Hesperidin ameliorates immunological outcome and reduces neuroinflammation in the mouse model of multiple sclerosis

Flavonoids as Potential Therapeutics Against Neurodegenerative Disorders: Unlocking the Prospects

Neurodegeneration, the decline of nerve cells in the brain, is a common feature of neurodegenerative disorders (NDDs). Oxidative stress, a key factor in NDDs such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease can lead to neuronal cell death, mitochondria impairment, excitotoxicity, and Ca2+ stress. Environmental factors compromising stress response lead to cell damage, necessitating novel therapeutics for preventing or treating brain disorders in older individuals and an aging population. Synthetic medications offer symptomatic benefits but can have adverse effects. This research explores the potential of flavonoids derived from plants in treating NDDs. Flavonoids compounds, have been studied for their potential to enter the brain and treat NDDs. These compounds have diverse biological effects and are currently being explored for their potential in the treatment of central nervous system disorders. Flavonoids have various beneficial effects, including antiviral, anti-allergic, antiplatelet, anti-inflammatory, anti-tumor, anti-apoptotic, and antioxidant properties. Their potential to alleviate symptoms of NDDs is significant.

Polyphenols: immunonutrients tipping the balance of immunometabolism in chronic diseases

Mounting evidence progressively appreciates the vital interplay between immunity and metabolism in a wide array of immunometabolic chronic disorders, both autoimmune and non-autoimmune mediated. The immune system regulates the functioning of cellular metabolism within organs like the brain, pancreas and/or adipose tissue by sensing and adapting to fluctuations in the microenvironment's nutrients, thereby reshaping metabolic pathways that greatly impact a pro- or anti-inflammatory immunophenotype. While it is agreed that the immune system relies on an adequate nutritional status to function properly, we are only just starting to understand how the supply of single or combined nutrients, all of them termed immunonutrients, can steer immune cells towards a less inflamed, tolerogenic immunophenotype. Polyphenols, a class of secondary metabolites abundant in Mediterranean foods, are pharmacologically active natural products with outstanding immunomodulatory actions. Upon binding to a range of receptors highly expressed in immune cells (e.g. AhR, RAR, RLR), they act in immunometabolic pathways through a mitochondria-centered multi-modal approach. First, polyphenols activate nutrient sensing via stress-response pathways, essential for immune responses. Second, they regulate mammalian target of rapamycin (mTOR)/AMP-activated protein kinase (AMPK) balance in immune cells and are well-tolerated caloric restriction mimetics. Third, polyphenols interfere with the assembly of NLR family pyrin domain containing 3 (NLRP3) in endoplasmic reticulum-mitochondria contact sites, inhibiting its activation while improving mitochondrial biogenesis and autophagosome-lysosome fusion. Finally, polyphenols impact chromatin remodeling and coordinates both epigenetic and metabolic reprogramming. This work moves beyond the well-documented antioxidant properties of polyphenols, offering new insights into the multifaceted nature of these compounds. It proposes a mechanistical appraisal on the regulatory pathways through which polyphenols modulate the immune response, thereby alleviating chronic low-grade inflammation. Furthermore, it draws parallels between pharmacological interventions and polyphenol-based immunonutrition in their modes of immunomodulation across a wide spectrum of socioeconomically impactful immunometabolic diseases such as Multiple Sclerosis, Diabetes (type 1 and 2) or even Alzheimer's disease. Lastly, it discusses the existing challenges that thwart the translation of polyphenols-based immunonutritional interventions into long-term clinical studies. Overcoming these limitations will undoubtedly pave the way for improving precision nutrition protocols and provide personalized guidance on tailored polyphenol-based immunonutrition plans.

The protective effects of hesperidin as an antioxidant against quinolinic acid-induced toxicity on oligodendroglia cells: An in vitro study

INTRODUCTION

Multiple sclerosis (MS) is a complex central nervous system disorder, marked by neurodegenerative and inflammatory processes, where overproduction of reactive oxygen species (ROS) is a key factor in demyelination and neurodegeneration. The current study aims to investigate the effect of hesperidin and Quinolinic acid (QA) on ROS and antioxidant levels, and cell viability of OLN-93 cells.

METHODS

OLN-93 cell lines were treated with hesperidin and QA. OLN-93 cells were cultured in Dulbecco's modified Eagle's medium under controlled conditions. Cell viability assays were performed using resazurin to assess the toxicity of hesperidin and QA. Additionally, ROS levels were measured using DCFDA, and malondialdehyde (MDA) levels were determined to evaluate oxidative stress. Superoxide dismutase (SOD) activity and cell viability were assessed by trypan blue staining after exposure to hesperidin and QA.

RESULTS

The results of the current study showed that co-administration of 8 mM QA with 50, 100, and 200 μM hesperidin significantly reduced both ROS and MDA levels, demonstrating a substantial attenuation in comparison to the elevated ROS and MDA levels induced by 8 mM QA (p-value < 0.01). Furthermore, 8 mM QA + 50, 100, and 200 μM hesperidin significantly increased SOD levels compared with QA alone (p-value < 0.01). In addition, treatment of OLN cells with 8 mM QA + 50, 100, and 200 μM hesperidin led to higher cell viability compared to QA alone (p value <0.0001).

CONCLUSION

The current study demonstrated the antioxidant effect of hesperidin on OLN-93 cells suggesting new insights into the clinical application of hesperidin as an effective treatment for patients with MS. Future in vivo studies, focusing on cellular mechanisms are recommended.

Natural compounds as potential therapeutic candidates for multiple sclerosis: Emerging preclinical evidence

BACKGROUND

Multiple sclerosis is a chronic neurodegenerative disease, with main characteristics of pathological inflammation, neural damage and axonal demyelination. Current mainstream treatments demonstrate more or less side effects, which limit their extensive use.

PURPOSE

Increasing studies indicate that natural compounds benefit multiple sclerosis without remarkable side effects. Given the needs to explore the potential effects of natural compounds of plant origin on multiple sclerosis and their mechanisms, we review publications involving the role of natural compounds in animal models of multiple sclerosis, excluding controlled trials.

STUDY DESIGN AND METHODS

Articles were conducted on PubMed and Web of Science databases using the keywords ``multiple sclerosis'' and ``natural compounds'' published from January 1, 2008, to September 1, 2023.

RESULTS

This review summarized the effects of natural ingredients (flavonoids, terpenoids, polyphenols, alkaloids, glycosides, and others) from three aspects: immune regulation, oxidative stress suppression, and myelin protection and regeneration in multiple sclerosis.

CONCLUSION

Overall, we concluded 80 studies to show the preclinical evidence that natural compounds may attenuate multiple sclerosis progression via suppressing immune attacks and/or promoting myelin protection or endogenous repair processes. It would pave the roads for the future development of effective therapeutic regiments of multiple sclerosis.

Neuroprotective Potential of Hesperidin as Therapeutic Agent in the Treatment of Brain Disorders: Preclinical Evidence-based Review

Neurodegenerative disorders (NDs) are progressive morbidities that represent a serious health issue in the aging world population. There is a contemporary upsurge in worldwide interest in the area of traditional remedies and phytomedicines are widely accepted by researchers due to their health-promoted effects and fewer side effects. Hesperidin, a flavanone glycoside present in the peels of citrus fruits, possesses various biological activities including anti-inflammatory and antioxidant actions. In various preclinical studies, hesperidin has provided significant protective actions in a variety of brain disorders such as Alzheimer's disease, epilepsy, Parkinson's disease, multiple sclerosis, depression, neuropathic pain, etc. as well as their underlying mechanisms. The findings indicate that the neuroprotective effects of hesperidin are mediated by modulating antioxidant defence activities and neural growth factors, diminishing apoptotic and neuro-inflammatory pathways. This review focuses on the potential role of hesperidin in managing and treating diverse brain disorders.

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.

Plants and Their Derivatives as Promising Therapeutics for Sustainable Control of Honeybee (Apis mellifera) Pathogens

The most important pollinator for agricultural crops is the Western honeybee (Apis mellifera). During the winter and summer seasons, diseases and stresses of various kinds endanger honeybee numbers and production, resulting in expenses for beekeepers and detrimental effects on agriculture and ecosystems. Researchers are continually in search of therapies for honeybees using the resources of microbiology, molecular biology, and chemistry to combat diseases and improve the overall health of these important pollinating insects. Among the most investigated and most promising solutions are medicinal plants and their derivatives. The health of animals and their ability to fight disease can be supported by natural products (NPs) derived from living organisms such as plants and microbes. NPs contain substances that can reduce the effects of diseases by promoting immunity or directly suppressing pathogens, and parasites. This literature review summarises the advances that the scientific community has achieved over the years regarding veterinary treatments in beekeeping through the use of NPs. Their impact on the prevention and control of honeybee diseases is investigated both in trials that have been conducted in the laboratory and field studies.

Hesperidin may improve depressive symptoms by binding NLRP3 and influencing the pyroptosis pathway in a rat model

OBJECTIVE

Major depressive disorder (MDD) is a debilitating psychiatric disorder which is common and endangers human physical and mental health. Studies have shown that hesperidin could improve the symptoms of depression with unclear mechanisms.

METHOD

In this study, hesperidin was administered to chronic unpredictable mild stress (CUMS) depressed mice before behavioral test, network pharmacology analysis, RNA expression microarray analysis, pathway validation and molecular docking experiments.

RESULTS

we found that hesperidin intervention could significantly improve the depressive symptoms and downregulate the expression level of pyroptosis pathway including caspase 1 (Casp1), interleukin 18 (IL18), interleukin-1β (IL-1β) and NOD-like receptor thermal protein domain associated protein 3 (NLRP3). In addition, we found that hesperidin could possibly bind to NLRP3.

CONCLUSIONS

Our study demonstrated that hesperidin had huge potential as anti-depressive neuroprotectant, and may play a role in treating MDD by regulating NLRP3-mediated pyroptosis.

Natural products targeting cellular processes common in Parkinson's disease and multiple sclerosis

The hallmarks of Parkinson's disease (PD) include the loss of dopaminergic neurons and formation of Lewy bodies, whereas multiple sclerosis (MS) is an autoimmune disorder with damaged myelin sheaths and axonal loss. Despite their distinct etiologies, mounting evidence in recent years suggests that neuroinflammation, oxidative stress, and infiltration of the blood-brain barrier (BBB) all play crucial roles in both diseases. It is also recognized that therapeutic advances against one neurodegenerative disorder are likely useful in targeting the other. As current drugs in clinical settings exhibit low efficacy and toxic side effects with long-term usages, the use of natural products (NPs) as treatment modalities has attracted growing attention. This mini-review summarizes the applications of natural compounds to targeting diverse cellular processes inherent in PD and MS, with the emphasis placed on their neuroprotective and immune-regulating potentials in cellular and animal models. By reviewing the many similarities between PD and MS and NPs according to their functions, it becomes evident that some NPs studied for one disease are likely repurposable for the other. A review from this perspective can provide insights into the search for and utilization of NPs in treating the similar cellular processes common in major neurodegenerative diseases.

An assessment of the ameliorative role of hesperidin in Drosophila melanogaster model of cadmium chloride-induced toxicity

Cadmium chloride (CdCl₂) is an important heavy metal widely regarded as an environmental contaminant. Hesperidin, a flavanone glycoside found in citrus fruits, has an established properties against free radicals, apoptosis, and inflammation. The present study investigated the protective actions of hesperidin on CdCl₂-induced oxidative damage and inflammation in Drosophila melanogaster. For 7 consecutive days via their diet regimen, the flies were exposed to CdCl₂ alone (0.05 mM) or in combination with hesperidin (50 and 100 μM). Exposure to CdCl₂ significantly (p < 0.05) increased mortality rate of flies, whereas the survived flies demonstrated significant oxidative toxicity from decreased activities of catalase and Glutathione S-transferase (GST) and Total Thiol (T-SH) and Non-Protein Thiols (NPSH) levels as well as accumulation of Nitric Oxide (NO (nitrite/nitrate)), protein carbonyl and Hydrogen Peroxide (H₂O₂). However, hesperidin-supplemented diet improved Acetylcholinesterase (AChE) activity, mitochondrial metabolic rate (cell viability), locomotor activity, and amelioration of oxidative damage and lipid peroxidation induced by CdCl₂. The hesperidin diet supplement boosted the antioxidant milieu and ameliorated the oxidative damage in the treated flies. Overall, the findings revealed that hesperidin improved antioxidative protective capacity in Drosophila melanogaster model of CdCl₂-induced toxicity. This suggests hesperidin as a potential therapeutic agent against oxidative stress disorders due to exposure to CdCl₂ and or related toxicants.

Potential Use of Agave Genus in Neuroinflammation Management

Agavaceae contains about 480 species, commonly used in the production of alcoholic beverages such as tequila and mezcal, making it a resource of economic and cultural importance. Uses of this plant rely mainly on the stem; other components such as the leaves are discarded, generating agro-industrial waste, despite being a source of bioactive and nutraceutical products. Reports show anti-inflammatory and anti-neuroinflammatory effects of these species, with flavonoids and saponins being mainly responsible. Neuroinflammation is a brain process that plays a key role in the pathogenesis of various neurodegenerative disorders and its effects contribute greatly to mortality and morbidity worldwide. This can be triggered by mechanisms such as glial reactions that lead to the release of inflammatory and oxidative molecules, causing damage to the CNS. Treatments do not cure chronic disease associated with inflammation; they only slow its progression, producing side effects that affect quality of life. Plant-based therapy is promising for treating these diseases. Pharmacological activities have been described for the Agavaceae family; however, their role in neuroinflammation has not been fully investigated, and represents an important target for study. This review synthesizes the existing literature on the biologically active compounds of Agave species that are related in some way to inflammation, which will allow us to propose a line of research with this genus on the forefront to orient experimental designs for treating neuroinflammation and associated diseases.

Prospective Medicinal Plants and Their Phytochemicals Shielding Autoimmune and Cancer Patients Against the SARS-CoV-2 Pandemic: A Special Focus on Matcha

Background

Being "positive" has been one of the most frustrating words anyone could hear since the end of 2019. This word had been overused globally due to the high infectious nature of SARS-CoV-2. All citizens are at risk of being infected with SARS-CoV-2, but a red warning sign has been directed towards cancer and immune-compromised patients in particular. These groups of patients are not only more prone to catch the virus but also more predisposed to its deadly consequences, something that urged the research community to seek other effective and safe solutions that could be used as a protective measurement for cancer and autoimmune patients during the pandemic.

Aim

The authors aimed to turn the spotlight on specific herbal remedies that showed potential anticancer activity, immuno-modulatory roles, and promising anti-SARS-CoV-2 actions.

Methodology

To attain the purpose of the review, the research was conducted at the States National Library of Medicine (PubMed). To search databases, the descriptors used were as follows: "COVID-19"/"SARS-CoV-2", "Herbal Drugs", "Autoimmune diseases", "Rheumatoid Arthritis", "Asthma", "Multiple Sclerosis", "Systemic Lupus Erythematosus" "Nutraceuticals", "Matcha", "EGCG", "Quercetin", "Cancer", and key molecular pathways.

Results

This manuscript reviewed most of the herbal drugs that showed a triple action concerning anticancer, immunomodulation, and anti-SARS-CoV-2 activities. Special attention was directed towards "matcha" as a novel potential protective and therapeutic agent for cancer and immunocompromised patients during the SARS-CoV-2 pandemic.

Conclusion

This review sheds light on the pivotal role of "matcha" as a tri-acting herbal tea having a potent antitumorigenic effect, immunomodulatory role, and proven anti-SARS-CoV-2 activity, thus providing a powerful shield for high-risk patients such as cancer and autoimmune patients during the pandemic.

Drug Candidates for Autoimmune Diseases

Most of the immunosuppressive drugs used in the clinic to prevent organ rejection or to treat autoimmune disorders were originally isolated from fungi or bacteria. Therefore, in addition to plants, these are valuable sources for identification of new potent drugs. Many side effects of established drugs limit their usage and make the identification of new immunosuppressants necessary. In this review, we present a comprehensive overview of natural products with potent anti-inflammatory activities that have been tested successfully in different models of chronic inflammatory autoimmune diseases. Some of these candidates already have passed first clinical trials. The anti-inflammatory potency of these natural products was often comparable to those of established drugs, and they could be used at least in addition to standard therapy to reduce their dose to minimize unwanted side effects. A frequent mode of action is the inhibition of classical inflammatory signaling pathways, such as NF-κB, in combination with downregulation of oxidative stress. A drawback for the therapeutic use of those natural products is their moderate bioavailability, which can be optimized by chemical modifications and, in addition, further safety studies are necessary. Altogether, very interesting candidate compounds exist which have the potential to serve as starting points for the development of new immunosuppressive drugs.

Dietary Plant Polyphenols as the Potential Drugs in Neurodegenerative Diseases: Current Evidence, Advances, and Opportunities

Neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD), are characterized by the progressive degeneration of neurons. Although the etiology and pathogenesis of neurodegenerative diseases have been studied intensively, the mechanism is still in its infancy. In general, most neurodegenerative diseases share common molecular mechanisms, and multiple risks interact and promote the pathologic process of neurogenerative diseases. At present, most of the approved drugs only alleviate the clinical symptoms but fail to cure neurodegenerative diseases. Numerous studies indicate that dietary plant polyphenols are safe and exhibit potent neuroprotective effects in various neurodegenerative diseases. However, low bioavailability is the biggest obstacle for polyphenol that largely limits its adoption from evidence into clinical practice. In this review, we summarized the widely recognized mechanisms associated with neurodegenerative diseases, such as misfolded proteins, mitochondrial dysfunction, oxidative damage, and neuroinflammatory responses. In addition, we summarized the research advances about the neuroprotective effect of the most widely reported dietary plant polyphenols. Moreover, we discussed the current clinical study and application of polyphenols and the factors that result in low bioavailability, such as poor stability and low permeability across the blood-brain barrier (BBB). In the future, the improvement of absorption and stability, modification of structure and formulation, and the combination therapy will provide more opportunities from the laboratory into the clinic for polyphenols. Lastly, we hope that the present review will encourage further researches on natural dietary polyphenols in the treatment of neurodegenerative diseases.

Nobiletin attenuates inflammation via modulating proinflammatory and antiinflammatory cytokine expressions in an autoimmune encephalomyelitis mouse model

The aim of this study is to investigate the potential preventive and therapeutic effects of nobiletin by evaluating the expression of cytokines associated with inflammatory reactions in an autoimmune encephalomyelitis mouse model. A total of 60 male C57BL/6 mice aged between 8 and 10 weeks were used. Mice were divided into six groups (n = 10 mice per group): control, EAE, low-prophylaxis, high-prophylaxis, low-treatment and high-treatment. Experimental autoimmune encephalomyelitis (EAE) was induced by myelin oligodendrocyte glycoprotein (MOG) and pertussis toxin. Nobiletin was administered in low (25 mg/kg) and high (50 mg/kg) doses, intraperitoneally. The prophylactic and therapeutic effects of nobiletin on brain tissue and spinal cord were evaluated by expression of interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), interferon gamma (IFNγ), IL-6, IL-10 and transforming growth factor-beta (TGF-β) using immunohistochemistry and real-time polymerase chain reaction (RT-PCR). Prophylactic and therapeutic use of nobiletin inhibited EAE-induced increase of TNF-α, IL-1β and IL-6 activities to alleviate inflammatory response in brain and spinal cord. Moreover, nobiletin supplement dramatically increased the IL-10, TGF-β and IFNγ expressions in prophylaxis and treatment groups compared with the EAE group in the brain and spinal cord. The results obtained from this study show that prophylactic and therapeutic nobiletin modulates expressions of proinflammatory and antiinflammatory cytokines in brain and spinal cord dose-dependent manner in EAE model. These data demonstrates that nobiletin has a potential to attenuate inflammation in EAE mouse model. These experimental findings need to be supported by clinical studies.

Acetylcholinesterase Inhibitors in the Treatment of Neurodegenerative Diseases and the Role of Acetylcholinesterase in their Pathogenesis

Acetylcholinesterase (AChE) plays an important role in the pathogenesis of neurodegenerative diseases by influencing the inflammatory response, apoptosis, oxidative stress and aggregation of pathological proteins. There is a search for new compounds that can prevent the occurrence of neurodegenerative diseases and slow down their course. The aim of this review is to present the role of AChE in the pathomechanism of neurodegenerative diseases. In addition, this review aims to reveal the benefits of using AChE inhibitors to treat these diseases. The selected new AChE inhibitors were also assessed in terms of their potential use in the described disease entities. Designing and searching for new drugs targeting AChE may in the future allow the discovery of therapies that will be effective in the treatment of neurodegenerative diseases.

The neuroprotective effects of polyphenols, their role in innate immunity and the interplay with the microbiota

Neurodegenerative disorders, particularly in the elderly population, represent one of the most pressing social and health-care problems in the world. Besides the well-established role of both oxidative stress and inflammation, alterations of the immune response have been found to be closely linked to the development of neurodegenerative diseases. Interestingly, various scientific evidence reported that an altered gut microbiota composition may contribute to the development of neuroinflammatory disorders. This leads to the proposal of the concept of the gut-brain-immune axis. In this scenario, polyphenols play a pivotal role due to their ability to exert neuroprotective, immunomodulatory and microbiota-remodeling activities. In the present review, we summarized the available literature to provide a scientific evidence regarding this neuroprotective and immunomodulatory effects and the interaction with gut microbiota of polyphenols and, the main signaling pathways involved that can explain their potential therapeutic application in neurodegenerative diseases.

Role of Plant-Derived Natural Compounds in Experimental Autoimmune Encephalomyelitis: A Review of the Treatment Potential and Development Strategy

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system that is mainly mediated by pathological T-cells. Experimental autoimmune encephalomyelitis (EAE) is a well-known animal model of MS that is used to study the underlying mechanism and offers a theoretical basis for developing a novel therapy for MS. Good therapeutic effects have been observed after the administration of natural compounds and their derivatives as treatments for EAE. However, there has been a severe lag in the research and development of drug mechanisms related to MS. This review examines natural products that have the potential to effectively treat MS. The relevant data were consulted in order to elucidate the regulated mechanisms acting upon EAE by the flavonoids, glycosides, and triterpenoids derived from natural products. In addition, novel technologies such as network pharmacology, molecular docking, and high-throughput screening have been gradually applied in natural product development. The information provided herein can help improve targeting and timeliness for determining the specific mechanisms involved in natural medicine treatment and lay a foundation for further study.

Flavonoids from edible fruits as therapeutic agents in neuroinflammation - a comprehensive review and update

Neuroinflammation is a key process in the pathogenesis of many neurological disorders, i.e. Alzheimer's disease and Parkinson's disease. However, there are no anti-inflammatory medical interventions recommended so far in the treatment of neuroinflammation-related brain disorders. Therefore, the burden of searching for effective and safe antineuroinflammatory agents is well founded, especially in the aging society. Compounds of plant origin, mainly (poly)phenols, have attracted considerable attention in recent years. Notably, the role of flavonoids in ameliorating neuroinflammation is in the limelight. Thus, we used comprehensive literature retrieval to summarize the effects and active components of edible fruits and their phenolic compounds. As a result, this review presents a valuable summary of results of in vitro, ex vivo, and in vivo studies on the antineuroinflammatory effects of edible fruits and their (poly)phenolic extracts as well as dietary flavonoids and other selected (poly)phenols based on the detailed description of foregoing studies. Additionally, problems resulting from the limited bioavailability of (poly)phenols were discussed.

Flavonoids, the compounds with anti-inflammatory and immunomodulatory properties, as promising tools in multiple sclerosis (MS) therapy: A systematic review of preclinical evidence

Multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), an animal model of MS, are diseases resulting in neurological disabilities that are regarded as chronic, inflammatory, and autoimmune diseases of central nervous system (CNS). In this respect, the use of anti-inflammatory compounds including flavonoids, polyphenolic compounds abundantly found in vegetables and fruits, has proposed to combat MS to dampen the inflammation and thereby ameliorating the disease severity. The objective of this study was to clarify the probable therapeutic effect of flavonoids for treatment of MS. Therefore, only English published articles that reported the therapeutic effect of flavonoids alone or in combination with other anti-MS therapeutic agents on MS, were selected by searching scientific electronic databases including PubMed, Scopus and Web of Science. Evaluation of the selected researches (686) showed that a total of 13 studies were suitable to be included in this systematic review. Interestingly, all of the studies (11 studies concerning EAE and 2 studies concerning MS) reported positive outcomes for the therapeutic effect of flavonoids on EAE and MS. All flavonoid compounds which are mentioned herein could successfully decrease the maximum clinical score of EAE, which is particularly connected to the anti-inflammatory property of these compounds. The literature review clearly discloses that flavonoids alone or in combination with other anti-MS therapeutic agents can pave the way for improving MS therapeutic strategies.

Hesperetin's health potential: moving from preclinical to clinical evidence and bioavailability issues, to upcoming strategies to overcome current limitations

Flavonoids are common in the plant kingdom and many of them have shown a wide spectrum of bioactive properties. Hesperetin (Hst), the aglycone form of hesperidin, is a great example, and is the most abundant flavonoid found in Citrus plants. This review aims to provide an overview on the in vitro, in vivo and clinical studies reporting the Hst pharmacological effects and to discuss the bioavailability-related issues. Preclinical studies have shown promising effects on cancer, cardiovascular diseases, carbohydrate dysregulation, bone health, and other pathologies. Clinical studies have supported the Hst promissory effects as cardioprotective and neuroprotective agent. However, further well-designed clinical trials are needed to address the other Hst effects observed in preclinical trials, as well as to a more in-depth understanding of its safety profile.

The moss flavone synthase I positively regulates the tolerance of plants to drought stress and UV-B radiation

Flavonoids are extensively distributed secondary metabolites in land plants. They play a critical role in plant evolution from aquatic to terrestrial and plant adaption to ultraviolet radiation. However, the downstream branching pathway of flavonoids and its regulatory mechanism in bryophytes, which are the most ancient of terrestrial plants, remain unclear. Here, a type I flavone synthase (PnFNSI) was characterized from the Antarctic moss Pohlia nutans. PnFNSI was primarily distributed in the cytoplasm, as detected by subcellular localization. PnFNSI could catalyze the conversion of naringenin to apigenin with an optimal temperature between 15 and 20 °C in vitro. Overexpression of PnFNSI in Arabidopsis alleviated the growth restriction caused by naringenin and accumulated apigenin product. PnFNSI-overexpressing plants showed enhanced plant tolerance to drought stress and UV-B radiation. PnFNSI also increased the enzyme activities and gene transcription levels of reactive oxygen species (ROS) scavengers, protecting plants against oxidative stress. Moreover, overexpression of PnFNSI enhanced the flavone biosynthesis pathway in Arabidopsis. Therefore, this moss FNSI-type enzyme participates in flavone metabolism, conferring protection against drought stress and UV-B radiation.

Protective effects of maternal administration of curcumin and hesperidin in the rat offspring following repeated febrile seizure: Role of inflammation and TLR4

Neuroinflammation has a key role in seizure generation and perpetuation in the neonatal period, and toll-like receptor 4 (TLR4) pathway has a prominent role in neuroinflammatory diseases. Administration of antioxidants and targeting TLR4 in the embryonic period may protect rat offspring against the next incidence of febrile seizure and its harmful effects. Curcumin and hesperidin are natural compounds with anti-inflammatory and antioxidant properties and have an inhibitory action on TLR4 receptors. We evaluated the effect of maternal administration of curcumin and hesperidin on infantile febrile seizure and subsequent memory dysfunction in adulthood. Hyperthermia febrile seizure was induced on postnatal days 9-11 on male rat pups with 24 h intervals, in a Plexiglas box that was heated to ~45 °C by a heat lamp. We used enzyme-linked immunosorbent assay, Western blotting, malondialdehyde (MDA), and glutathione (GSH) assessment for evaluation of inflammatory cytokine levels, TLR4 protein expression, and oxidative responses in the hippocampal tissues. For assessing working memory and long-term potentiation, the double Y-maze test and Schaffer collateral-CA1 in vivo electrophysiological recording were performed, respectively Our results showed that curcumin and hesperidin decreased TNF-α, IL-10, and TLR4 protein expression and reversed memory dysfunction. However, they did not provoke a significant effect on GSH content or amplitude and slope of recorded fEPSPs in the hippocampus. In addition, curcumin, but not hesperidin, decreased interleukin-1β (IL-1β) and MDA levels. These findings imply that curcumin and hesperidin induced significant protective effects on febrile seizures, possibly via their anti-inflammatory and antioxidant properties and downregulation of TLR4.

Recent advances in extracting phenolic compounds from food and their use in disease prevention and as cosmetics

Phenolic compounds in plants are essential components of human nutrition, which provide various health benefits. However, some missing links became the research in phenolic compounds structures and potential applications in a challenging work. Despite universal extraction methods with mixtures of different organic solvents are generally adopted in the analysis of phenolic compounds, a need for establish a specific procedure is still open. The great heterogeneity in food and food by-products matrices and the lack of standardized methods which combine chromatographic with spectrophotometric techniques to calculate the amount of phenolic compounds joined with the absence of specific standards hamper to accurate know the real amount of phenolic compounds. Indeed, the high complexity in nature and chemistry of phenolic compounds clearly difficult to establish a daily intake to obtain certain healthy outcomes. Hence, despite the potential of phenolic compounds to use them in cosmetic and healthy applications have been widely analyzed, some concerns must be considered. The chemical complexity, the interactions between phenolic compounds and other food components and the structural changes induced by food processing joined with the lack in the understanding of phenolic compounds metabolism and bioavailability undergo the need to conduct a comprehensive review of each factors influencing the final activity of phenolic compounds. This paper summarizes the potential of phenolic compounds for disease prevention and cosmetics production, as well as their many other uses derived from their antioxidant activity. This paper illustrates the potential of phenolic compounds for disease prevention and cosmetics production, as well as their many other uses derived from their antioxidant activity.

Therapeutic effects of extracellular vesicles from human adipose-derived mesenchymal stem cells on chronic experimental autoimmune encephalomyelitis

Since in cell therapy, there are always concerns about immune rejection, genetic disability, and malignancies, special attention has been paid to extracellular vesicles (EVs) which are secreted by mesenchymal stem cells (MSCs). In the present study, we assessed and compared the therapeutic effects of human adipose-derived mesenchymal stem cells (hADSC) and hADSC-EVs from adipose tissue on experimental autoimmune encephalomyelitis (EAE). After induction of EAE in C57Bl/6 mice, they were treated with hADSCs, hADSC-EVs, or vehicle intravenously. The clinical score of all mice was recorded every other day. Mice were killed at Day 30 and splenocytes were isolated for proliferation assay and determination of the frequency of Treg cells by flow cytometry. Leukocyte infiltration by hematoxylin and eosin, percentages of demyelination areas by luxol fast blue, and mean fluorescence intensity of oligodendrocyte transcription factor 2 (OLIG2) and myelin basic protein (MBP) by immunohistochemistry were assessed in the spinal cord. Our results showed that the maximum mean clinical score and myelin oligodendrocyte glycoprotein-induced proliferation of splenocytes in hADSC- and hADSC-EV-treated mice were significantly lower than the control mice (p < .05). We also demonstrated that the frequency of CD4⁺ CD25⁺ Foxp3⁺ cells was significantly higher in the spleen of hADSC-treated mice than EAE control mice (p = .023). The inflammation score and the percentages of demyelination areas in hADSC- and hADSC-EV-treated groups significantly declined compared with the untreated control group (p < .05). We also showed that there was no significant difference in MFI of MBP and OLIG2 in the spinal cord of studied groups. Overall, we suggest that intravenous administration of hADSC-EVs attenuates the induced EAE through diminishing proliferative potency of T cells, mean clinical score, leukocyte infiltration, and demyelination in a chronic model of multiple sclerosis.

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.

A modified flavonoid accelerates oligodendrocyte maturation and functional remyelination

Myelination delay and remyelination failure following insults to the central nervous system (CNS) impede axonal conduction and lead to motor, sensory and cognitive impairments. Both myelination and remyelination are often inhibited or delayed due to the failure of oligodendrocyte progenitor cells (OPCs) to mature into myelinating oligodendrocytes (OLs). Digestion products of the glycosaminoglycan hyaluronan (HA) have been implicated in blocking OPC maturation, but how these digestion products are generated is unclear. We tested the possibility that hyaluronidase activity is directly linked to the inhibition of OPC maturation by developing a novel modified flavonoid that functions as a hyaluronidase inhibitor. This compound, called S3, blocks some but not all hyaluronidases and only inhibits matrix metalloproteinase activity at high concentrations. We find that S3 reverses HA-mediated inhibition of OPC maturation in vitro, an effect that can be overcome by excess recombinant hyaluronidase. Furthermore, we find that hyaluronidase inhibition by S3 accelerates OPC maturation in an in vitro model of perinatal white matter injury. Finally, blocking hyaluronidase activity with S3 promotes functional remyelination in mice with lysolecithin-induced demyelinating corpus callosum lesions. All together, these findings support the notion that hyaluronidase activity originating from OPCs in CNS lesions is sufficient to prevent OPC maturation, which delays myelination or blocks remyelination. These data also indicate that modified flavonoids can act as selective inhibitors of hyaluronidase activity and can promote OPC maturation, making them excellent candidates to accelerate myelination or promote remyelination following perinatal and adult CNS insults.

Prevention and treatment of experimental autoimmune encephalomyelitis induced mice with 1, 25-dihydroxyvitamin D3

Multiple sclerosis (MS) is a complex inflammatory and demyelinating disease of the central nervous system (CNS) frequently starts in young adulthood. Demyelination, inflammatory and axonal damage in the CNS is the pathological hallmark of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. 1, 25-dihydroxyvitamin D₃ (Vitamin D₃) is involved in calcium regulation, phosphorus homeostasis, and bone mineralization. In addition, vitamin D₃ has potential inhibitory effects on immune cells in various inflammatory and autoimmunity disease. C57BL/6 female mice were divided into prevention groups (low, middle and high doses) and treatment groups (middle and high doses). Prevention groups received vitamin D₃ 2 weeks before EAE induction, and treatment groups were treated with vitamin D₃ simultaneous with EAE induction. Vitamin D₃ inhibits the development of EAE in a dose-dependent manner. Histological studies revealed reduced demyelination and limited infiltration into CNS, moreover vitamin D₃ increased the production of IL-4, IL-10, and TGF-β, while a significant reduction in the production of IFN-γ, IL-6, TNF-α, and IL-17 was observed. Flow cytometry results for CD4⁺ T cell subsets in compliance with ELISA cytokine assay results showed a significant decrease in the percentage of Th1 and Th17, but also a significant increase in the percentage of Th2 and Treg for middle and high dose vitamin D₃ treated mice. Real-time PCR results indicated that middle and high dose vitamin D₃ treatment reduced T-bet and ROR-γt expression, but enhanced GATA3 and Foxp3 expression. Real-Time PCR results in CNS for T cell subsets related cytokines and transcription factors supported the results of flow cytometry and ELISA. This study indicated that middle and high doses of vitamin D3 deviate the balance between Th1/Th2 and Th17/Treg to Th2 and Treg. Moreover, vitamin D3 could reduce the incidence and severity of EAE clinical disease.

An unmet clinical need: roads to remyelination in MS

Background

In the central nervous system (CNS) myelin sheaths stabilize, protect, and electrically insulate axons. However, in demyelinating autoimmune CNS diseases such as multiple sclerosis (MS) these sheaths are destroyed which ultimately leads to neurodegeneration. The currently available immunomodulatory drugs for MS effectively control the (auto)inflammatory facets of the disease but are unable to regenerate myelin by stimulating remyelination via oligodendroglial precursor cells (OPCs). Accordingly, there is broad consensus that the implementation of new regenerative approaches constitutes the prime goal for future MS pharmacotherapy.

Main text

Of note, recent years have seen several promising clinical studies investigating the potential of substances and monoclonal antibodies such as, for instance, clemastine, opicinumab, biotin, simvastatin, quetiapin and anti-GNbAC1. However, beyond these agents which have often been re-purposed from other medical indications there is a multitude of further molecules influencing OPC homeostasis. Here, we therefore discuss these possibly beneficial regulators of OPC differentiation and assess their potential as new pharmacological targets for myelin repair in MS.

Conclusion

Remyelination remains the most important therapeutic treatment goal in MS in order to improve clinical deficits and to avert neurodegeneration. The promising molecules presented in this review have the potential to promote remyelination and therefore warrant further translational and clinical research.

Hesperidin as a Neuroprotective Agent: A Review of Animal and Clinical Evidence

Neuroprotection is the preservation of function and networks of neural tissues from damages caused by various agents, as well as neurodegenerative diseases such as Parkinson's, Alzheimer's, Huntington's diseases, and multiple sclerosis. Hesperidin, a flavanone glycoside, is a natural phenolic compound with a wide range of biological effects. Mounting evidence has demonstrated that hesperidin possesses inhibitory effect against development of neurodegenerative diseases. Our review discusses neuropharmacological mechanisms for preventive and therapeutic effects of hesperidin in neurodegenerative diseases. In addition, the review examines clinical evidence confirming its neuroprotective function. Various cellular and animal models specific to neurodegenerative diseases have been conducted to evaluate the underlying neuropharmacological mechanisms of hesperidin. Neuroprotective potential of this flavonoid is mediated by improvement of neural growth factors and endogenous antioxidant defense functions, diminishing neuro-inflammatory and apoptotic pathways. Despite the various preclinical studies on the role of hesperidin in the neurodegenerative diseases, less is known about its definite effect on humans. A limited number of clinical trials showed that hesperidin-enriched dietary supplements can significantly improve cerebral blood flow, cognition, and memory performance. Further clinical trials are also required for confirming neuroprotective efficacy of this natural flavonoid and evaluating its safety profile.

Hesperidin inhibits keratinocyte proliferation and imiquimod-induced psoriasis-like dermatitis via the IRS-1/ERK1/2 pathway

AIMS

To evaluate the therapeutic benefits of Hesperidin (Hes) using an imiquimod (IMQ)-induced psoriasis-like mouse model and human immortalized keratinocytes (HaCaT) cells stimulated with lipopolysaccharide (LPS).

METHODS

Mice were treated with IMQ and orally administered Hes (125-500 mg/kg/day), methotrexate (MTX) 1 mg/kg/day or distilled water. HaCaT cells were stimulated with LPS (1 μg/mL) and relevant indices were measured after administration with different concentrations of Hes (5-20 μg/mL) for 24 h. Inflammatory skin lesions in IMQ mice were evaluated using the psoriasis area severity index (PASI) and pathological staining. Proteins in the IRS-1/ERK1/2 pathway and inflammatory factors were assessed using western blotting or quantitative real-time PCR. In addition, factors related to IRS-1 secretion levels were assessed by enzyme-linked immunosorbent assays. Extracellular flux (XF) analysis was used to assess cellular metabolic levels.

KEY FINDINGS

Hes significantly improved psoriasis-like skin lesions of IMQ-treated mice and inhibited LPS-induced HaCaT cell proliferation. In addition, Hes remarkably decreased PASI scores, reduced epidermal thickness, decreased proliferation and differentiation of epidermal cells, inhibited mRNA expression of inflammatory factors, reduced local skin lesions and serum insulin and glucose levels. Furthermore, Hes modulated the secretion levels of serum Leptin, Adiponectin and Resistin, and inhibited the activation of the IRS-1/ERK1/2 signaling pathway and regulated HaCaT cells metabolism.

SIGNIFICANCE

This study demonstrated that Hes administration could have significant therapeutic value for the prevention and clinical treatment of psoriasis.

Beneficial effects of Thymus vulgaris extract in experimental autoimmune encephalomyelitis: Clinical, histological and cytokine alterations

The imbalance between pro and anti-inflammatory cytokines plays an important role in the pathogenesis of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Thymus vulgaris (thyme) as a traditional medicinal plant has been reported to exert antimicrobial, antioxidant, and anti-inflammatory effects. Therefore, this study evaluated the modulatory effects of Thymus vulgaris on the clinical symptoms, histopathological scores, and the production of some anti-inflammatory (TGF-β, IL-4, and IL-10) and pro-inflammatory (IFN-γ, IL-6 and IL-17) cytokines in EAE model. EAE was induced by MOG35-55 peptide and mice were treated intra-peritoneally (i.p) with phosphate buffered saline (PBS) in the control group or thyme extract (50 or 100 mg/kg of body weight, every other day) in thyme-treated EAE groups, from day 0 to +21 of post MOG immunization. Mice were sacrificed at day 22, and splenocytes were isolated and re-stimulated in vitro with MOG in order to measure the cytokine production and proliferation of re-stimulated cells by enzyme linked immunosorbent assay (ELISA) method and WST-1 reagent, respectively. The clinical symptoms and histopathological scores of the CNS were lower in thyme-treated than EAE control group. Furthermore, the production of IFN-γ and IL-6 by splenocytes was lower in thyme-treated EAE than in the control group. The production of IL-10 and TGF-β increased in mice treated with thyme extract compared to the control group. In this study, we showed for the first time that the immunomodulatory effects of Thymus vulgaris in EAE model. Thus, the possible therapeutic potential of thyme for treatment of MS could be considered in future research.

The Role of Diet in Multiple Sclerosis: Mechanistic Connections and Current Evidence

PURPOSE OF REVIEW

This review seeks to examine current research related to the role of diet in multiple sclerosis (MS).

RECENT FINDINGS

Recent research in preclinical models, epidemiologic studies, and limited prospectively followed cohorts provide preliminary evidence that dietary factors influence MS incidence, disease course, and symptomatology. Current evidence for the effects of fatty acids, fruits and vegetables, whole grains, dairy, and salt are reviewed. Dietary patterns including overall diet quality, caloric restriction, McDougall diet, Paleolithic diet, and Mediterranean diet are discussed. Hypotheses regarding potential mechanistic connections underlying observed effects are also presented. Several individual dietary components and patterns demonstrate potential for significant impact in MS. Definitive answers regarding the ability of diet to act as a disease modifier in MS will ultimately require large-scale clinical trials. Continued prospective studies and clinical trials to further advance this line of research are warranted.

Hesperetin reduces myelin damage and ameliorates glial activation in lysolecithin-induced focal demyelination model of rat optic chiasm

Visual impairment is considered as the most common initial manifestation of multiple sclerosis (MS) patients. It has been shown that hesperetin (Hst), a flavonoid of citrus fruit, possesses anti-inflammatory and antioxidant effects both in vitro and in vivo. The present study was designed to evaluate the pharmacological/medicinal effects of Hst treatment on myelin repair and glial activation in lysolecithin (LPC)-induced focal demyelination model. In order to induce local demyelination model, LPC 1% (2 μL) was injected into the optic chiasm of rats. Animals received oral administration of Hst at dose of 20 mg/kg for 14 or 21 days post lesion induction. Visual evoked potential (VEP) recordings were conducted before and also on days 7, 14 and 21 post LPC injection. Glial activation and myelination of optic chiasm were evaluated by immunostaining on brain sections. Analysis of VEPs data revealed that oral administration of Hst effectively reduced the latency of N1 waves. Immunostaining results showed the reduced number of astrocytes and microglia in animal which were treated with Hst. Furthermore, the extent of demyelination area was decreased in animals treated by Hst. Taken together; our results suggest that Hst treatment significantly protects and repairs myelin sheath, therefore it might be regarded as effective supplementary agent in demyelinating disorders, particularly MS.

Bifidobacterium animalis in combination with human origin of Lactobacillus plantarum ameliorate neuroinflammation in experimental model of multiple sclerosis by altering CD4+ T cell subset balance

BACKGROUND

Multiple Sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system (CNS). Recent reports have shown that probiotics can induce immunomodulatory activity with promising effects in inflammatory diseases. This study was designed to reveal the molecular and cellular mechanisms underlying the effect of Lactobacillus plantarum A7, which comprises human commensal bacteria, and Bifidobacterium animalis, a potential probiotic strain, on alleviation of experimental autoimmune encephalomyelitis (EAE), an animal model of MS.

METHODS

To evaluate the therapeutic effects of probiotic strains, female C57BL/6 mice (8-10 wks old) received Lactobacillus plantarum A7, Bifidobacterium animalis PTCC 1631or a mixture of both strains through oral administration daily for 22days beginning simultaneous with induction of EAE. The clinical parameters were recorded daily. On Day 22, each mouse was bled, and their spinal cord was removed for histology analysis. The effects of the treatments on regulatory T (Treg) cells level were evaluated using flow cytometry, and T-cell proliferation was assessed using a BrdU incorporation assay. The supernatants of spleen and lymph nodes cultured and mononuclear cells were collected for quantification of different panel of pro and anti-inflammatory cytokines by ELISA. The analysis of gene expression was performed at RNA level for transcription factors by real-time PCR.

RESULTS

The results showed that treatment with a mixture of the two strains caused a more significant delay in the time of disease onset and clinical score compared to when the strains were used alone. The pathological features of the disease, such as mononuclear infiltration into the CNS, were also inhibited more significantly by the combinational approach. The results also revealed that treatment with combination of both strains enhanced the population of CD4⁺CD25⁺Foxp3⁺-expressing T-cells in the lymph nodes and the spleen.

TREATMENT

with our probiotic strains markedly inhibited disease associated cytokines while increased anti-inflammatory cytokines. Additionally, L. plantarumA7 and B. animalis ameliorated EAE condition by favoring Th2 and Treg differentiation via up-regulation of Foxp3 and GATA3 in the brain and spleen as well as inhibited the differentiation of Th1 and Th17 cells.

CONCLUSIONS

The current research provided evidence that probiotic therapy with L. plantarum and B. animalis can effectively attenuate EAE progression as well as reinforce the polarization of regulatory T-cells.