of the curcumin/AA combination and identifies several candidate genes that may regulate the response of varied cancer cells to curcumin and AA.

Apigenin, a Natural Flavonoid, Attenuates EAE Severity Through the Modulation of Dendritic Cell and Other Immune Cell Functions

Apigenin, a natural flavonoid, found in several plants, fruits, vegetables, herbs, and spices, is known to have anti-oxidant and anti-inflammatory properties that are evident in the use of these substances for centuries as medicinal approaches to treat asthma, insomnia, Parkinson's disease, neuralgia, and shingles. However, there is a considerable dearth of information regarding its effect on immune cells, especially dendritic cells (DC) that maintain the critical balance between an immunogenic and tolerogenic immune response, in an immunospecialized location like the central nervous system (CNS). In this paper we looked at the anti-inflammatory properties of Apigenin in restoration of immune function and the resultant decrease in neuroinflammation. In vivo, a significant reduction in severity of experimental autoimmune encephalomyelitis (EAE) progression and relapse was observed in C57BL/6 (progressive) and SJL/J (relapse-remitting) mouse models of multiple sclerosis upon treatment with Apigenin. Apigenin treated EAE mice show decreased expression of α4 integrin and CLEC12A on splenic DCs and an increased retention of immune cells in the periphery compared to untreated EAE mice. This correlated consequently with immunohistochemistry findings of decreased immune cell infiltration and reduced demyelination in the CNS. These results indicate a protective role of Apigenin against the neurodegenerative effects resulting from the entry of DC stimulated pathogenic T cells into the CNS thus implicating a potential therapy for neuroinflammatory disease.

Luteolin as an anti-inflammatory and neuroprotective agent: A brief review

According to the World Health Organization, two billion people will be aged 60 years or older by 2050. Aging is a major risk factor for a number of neurodegenerative disorders. These age-related disorders currently represent one of the most important and challenging health problems worldwide. Therefore, much attention has been directed towards the design and development of neuroprotective agents derived from natural sources. These phytochemicals have demonstrated high efficacy and low adverse effects in multiple in vitro and in vivo studies. Among these phytochemicals, dietary flavonoids are an important and common chemical class of bioactive products, found in several fruits and vegetables. Luteolin is an important flavone, which is found in several plant products, including broccoli, pepper, thyme, and celery. Numerous studies have shown that luteolin possesses beneficial neuroprotective effects both in vitro and in vivo. Despite this, an overview of the neuroprotective effects of luteolin has not yet been accomplished. Therefore, the aim of this paper is to provide a review of the available literature regarding the neuroprotective effects of luteolin and its molecular mechanisms of action. Herein, we also review the available literature regarding the chemistry of luteolin, its herbal sources, and bioavailability as a pharmacological agent for the treatment and management of age-related neurodegenerative disorders.

Over-the-counter anti-oxidant therapies for use in multiple sclerosis: A systematic review

BACKGROUND

Anti-oxidant compounds that are found in over-the-counter (OTC) supplements and foods are gaining interest as treatments for multiple sclerosis (MS). They are widely used by patients, sometimes without a clear evidence base.

OBJECTIVE

We conducted a systematic review of animal and clinical research to determine the evidence for the benefits of OTC anti-oxidants in MS.

METHODS

Using predefined criteria, we searched key databases. Two authors scrutinized all studies against inclusion/exclusion criteria, assessed study risk-of-bias and extracted results.

RESULTS

Of the 3507 titles, 145 met criteria and included compounds, α(alpha)-lipoic acid (ALA), anti-oxidant vitamins, Ginkgo biloba, quercetin, resveratrol and epigallocatechin-3-gallate (ECGC). The strongest evidence to support OTC anti-oxidants was for compounds EGCG and ALA in animal models; both consistently showed anti-inflammatory/anti-oxidant effects and reduced neurological impairment. Only vitamin E, Ginkgo biloba and ALA were examined for efficacy in pilot clinical trials with either conflicting evidence or evidence of no benefit.

CONCLUSION

OTC anti-oxidants EGCG and ALA show the most consistent benefit, however only in preclinical studies. There is no evidence that they alter MS relapses or progression. Future work should focus on testing more of these therapies for clinical efficacy before recommending them to MS patients.

Transcriptional Regulation of Brain-Derived Neurotrophic Factor (BDNF) by Methyl CpG Binding Protein 2 (MeCP2): a Novel Mechanism for Re-Myelination and/or Myelin Repair Involved in the Treatment of Multiple Sclerosis (MS)

Multiple sclerosis (MS) is a chronic progressive, neurological disease characterized by the targeted immune system-mediated destruction of central nervous system (CNS) myelin. Autoreactive CD4+ T helper cells have a key role in orchestrating MS-induced myelin damage. Once activated, circulating Th1-cells secrete a variety of inflammatory cytokines that foster the breakdown of blood-brain barrier (BBB) eventually infiltrating into the CNS. Inside the CNS, they become reactivated upon exposure to the myelin structural proteins and continue to produce inflammatory cytokines such as tumor necrosis factor α (TNFα) that leads to direct activation of antibodies and macrophages that are involved in the phagocytosis of myelin. Proliferating oligodendrocyte precursors (OPs) migrating to the lesion sites are capable of acute remyelination but unable to completely repair or restore the immune system-mediated myelin damage. This results in various permanent clinical neurological disabilities such as cognitive dysfunction, fatigue, bowel/bladder abnormalities, and neuropathic pain. At present, there is no cure for MS. Recent remyelination and/or myelin repair strategies have focused on the role of the neurotrophin brain-derived neurotrophic factor (BDNF) and its upstream transcriptional repressor methyl CpG binding protein (MeCP2). Research in the field of epigenetic therapeutics involving histone deacetylase (HDAC) inhibitors and lysine acetyl transferase (KAT) inhibitors is being explored to repress the detrimental effects of MeCP2. This review will address the role of MeCP2 and BDNF in remyelination and/or myelin repair and the potential of HDAC and KAT inhibitors as novel therapeutic interventions for MS.

Anticancer mechanism of apigenin and the implications of GLUT-1 expression in head and neck cancers

Apigenin, a natural phytoestrogen flavonoid, has potential biological effects, including antioxidative, anti-inflammatory and anticancer activities. The mechanisms of anticancer activities of apigenin are unknown. Some studies have found that apigenin inhibits GLUT-1 mRNA and protein expression in cancer cells. Thus, we hypothesized that apigenin exerts similar effects on head and neck cancers through its inhibition of GLUT-1 expression. In this article, we review the anticancer mechanism of apigenin and the implications of GLUT-1 expression in head and neck cancers. In addition, we describe the current state of knowledge about the relationship between apigenin and GLUT-1 expression in head and neck cancers.

Multiple sclerosis: molecular mechanisms and therapeutic opportunities

The pathophysiology of multiple sclerosis (MS) involves several components: redox, inflammatory/autoimmune, vascular, and neurodegenerative. All of them are supported by the intertwined lines of evidence, and none of them should be written off. However, the exact mechanisms of MS initiation, its development, and progression are still elusive, despite the impressive pace by which the data on MS are accumulating. In this review, we will try to integrate the current facts and concepts, focusing on the role of redox changes and various reactive species in MS. Knowing the schedule of initial changes in pathogenic factors and the key turning points, as well as understanding the redox processes involved in MS pathogenesis is the way to enable MS prevention, early treatment, and the development of therapies that target specific pathophysiological components of the heterogeneous mechanisms of MS, which could alleviate the symptoms and hopefully stop MS. Pertinent to this, we will outline (i) redox processes involved in MS initiation; (ii) the role of reactive species in inflammation; (iii) prooxidative changes responsible for neurodegeneration; and (iv) the potential of antioxidative therapy.

Discovery of curcumin, a component of golden spice, and its miraculous biological activities

1. Curcumin is the active ingredient of the dietary spice turmeric and has been consumed for medicinal purposes for thousands of years. Modern science has shown that curcumin modulates various signalling molecules, including inflammatory molecules, transcription factors, enzymes, protein kinases, protein reductases, carrier proteins, cell survival proteins, drug resistance proteins, adhesion molecules, growth factors, receptors, cell cycle regulatory proteins, chemokines, DNA, RNA and metal ions. 2. Because of this polyphenol's potential to modulate multiple signalling molecules, it has been reported to possess pleiotropic activities. First demonstrated to have antibacterial activity in 1949, curcumin has since been shown to have anti-inflammatory, anti-oxidant, pro-apoptotic, chemopreventive, chemotherapeutic, antiproliferative, wound healing, antinociceptive, antiparasitic and antimalarial properties as well. Animal studies have suggested that curcumin may be active against a wide range of human diseases, including diabetes, obesity, neurological and psychiatric disorders and cancer, as well as chronic illnesses affecting the eyes, lungs, liver, kidneys and gastrointestinal and cardiovascular systems. 3. Although many clinical trials evaluating the safety and efficacy of curcumin against human ailments have already been completed, others are still ongoing. Moreover, curcumin is used as a supplement in several countries, including India, Japan, the US, Thailand, China, Korea, Turkey, South Africa, Nepal and Pakistan. Although inexpensive, apparently well tolerated and potentially active, curcumin has not been approved for the treatment of any human disease. 4. In the present article, we discuss the discovery and key biological activities of curcumin, with a particular emphasis on its activities at the molecular and cellular levels, as well as in animals and humans.

Beneficial effects of blueberries in experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is an animal model of autoimmune disease that presents with pathological and clinical features similar to those of multiple sclerosis (MS) including inflammation and neurodegeneration. This study investigated whether blueberries, which possess immunomodulatory, anti-inflammatory, and neuroprotective properties, could provide protection in EAE. Dietary supplementation with 1% whole, freeze-dried blueberries reduced disease incidence by >50% in a chronic EAE model (p < 0.01). When blueberry-fed mice with EAE were compared with control-fed mice with EAE, blueberry-fed mice had significantly lower motor disability scores (p = 0.03) as well as significantly greater myelin preservation in the lumbar spinal cord (p = 0.04). In a relapsing-remitting EAE model, blueberry-supplemented mice showed improved cumulative and final motor scores compared to control diet-fed mice (p = 0.01 and 0.03, respectively). These data demonstrate that blueberry supplementation is beneficial in multiple EAE models, suggesting that blueberries, which are easily administered orally and well-tolerated, may provide benefit to MS patients.

May diet and dietary supplements improve the wellness of multiple sclerosis patients? A molecular approach

Multiple sclerosis is a complex and multifactorial neurological disease, and nutrition is one of the environmental factors possibly involved in its pathogenesis. At present, the role of nutrition is unclear, and MS therapy is not associated to a particular diet. MS clinical trials based on specific diets or dietary supplements are very few and in some cases controversial. To understand how diet can influence the course of MS and improve the wellness of MS patients, it is necessary to identify the dietary molecules, their targets and the molecular mechanisms involved in the control of the disease. The aim of this paper is to provide a molecular basis for the nutritional intervention in MS by evaluating at molecular level the effect of dietary molecules on the inflammatory and autoimmune processes involved in the disease.

Postischemic administration of liposome-encapsulated luteolin prevents against ischemia-reperfusion injury in a rat middle cerebral artery occlusion model

Oxidative stress-induced neuronal cell death has been implicated in neurodegenerative diseases; one such disease is ischemic stroke. Using reactive oxygen species (ROS)-insulted primary neurons, we screened neuroprotectants with clinical potential and then, using ischemia/reperfusion (I/R) model, investigated the anti-ischemic potential of candidate neuroprotectants. Here, we showed that luteolin, isolated from the ripe fruit of Perilla frutescens (L.) Britt, exhibited a neuroprotective action upon the in vitro platform, thus serving as candidate for in vivo pharmacological evaluation. Liposome-encapsulated luteolin produced dramatic preventing effects on I/R-induced behavioral and histological injuries after a 13-day post-ischemic treatment. Furthermore, this phytochemical not only lowered the increased level of mitochondrial ROS but also substantially up-regulated the decreased activity of catalase and glutathione in I/R rat brains. Collectively, luteolin as a neuroprotectant acts by anti-ischemic activity likely through a rebalancing of pro-oxidant/antioxidant status. Its multitarget mechanisms implicate potential effectiveness for clinically treating ischemia stroke.

Purple sweet potato color ameliorates cognition deficits and attenuates oxidative damage and inflammation in aging mouse brain induced by d-galactose

Purple sweet potato color (PSPC), a naturally occurring anthocyanin, has a powerful antioxidant activity in vitro and in vivo. This study explores whether PSPC has the neuroprotective effect on the aging mouse brain induced by D-galactose (D-gal). The mice administrated with PSPC (100 mg/kg.day, 4 weeks, from 9th week) via oral gavage showed significantly improved behavior performance in the open field and passive avoidance test compared with D-gal-treated mice (500 mg/kg.day, 8 weeks). We further investigate the mechanism involved in neuroprotective effects of PSPC on mouse brain. Interestingly, we found, PSPC decreased the expression level of glial fibrillary acidic protein (GFAP), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), inhibited nuclear translocation of nuclear factor-kappaB (NF-kappaB), increased the activity of copper/zinc superoxide dismutase (Cu/Zn-SOD) and catalase (CAT), and reduced the content of malondialdehyde (MDA), respectively. Our data suggested that PSPC attenuated D-gal-induced cognitive impairment partly via enhancing the antioxidant and anti-inflammatory capacity.

Immunomodulatory responses of peripheral blood mononuclear cells from multiple sclerosis patients upon in vitro incubation with the flavonoid luteolin: additive effects of IFN-beta

The study is aimed to determine the role of luteolin (3',4',5,7-tetrahydroxyflavone), alone and in combination with human interferon-beta (IFN-beta), in modulating the immune response(s) of peripheral blood mononuclear cells (PBMCs) isolated from multiple sclerosis (MS) patients. PBMC proliferation in the presence or absence of these drugs was determined and the production of pro-inflammatory cytokines (IL-1beta, TNF-alpha), and the ratio of cell migration mediator MMP-9, and its inhibitor, TIMP-1 was assessed in the culture supernatants. Luteolin reduced, in a dose-dependent manner, the proliferation of PBMCs, and modulated the levels of IL-1beta and TNF-alpha released by PBMCs in the culture supernatants. Luteolin reduced the MMP-9/TIMP-1 ratio via lowering MMP-9 production. In the majority of cases, luteolin, when combined with IFN-beta, had additive effects in modulating cell proliferation, IL-1beta, TNF-alpha, MMP-9 and TIMP-1.

Potential therapeutic effects of curcumin, the anti-inflammatory agent, against neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases

Although safe in most cases, ancient treatments are ignored because neither their active component nor their molecular targets are well defined. This is not the case, however, with curcumin, a yellow-pigment substance and component of turmeric (Curcuma longa), which was identified more than a century ago. For centuries it has been known that turmeric exhibits anti-inflammatory activity, but extensive research performed within the past two decades has shown that this activity of turmeric is due to curcumin (diferuloylmethane). This agent has been shown to regulate numerous transcription factors, cytokines, protein kinases, adhesion molecules, redox status and enzymes that have been linked to inflammation. The process of inflammation has been shown to play a major role in most chronic illnesses, including neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases. In the current review, we provide evidence for the potential role of curcumin in the prevention and treatment of various proinflammatory chronic diseases. These features, combined with the pharmacological safety and negligible cost, render curcumin an attractive agent to explore further.

CURCUMIN: THE INDIAN SOLID GOLD

Turmeric, derived from the plant Curcuma longa, is a gold-colored spice commonly used in the Indian subcontinent, not only for health care but also for the preservation of food and as a yellow dye for textiles. Curcumin, which gives the yellow color to turmeric, was first isolated almost two centuries ago, and its structure as diferuloylmethane was determined in 1910. Since the time of Ayurveda (1900 Bc) numerous therapeutic activities have been assigned to turmeric for a wide variety of diseases and conditions, including those of the skin, pulmonary, and gastrointestinal systems, aches, pains, wounds, sprains, and liver disorders. Extensive research within the last half century has proven that most of these activities, once associated with turmeric, are due to curcumin. Curcumin has been shown to exhibit antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, and anticancer activities and thus has a potential against various malignant diseases, diabetes, allergies, arthritis, Alzheimer's disease, and other chronic illnesses. These effects are mediated through the regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other enzymes. Curcumin exhibits activities similar to recently discovered tumor necrosis factor blockers (e.g., HUMIRA, REMICADE, and ENBREL), a vascular endothelial cell growth factor blocker (e.g., AVASTIN), human epidermal growth factor receptor blockers (e.g., ERBITUX, ERLOTINIB, and GEFTINIB), and a HER2 blocker (e.g., HERCEPTIN). Considering the recent scientific bandwagon that multitargeted therapy is better than monotargeted therapy for most diseases, curcumin can be considered an ideal "Spice for Life".

Antioxidants in multiple sclerosis: do they have a role in therapy?

Multiple sclerosis (MS) is an immune-mediated disease, with inflammation and neurodegeneration contributing to neuronal demyelination and axonal injury. Current therapies for MS are directed toward modulation of the immune response; however, there is increasing evidence that oxidative stress is an important component in the pathogenesis of MS. The inflammatory environment in demyelinating lesions is conducive to the generation of reactive oxygen species. When these species are generated in MS and animal models of MS, products such as peroxynitrite and superoxide are formed that are highly toxic to cells. There are several examples of potential beneficial effects from various antioxidants in animal models of MS, but the efficacy may vary between different agents and, in some instances, may yield deleterious effects. Despite these promising results in animal models, there is limited and conflicting evidence of potential therapeutic effects of antioxidants such as vitamins C and E in treating MS. However, clinical trials in MS patients with more potent antioxidants, identified in animal studies, have been initiated.

Quercetin reverses D-galactose induced neurotoxicity in mouse brain

We assessed the neuroprotective effects of quercetin-feeding at doses of 5 and 10 mg/(kg day) on Kunming mice injected daily with D-gal (50 mg/(kg day)) by behavioral tests. Quercetin-fed mice showed higher activity upon induction by new environmental stimuli, lower anxiety and higher novelty-seeking behavior in the open field tasks, and significantly improved learning and memory ability in step-through and Morris water Maze tests compared with D-gal-treated mice. We further investigated the mechanisms involved in the neuroprotective effects of quercetin on mouse brain. Quercetin significantly increased superoxide dismutase (SOD) activity and decreased the malondialdehyde (MDA) level. These results imply that quercetin can reverse oxidant impairment induced by D-gal in mouse brain. Neurotoxicity is also associated with Ca(2+) overload induced by oxidant stress. Quercetin could maintain the Ca(2+) homeostasis in the brain of D-gal-treated mice. Furthermore, we also examined the expression of growth-associated protein GAP43 mRNA in mouse brain by in situ hybridization. We found that quercetin dramatically elevated the GAP43 mRNA expression in the brain of D-gal-treated mice to regenerate normal function of neurons against the cellular injury caused by D-gal.