Study of curcumin immunomodulatory effects on reactive astrocyte cell function

An overview of the efficacy of inhaled curcumin: a new mode of administration for an old molecule

INTRODUCTION

Curcumin is a polyphenol with a variety of pharmacological actions. Despite its therapeutic effects and well-known safety profile, the utility of curcumin has been limited due to its deprived physical, chemical, and pharmacokinetic profile resulting from limited solubility, durability, prompt deterioration and pitiable systemic availability. Employment of an amalgamated framework integrating the potential advantages of a nanoscaffold alongside the beneficial traits of inhalational drug delivery system beautifully bringing down the restricting attributes of intended curative interventions and further assures its clinical success.

AREAS COVERED

Current review discussed different application of inhalable nanocurcumin in different medical conditions. Lung diseases have been the prime field in which inhalable nanocurcumin had resulted in significant beneficial effects. Apart from this several lung protective potentials of the inhaled nanocurcumin have been discussed against severe pulmonary disorders such as pulmonary fibrosis, radiation pneumonitis and IUGR induced bronchopulmonary dysplasia. Also, application of the disclosed intervention in the clinical management of COVID-19 and Alzheimer's Disease has been discussed.

EXPERT OPINION

In this portion, the potential of inhalable nanocurcumin in addressing various medical conditions along with ongoing advancements in nanoencapsulation techniques and the existing challenges in transitioning from pre-clinical models to clinical practice has been summarized.

Curcumin and targeting of molecular and metabolic pathways in multiple sclerosis

Multiple sclerosis (MS) is a life-threading disease that poses a great threat to the human being lifestyle. Having said extensive research in the realm of underlying mechanisms and treatment procedures, no definite remedy has been found. Over the past decades, many medicines have been disclosed to alleviate the symptoms and marking of MS. Meanwhile, the substantial efficacy of herbal medicines including curcumin must be underscored. Accumulated documents demonstrated the fundamental role of curcumin in the induction of the various signaling pathways. According to evidence, curcumin can play a role in mitochondrial dysfunction and apoptosis, autophagy, and mitophagy. Also, by targeting the signaling pathways AMPK, PGC-1α/PPARγ, and PI3K/Akt/mTOR, curcumin interferes with the metabolism of MS. The anti-inflammatory, antioxidant, and immune regulatory effects of this herbal compound are involved in its effectiveness against MS. Thus, the present review indicates the molecular and metabolic pathways associated with curcumin's various pharmacological actions on MS, as well as setting into context the many investigations that have noted curcumin-mediated regulatory effects in MS.

Curcumin and chemokines: mechanism of action and therapeutic potential in inflammatory diseases

Chemokines belong to the family of cytokines with chemoattractant properties that regulate chemotaxis and leukocyte migration, as well as the induction of angiogenesis and maintenance of hemostasis. Curcumin, the major component of the Curcuma longa rhizome, has various pharmacological actions, including anti-inflammatory, immune-regulatory, anti-oxidative, and lipid-modifying properties. Chemokines and chemokine receptors are influenced/modulated by curcumin. Thus, the current review focuses on the molecular mechanisms associated with curcumin's effects on chemoattractant cytokines, as well as putting into context the many studies that have reported curcumin-mediated regulatory effects on inflammatory conditions in the organs/systems of the body (e.g., the central nervous system, liver, and cardiovascular system). Curcumin's effects on viral and bacterial infections, cancer, and adverse pregnancy outcomes are also reviewed.

Antioxidant and Anti-Inflammatory Effects of Carotenoids in Mood Disorders: An Overview

Depression has a multifactorial etiology comprising family history and unemployment. This review aims to summarize the evidence available for the antioxidant and anti-inflammatory effects of carotenoids in mood disorders. This review article’s methodologies were based on a search of the PubMed database for all linked published papers. Epidemiological studies indicate that a diet rich in vegetables, fruits, nuts, fish, and olive oil may prevent the development of depression. Antioxidant supplementation has been found to combat various stress-induced psychiatric disorders, including depression and anxiety. A growing body of evidence indicates that carotenoids have both antioxidant and anti-inflammatory. Studies also suggest that poor dietary intake, particularly low intakes of fruit and vegetables and high intakes of fast food and other convenience foods, may increase the risk of developing depression. Thus, dietary interventions have the potential to help mitigate the risk of mental health decline in both the general population and those with mood disorders. Considering that carotenoids have both antioxidant and anti-inflammatory effects, it is expected that they might exert a promising antidepressant effect. Nevertheless, further studies (including interventional and mechanistic studies) assessing the effect of carotenoids on preventing and alleviating depression symptoms are needed.

Multiple mechanisms of curcumin targeting spinal cord injury

Spinal cord injury (SCI) is an irreversible disease process with a high disability and mortality rate. After primary spinal cord injury, the secondary injury may occur in sequence, which is composed of ischemia and hypoxia, excitotoxicity, calcium overload, oxidative stress and inflammation, resulting in massive death of parenchymal cells in the injured area, followed by the formation of syringomyelia. Effectively curbing the process of secondary injury can promote nerve repair and improve functional prognosis. As the main active ingredient in turmeric, curcumin can play an important role in reducing inflammation and oxidation, protecting the neurons, and ultimately reducing spinal cord injury. This article reviews the effects of curcumin on the repair of nerve injury, with emphasis on the various mechanisms by which curcumin promotes the treatment of spinal cord injury.

Unfavorable left ventricular remodeling due to experience of chronic sleep restriction after myocardial infarction: The role of matrix metalloproteinases & oxidative stress

Disturbed sleep or sleep loss due to vocational or lifestyle changes following MI is a common problem that may affect many physiological processes involved in left ventricle (LV) remodeling. Herein, we proposed that experience of sleep disruption and/or restriction after myocardial infarction (MI) may aggravate cardiac extracellular matrix remodeling and induce apoptosis in the cardiomyocytes. MI was induced in adult male rats by permanent ligation of the left anterior descending coronary artery. Twenty-four hours after surgery, some animals experienced chronic sleep restriction (CSR) for 6 days. Serum levels of CK-MB, PAB, and TNF-α were evaluated at days 1, 8, and 21 postsurgery. Twenty-one days after surgery, hemodynamic parameters and expression of MMP-2, MMP-9, TIMP-1, and TNF-α, as well as myocardial fibrosis and apoptosis in the noninfarcted area of the LV were assessed. Our results showed a clear decrease in serum concentrations of CK-MB, PAB and TNF-α at day 21 postsurgery in the MI group as compared to MI+SR animals in which these markers remained at high levels. CSR following MI deteriorated LV hemodynamic indexes and also impaired the balance between MMPs and TIMP-1. Further, it yielded an increase in oxidant and inflammatory state which caused deleterious fibrotic and apoptotic effects on cardiomycytes. Our data suggest post-MI sleep loss may cause adverse LV remodeling due to increased inflammatory reactions as well as oxidative burden and/or anti-oxidative insufficiency that in turn impede the balance between MMPs and their inhibitors.

Recent Progress in Research on Mechanisms of Action of Natural Products against Alzheimer's Disease: Dietary Plant Polyphenols

Alzheimer's disease (AD) is an incurable degenerative disease of the central nervous system and the most common type of dementia in the elderly. Despite years of extensive research efforts, our understanding of the etiology and pathogenesis of AD is still highly limited. Nevertheless, several hypotheses related to risk factors for AD have been proposed. Moreover, plant-derived dietary polyphenols were also shown to exert protective effects against neurodegenerative diseases such as AD. In this review, we summarize the regulatory effects of the most well-known plant-derived dietary polyphenols on several AD-related molecular mechanisms, such as amelioration of oxidative stress injury, inhibition of aberrant glial cell activation to alleviate neuroinflammation, inhibition of the generation and promotion of the clearance of toxic amyloid-β (Aβ) plaques, inhibition of cholinesterase enzyme activity, and increase in acetylcholine levels in the brain. We also discuss the issue of bioavailability and the potential for improvement in this regard. This review is expected to encourage further research on the role of natural dietary plant polyphenols in the treatment of AD.

Medicinal herbs and multiple sclerosis: Overview on the hard balance between new therapeutic strategy and occupational health risk

Multiple sclerosis (MS) is an autoimmune disease characterized by demyelination and axonal loss of the central nervous system (CNS). Despite its spread throughout the world, the mechanisms that determine its onset are still to be defined. Immunological, genetic, viral, and environmental factors and exposure to chemicals may trigger MS. Many studies have highlighted the anti-inflammatory and anti-oxidant effects of medicinal herbs, which make them a natural and complementary treatment for neurodegenerative diseases. A severe reduction of several MS symptoms occurs with herbal therapy. Thus, the request for medicinal plants with potential beneficial effects, for MS patients, is constantly increasing. Consequently, a production increase needs. Unfortunately, many medicinal herbs were untested and their action mechanism, possible adverse effects, contraindications, or interactions with other drugs, are poorly or not investigated. Keeping in mind the pathological mechanisms of MS and the oxidative damages and mitochondrial dysfunctions induced by pesticides, it is important to understand if pesticides used to increase agricultural productivity and their residues in medicinal plants, may increase the risk of developing MS in both workers and consumers. Studies providing some indication about the relationship between environmental exposure to pesticides and MS disease incidence are few, fragmentary, and discordant. The aim of this article is to provide a glance at the therapeutic potential of medicinal plants and at the risk for MS onset of pesticides used by medicinal plant growers and present in medicinal herbs.

Ameliorating potential of curcumin and its analogue in central nervous system disorders and related conditions: A review of molecular pathways

Curcumin, isolated from turmeric (Curcuma longa L.) is one of the broadly studied phytomolecule owing to its strong antioxidant and anti-inflammatory potential and has been considered a promising therapeutic candidate in a wide range of disorders. Considering, its low bioavailability, different curcumin analogs have been developed to afford desired pharmacokinetic profile and therapeutic outcome in varied pathological states. Several preclinical and clinical studies have indicated that curcumin ameliorates mitochondrial dysfunction, inflammation, oxidative stress apoptosis-mediated neural cell degeneration and could effectively be utilized in the treatment of different neurodegenerative diseases. Hence, in this review, we have summarized key findings of experimental and clinical studies conducted on curcumin and its analogues with special emphasis on molecular pathways, viz. NF-kB, Nrf2-ARE, glial activation, apoptosis, angiogenesis, SOCS/JAK/STAT, PI3K/Akt, ERK1/2 /MyD88 /p38 MAPK, JNK, iNOS/NO, and MMP pathways involved in imparting ameliorative effects in the therapy of neurodegenerative disorders and associated conditions.

The effects of nano-curcumin supplementation on adipokines levels in obese and overweight patients with migraine: a double blind clinical trial study

Objective

The present study aimed to investigate the effects of nano-curcumin supplementation on adipokines levels and clinical signs in obese and overweight patients with migraine.

Results

Forty-four patients with episodic migraine participated in this clinical trial and were divided into two groups nano-curcumin (80 mg/day) and the control group over 2-month period. At the baseline and the end of the research, the serum levels of MCP-1, Resistin, and Visfatin were measured using the ELISA method. In addition, the headache attack frequencies, severity, and duration of pain were recorded. The results of the present study showed that nano-curcumin can significantly reduce MCP-1 serum levels in the nano-curcumin supplemented group (P = 0.015, size effect = 13.4%). In the case of resistin and visfatin, nano-curcumin supplementation exerted no statistically significant changes in serum levels (P > 0.05). Nano-curcumin also significantly reduced the attack frequencies, severity, and duration of headaches (P < 0.05). These findings indicate that targeting curcumin can be a promising approach to migraine management. However, further comprehensive human trials are needed to confirm these findings.

Trial Registration

This study was registered in the Iranian Registry of Clinical Trials (IRCT) with ID number: IRCT20160626028637N2 on the date 2020-07-10.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-06074-4.

Immunomodulatory effects of curcumin in systemic autoimmune diseases

Systemic autoimmune diseases like rheumatoid arthritis, multiple sclerosis, and systemic lupus erythematosus represent various autoimmune conditions identified by immune system dysregulation. The activation of immune cells, auto-antigen outbreak, inflammation, and multi-organ impairment is observed in these disorders. The immune system is an essential complex network of cells and chemical mediators which defends the organism's integrity against foreign microorganisms, and its precise operation and stability are compulsory to avoid a wide range of medical complications. Curcumin is a phenolic ingredient extracted from turmeric and belongs to the Zingiberaceae, or ginger family. Curcumin has multiple functions, such as inhibiting inflammation, oxidative stress, tumor cell proliferation, cell death, and infection. Nevertheless, the immunomodulatory influence of curcumin on immunological reactions/processes remains mostly unknown. In the present narrative review, we sought to provide current information concerning the preclinical and clinical uses of curcumin in systemic autoimmune diseases.

New Promising Therapeutic Avenues of Curcumin in Brain Diseases

Curcumin, the dietary polyphenol isolated from Curcuma longa (turmeric), is commonly used as an herb and spice worldwide. Because of its bio-pharmacological effects curcumin is also called "spice of life", in fact it is recognized that curcumin possesses important proprieties such as anti-oxidant, anti-inflammatory, anti-microbial, antiproliferative, anti-tumoral, and anti-aging. Neurodegenerative diseases such as Alzheimer's Diseases, Parkinson's Diseases, and Multiple Sclerosis are a group of diseases characterized by a progressive loss of brain structure and function due to neuronal death; at present there is no effective treatment to cure these diseases. The protective effect of curcumin against some neurodegenerative diseases has been proven by in vivo and in vitro studies. The current review highlights the latest findings on the neuroprotective effects of curcumin, its bioavailability, its mechanism of action and its possible application for the prevention or treatment of neurodegenerative disorders.

Mechanistic insight into immunomodulatory effects of food-functioned plant secondary metabolites

Medicinally important plant-foods offer a balanced immune function, which is essential for protecting the body against antigenic invasion, mainly by microorganisms. Immunomodulators play pivotal roles in supporting immune function either suppressing or stimulating the immune system's response to invading pathogens. Among different immunomodulators, plant-based secondary metabolites have emerged as high potential not only for immune defense but also for cellular immunoresponsiveness. These natural immunomodulators can be developed into safer alternatives to the clinically used immunosuppressants and immunostimulant cytotoxic drugs which possess serious side effects. Many plants of different species have been reported to possess strong immunomodulating properties. The immunomodulatory effects of plant extracts and their bioactive metabolites have been suggested due to their diverse mechanisms of modulation of the complex immune system and their multifarious molecular targets. Phytochemicals such as alkaloids, flavonoids, terpenoids, carbohydrates and polyphenols have been reported as responsible for the immunomodulatory effects of several medicinal plants. This review illustrates the potent immunomodulatory effects of 65 plant secondary metabolites, including dietary compounds and their underlying mechanisms of action on cellular and humoral immune functions in in vitro and in vivo studies. The clinical potential of some of the compounds to be used for various immune-related disorders is highlighted.

The Role of Nutritional Lifestyle and Physical Activity in Multiple Sclerosis Pathogenesis and Management: A Narrative Review

Studies on the role of nutritional factors and physical activity (PA) in the pathogenesis of multiple sclerosis (MS) go back a long time. Despite the intrinsic difficulty of studying their positive or negative role in MS, the interest of researchers on these topics increased during the last few decades, since the role of diet has been investigated with the perspective of the association with disease-modifying drugs (DMD). The association of DMD, diets, and PA might have an additive effect in modifying disease severity. Among the various diets investigated (low-carbohydrate, gluten-free, Mediterranean, low-fat, fasting-mimicking, and Western diets) only low-carbohydrate, Mediterranean, and fast-mimicking diets have shown both in animal models and in humans a positive effect on MS course and in patient-reported outcomes (PROs). However, the Mediterranean diet is easier to be maintained compared to fast-mimicking and low-carbohydrate diets, which may lead to detrimental side effects requiring careful clinical monitoring. Conversely, the Western diet, which is characterized by a high intake of highly saturated fats and carbohydrates, may lead to the activation of pro-inflammatory immune pathways and is therefore not recommended. PA showed a positive effect both in animal models as well as on disease course and PROs in humans. Training with combined exercises is considered the more effective approach.

ProspeCtive study to evaluate efficacy, safety and tOlerability of dietary supplemeNT of Curcumin (BCM95) in subjects with Active relapsing MultIple Sclerosis treated with subcutaNeous Interferon beta 1a 44 mcg TIW (CONTAIN): A randomized, controlled trial

BACKGROUND

multiple sclerosis (MS) is a complex disease sustained by several pathogenic mechanisms. As such, combination therapy strategies, targeting a range of disease mechanisms, might represent the ideal therapeutic approach. Here we investigated the efficacy of curcumin, a naturally occurring poly-phenolic phytochemical with potent anti-inflammatory and antioxidant properties, in subjects under treatment with IFN β-1a, to test the effects of this combination therapy on clinical and MRI parameters of inflammation and neurodegeneration in relapsing MS (RMS).

METHODS

eighty active RMS were prospectively enrolled, randomized (1:1) to either the IFN-curcumin or the IFN-placebo group and followed up longitudinally with clinical and MRI assessments for 24 months. Primary endpoint was the efficacy of curcumin versus placebo as add-on therapy on new/enlarging T2 lesions in RMS subjects under treatment with subcutaneous IFN β-1a 44 mcg TIW. Efficacy on clinical parameters (relapses and disability progression), other MRI parameters of inflammation (T1 Gd-enhancing lesions, combined unique active-CUA lesions) and neurodegeneration (T1-hypointense lesions, grey matter loss and white matter microstructural damage) as well as safety and tolerability of curcumin were explored as secondary endpoints.

RESULTS

ten subjects dropped out from the study by month 12 (6 in the IFN-curcumin group and 4 in the IFN-placebo group), and 27 by month 24 (11 in the IFN-curcumin group and 16 in the IFN-placebo group). Although no between-group difference was present in terms of proportion of subjects free from new/enlarging T2 lesions, a lower proportion of patients with CUA lesions was noted at month 12 in the IFN-curcumin group in comparison with the IFN-placebo group (7.5% vs 17.5%, χ² test p= 0.0167). This result was not confirmed at month 24. The statistical analysis failed to reveal any difference between the two treatment groups - IFN-curcumin and IFN-placebo - in terms of relapses, disability progression, other MRI metrics of inflammation and MRI changes suggestive of ongoing neurodegeneration. No difference in the rate and nature of adverse events was observed between the two treatment groups.

CONCLUSION

Although the study drop-out rate was too high to allow definite conclusions, our findings suggest that curcumin might add to IFN β-1a efficacy on radiological signs of inflammation in MS, while it did not seem to exert any neuroprotective effect as assessed by clinical and MRI parameters. (NCT01514370).

Mechanistic Insight into the Effects of Curcumin on Neuroinflammation-Driven Chronic Pain

Chronic pain is a persistent and unremitting condition that has immense effects on patients' quality of life. Studies have shown that neuroinflammation is associated with the induction and progression of chronic pain. The activation of microglia and astrocytes is the major hallmark of spinal neuroinflammation leading to neuronal excitability in the projection neurons. Excessive activation of microglia and astrocytes is one of the major contributing factors to the exacerbation of pain. However, the current chronic pain treatments, mainly by targeting the neuronal cells, remain ineffective and unable to meet the patients' needs. Curcumin, a natural plant product found in the Curcuma genus, improves chronic pain by diminishing the release of inflammatory mediators from the spinal glia. This review details the role of curcumin in microglia and astrocytes both in vitro and in vivo and how it improves pain. We also describe the mechanism of curcumin by highlighting the major glia-mediated cascades in pain. Moreover, the role of curcumin on inflammasome and epigenetic regulation is discussed. Furthermore, we discuss the strategies used to improve the efficacy of curcumin. This review illustrates that curcumin modulating microglia and astrocytes could assure the treatment of chronic pain by suppressing spinal neuroinflammation.

The Protective Effects of Nebulized Nano-Curcumin Against Bleomycin-Induced Pulmonary Fibrosis in Rats

Background: Idiopathic pulmonary fibrosis (IPF) is a progressive fatal disease affecting the lung, and currently there is no efficient therapy for this condition. Curcumin, as a natural anti-inflammatory and antioxidant agent, could repress the pulmonary fibrosis (PF) caused by Bleomycin (BLM). Objectives: The aim of the research was to evaluate the protective activity of a nano-formulation of curcumin administered by inhalation on BLM-induced PF in rats. Methods: Eighty rats were randomly divided into eight experimental groups. Group one (control) that received saline intratracheally (IT) and subjected to vehicle inhalation. Group two to eight each received a single dose of BLM (5 IU/kg, IT) along with vehicle inhalation, oral prednisolone, oral curcumin, curcumin inhalation, and nano-curcumin inhalation with the doses of 50, 100, and 200 µg/kg, respectively. In the control and other groups, BLM was injected intratracheally on the first day of the experiment. In the treatment groups, curcumin suspension was prepared in distilled water and applied through nebulization for 21 consecutive days after BLM intratracheal administration. Then the rats were euthanized, and inflammatory cytokines (TNF-α, TGF-β, PDGF), hydroxyproline, and IL-10 (as a protective cytokine) were measured. Also, lung histopathological features were examined. Results: The synthesized nano-formulation reduced the overall hydroxyproline content of lungs in BLM-treated rats (P < 0.002). In addition, TNF-α, TGF-β, and PDGF levels significantly increased in the lungs of BLM-instilled rats (P < 0.001). However, the nano-formulation of curcumin (200 µg/kg) significantly decreased the levels of these inflammatory cytokines (P < 0.001) and increased IL-10 level (P = 0.0144) compared with the control group. Conclusions: The nebulization of nano-curcumin is suggested as a novel approach for the treatment of PF induced by BLM in rats. Our findings revealed that the inhalation (as a safe local drug delivery system approach) of the nano-curcumin at a dose of 200 µg/kg (formulated by cyclodextrin) could effectively protect the lung against PF.

Molecular effects of curcumin on the experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is an animal model of multiple sclerosis (MS). Previous studies have shown that myelin degradation during MS and EAE resulted in reduced expression of some of the proteins, e.g., the MBP (myelin basic protein), and increased expression of genes such as iNOS (Inducible nitric oxide synthase) and NOGO-A in the affected patients. In the present study, EAE was induced by immunizing Wistar rats (n=12) with homogenized spinal cord of guinea pig and Freund's complete adjuvant. Curcumin is an active ingredient in turmeric with anti-inflammatory properties, which has been studied in this article. In this study, the effect of curcumin administration on the change of the expression of MBP, NOGO-A, and iNOS genes was evaluated using the RT-PCR (Reverse transcription-polymerase chain reaction) technique. The obtained results indicated it could be concluded that curcumin was able to improve EAE by increasing the amount of MBP gene expression and reducing the intensity of NOGO-A expression.

A comprehensive review on the role of chemokines in the pathogenesis of multiple sclerosis

Multiple sclerosis (MS) as a chronic inflammatory disorder of the central nervous system (CNS) is thought to be caused by the abnormal induction of immune responses. Chemokines as molecules that can engage leukocytes into the location of inflammation, actively participate in the pathogenesis of MS. Several members of this family of chemo attractants have been shown to be dysregulated in the peripheral blood, cerebrospinal fluid or CNS lesions of MS patients. Studies in animal models of MS particularly experimental autoimmune encephalomyelitis have indicated the critical roles of chemokines in the pathophysiology of MS. In the current review, we summarize the data regarding the role of CCL2, CCL3, CCL4, CCL11, CCL20, CXCL1, CXCL2, CXCL8, CXCL10, CXCL12 and CXCL13 in the pathogenesis of MS.

Novel Therapeutic Delivery of Nanocurcumin in Central Nervous System Related Disorders

Nutraceuticals represent complementary or alternative beneficial products to the expensive and high-tech therapeutic tools in modern medicine. Nowadays, their medical or health benefits in preventing or treating different types of diseases is widely accepted, due to fewer side effects than synthetic drugs, improved bioavailability and long half-life. Among herbal and natural compounds, curcumin is a very attractive herbal supplement considering its multipurpose properties. The potential effects of curcumin on glia cells and its therapeutic and protective properties in central nervous system (CNS)-related disorders is relevant. However, curcumin is unstable and easily degraded or metabolized into other forms posing limits to its clinical development. This is particularly important in brain pathologies determined blood brain barrier (BBB) obstacle. To enhance the stability and bioavailability of curcumin, many studies focused on the design and development of curcumin nanodelivery systems (nanoparticles, micelles, dendrimers, and diverse nanocarriers). These nanoconstructs can increase curcumin stability, solubility, in vivo uptake, bioactivity and safety. Recently, several studies have reported on a curcumin exosome-based delivery system, showing great therapeutical potential. The present work aims to review the current available data in improving bioactivity of curcumin in treatment or prevention of neurological disorders.

Curcumin Formulations and Trials: What's New in Neurological Diseases

Curcumin’s pharmacological properties and its possible benefits for neurological diseases and dementia have been much debated. In vitro experiments show that curcumin modulates several key physiological pathways of importance for neurology. However, in vivo studies have not always matched expectations. Thus, improved formulations of curcumin are emerging as powerful tools in overcoming the bioavailability and stability limitations of curcumin. New studies in animal models and recent double-blinded, placebo-controlled clinical trials using some of these new formulations are finally beginning to show that curcumin could be used for the treatment of cognitive decline. Ultimately, this work could ease the burden caused by a group of diseases that are becoming a global emergency because of the unprecedented growth in the number of people aged 65 and over worldwide. In this review, we discuss curcumin’s main mechanisms of action and also data from in vivo experiments on the effects of curcumin on cognitive decline.

Effect of dietary supplementation of nanocurcumin on oxidant stability of broiler chicken breast meat infected with Eimeria species

Poultry meat is very susceptible to oxidation because of the high concentration of polyunsaturated fatty acids, which negatively affects the quality and nutritional values of chicken meat. Coccidiosis is the most common parasitic disease of poultry. Intending to limit anti-parasites usage in poultry feed and also because of the concerns about antibiotic resistance and residues in poultry products, there is a need for research to discover natural alternatives. The effect of nanocurcumin on antioxidant profile (carotenoid and vitamin E contents, lipid oxidation and antioxidant capacity) and pH of broiler chicken breast meat infected with Eimeria species was investigated. Fifty, one-day-old male Ross 308 broiler chickens were assigned to five treatments including non-infected and non-medicated control (NNC), infected non-supplemented control (INC), infected and medicated with nanocurcumin 300 mg kg^-1 feed (NCRM1), infected and medicated with nanocurcumin 400 mg kg^-1 feed (NCRM2) and infected and antibiotic medicated group. Infection with Eimeria acervulina, E. maxima, and E. tenella decreased vitamin E and carotenoid contents of chicken breast meat significantly. The NCRM2 had significantly enhanced carotenoid and vitamin E levels in chicken breast meat, so  there was no significant difference between NCRM2 and NNC group. No significant change was observed in pH value among groups. Malondialdehyde value of breast meat was significantly lower in NCRM1 and NCRM2 than the INC group. The NCRM2 and NCRM1 showed the best antioxidant capacity even better than NNC. In conclusion, nanocurcumin could be a potential feed additive that can increase oxidant stability of broiler chicken breast meat.

Effects of curcumin on neurological diseases: focus on astrocytes

Astrocytes are the most abundant glial cells in the central nervous system, and are important players in both brain injury and neurodegenerative disease. Curcumin (1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione), the major active component of turmeric, belongs to the curcuminoid family that was originally isolated from the plant Curcuma longa. Several studies suggest that curcumin may have a beneficial impact on the brain pathology and aging. These effects are due to curcumin's antioxidant, free-radical scavenging, and anti-inflammatory activity. In light of this, our current review aims to discuss the role of astrocytes as essential players in neurodegenerative diseases and suggest that curcumin is capable of direct inhibition of astrocyte activity with a particular focus on its effects in Alexander disease, Alzheimer's disease, ischemia stroke, spinal cord injury, Multiple sclerosis, and Parkinson's disease.

Liposomal Encapsulated Curcumin Effectively Attenuates Neuroinflammatory and Reactive Astrogliosis Reactions in Glia Cells and Organotypic Brain Slices

Introduction

The polyphenolic spice and food coloring ingredient curcumin has beneficial effects in a broad variety of inflammatory diseases. Amongst them, curcumin has been shown to attenuate microglia reaction and prevent from glial scar formation in spinal cord and brain injuries.

Methods

We developed a protocol for the efficient encapsulation of curcumin as a model for anti-inflammatory drugs yielding long-term stable, non-toxic liposomes with favorable physicochemical properties. Subsequently, we evaluate the effects of liposomal curcumin in experimental models for neuroinflammation and reactive astrogliosis.

Results

We could show that liposomal curcumin can efficiently reduce the reactivity of human microglia and astrocytes and preserve tissue integrity of murine organotypic cortex slices.

Discussion and Perspective

In perspective, we want to administer this curcumin formulation in brain implant coatings to prevent neuroinflammation and glial scar formation as foreign body responses of the brain towards implanted materials.

Curcumin and neurological diseases

Objectives: The beneficial effects of many substances have been discovered because of regular dietary consumption. This is also the case with curcumin, whose effects have been known for more than 4,000 years in Eastern countries such as China and India. A curcumin-rich diet has been known to counteract many human diseases, including cancer and diabetes, and has been shown to reduce inflammation. The effect of a curcumin treatment for neurological diseases, such as spinal muscular atrophy; Alzheimer's disease; Parkinson's disease; amyotrophic lateral sclerosis; multiple sclerosis; and others, has only recently been brought to the attention of researchers and the wider population.Methods: In this paper, we summarise the studies on this natural product, from its isolation two centuries ago to its characterisation a century later.Results: We describe its role in the treatment of neurological diseases, including its cellular and common molecular mechanisms, and we report on the clinical trials of curcumin with healthy people and patients.Discussion: Commenting on the different approaches adopted by the efforts made to increase its bioavailability.

Study on the mechanism of curcumin to reduce the inflammatory response of temporal lobe in Alzheimer's disease by regulating miR-146a

BACKGROUND

To explore the potential mechanism of curcumin in the treatment of Alzheimer's disease and clarify the role of miR-146a in the neuroinflammatory response to Alzheimer's disease.

METHODS

Clinical case study: 20 AD patients and 20 age-gender matched non-inflammatory and non-dementia patients in the department of neurology of our hospital were included, peripheral venous blood and cerebrospinal fluid were collected, and mir-146a levels in peripheral blood and cerebrospinal fluid were detected by real-time fluorescence quantitative PCR. Animal experimental study group: There were 3 groups, including APP/PS1 mice control group, APP/PS1 mice low-dose curcumin treatment group, and C57BL/6J mice wild-type (WT) control group, with 10 mice in each group. mir-146a levels in mice brain tissue were detected by quantitative real-time PCR. Aβ, APP, complement factor H (CFH) and M1 microglia labeled IL-1 β and iNOS in temporal lobe tissues of mice were detected by using Westernblot method.

RESULTS

The plasma miRNA-146a level in AD group was 39.10 ±12.97 fmol/L, and that in control group was 60.54 ±13.16 fmol/L. The plasma miRNA-146a level in AD group was significantly lower than that in control group. The level of miRNA-146a in cerebrospinal fluid of AD group (25.16 ± 5.16 fmol/L) was significantly higher than that of control group (11.35 ±3.58 fmol/L). After treatment with low dose curcumin, the level of miRNA-146a in APP/PS1 mice decreased significantly, and the expression of A β and APP/PS1 in temporal lobe of mice detected by Western blot decreased significantly, the levels of IL-1 β and iNOS protein decreased significantly, and the protein of CFH increased signifanctly.

CONCLUSIONS

miRNA-146a can be used as one of the potential biomarkers of AD. Low dose curcumin can significantly reduce the level of neuropro-inflammatory miR-146A, up-regulate the expression of CFH protein, inhibit the phenotype of M1 microglia, and play a role in the treatment of AD by promoting the phagocytosis and clearance mechanism of A β.

Role of curcumin and its nanoformulations in neurotherapeutics: A comprehensive review

Curcumin, a dietary polyphenol and major constituent of Curcuma longa (Zingiberaceae), is extensively used as a spice in Asian countries. For ages, turmeric has been used in traditional medicine systems to treat various diseases, which was possible because of its anti-inflammatory, antioxidant, anticancerous, antiepileptic, antidepressant, immunomodulatory, neuroprotective, antiapoptotic, and antiproliferative effects. Curcumin has potent antioxidant, anti-inflammatory, antiapoptotic, neurotrophic activities, which support its plausible neuroprotective effects in neurodegenerative disease. However, there is limited information available regarding the clinical efficacy of curcumin in neurodegenerative cases. The low oral bioavailability of curcumin may be speculated as a plausible factor that limits its effects in humans. Therefore, utilization of several approaches for the enhancement of bioavailability may improve clinical outcomes. Furthermore, the use of nanotechnology and a targeted drug delivery system may improve the bioavailability of curcumin. The present review is designed to summarize the molecular mechanisms pertaining to the neuroprotective effects of curcumin and its nanoformulations.

Long term multiple sclerosis drug delivery using dendritic polyglycerol flower-like microspheres

The purpose of this study was to produce and characterize the dendritic polyglycerol microspheres (DPGlyM) carrier with potential for use in the treatment of multiple sclerosis (MS). This novel drug delivery system is comprised of DPGlyM as carrier for dimethyl fumarate (DMF) and curcumin (CUR). Molecular docking (MD) was used as in-silico tool to guide the drug entrapment and indicates a spontaneous interactions of DPGlyM with DMF (ΔG° = -11.3 kJ mol^-1) and CUR (ΔG° = -23.8 kJ mol^-1). The DPGlyM morphology and size distribution were determined using a scanning electron microscopy (SEM). The average size of the microspheres was 30-40 μm. The highest encapsulation efficiency and loading efficiency for CUR and DMF were 94.1% and 65.3%, respectively. The zeta potential indicates that CUR and DMF loaded DPGlyM form stable suspension in phosphate buffer solution (PBS) at pH 7.4. Cytotoxicity and hemocompatibility studies suggest that CUR and DMF loaded DPGlyM not influenced cell viability and are well tolerated in hemolysis assays without any damaging effects even at high concentrations up to 50 mg/mL. The in-vitro release of DMF and CUR in phosphate buffer of pH 7.4 followed a kinetics type super case II transport. The activation energy for CUR and DMF release from DPGlyM was found to be 56.95 kJ/mol and 13.87 kJ/mol for CUR and DMF, respectively. The in vitro release assays show that the DPGlyM has good sustained release of CUR and DMF for 5 days. CUR and DMF loaded DPGlyM have shown promising results for a sustained release during enhanced time duration.

Neuroprotective effects of curcumin lipid-core nanocapsules in a model Alzheimer's disease induced by β-amyloid 1-42 peptide in aged female mice

Alzheimer's disease (AD) is a progressive neurodegenerative disease and the most common form of dementia, representing about 60-70% of cases. Curcumin is a natural compound extracted from Curcuma longa Linn, widely used in cooking, presenting several biological activities, including neuroprotection. However, it has low solubility and consequently its bioavailability is limited. In recent years, researchers have focused their attention on delivery systems based on nanotechnology because of their promising potential and advantages over conventional approaches. This study investigated the neuroprotective effects of curcumin loaded lipid-core nanocapsules (LNC) in a model of Alzheimer's disease (AD) induced by intracerebroventricular injections of β-amyloid_1-42 (Aβ_1-42) peptide in aged female mice, and compared these effects with those from free curcumin. Aged female mice received curcumin, free (50 mg/kg, p.o.) or loaded nanocapsules (10 or 1 mg/kg, p.o.) for 14 days after Aβ_1-42 administration. Aβ_1-42 induced significant cognitive deficit (Morris Water Maze test), as well as caused increased the levels of inflammatory cytokines in prefrontal cortex, hippocampus and serum of mice. LNC displayed significant neuroprotection against Aβ_1-42-induced behavioral and neurochemical changes in a model of AD. These results provide insights into the neuroprotective actions of curcumin and its nanoencapsulation as a promising approach for application as an neuroprotective agent in the prevention of AD.

Targeting the balance of T helper cell responses by curcumin in inflammatory and autoimmune states

CD4⁺ T helper (Th) cells are a crucial player in host defense but under certain conditions can contribute to the pathogenesis of inflammatory and autoimmune diseases. Beside the Th1/Th2 subset, several additional Th subsets have been identified, each with a distinctive transcription factor, functional properties, signature cytokine profile, and possible role in the pathophysiology of diseases. These newer Th subsets include Th17, regulatory Th cells (Tregs), and more recently, Th9, Th22, and follicular T helper cells. Interestingly, imbalance of Th subsets contributes to the immunopathology of several disease states. Therefore, targeting the imbalance of Th subsets and their signature cytokine profiles by a safe, effective and inexpensive nutraceutical agent such as curcumin could be helpful to treat autoimmune and inflammatory diseases. In this study different Th subsets and how the imbalance of these subsets could promote pathology of several diseases has been reviewed. Furthermore, the role of curcumin in this process will be discussed and the impact of targeting Th subsets by curcumin.

Clinical safety and efficacy of curcumin use for oral lichen planus: a systematic review

Objective: Oral lichen planus (OLP) is a relatively common immunological mucocutaneous disease that causes pain and poor quality of life. Curcumin has been reported to be a safe and effective treatment for OLP. The objective of this review is to evaluate the existing evidence for the safety of curcumin in treating OLP as well as its efficacy compared with that of corticosteroids. Methods: We reviewed the published literature by searching PubMed, EMBASE, EBSCO, and Cochrane Library, and then retrieved and analyzed several variables from patient records. Results: Nine studies met the inclusion criteria, including six randomized, double-blind clinical trials; two pilot clinical trials; and one case report. A total of 259 OLP patients were included in the systematic review. Seven studies showed statistically significant differences in pain severity and clinical appearance of oral lesions after treatment with curcumin for a period of time, compared to baseline (p < .05). Three controlled clinical trials compared the efficacy of curcumin to that of corticosteroids; all of these trials showed no statistically significant differences in pain severity and clinical appearance of oral lesions. Conclusions: Curcumin is a safe treatment and can be used as an adjunct in combination with corticosteroids to reduce pain, burning sensations, and the clinical appearance of oral lesions in OLP patients.

Modulatory effect of curcumin on ketamine-induced toxicity in rat thymocytes: Involvement of reactive oxygen species (ROS) and the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway

Ketamine is a widely used anesthetic in pediatric clinical practice. Previous studies have demonstrated that ketamine induces neurotoxicity and has a modulatory effect on the cells of the immune system. Here, we evaluated the potential protective effect and underlying mechanisms of natural phenolic compound curcumin against ketamine-induced toxicity in rat thymocytes. Rat thymocytes were exposed to 100 µM ketamine alone or combined with increasing concentrations of curcumin (0.3, 1, and 3 μM) for 24 hours. Cell viability was analyzed with CCK-8 assay kit. Apoptosis was analyzed using flow cytometry and propidium iodide as well as Z-VAD-FMK and Z-LEHD-FMK inhibitors. Reactive oxygen species (ROS) production and mitochondrial membrane potential [MMP] were measured by flow cytometry. Colorimetric assay with DEVD-pNA substrate was used for assessing caspase-3 activity. Involvement of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was tested with Wortmannin inhibitor. Ketamine induced toxicity in cells, increased the number of hypodiploid cells, caspase-3 activity and ROS production, and inhibited the MMP. Co-incubation of higher concentrations of curcumin (1 and 3 μM) with ketamine markedly decreased cytotoxicity, apoptosis rate, caspase-3 activity, and ROS production in rat thymocytes, and increased the MMP. Application of Z-VAD-FMK (a pan caspase inhibitor) or Z-LEHD-FMK (caspase-9 inhibitor) with ketamine effectively attenuated the ketamine-induced apoptosis in rat thymocytes. Administration of Wortmannin (a PI3K inhibitor) with curcumin and ketamine significantly decreased the protective effect of curcumin on rat thymocytes. Our results indicate that ketamine-induced toxicity in rat thymocytes mainly occurs through the mitochondria-mediated apoptotic pathway and that the PI3K/Akt signaling pathway is involved in the anti-apoptotic effect of curcumin.

Inhalation treatment of idiopathic pulmonary fibrosis with curcumin large porous microparticles

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease with high mortality and poor prognosis. Curcumin shows anti-inflammatory effect by suppressing pro-inflammatory cytokines and inhibiting NF-κB mediated inflammation. Here, we developed inhalable curcumin-loaded poly(lactic-co-glycolic)acid (PLGA) large porous microparticles (LPMPs) for the treatment of IPF. Curcumin LPMPs were rough and loose particles with many pores on the surfaces and channels in the inner spaces. The mean geometric diameter of them was larger than 10 µm while the aerodynamic diameter was only 3.12 µm due to their porous structures. They showed a fine particle fraction (FPF) <4.46 μm of 13.41%, 71% cumulative release after 9 h, and more importantly, they avoided uptake by alveolar macrophages. Therefore, most of released curcumin had opportunities to enter lung tissues. Rat pulmonary fibrosis models were established via once intratracheal administration of bleomycin. Curcumin powders and curcumin LPMPs were administered on Days 2, 7, 14, and 21. Curcumin LPMPs remarkably attenuated lung injuries, decreased hydroxyproline contents, reduced the synthesis of collagen I, and inhibited the expressions of TNF-α, TGF-β1, NF-κB p65 and MMP9. Moreover, curcumin LPMPs showed higher antifibrotic activity than curcumin powders. Curcumin LPMPs are a promising inhalable medication for the treatment of IPF.

Protein phosphatase 2A regulates the p38 signaling pathway to affect the migration of astrocytes

The aim of the present study was to investigate the effect and mechanism of protein phosphatase 2A (PP2A) on the migration of astrocytes. The primary astrocytes of neonatal mice were isolated and cultured in vitro, and treated with the PP2A activator D-erythro-sphingosine (DES) (activated group) or inhibitor okadaic acid (inhibitory group). The control group was treated with equal amounts of dimethyl sulfoxide. The activity of PP2A in the cells was detected using a commercial kit and the migration of cells was investigated using a Transwell migration assay. The protein expression of p38, phosphorylated (p)-p38, matrix metalloproteinase (MMP)-2 and MMP-9 was detected by western blotting. Cell migration and the protein expression of p38, p-p38, MMP-2 and MMP-9 was also determined following treatment of astrocytes with the p38 signaling pathway inhibitor SB202190 with or without the PP2A activator DES. The results demonstrated that the activity of PP2A in the PP2A inhibitory group was significantly decreased compared with the control group, while that of the PP2A-activated cells was significantly increased compared with the control. The protein levels of MMP-2 and MMP-9 in the PP2A inhibitory group astrocytes were significantly decreased compared with the control group, while PP2A-activated astrocytes exhibited significantly increased levels of these proteins. By contrast, the p-p38 level in PP2A inhibitory group astrocytes was significantly increased compared with the control group, while astrocytes in the activated group exhibited significantly lower levels compared with the control group. Furthermore, the cell migration ability, and MMP-2 and MMP-9 protein levels, of astrocytes that received combined treatment with SB202190 and the PP2A activator DES were significantly increased compared with the levels in astrocytes treated with SB202190 alone. The results of the current study indicate that PP2A may negatively regulate the p38 signaling pathway to promote astrocyte migration.

The regulation and importance of monocyte chemoattractant protein-1

PURPOSE OF REVIEW

Monocyte chemoattractant protein (MCP)-1, a chemokine regulating monocyte chemotaxis and T-lymphocyte differentiation by binding to the CC chemokine receptor 2 (CCR2), plays a crucial role in the pathogenesis of inflammatory diseases, atherosclerosis and cancer. This review summarizes the current knowledge on the regulation and importance of the MCP-1/CCR2 axis, focusing on the therapeutic potential of its inhibition.

RECENT FINDINGS

Differential modulation of MCP-1 and CCR2 lead to downstream activation pathways, pathogenetic to differing disease conditions characterized by dysregulated monocyte/macrophage tissue recruitment. Pharmacological targeting of the MCP-1/CCR2 axis has led to selective MCP-1/CCR2 antagonists that have now entered phase I/II clinical trials for the treatment of inflammatory diseases, atherosclerosis and cancer. The pleiotropic nonselective MCP-1/CCR2 inhibition by current pharmacological agents is thought to contribute to their anti-inflammatory and antiatherosclerotic effects that is also seen for nutraceutical compounds such as curcumin.

SUMMARY

MCP-1 has a critical role in regulating chemotaxis both in health and disease, with increasing interest in its pharmacological inhibition. However, the therapeutic efficacy and safety of targeting the MCP-1/CCR2 axis is still in evolution.

Pre and post treatment with curcumin and resveratrol protects astrocytes after oxidative stress

The two most studied polyphenolic compounds, curcumin (Cur) and resveratrol (Res), have been reported to protect oxidative damage of astrocytes. The present study is designed to examine the comparative anti-oxidative effect of Cur and Res on astrocytes by studying their potential to protect H₂O₂ induced oxidative stress at 4 h and 24 h time exposure. The effect of Cur and Res on cell viability, ROS production, inflammation and astrogliosis was compared. The effect of these two on Nrf2 expression and its translocation to nuclear compartment was investigated. The results showed that both Cur and Res significantly increase astrocytes survival after oxidative stress at both time points, however, Res demonstrated better effect on cell viability than the Cur. Res, showing significant inhibition of ROS production at both time points. Cur displayed significant inhibition of ROS production at 4 h, suggesting that Cur is more active on ROS inhibition in the earlier phase of insult. Comparing the expression of NF-κB, Cur showed better anti-inflammatory action on NF-κB while Res did not have any effect of NF-κB expression at 4 h. Interestingly, Cur showed an upregulation of nuclear Nrf2 expression at 24 h whereas Res displayed no effect after 24 h incubation. Both Cur and Res inhibited the H₂O₂ induced translocation of Nrf2 into nucleus. In conclusion, based on our observation, we found that Cur and Res both protected astrocytes from oxidative stress. In addition, we observed that Cur is most effective in early hours of insult while Res is effective in late hours suggesting that Res may or may not have immediate effect on astrocytes.

Inhalation treatment of primary lung cancer using liposomal curcumin dry powder inhalers

Lung cancer is the leading cause of cancer-related deaths. Traditional chemotherapy causes serious toxicity due to the wide bodily distribution of these drugs. Curcumin is a potential anticancer agent but its low water solubility, poor bioavailability and rapid metabolism significantly limits clinical applications. Here we developed a liposomal curcumin dry powder inhaler (LCD) for inhalation treatment of primary lung cancer. LCDs were obtained from curcumin liposomes after freeze-drying. The LCDs had a mass mean aerodynamic diameter of 5.81 μm and a fine particle fraction of 46.71%, suitable for pulmonary delivery. The uptake of curcumin liposomes by human lung cancer A549 cells was markedly greater and faster than that of free curcumin. The high cytotoxicity on A549 cells and the low cytotoxicity of curcumin liposomes on normal human bronchial BEAS-2B epithelial cells yielded a high selection index partly due to increased cell apoptosis. Curcumin powders, LCDs and gemcitabine were directly sprayed into the lungs of rats with lung cancer through the trachea. LCDs showed higher anticancer effects than the other two medications with regard to pathology and the expression of many cancer-related markers including VEGF, malondialdehyde, TNF-α, caspase-3 and BCL-2. LCDs are a promising medication for inhalation treatment of lung cancer with high therapeutic efficiency.

DK1 Induces Apoptosis via Mitochondria-Dependent Signaling Pathway in Human Colon Carcinoma Cell Lines In Vitro

Extensive research has been done in the search for innovative treatments against colon adenocarcinomas; however, the incidence rate of patients remains a major cause of cancer-related deaths in Malaysia. Natural bioactive compounds such as curcumin have been substantially studied as an alternative to anticancer drug therapies and have been surmised as a potent agent but, nevertheless, remain deficient due to its poor cellular uptake. Therefore, efforts now have shifted toward mimicking curcumin to synthesize novel compounds sharing similar effects. A synthetic analog, (Z)-3-hydroxy-1-(2-hydroxyphenyl)-3-phenylprop-2-ene-1-one (DK1), was recently synthesized and reported to confer improved bioavailability and selectivity toward human breast cancer cells. This study, therefore, aims to assess the anticancer mechanism of DK1 in relation to the induction of in vitro cell death in selected human colon cancer cell lines. Using the3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay, the cytotoxicity of DK1 towards HT29 and SW620 cell lines were investigated. Acridine orange/propidium iodide (AO/PI) dual-staining assay and flow cytometry analyses (cell cycle analysis, Annexin/V-FITC and JC-1 assays) were incorporated to determine the mode of cell death. To further determine the mechanism of cell death, quantitative real-time polymerase chain reaction (qRT-PCR) and proteome profiling were conducted. Results from this study suggest that DK1 induced changes in cell morphology, leading to a decrease in cell viability and subsequent induction of apoptosis. DK1 treatment inhibited cell viability and proliferation 48 h post treatment with IC₅₀ values of 7.5 ± 1.6 µM for HT29 cells and 14.5 ± 4.3 µM for SW620 cells, causing cell cycle arrest with increased accumulation of cell populations at the sub-G₀/G₁phaseof 74% and 23%, respectively. Flow cytometry analyses showed that DK1 treatment in cancer cells induced apoptosis, as indicated by DNA fragmentation and depolarization of the mitochondrial membrane. qRT-PCR results show significant upregulation in the expression of caspase-9 in both HT29 and SW620 cell lines, further supporting that cell death induction by DK1 is via an intrinsic pathway. These outcomes, therefore, demonstrate DK1 as a potential anticancer agent for colon adenocarcinoma due to its anti-apoptotic attributes.

Curcumin: A natural modulator of immune cells in systemic lupus erythematosus

Curcumin is a polyphenol natural product isolated from turmeric, interacting with different cellular and molecular targets and, consequently, showing a wide range of pharmacological effects. Recent preclinical and clinical trials have revealed immunomodulatory properties of curcumin that arise from its effects on immune cells and mediators involved in the immune response, such as various T-lymphocyte subsets and dendritic cells, as well as different inflammatory cytokines. Systemic lupus erythematosus (SLE) is an inflammatory, chronic autoimmune-mediated disease characterized by the presence of autoantibodies, deposition of immune complexes in various organs, recruitment of autoreactive and inflammatory T cells, and excessive levels of plasma proinflammatory cytokines. The function and numbers of dendritic cells and T cell subsets, such as T helper 1 (Th1), Th17, and regulatory T cells have been found to be significantly altered in SLE. In the present report, we reviewed the results of in vitro, experimental (pre-clinical), and clinical studies pertaining to the modulatory effects that curcumin produces on the function and numbers of dendritic cells and T cell subsets, as well as relevant cytokines that participate in SLE.

Therapeutic potential of curcumin for multiple sclerosis

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease of the central nervous system (CNS), characterized by demyelination, neuronal injury, and breaching of the blood-brain barrier (BBB). Epidemiological studies have shown that immunological, genetic, and environmental factors contribute to the progression and development of MS. T helper 17 (Th17) cells are crucial immunological participant in the pathophysiology of MS. The aberrant production of IL-17 and IL-22 by Th17 cells crosses BBB promotes its disruption and interferes with transmission of nerve signals through activation of neuroinflammation in the CNS. These inflammatory responses promote demyelination through transcriptional activation of signal transducers and activators of transcription-1 (STAT-1), nuclear factor kappa-B (NF-κB), matrix metalloproteinases (MMPs), interferon ϒ (IFNϒ), and Src homology region 2 domain-containing phosphatase-1 (SHP-1). B cells also contribute to disease progression through abnormal regulation of antibodies, cytokines, and antigen presentation. Additionally, oxidative stress has been known as a causative agent for the MS. Curcumin is a hydrophobic yellowish diphenolic component of turmeric, which can interact and modulate multiple cell signaling pathways and prevent the development of various autoimmune neurological diseases including MS. Studies have reported curcumin as a potent anti-inflammatory, antioxidant agent that could modulate cell cycle regulatory proteins, enzymes, cytokines, and transcription factors in CNS-related disorders including MS. The current study summarizes the reported knowledge on therapeutic potential of curcumin against MS, with future indication as neuroprotective and neuropharmacological drug.

Immunomodulatory basis of antioxidant therapy and its future prospects: an appraisal

Antioxidants are agents which can modulate oxidant-antioxidant profile of body system by neutralizing pro-oxidant molecules. The current scientific knowledge on mechanisms of antioxidant activity of biomolecules was critically reviewed with a special emphasis on immunomodulation. The immuno-oxidative wreckage of animals in various disease conditions and the role of biomodulators in curbing the oxidative stress through immune pathways were analyzed. The critical role of immunomodulatory mechanisms in controlling oxidative damage was identified. Selection of antioxidant therapy considering the immunopharmacology of the drug as well as immunological basis of disease may reduce treatment failure and adverse health effects. Hence, it is suggested that future studies on antioxidants may focus on the immuno-oxidative pathobiology to better understand its clinical effects and effective disease management.

Curcumin decreases astrocytic reaction after gliotoxic injury in the rat brainstem

ABSTRACT Recent studies have demonstrated that curcumin (Cur) has antioxidant, anti-inflammatory and anti-fibrotic effects. Ethidium bromide (EB) injections into the central nervous system (CNS) are known to induce local oligodendroglial and astrocytic loss, resulting in primary demyelination and neuroinflammation. Peripheral astrogliosis is seen around the injury site with increased immunoreactivity to glial fibrillary acidic protein (GFAP). This investigation aimed to evaluate the effect of Cur administration on astrocytic response following gliotoxic injury. Wistar rats were injected with EB into the cisterna pontis and treated, or not, with Cur (100 mg/kg/day, intraperitoneal route) during the experimental period. Brainstem sections were collected at 15, 21 and 31 days after EB injection and processed for GFAP immunohistochemical staining. Astrocytic reactivity was measured in a computerized system for image analysis. In Cur-treated rats, the GFAP-stained area around the lesion was significantly smaller in all periods after EB injection compared to untreated animals, showing that Cur reduces glial scar development following injury.

Carotenoids: biochemistry, pharmacology and treatment

Carotenoids and retinoids have several similar biological activities such as antioxidant properties, the inhibition of malignant tumour growth and the induction of apoptosis. Supplementation with carotenoids can affect cell growth and modulate gene expression and immune responses. Epidemiological studies have shown a correlation between a high carotenoid intake in the diet with a reduced risk of breast, cervical, ovarian, colorectal cancers, and cardiovascular and eye diseases. Cancer chemoprevention by dietary carotenoids involves several mechanisms, including effects on gap junctional intercellular communication, growth factor signalling, cell cycle progression, differentiation-related proteins, retinoid-like receptors, antioxidant response element, nuclear receptors, AP-1 transcriptional complex, the Wnt/β-catenin pathway and inflammatory cytokines. Moreover, carotenoids can stimulate the proliferation of B- and T-lymphocytes, the activity of macrophages and cytotoxic T-cells, effector T-cell function and the production of cytokines. Recently, the beneficial effects of carotenoid-rich vegetables and fruits in health and in decreasing the risk of certain diseases has been attributed to the major carotenoids, β-carotene, lycopene, lutein, zeaxanthin, crocin (/crocetin) and curcumin, due to their antioxidant effects. It is thought that carotenoids act in a time- and dose-dependent manner. In this review, we briefly describe the biological and immunological activities of the main carotenoids used for the treatment of various diseases and their possible mechanisms of action.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.