Efficacy and Safety of Phytosomal Curcumin in Non-Alcoholic Fatty Liver Disease: A Randomized Controlled Trial

Beneficial Effects of Plant-Derived Natural Products on Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease is becoming in one of the most prevalent liver diseases that leads to liver transplantation. This health problem is a multisystem disease with a complex pathogenesis that involves liver, adipose tissue, gut, and muscle. Although several pharmacological agents have been investigated to prevent or treat non-alcoholic fatty liver disease, currently there is no effective treatment for the management of this chronic liver disease. Nonetheless, the use of natural products has emerged as a alternative therapeutic for the treatment of hepatic diseases, including non-alcoholic fatty liver disease, due to its anti-inflammatory, antioxidant, antidiabetic, insulin-sensitizing, antiobesity, hypolipidemic, and hepatoprotective properties. In the present review, we have discussed the evidence from experimental and clinical studies regarding the potential beneficial effects of plant-derived natural products (quercetin, resveratrol, berberine, pomegranate, curcumin, cinnamon, green tea, coffee, garlic, ginger, ginseng, and gingko biloba) for the treatment or prevention of non-alcoholic fatty liver disease.

Turmeric and Curcumin: From Traditional to Modern Medicine

The rhizome of turmeric (Curcuma longa L.) has been used as an herbal medicine, coloring agent, spice, and food additive for thousands of years in different parts of the world particularly in Asian countries. It has been used for a range of diseases in many traditional medical schools, including Islamic traditional medicine, Chinese traditional medicine, and Ayurveda. It has been used mainly for digestive problems, as a cardio-, hepato-, and neuroprotective agent as well as in many inflammatory conditions such as arthritis and for enhancing immune system. Curcumin, a diarylheptanoid derivative found in turmeric, has anti-inflammatory, antioxidant, and anticancer properties; controls obesity and metabolic problems; and improves memory and mood disorders. Therapeutically, curcumin exhibits promising potential in preclinical and clinical studies and is currently in human trials for a variety of conditions, including metabolic syndrome, nonalcoholic fatty liver disease, rheumatoid arthritis, migraine, premenstrual syndrome, ulcerative colitis, knee osteoarthritis, polycystic ovarian syndrome, atherosclerosis, liver cirrhosis, amyotrophic lateral sclerosis, depression, psoriasis, and Alzheimer's disease. Among all beneficial activities reported for curcumin, the research toward the obesity and metabolic-preventing/suppressing aspects of curcumin is growing. These findings emphasize that most of the traditional applications of turmeric is due to the presence of its key constituent, curcumin. According to the traditional background of turmeric use and clinical values of curcumin, further preclinical studies for unstudied properties and clinical studies with larger sample sizes for confirmed activities are expected.

Curcumin and Its Derivatives as Theranostic Agents in Alzheimer's Disease: The Implication of Nanotechnology

Curcumin is a polyphenolic natural compound with diverse and attractive biological properties, which may prevent or ameliorate pathological processes underlying age-related cognitive decline, Alzheimer's disease (AD), dementia, or mode disorders. AD is a chronic neurodegenerative disorder that is known as one of the rapidly growing diseases, especially in the elderly population. Moreover, being the eminent cause of dementia, posing problems for families, societies as well a severe burden on the economy. There are no effective drugs to cure AD. Although curcumin and its derivatives have shown properties that can be considered useful in inhibiting the hallmarks of AD, however, they have low bioavailability. Furthermore, to combat diagnostic and therapeutic limitations, various nanoformulations have also been recognized as theranostic agents that can also enhance the pharmacokinetic properties of curcumin and other bioactive compounds. Nanocarriers have shown beneficial properties to deliver curcumin and other nutritional compounds against the blood-brain barrier to efficiently distribute them in the brain. This review spotlights the role and effectiveness of curcumin and its derivatives in AD. Besides, the gut metabolism of curcumin and the effects of nanoparticles and their possible activity as diagnostic and therapeutic agents in AD also discussed.

Counteracting arsenic toxicity: Curcumin to the rescue?

Arsenicosis leads to various irreversible damages in several organs and is considered to be a carcinogen. The effects of chronic arsenic poisoning are a result of an imbalance between pro- and antioxidant homeostasis, oxidative stress, as well as DNA and protein damage. Curcumin, the polyphenolic pigment extracted from the rhizome of Curcuma longa, is well-known for its pleiotropic medicinal effects. Curcumin has been shown to have ameliorative effects in arsenic-induced genotoxicity, nephrotoxicity, hepatotoxicity, angiogenesis, skin diseases, reproductive toxicity, neurotoxicity, and immunotoxicity. This review aims to summarize the scientific evidence on arsenic toxicity in various organs and the ameliorative effects of curcumin on the arsenic toxicity.

Roles of Nrf2 in Liver Diseases: Molecular, Pharmacological, and Epigenetic Aspects

Liver diseases represent a critical health problem with 2 million deaths worldwide per year, mainly due to cirrhosis and its complications. Oxidative stress plays an important role in the development of liver diseases. In order to maintain an adequate homeostasis, there must be a balance between free radicals and antioxidant mediators. Nuclear factor erythroid 2-related factor (Nrf2) and its negative regulator Kelch-like ECH-associated protein 1 (Keap1) comprise a defense mechanism against oxidative stress damage, and growing evidence considers this signaling pathway as a key pharmacological target for the treatment of liver diseases. In this review, we provide detailed and updated evidence regarding Nrf2 and its involvement in the development of the main liver diseases such as alcoholic liver damage, viral hepatitis, steatosis, steatohepatitis, cholestatic damage, and liver cancer. The molecular and cellular mechanisms of Nrf2 cellular signaling are elaborated, along with key and relevant antioxidant drugs, and mechanisms on how Keap1/Nrf2 modulation can positively affect the therapeutic response are described. Finally, exciting recent findings about epigenetic modifications and their link with regulation of Keap1/Nrf2 signaling are outlined.

Anti-inflammatory Augmentation Therapy in Obsessive-compulsive Disorder: A Review

Background:

Obsessive-Compulsive Disorder (OCD) is considered as a serious disabling psychiatric disorder, influencing 2-3% of the total general population, with an unknown etiology.

Methods:

A comprehensive literature search in electronic databases was performed to investigate treatments targeting inflammation in patients suffering from OCD.

Results:

Recent studies display that inflammation processes and the dysfunction of the immune system are likely to play a role in the pathophysiology of OCD, indicating that the disturbances in neurotransmitters such as serotonin and dopamine cannot be alone involved in the development of OCD. Therefore, it seems that medications with anti-inflammatory effects have the potential to be evaluated as a new therapeutic strategy for OCD. However, this issue can be studied closely if OCD etiological factors are thoroughly understood. The present review study aims at gathering all obtained results concerning new treatments targeting inflammation in OCD patients. Reviewing the conducted studies shows that the use of agents with anti-inflammatory properties, including some NSAIDs, Minocycline and Atorvastatin, could lead to promising and intriguing results in the treatment of OCD. Curcumin also showed good efficacy in the reduction of OCD-like behavior when it has been used in an animal model. However, there is still no definitive and conclusive evidence for any of the medications proposed.

Conclusion:

More future studies are needed to investigate anti-inflammatory treatment strategies for OCD and its other subtypes such as Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS), and Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal infection (PANDAS).

The effect of adiponectin in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) and the potential role of polyphenols in the modulation of adiponectin signaling

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide, as it affects up to 30 % of adults in Western countries. Moreover, NAFLD is also considered an independent risk factor for cardiovascular diseases. Insulin resistance and inflammation have been identified as key factors in the pathophysiology of NAFLD. Although the mechanisms associated with the development of NAFLD remain to be fully elucidated, a complex interaction between adipokines and cytokines appear to play a crucial role in the development of this condition. Adiponectin is the most common adipokine known to be inversely linked with insulin resistance, lipid accumulation, inflammation and NAFLD. Consequently, the focus has been on the use of new therapies that may enhance hepatic expression of adiponectin downstream targets or increase the serum levels of adiponectin in the treatment NAFLD. While currently used therapies show limited efficacy in this aspect, accumulating evidence suggest that various dietary polyphenols may stimulate adiponectin levels, offering potential protection against the development of insulin resistance, inflammation and NAFLD as well as associated conditions of metabolic syndrome. As such, this review provides a better understanding of the role polyphenols play in modulating adiponectin signaling to protect against NAFLD. A brief discussion on the regulation of adiponectin during disease pathophysiology is also covered to underscore the potential protective effects of polyphenols against NAFLD. Some of the prominent polyphenols described in the manuscript include aspalathin, berberine, catechins, chlorogenic acid, curcumin, genistein, piperine, quercetin, and resveratrol.

Potential effects of curcumin in the treatment of COVID-19 infection

Coronavirus disease 2019 (COVID-19) outbreak is an ongoing pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with considerable mortality worldwide. The main clinical manifestation of COVID-19 is the presence of respiratory symptoms, but some patients develop severe cardiovascular and renal complications. There is an urgency to understand the mechanism by which this virus causes complications so as to develop treatment options. Curcumin, a natural polyphenolic compound, could be a potential treatment option for patients with coronavirus disease. In this study, we review some of the potential effects of curcumin such as inhibiting the entry of virus to the cell, inhibiting encapsulation of the virus and viral protease, as well as modulating various cellular signaling pathways. This review provides a basis for further research and development of clinical applications of curcumin for the treatment of newly emerged SARS-CoV-2.

Curcumin derivatives for Type 2 Diabetes management and prevention of complications

Type 2 diabetes Mellitus (T2DM) is characterized by chronically increased blood glucose levels, which is associated with impairment of the inflammatory and oxidative state and dyslipidaemia. Although it is considered a world heath concern and one of the most studied diseases, we are still pursuing an effective therapy for both the pathophysiological mechanisms and the complications. Curcumin, a natural compound found in the rhizome of Curcuma longa, is well known for its numerous biological activities, as demonstrated by several studies supporting that curcumin possesses hypoglycaemic, hypolipidemic, anti-inflammatory and antioxidant properties, among others. These effects have been explored to the attenuation of hyperglycaemia and progression of DM complications, being appointed as a potential therapeutic approach. Besides its strong intrinsic activity, the polyphenol has low bioavailability, compromising its therapeutic efficacy. In order to overcome this limitation, several chemical strategies have been applied to curcumin, such as drug delivery systems, chemical manipulation and the use of adjuvant therapies. Given the promising results obtained with curcumin derivative, in this review we discuss not only the therapeutic targets of curcumin, but also its most recently developed analogues and their efficacy in the management of T2DM pathophysiology and complications.

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.

A pilot study of the effect of curcumin on epigenetic changes and DNA damage among patients with non-alcoholic fatty liver disease: A randomized, double-blind, placebo-controlled, clinical trial

BACKGROUND

The enhancement of oxidative stress in non-alcoholic fatty liver disease (NAFLD) patients may cause mutation in DNA by deamination of cytosine to 5-hydroxyuracil or uracil. This study aimed to discover the effects of curcumin on NAFLD progress, DNA damage caused by oxidative stress, and promoter methylation of mismatch repair enzymes.

MATERIAL AND METHODS

in this study, 54 NAFLD patients were randomly devided into two groups, according to a double blind parallel design either phytosomal curcumin (250 mg/day) or placebo for 8 weeks. Fasting blood samples and anthropometric measures were taken twice, once at the baseline and once at the end of the study. Promoter methylation and 8-hydroxy-2' -deoxyguanosine (8-OHdG) concentration as DNA damage mediator were measured by restriction enzymes and enzyme-linked immunosorbent assay, respectively.

RESULT

Analysis was performed on 44 patients. According to our between groups analysis, curcumin significantly reduced the methylation in MutL homolog 1 (MLH1) and MutS homolog 2 (MSH2) promoter regions. The within-group comparison revealed that anthropometric variables significantly decreased. However, the result of the between groups comparison indicated no significant changes in the anthropometric variables except for BMI. Liver enzymes and 8-OHdG did not significantly change at the end of the study, neither in curcumin group nor in placebo group.

CONCLUSION

Curcumin might be able to reduce the risk of mismatch base pair in DNA among the NAFLD patients. However, it did not change the DNA damage mediator and liver enzymes. For confirming these results, more studies with longer duration, more numbers of examined genes, higher dose of curcumin, and larger sample size are required.

Natural products that target macrophages in treating non-alcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is the progressive subtype of non-alcoholic fatty liver disease and potentiates risks for both hepatic and metabolic diseases. Although the pathophysiology of NASH is not completely understood, recent studies have revealed that macrophage activation is a major contributing factor for the disease progression. Macrophages integrate the immune response and metabolic process and have become promising targets for NASH therapy. Natural products are potential candidates for NASH treatment and have multifactorial underlying mechanisms. Macrophage involvement in the development of steatosis and inflammation in NASH has been widely investigated. In this review, we assess the evidence for natural products or their active ingredients in the modulation of macrophage activation, recruitment, and polarization, as well as the metabolic status of macrophages. Our work may highlight the possible natural products that target macrophages as potential treatment options for NASH.

Herbal Medicine in the Treatment of Non-Alcoholic Fatty Liver Diseases-Efficacy, Action Mechanism, and Clinical Application

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease with high prevalence in the developed countries. NAFLD has been considered as one of the leading causes of cryptogenic cirrhosis and chronic liver disease. The individuals with obesity, insulin resistance and diabetes mellitus, hyperlipidaemia, and hypertension cardiovascular disease have a high risk to develop NAFLD. The related critical pathological events are associated with the development of NAFLD including insulin resistance, lipid metabolism dysfunction, oxidative stress, inflammation, apoptosis, and fibrosis. The development of NAFLD range from simple steatosis to non-alcoholic steatohepatitis (NASH). Hepatic steatosis is characterized by fat accumulation, which represents the early stage of NAFLD. Then, inflammation triggered by steatosis drives early NAFLD progression into NASH. Therefore, the amelioration of steatosis and inflammation is essential for NAFLD therapy. The herbal medicine have taken great effects on the improvement of steatosis and inflammation for treating NAFLD. It has been found out that these effects involved the multiple mechanisms underlying lipid metabolism and inflammation. In this review, we pay particular attention on herbal medicine treatment and make summary about the research of herbal medicine, including herb formula, herb extract and naturals compound on NAFLD. We make details about their protective effects, the mechanism of action involved in the amelioration steatosis and inflammation for NAFLD therapy as well as the clinical application.

The long-term protective effects of neonatal administration of curcumin against nonalcoholic steatohepatitis in high-fructose-fed adolescent rats

There is an increased prevalence of nonalcoholic steatohepatitis (NASH) in adolescents. The suckling period is developmentally plastic, affecting later health outcomes. We investigated whether neonatal administration of curcumin would provide protection against the development of NASH later in adolescence in rats fed a high-fructose diet. From postnatal day (PN) 6 to PN 21, the pups (N = 128) were allocated to four groups and orally gavaged daily with either 0.5% dimethyl sulfoxide solution (vehicle control), curcumin (500 mg·kg^-1 ), fructose (20%, w/v) or curcumin and fructose combined. All the pups were weaned and half the rats in each group had tap water, whereas the other received fructose (20%) as their drinking fluid ad libitum for 6 weeks. The rats' liver NASH scores, lipid content, and RNA gene expression ratios of AMPKα and TNFα were determined. Hepatic lipid content was similar across the treatment groups in the males (P > 0.05, ANOVA). In the females, the hepatic lipid content in the treatment groups ranged from 2.7 to 4.3%. The livers of male and female rats that had fructose either as neonates and/or postweaning had significantly marked inflammation (P = 0.0112, Kruskal-Wallis) and fibrosis (P < 0.0001, ANOVA) which were attenuated by curcumin. The hepatic gene expression ratios for AMPKα in both sexes were significantly downregulated (P < 0.0001, ANOVA), whereas the expression ratios of TNFα were significantly upregulated (P < 0.0001) in rats fed a high-fructose diet pre and/or postweaning compared to the other groups. Neonatal curcumin administration is a potential natural pharmacological candidate for the prevention of NASH.

The beneficial effects of nutraceuticals and natural products on small dense LDL levels, LDL particle number and LDL particle size: a clinical review

Cardiovascular diseases (CVDs) are globally the major causes of morbidity and mortality. Evidence shows that smaller and denser low-dense lipoprotein (sdLDL) particles are independent atherogenic risk factors for CVD due to their greater susceptibility to oxidation, and permeability in the endothelium of arterial walls. sdLDL levels are an independent risk factor and of more predictive value than total LDL-C for the assessment of coronary artery disease and metabolic syndrome. Functional food ingredients have attracted significant attention for the management of dyslipidemia and subsequently increase cardio-metabolic health. However, to date there is no study that has investigated the effect of these bioactive natural compounds on sdLDL levels. Therefore, the aim of the present review is to summarize the evidence accrued on the effect of special dietary ingredients such as omega-3 polyunsaturated fatty acids, nutraceuticals and herbal medicines on the levels of sdLDL, LDL particle number, and LDL particle size. Based on the results of the existing clinical trials this review suggests that natural products such as medicinal plants, nutraceuticals and omega-3 fatty acids can be used as adjunct or complementary therapeutic agents to reduce sdLDL levels, LDL particle numbers or increase LDL particle size and subsequently may prevent and treat CVD, with the advantage that theses natural agents are generally safe, accessible, and inexpensive.

Liver Fibrosis: Mechanistic Concepts and Therapeutic Perspectives

Liver fibrosis due to viral or metabolic chronic liver diseases is a major challenge of global health. Correlating with liver disease progression, fibrosis is a key factor for liver disease outcome and risk of hepatocellular carcinoma (HCC). Despite different mechanism of primary liver injury and disease-specific cell responses, the progression of fibrotic liver disease follows shared patterns across the main liver disease etiologies. Scientific discoveries within the last decade have transformed the understanding of the mechanisms of liver fibrosis. Removal or elimination of the causative agent such as control or cure of viral infection has shown that liver fibrosis is reversible. However, reversal often occurs too slowly or too infrequent to avoid life-threatening complications particularly in advanced fibrosis. Thus, there is a huge unmet medical need for anti-fibrotic therapies to prevent liver disease progression and HCC development. However, while many anti-fibrotic candidate agents have shown robust effects in experimental animal models, their anti-fibrotic effects in clinical trials have been limited or absent. Thus, no approved therapy exists for liver fibrosis. In this review we summarize cellular drivers and molecular mechanisms of fibrogenesis in chronic liver diseases and discuss their impact for the development of urgently needed anti-fibrotic therapies.

Curcumin: a phytochemical modulator of estrogens and androgens in tumors of the reproductive system

Curcumin (Cur) is an active derivative extracted from turmeric which exerts a wide range of interactions with biomolecules through complex signaling pathways. Cur has been extensively shown to possess potential antitumor properties. In addition, there is growing body of evidence suggesting that Cur may exert potential anti-estrogen and anti-androgen activity. In vitro and in vivo studies suggest that anticancer properties of Cur against tumors affecting the reproductive system in females and males may be underlied by the Cur-mediated inhibition of androgen and estrogen signaling pathways. In this review we examine various studies assessing the crosstalk between Cur and both androgen and estrogen hormonal activity. Also, we discuss the potential chemopreventive and antitumor role of Cur in the most prevalent cancers affecting the reproductive system in females and males.

Effects of Plant and Animal Natural Products on Mitophagy

Mitophagy is a protected cellular process that is essential for autophagic removal of damaged mitochondria and for preservation of a healthy mitochondrial population. In the last years, a particular interest has been devoted in studying the effects of natural compounds on mitophagy. Different natural compounds may modulate mitochondrial oxidative phosphorylation, the production of mitochondrial reactive oxygen species, the expression of mitophagy- and autophagy-related genes, and the activities of transcription factors which regulate the expression of mitochondrial proteins, thereby controlling mitochondrial damage and mitophagy. Remarkably, since mitochondrial function has a crucial role in the pathogenesis of various diseases (e.g., cancer, atherosclerosis, Duchenne muscular dystrophy, diabetes complications, Alzheimer's disease, and hepatic steatosis), these effects might have important therapeutic implications. In this review, preclinical studies investigating the role of different natural compounds in the modulation of mitophagy will be discussed.

Epigenetic aspects of multiple sclerosis and future therapeutic options

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease accompanied by demyelination of neurons in the central nervous system that mostly affects young adults, especially women. This disease has two phases including relapsing-remitting form (RR-MS) by episodes of relapse and periods of clinical remission and secondary-progressive form (SP-MS), which causes more disability. The inheritance pattern of MS is not exactly identified and there is an agreement that it has a complex pattern with an interplay among environmental, genetic and epigenetic alternations. Epigenetic mechanisms that are identified for MS pathogenesis are DNA methylation, histone modification and some microRNAs' alternations. Several cellular processes including apoptosis, differentiation and evolution can be modified along with epigenetic changes. Some alternations are associated with epigenetic mechanisms in MS patients and these changes can become key points for MS therapy. Therefore, the aim of this review was to discuss epigenetic mechanisms that are associated with MS pathogenesis and future therapeutic approaches.

Effect of curcumin supplementation on disease severity in patients with liver cirrhosis: A randomized controlled trial

Recent reports indicated that curcumin had beneficial effects in animal models of liver injury and cirrhosis. Current study aimed to investigate the effects of curcumin supplementation in patients with liver cirrhosis. In this randomized double-blind placebo-controlled trial, 70 patients with liver cirrhosis aged 20-70 years were randomly divided into two groups to receive 1,000 mg/day curcumin (n = 35) or placebo (n = 35) for 3 months. Model for end-stage liver disease (MELD) (i), MELD, MELD-Na, and Child-Pugh scores were used to assess the severity of cirrhosis. Sixty patients (29 in the curcumin group and 31 in the placebo group) completed the study. MELD(i) (15.55 ± 3.78 to 12.41 ± 3.07), MELD (15.31 ± 3.07 to 12.03 ± 2.79), MELD-Na (15.97 ± 4.02 to 13.55 ± 3.51), and Child-Pugh (7.17 ± 1.54 to 6.72 ± 1.31) scores decreased significantly in the curcumin group after 3-month intervention (p < .001, p < .001, p = .001, and p = .051, respectively), whereas they increased significantly in the placebo group (p < .001, p < .001, p < .001, p = .001, respectively). Significant differences were only observed between the two groups in MELD(i), MELD, MELD-Na, and Child-Pugh scores after 3-month intervention (p < .001 for all of them). In this pilot study, beneficial effects of curcumin supplementation were observed in decreasing disease activity scores and severity of cirrhosis in patients with cirrhosis.

Herbal medicines for the liver: from bench to bedside

The liver is one of the most complex organs of the human body and is involved in various metabolic processes. Due to its anatomical proximity to the digestive tract, its blood flow, and its contribution to the detoxification process, the liver is susceptible to a wide variety of disorders. Hepatic diseases can be caused by alcoholism, viral infections, malnutrition and xenobiotics, which result in a high frequency of patients with liver disease and subsequent increase in the number of deaths from these diseases, for which adequate treatments are not yet available. Therefore, the search for new alternatives to treat these liver conditions is mandatory. In recent decades, there has been an increase in interest in medicinal herbs due to their safety and hepatoprotective properties that arise from their anti-inflammatory, antioxidant, antifibrotic, antiviral, immunomodulatory and anticancer properties. Epidemiological and clinical studies have shown that the consumption of these compounds is associated with a decrease in the risk of developing liver diseases; thus, medicinal herbs have emerged as a viable option for the treatment of these hepatic pathologies. However, more basic and clinical studies are needed before reaching a final recommendation to treat human liver diseases. This review provides molecular and clinical information on some natural compounds and medicinal herbs that have hepatoprotective effects and could be useful for the treatment of hepatic disorders.

The role of TFEB in tumor cell autophagy: Diagnostic and therapeutic opportunities

Autophagy is a conserved "self-eating" recycling process which removes aggregated or misfolded proteins, or defective organelles, to maintain cellular hemostasis. In the autophagy-lysosome pathway (ALP), clearance of unwanted debris and materials occurs through the generation of the autophagosome, a complex of double-membrane bounded vesicles that form around cytosolic cargos and catabolize their contents by fusion to lysosomes. In tumors, autophagy has dichotomous functions via preventing tumor initiation but promoting tumor progression. The basic helix-loop-helix leucine zipper transcription factor EB (TFEB) activates the promoters of genes encoding for proteins, which participate in this cellular degradative system by regulating lysosomal biogenesis, lysosomal acidification, lysosomal exocytosis and autophagy. In humans, disturbances of ALP are related to various pathological conditions. Recently, TFEB dysregulation was found to have a crucial pathogenic role in different tumors by modulating tumor cell autophagy. Notably, in renal cell carcinomas, different TFEB gene fusions were reported to promote oncogenic features. In this review, we discuss the role of TFEB in human cancers with a special focus on potential diagnostic and therapeutic implications.

MicroRNA-mediated regulation of Nrf2 signaling pathway: Implications in disease therapy and protection against oxidative stress

MicroRNAs (miRs) are small non-coding pieces of RNA that are involved in a variety of physiologic processes such as apoptosis, cell proliferation, cell differentiation, cell cycle and cell survival. These multifunctional nucleotides are also capable of preventing oxidative damages by modulating antioxidant defense systems in a variety of milieu, such as in diabetes. Although the exact molecular mechanisms by which miRs modulate the antioxidant defense elements are unclear, some evidence suggests that they may exert these effects via nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. This intracellular mechanism is crucial in the maintenance of the physiologic redox balance by regulating the expression and activity of various cellular antioxidative defense elements and thereby plays a pivotal role in the development of oxidative stress. Any impairment in the Nrf2 signaling pathway may result in oxidative damage-dependent complications such as various diabetic complications, neurological disorders and cancer. In the current review, we discuss the modulatory effects of miRs on the Nrf2 signaling pathway, which can potentially be novel therapeutic targets.

The effects of curcumin supplementation on body mass index, body weight, and waist circumference in patients with nonalcoholic fatty liver disease: A systematic review and dose-response meta-analysis of randomized controlled trials

Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver-related morbidity; its prevalence is elevating due to the rising epidemic of obesity. Several clinical trials have examined the effects of curcumin supplementation on anthropometric variables in NAFLD patients with inconclusive results. This dose-response meta-analysis aimed to evaluate the impact of curcumin supplementation on body mass index (BMI), body weight, and waist circumference (WC) in patients with NAFLD. A systematic review of the literature was conducted using PubMed/Medline, ISI Web of Science, Scopus, Cochrane Library, EMBASE, Google Scholar, Sid.ir, and Magiran.com to identify eligible studies up to March 2019. A meta-analysis of eligible studies was performed using the random-effects model to estimate the pooled effect size. Eight randomized controlled trials with 520 participants (curcumin group = 265 and placebo group = 255) were included. Supplementation dose and duration ranged from 70 to 3,000 mg/day and 8 to 12 weeks, respectively. Curcumin supplementation significantly reduced BMI (weighted mean difference [WMD] = -0.34 kg/m² , 95% CI [-0.64, -0.04], p < .05) and WC (WMD = -2.12 cm, 95% CI [-3.26, -0.98], p < .001). However, no significant effects of curcumin supplementation on body weight were found. These results suggest that curcumin supplementation might have a positive effect on visceral fat and abdominal obesity that have been associated with NAFLD.

The Bioprotective Effects of Polyphenols on Metabolic Syndrome against Oxidative Stress: Evidences and Perspectives

Polyphenols are the general designation of various kinds of phytochemicals, mainly classified as flavonoids and nonflavonoids. Polyphenolic compounds have been confirmed to exhibit numerous bioactivities and potential health benefits both in vivo and in vitro. Dietary polyphenols have been shown to significantly alleviate several manifestations of metabolic syndrome, namely, central obesity, hypertension, dyslipidemia, and high blood sugar. This review is aimed at discussing the bioprotective effects and related molecular mechanisms of polyphenols, mainly by increasing antioxidant capacity or oxygen scavenging capacity. Polyphenols can exert their antioxidative activity by balancing the organic oxidoreductase enzyme system, regulating antioxidant responsive signaling pathways, and restoring mitochondrial function. These data are helpful for providing new insights into the potential biological effects of polyphenolic compounds and the development of future antioxidant therapeutics.

The Effect of Curcumin on the Differentiation of Mesenchymal Stem Cells into Mesodermal Lineage

Curcumin has been placed at the forefront of the researcher's attention due to its pleiotropic pharmacological effects and health benefits. A considerable volume of articles has pointed out curcumin's effects on the fate of stem cell differentiation. In this review, a descriptive mechanism of how curcumin affects the outcome of the differentiation of mesenchymal stem cells (MSCs) into the mesodermal lineage-i.e., adipocyte, osteocyte, and chondrocyte differentiation-is compiled from the literature. The sections include the mechanism of inhibition or induction of MSCs differentiation to each lineage, their governing molecular mechanisms, and their signal transduction pathways. The effect of different curcumin doses and its structural modifications on the MSCs differentiation is also discussed.

The effect of Curcumin/Turmeric on blood pressure modulation: A systematic review and meta-analysis

BACKGROUND AND AIM

Hypertension is a chronic condition that can lead to several health problems, such as cardiovascular diseases, myocardial infarction, stroke, retinopathy and renal failure. In the present study, a systematic review and meta-analysis was undertaken with the main aim of estimating the quantitative effect of curcumin/turmeric supplementation on blood pressure (BP).

METHODS

A systematic search was undertaken in Medline, Embase, Scopus, ISI Web of Science, Google Scholar and Cochrane library up to May 2019 to identify randomized clinical trials assessing the effect of curcumin/turmeric on systolic BP (SBP) and diastolic BP (DBP). A random-effects model was used to analyze the impact of combined trials. Cochrane Risk of Bias Tool was applied to assess potential risks of bias.

RESULTS

A total of 11 studies comprising 734 participants were eligible and included in the meta-analysis to estimate pooled effect size. Results of the meta-analysis did not indicate any significant effect of curcumin/turmeric on SBP (-0.69 mmHg; 95% CI: -2.01, 0.64; I² = 18%) and DBP (0.28 mmHg; 95% CI: -1.12, 1.68; I² = 53%). However, subgroup analysis revealed a significant reduction only in SBP levels (-1.24 mmHg; 95% CI: -2.26, -0.22; I² = 0%) but not DBP (0.29 mmHg; 95% CI: -0.65, 1.22; I² = 1%) in studies with ≥12-week supplementation. No favorable effect of curcumin administration on SBP or DBP levels was found after stratification according to either participant's condition or type of intervention (turmeric, crude curcumin and high-absorption curcumin).

CONCLUSION

The present meta-analysis suggests that consuming curcumin/turmeric may improve SBP when administered in long durations. However, more studies are needed to confirm these results.

Efficacy of curcumin on prevention of drug-induced nephrotoxicity: A review of animal studies

Drug-induced nephrotoxicity is a frequent serious adverse effect, contributing to morbidity and increased healthcare utilization. Prevention or reversal is key. Curcumin has useful biological features that include antioxidant, anti-inflammatory, and anticancer properties. This review covers aspects of curcumin in relation to prevention of drug-induced nephrotoxicity: dosage and schedule, effect on kidney biomarkers and histological changes, and mechanisms of curcumin's protective effects. Despite success in some animal models, human studies and clinical administration of curcumin for nephroprotection remains limited due to difficulty in achieving therapeutic levels following oral administration and in determining the optimal dosing schedule. Lack of sufficient evidence from animal studies, coupled with low systemic bioavailability, continues to limit the utilization of curcumin in addressing and controlling drug-induced nephrotoxicity. Therefore, human studies are required to fully assess and validate the therapeutic potential of curcumin.

Modulatory effects of curcumin on heat shock proteins in cancer: A promising therapeutic approach

Cancer metastasis represents a multistep process, including alteration of cell adhesion/motility in the microenvironment and sustained angiogenesis, which is essential for supporting cancer growth in tissues that are distant from the primary tumor. There is growing evidence suggesting that heat shock proteins (HSPs) (also known as heat stress proteins), which constitute a family of stress-inducible proteins, may be involved in the pathogenesis of cancer. Curcumin (diferuloylmethane) is a potent anti-inflammatory, antioxidant, antimicrobial, and antitumor agent. Curcumin has been shown to regulate different members of HSPs including HSP27, HSP40, HSP60, HSP70, and HSP90 in cancer. Here, we present extent findings suggesting that curcumin may act as a potential therapeutic agent for the treatment of cancer through its regulation of HSPs.

Targeted inhibition of STAT3 as a potential treatment strategy for atherosclerosis

Atherosclerosis is the main pathological basis of ischemic cardiovascular and cerebrovascular diseases and has attracted more attention in recent years. Multiple studies have demonstrated that the signal transducer and activator of transcription 3 (STAT3) plays essential roles in the process of atherosclerosis. Moreover, aberrant STAT3 activation has been shown to contribute to the occurrence and development of atherosclerosis. Therefore, the study of STAT3 inhibitors has gradually become a focal research topic. In this review, we describe the crucial roles of STAT3 in endothelial cell dysfunction, macrophage polarization, inflammation, and immunity during atherosclerosis. STAT3 in mitochondria is mentioned as well. Then, we present a summary and classification of STAT3 inhibitors, which could offer potential treatment strategies for atherosclerosis. Furthermore, we enumerate some of the problems that have interfered with the development of mature therapies utilizing STAT3 inhibitors to treat atherosclerosis. Finally, we propose ideas that may help to solve these problems to some extent. Collectively, this review may be useful for developing future STAT3 inhibitor therapies for atherosclerosis.

Efficacy of phospholipidated curcumin in nonalcoholic fatty liver disease: a clinical study

Curcumin is a safe and dietary phytochemical that can improve different pathophysiologic features of non-alcoholic fatty liver disease (NAFLD). Here, we investigated the efficacy of phospholipidated curcumin supplementation in NAFLD patients. In this single-arm study, 36 patients were recruited. Each patient received three capsules a day (each containing 500 mg of phospholipidated curcumin [overall content of curcuminoids per capsule: 100 mg]) for a period of 8 weeks. The results indicated that phospholipidated curcumin supplementation reduced NAFLD severity and ameliorated ultrasonographic and biochemical measures (including liver transaminases and lipid profile) associated with disease progression.

Medicinal plants in traumatic brain injury: Neuroprotective mechanisms revisited

Traumatic brain injury (TBI) is the most prevalent health problem affecting all age groups, and leads to many secondary problems in other organs especially kidneys, gastrointestinal tract, and heart function. In this review, the search terms were TBI, fluid percussion injury, cold injury, weight drop impact acceleration injury, lateral fluid percussion, cortical impact injury, and blast injury. Studies with Actaea racemosa, Artemisia annua, Aframomum melegueta, Carthamus tinctorius, Cinnamomum zeylanicum, Crocus sativus, Cnidium monnieri, Curcuma longa, Gastrodia elata, Malva sylvestris, Da Chuanxiong Formula, Erigeron breviscapus, Panax ginseng, Salvia tomentosa, Satureja khuzistanica, Nigella sativa, Drynaria fortune, Dracaena cochinchinensis, Polygonum cuspidatum, Rosmarinus officinalis, Rheum tanguticum, Centella asiatica, and Curcuma zedoaria show a significant decrease in neuronal injury by different mechanisms such as increasing superoxide dismutase and catalase activities, suppressing nuclear factor kappa B (NF-κB), interleukin 1 (IL-1), glial fibrillary acidic protein, and IL-6 expression. The aim of this study was to evaluate the neuroprotective effects of medicinal plants in central nervous system pathologies by reviewing the available literature.

Does Turmeric/curcumin Supplementation Change Anthropometric Indices in Patients with Non-alcoholic Fatty Liver Disease? A Systematic Review and Meta-analysis of Randomized Controlled Trials

Curcumin is the principal polylphenol of turmeric that has been used to treat various disorders. However, its anti-obesity effects in patients with non-alcoholic fatty liver disease (NAFLD) remain controversial. Therefore, we aimed to perform a meta-analysis on the effects of supplementation with turmeric/curcumin on body weight, body mass index (BMI) and waist circumference (WC) in these patients. PubMed, Scopus, Cochrane Library, and ISI Web of Science were searched until January 2019, without any restrictions. Clinical trials that reported body weight, BMI and WC in patients with NAFLD were included. Weighted mean differences (WMDs) were pooled using a random-effects model. Eight studies (449 participants) fulfilled the eligibility criteria of the present meta-analysis. Overall, meta-analysis could not show any beneficial effect of turmeric/curcumin supplementation on body weight (WMD, -0.54 kg; 95% confidence interval [CI], -2.40, 1.31; p = 0.56; I2 = 0.0%), BMI (WMD, -0.21 kg/m2; 95% CI, -0.71, 0.28; p = 0.39; I2 = 0.0%) and WC (WMD, -0.88 cm; 95% CI, -3.76, 2.00; p = 0.54; I2 = 0.0%). Subgroup analysis based on participants' baseline BMI, type of intervention, and study duration did not show any significant association in all subgroups. The results showed that turmeric/curcumin supplementation had no significant effect on body weight, BMI and WC in patients with NAFLD. Further studies with large-scale are needed to find out possible anti-obesity effects of turmeric/curcumin.

Traditional Chinese medicine combined with hepatic targeted drug delivery systems: A new strategy for the treatment of liver diseases

Liver diseases are clinically common and present a substantial public health issue. Many of the currently available drugs for the treatment of liver diseases suffer from limitations that include low hepatic distribution, lack of target effects, poor in vivo stability and adverse effects on other organs. Consequently, conventional treatment of hepatic diseases is ineffective. TCM is commonly used in the treatment of liver diseases worldwide, particularly in China, and has advantages over conventional therapy. HTDDS can be designed to enhance clinical efficacy in the treatment of liver diseases. We have conducted an extensive review of 335 studies reported since 1964. These included about 166 references involving the treatment of liver diseases with TCM (covering active components of TCM, single TCM and Chinese medicine formulas), 169 reports on HTDDS and background studies on liver-related diseases. Here we review the long history of TCM in the treatment of liver diseases.We have also reviewed the status of studies on active components of TCM using nanotechnology-based targeted delivery systems to provide support for further research and development of TCM-based targeted preparations for the treatment of liver disease.

The Effects of Curcumin on Weight Loss Among Patients With Metabolic Syndrome and Related Disorders: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background and objective: The current systematic review and meta-analysis of randomized controlled trials (RCTs) was carried out to assess the influence of curcumin intake on weight among patients with metabolic syndrome and related disorders.

Methods: We searched the following databases up until January 2018: MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. The relevant data were extracted and evaluated for quality of the studies in accordance with the Cochrane risk of bias tool. Data were pooled using the inverse variance method and expressed as standardized mean difference (SMD) with 95% confidence intervals (95% CI).

Results: Eighteen articles (21 studies) that comprised a total of 1,604 individuals were finally included in the meta-analysis. Curcumin intake significantly reduced body mass index (BMI) (SMD −0.37; 95% CI, −0.61, −0.13; P < 0.01), weight (SMD −0.23; 95% CI, −0.39, −0.06; P < 0.01), waist-circumference (WC) (SMD −0.25; 95% CI, −0.44, −0.05; P = 0.01), leptin levels (SMD −0.97; 95% CI, −1.18, −0.75; P < 0.001) and increased adiponectin levels (SMD 1.05; 95% CI, 0.23, 1.87; P = 0.01). We found no significant effect of curcumin intake on hip ratio (HR) (SMD −0.17; 95% CI, −0.42, 0.08; P = 0.18).

Conclusions: Overall, we have found that curcumin intake among patients with metabolic syndrome and related disorders was correlated with a significant reduction in BMI, weight, WC, and leptin, and a significant increase in adiponectin levels, but did not affect HR.

Curcuminoids plus piperine improve nonalcoholic fatty liver disease: A clinical trial

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) as a prevalent hepatic disease is associated with an increased risk of morbidity and mortality related to the liver and cardiovascular disease (CVD). Lifestyle modification and good metabolic control is the first line of treatment, but not always efficacious in reversing NAFLD pathogenesis. Curcumin is a dietary phytochemical with hepatoprotective activities, though its low bioavailability is considered as a major challenge for clinical applications. Therefore, in this study, in order to improve the bioavailability of curcumin, it was coadministered with piperine and we investigated the effects of this bioavailability-enhanced curcumin on serum hepatic enzymes, lipid profile, and glycemic indices in patients with NAFLD.

METHODS

In this randomized controlled parallel-group trial, 70 subjects with ultrasound-determined NAFLD were randomized to either 500 mg curcuminoids coadministered with 5 mg piperine daily or placebo for 12 weeks. NAFLD severity (on the basis of sonography) and hepatic function was assessed at baseline and at the study end.

RESULTS

Seventy subjects completed the study. Supplementation with curcuminoids plus piperine significantly reduced the hematocrit (P = 0.027), erythrocyte sedimentation rate (P = 0.048) and the serum concentrations of alanine aminotransferase (P = 0.035), aspartate aminotransferase (P = 0.042), alkaline phosphatase (P = 0.004), cholesterol (P < 0.016), low-density lipoprotein cholesterol (P < 0.017), Iron (P = 0.026), and Hemoglobin (P = 0.025) and increased total iron-binding capacity (P = 0.003). However, except albumin, changes in other parameters were not statistically different between groups. In addition, administration of curcuminoids plus piperine significantly improved NAFLD severity (P < 0.001), which was statistically different compared with the placebo group (P = 0.022). Also, the percentage of improved patients was marginally higher in the curcuminoids plus piperine group when compared with the placebo group (P = 0.058).

CONCLUSION

This study suggested beneficial effects of combined curcuminoids and piperine supplementation on disease severity in patients with NAFLD.

Targeting Oxidative Stress for the Treatment of Liver Fibrosis

Oxidative stress is a reflection of the imbalance between the production of reactive oxygen species (ROS) and the scavenging capacity of the antioxidant system. Excessive ROS, generated from various endogenous oxidative biochemical enzymes, interferes with the normal function of liver-specific cells and presumably plays a role in the pathogenesis of liver fibrosis. Once exposed to harmful stimuli, Kupffer cells (KC) are the main effectors responsible for the generation of ROS, which consequently affect hepatic stellate cells (HSC) and hepatocytes. ROS-activated HSC undergo a phenotypic switch and deposit an excessive amount of extracellular matrix that alters the normal liver architecture and negatively affects liver function. Additionally, ROS stimulate necrosis and apoptosis of hepatocytes, which causes liver injury and leads to the progression of end-stage liver disease. In this review, we overview the role of ROS in liver fibrosis and discuss the promising therapeutic interventions related to oxidative stress. Most importantly, novel drugs that directly target the molecular pathways responsible for ROS generation, namely, mitochondrial dysfunction inhibitors, endoplasmic reticulum stress inhibitors, NADPH oxidase (NOX) inhibitors, and Toll-like receptor (TLR)-affecting agents, are reviewed in detail. In addition, challenges for targeting oxidative stress in the management of liver fibrosis are discussed.

A systematic review and meta-analysis of the effect of curcuminoids on adiponectin levels

INTRODUCTION

Curcuminoids are known anti-inflammatory molecules with multiple mechanisms of action while adiponectin is an anti-inflammatory molecule secreted by the adipocytes. Curcuminoids may upregulate the expression of adiponectin and thus modulate their levels in serum. A meta-analysis was performed to identify randomized controlled trials evaluating the effect of curcuminoids on adiponectin concentrations.

MATERIALS AND METHODS

The search included PubMed-Medline, Scopus, ISI Web of Science and Google Scholar databases (from inception to October 20, 2018) and the quality of studies was assessed according to Cochrane criteria. Quantitative data synthesis was conducted using a random-effects model and sensitivity analysis by the leave-one out method. Additional analysis was performed to assess the impact of potential confounders on adiponectin levels.

RESULTS

The meta-analysis of five randomized clinical trials (n = 686) showed a significant elevation of plasma adiponectin concentrations following supplementation with curcuminoids (WMD: 6.47 ng/mL, 95% CI: 1.85, 11.10, p  = 0.010; I² = 94.85%). The effect size was robust in the leave-one-out sensitivity analysis and the effect size was not driven by a single study in the meta-analysis.

CONCLUSION

This meta-analysis showed a significant increase in plasma levels of adiponectin following curcuminoids therapy, which may be one of the mechanisms of anti-inflammatory activity of curcumin.

Biological properties of metal complexes of curcumin

Curcumin, a naturally occurring phenolic compound isolated from Curcuma longa, has different pharmacological effects, including antiinflammatory, antimicrobial, antioxidant, and anticancer properties. However, curcumin has been found to have a limited bioavailability because of its hydrophobic nature, low-intestinal absorption, and rapid metabolism. Therefore, there is a need for enhancing the bioavailability and its solubility in water in order to increase the pharmacological effects of this bioactive compound. One strategy is curcumin complexation with transition metals to circumvent the abovementioned problems. Curcumin can undergo chelation with various metal ions to form metallo-complexes of curcumin, which may show greater effects as compared with curcumin alone. Promising results with metal curcumin complexes have been observed with regard to antioxidant, anticancer, and antimicrobial activity, as well as in treatment of Alzheimer's disease. The present review provides a concise summary of the characterization and biological properties of curcumin-metal complexes. © 2019 BioFactors, 45(3):304-317, 2019.

Curcumin: a potent agent to reverse epithelial-to-mesenchymal transition

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) is involved in tumor progression, invasion, migration and metastasis. EMT is a process by which polarized epithelial cells acquire motile mesothelial phenotypic features. This process is initiated by disassembly of cell-cell contacts through the loss of epithelial markers and replacement of these markers by mesenchymal markers. Reconstruction of the cytoskeleton and degradation of the tumor basement membrane ensures the spread of invasive malignant tumor cells to distant locations. Accumulating evidence indicates that curcumin, as a well-known phytochemical, can inhibit EMT/metastasis through various mechanisms and pathways in human tumors.

CONCLUSIONS

In this review, we summarize the mechanisms by which curcumin may affect EMT in cells under pathological conditions to understand its potential as a novel anti-tumor agent. Curcumin can exert chemo-preventive effects by inhibition and reversal of the EMT process through both TGF-β-dependent (e.g. in hepatoma and retinal pigment epithelial cancer) and -independent (e.g. in oral cancer, colorectal cancer, pancreatic cancer, hepatocellular carcinoma, breast cancer, melanoma, prostate cancer, bladder cancer, thyroid cancer and lung cancer) pathways. Curcumin can also mitigate chemoresistance through EMT suppression and promotion of the antiproliferative effects of conventional chemotherapeutics. Therefore, curcumin has the potential to be used as a novel adjunctive agent to prevent tumor metastasis, which may at least partly be attributed to its hampering of the EMT process.