Targeted delivery of curcumin for treating type 2 diabetes

Polyethylene Glycol-Based Polymer-Drug Conjugates: Novel Design and Synthesis Strategies for Enhanced Therapeutic Efficacy and Targeted Drug Delivery

Due to their potential to enhance therapeutic results and enable targeted drug administration, polymer-drug conjugates that use polyethylene glycol (PEG) as both the polymer and the linker for drug conjugation have attracted much research. This study seeks to investigate recent developments in the design and synthesis of PEG-based polymer-drug conjugates, emphasizing fresh ideas that fill in existing knowledge gaps and satisfy the increasing need for more potent drug delivery methods. Through an extensive review of the existing literature, this study identifies key challenges and proposes innovative strategies for future investigations. The paper presents a comprehensive framework for designing and synthesizing PEG-based polymer-drug conjugates, including rational molecular design, linker selection, conjugation methods, and characterization techniques. To further emphasize the importance and adaptability of PEG-based polymer-drug conjugates, prospective applications are highlighted, including cancer treatment, infectious disorders, and chronic ailments.

Metabolic memory: mechanisms and diseases

Metabolic diseases and their complications impose health and economic burdens worldwide. Evidence from past experimental studies and clinical trials suggests our body may have the ability to remember the past metabolic environment, such as hyperglycemia or hyperlipidemia, thus leading to chronic inflammatory disorders and other diseases even after the elimination of these metabolic environments. The long-term effects of that aberrant metabolism on the body have been summarized as metabolic memory and are found to assume a crucial role in states of health and disease. Multiple molecular mechanisms collectively participate in metabolic memory management, resulting in different cellular alterations as well as tissue and organ dysfunctions, culminating in disease progression and even affecting offspring. The elucidation and expansion of the concept of metabolic memory provides more comprehensive insight into pathogenic mechanisms underlying metabolic diseases and complications and promises to be a new target in disease detection and management. Here, we retrace the history of relevant research on metabolic memory and summarize its salient characteristics. We provide a detailed discussion of the mechanisms by which metabolic memory may be involved in disease development at molecular, cellular, and organ levels, with emphasis on the impact of epigenetic modulations. Finally, we present some of the pivotal findings arguing in favor of targeting metabolic memory to develop therapeutic strategies for metabolic diseases and provide the latest reflections on the consequences of metabolic memory as well as their implications for human health and diseases.

Molecular Mechanisms of Curcumin in the Pathogenesis of Metabolic Dysfunction Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a multifactorial condition characterized by insulin resistance, oxidative stress, chronic low-grade inflammation, and sometimes fibrosis. To date, no effective pharmacological therapy has been approved for the treatment of metabolic-associated steatohepatitis (MASH), the progressive form of MASLD. Recently, numerous in vitro and in vivo studies have described the efficacy of nutraceutical compounds in the diet has been tested. Among them, curcumin is the most widely used polyphenol in the diet showing potent anti-inflammatory and antifibrotic activities. This review aims to summarize the most important basic studies (in vitro and animal models studies), describing the molecular mechanisms by which curcumin acts in the context of MASLD, providing the rationale for its effective translational use in humans.

A review of the role of liposome-encapsulated phytochemicals targeting PPAR Ɣ and associated pathways to combat obesity

A limited number of studies have directly examined the effects of liposomal encapsulated phytochemicals and their anti-obesity effects in adults. This study aimed to summarize the evidence on the effect of liposomal encapsulated phytochemicals and their role in regulating major pathways involved in the anti-obesity mechanism. A systematic search was performed using several search engines like Science Direct, Google Scholar, and other online journals, focusing on laboratory research, systematic reviews, clinical trials, and meta-analysis that focused on liposomal encapsulated phytochemicals with anti-obesity properties, and followed the preferred reporting terms for this systematic review. An initial search provided a result of 1810 articles, and 93 papers were selected after the inclusion and exclusion criteria. Very few studies have been conducted on the liposomal encapsulation of phytochemicals or its synergistic study to combat obesity; hence this review paves the way for future obesity research and is mainly helpful for the pediatric obesity population. Liposomal encapsulation of phytochemicals has improved the efficiency of freely administered phytochemicals. Targeted delivery improved drug utilization and regulated the anti-obesity pathways. PPARƔ is a major therapeutic target for obesity as it inhibits adipocyte differentiation and maintains energy homeostasis.

Curcumin nanocrystals self-stabilized Pickering emulsion freeze-dried powder: Development, characterization, and suppression of airway inflammation

Curcumin, a diketone compound extracted from turmeric's rhizome, is an effective anti-inflammatory drug with multiple pharmacological activities. However, its low oral bioavailability due to its low water solubility and permeability severely limits its clinical applications. Therefore, to enhance the oral bioavailability of curcumin, further enhance its anti-inflammatory effects, and improve its potential in the treatment of airway inflammation, a curcumin nanocrystalline self-stabilizing Pickering emulsion (Cur-NSSPE) was prepared through high-pressure homogenization. Next, Cur-NSSPE was dried using a freeze-drying method to produce Cur-NSSPE-FDP. The prepared Cur-NSSPE and Cur-NSSPE-FDP were physically characterized. The release behavior and transmembrane transport capability of Cur-NSSPE-FDP in vitro were evaluated. Pharmacokinetic study was performed to evaluate its oral bioavailability. The anti-inflammatory effects of Cur-NSSPE-FDP in vivo and in vitro were investigated using RAW 264.7 macrophage inflammation model induced by LPS and IFN-γ and asthma model in BALB/c mice induced by OVA. The average particle size of Cur-NSSPE was (163.66 ± 6.78) nm, and the average drug content was (2.78 ± 0.01) mg/mL. The transmission electron microscopy results showed that the droplets were spherical in shape with a relatively uniform size, and the curcumin nanocrystals formed a spherical core-shell structure wrapped at the interface of the droplets. The scanning electron microscopy showed that Cur-NSSPE-FDP was a neatly arranged, having loose and porous network structure. Furthermore, it can significantly improve the cumulative release of curcumin in vitro and improve oral bioavailability in rats, increase the uptake of RAW264.7 and Caco-2 cells, promote the transport of curcumin across Caco-2 cells, significantly inhibit the expression of inflammatory factors NO, IL-6, TNF-a, MDA, IgE and ICAM-1, and improve the expression of IL-10 and SOD. These results indicated that the curcumin nanocrystalline self-stabilizing Pickering emulsion-freeze dried powder improved the oral bioavailability of curcumin and enhanced its therapeutic effect in airway inflammation.

Potentials of curcumin against polycystic ovary syndrome: Pharmacological insights and therapeutic promises

Polycystic ovary syndrome (PCOS) is a common hormonal disorder among women (4%-20%) when the ovaries create abnormally high levels of androgens, the male sex hormones that are typically present in women in trace amounts. The primary characteristics of PCOS include oxidative stress, inflammation, hyperglycemia, hyperlipidemia, hyperandrogenism, and insulin resistance. Generally, metformin, spironolactone, eflornithine and oral contraceptives are used to treat PCOS, despite their several side effects. Therefore, finding a potential candidate for treating PCOS is necessary. Curcumin is a major active natural polyphenolic compound derived from turmeric (Curcuma longa). A substantial number of studies have shown that curcumin has anti-inflammatory, anti-oxidative stress, antibacterial, and anti-apoptotic activities. In addition, curcumin reduces hyperglycemia, hyperlipidemia, hyperandrogenism, and insulin resistance in various conditions, including PCOS. The review highlighted the therapeutic aspects of curcumin against the pathophysiology of PCOS. We also offer a hypothesis to improve the development of medicines based on curcumin against PCOS.

Mechanistic insights into the beneficial effects of curcumin on insulin resistance: opportunities and challenges

The past couple of decades in particular have seen a rapid increase in the prevalence of type 2 diabetes mellitus (T2DM), a debilitating metabolic disorder characterised by insulin resistance. The insufficient efficacy of current management strategies for insulin resistance calls for additional therapeutic options. The preponderance of evidence suggests potential beneficial effects of curcumin on insulin resistance, while modern science provides a scientific basis for its potential applications against the disease. Curcumin combats insulin resistance by increasing the levels of circulating irisin and adiponectin, activating PPARγ, suppressing Notch1 signalling, and regulating SREBP target genes, among others. In this review, we bring together the diverse areas pertaining to our current understanding of the potential benefits of curcumin on insulin resistance, associated mechanistic insights, and new therapeutic possibilities. Teaser: Current approaches to manage insulin resistance are not highly efficacious, which necessitates additional therapeutic options; curcumin combats insulin resistance by improving the levels of circulating irisin and adiponectin, upregulating and activating PPARγ, and suppressing Notch‑1 signalling.

Therapeutic and Prophylactic Role of Vitamin D and Curcumin in Acetic Acid-Induced Acute Ulcerative Colitis Model

Ulcerative Colitis (UC) is a disease that negatively affects quality of life and is associated with sustained oxidative stress, inflammation and intestinal permeability. Vitamin D and Curcumin; It has pharmacological properties beneficial to health, including antioxidant and anti-inflammatory properties. Our study investigates the role of Vitamin D and Curcumin in acetic acid-induced acute colitis model. To investigate the effect of Vitamin D and Curcumin, Wistar-albino rats were given 0.4 mcg/kg Vitamin D (Post-Vit D, Pre-Vit D) and 200 mg/kg Curcumin (Post-Cur, Pre-Cur) for 7 days and acetic acid was injected into all rats except the control group. Our results; colon tissue TNF-α, IL-1β, IL-6, IFN-γ and MPO levels were found significantly higher and Occludin levels were found significantly lower in the colitis group compared to the control group (p < 0.05). TNF-α and IFN-γ levels decreased and Occludin levels increased in colon tissue of Post-Vit D group compared to colitis group (p < 0.05). IL-1β, IL-6 and IFN-γ levels were decreased in colon tissue of Post-Cur and Pre-Cur groups (p < 0.05). MPO levels in colon tissue decreased in all treatment groups (p < 0.05). Vitamin D and Curcumin treatment significantly reduced inflammation and restored the normal histoarchitecture of the colon. From the present study findings, we can conclude that Vitamin D and Curcumin protect the colon from acetic acid toxicity with their antioxidant and anti-inflammatory potential.

Bioactive Compounds as Inhibitors of Inflammation, Oxidative Stress and Metabolic Dysfunctions via Regulation of Cellular Redox Balance and Histone Acetylation State

Bioactive compounds (BCs) are known to exhibit antioxidant, anti-inflammatory, and anti-cancer properties by regulating the cellular redox balance and histone acetylation state. BCs can control chronic oxidative states caused by dietary stress, i.e., alcohol, high-fat, or high-glycemic diet, and adjust the redox balance to recover physiological conditions. Unique functions of BCs to scavenge reactive oxygen species (ROS) can resolve the redox imbalance due to the excessive generation of ROS. The ability of BCs to regulate the histone acetylation state contributes to the activation of transcription factors involved in immunity and metabolism against dietary stress. The protective properties of BCs are mainly ascribed to the roles of sirtuin 1 (SIRT1) and nuclear factor erythroid 2-related factor 2 (NRF2). As a histone deacetylase (HDAC), SIRT1 modulates the cellular redox balance and histone acetylation state by mediating ROS generation, regulating nicotinamide adenine dinucleotide (NAD+)/NADH ratio, and activating NRF2 in metabolic progression. In this study, the unique functions of BCs against diet-induced inflammation, oxidative stress, and metabolic dysfunction have been considered by focusing on the cellular redox balance and histone acetylation state. This work may provide evidence for the development of effective therapeutic agents from BCs.

A review on curcumin colon-targeted oral drug delivery systems for the treatment of inflammatory bowel disease

Synthetic drugs and monoclonal antibodies are the typical treatments to combat inflammatory bowel disease (IBD). However, side effects are present when these treatments are used, and their continued application could be restricted by the high relapse rate of the disease. One potential alternative to these treatments is the use of plant-derived products. The use curcumin is one such treatment option that has seen an increase in usage in treating IBD. Curcumin is derived from a rhizome of turmeric (Curcuma longa), and the results of studies on the use of curcumin to treat IBD are promising. These studies suggest that curcumin interacts with cellular targets such as NF-κB, JAKs/STATs, MAPKs, TNF-α, IL-6, PPAR, and TRPV1 and may reduce the progression of IBD. Potentially, curcumin can be used as a therapeutic agent for patients with IBD when it reduces the incidence of clinical relapse. This review discusses the strategies utilized in designing and developing an oral colonic delivery dosage form of curcumin.

Investigating Polyphenol Nanoformulations for Therapeutic Targets against Diabetes Mellitus

Diabetes mellitus (DM) is a fatal metabolic disorder, and its prevalence has escalated in recent decades to a greater extent. Since the incidence and severity of the disease are constantly increasing, plenty of therapeutic approaches are being considered as a promising solution. Many dietary polyphenols have been reported to be effective against diabetes along with its accompanying vascular consequences by targeting multiple therapeutic targets. Additionally, the biocompatibility of these polyphenols raises questions about their use as pharmacological mediators. Nevertheless, the pharmacokinetic and biopharmaceutical properties of these polyphenols limit their clinical benefit as therapeutics. Pharmaceutical industries have attempted to improve compliance and therapeutic effects. However, nanotechnological approaches to overcome the pharmacokinetic and biopharmaceutical barriers associated with polyphenols as antidiabetic medications have been shown to be effective to improve clinical compliance and efficacy. Therefore, this review highlighted a comprehensive and up-to-date assessment of polyphenol nanoformulations in the treatment of diabetes and vascular consequences.

How Curcumin Targets Inflammatory Mediators in Diabetes: Therapeutic Insights and Possible Solutions

Diabetes mellitus is a multifactorial chronic metabolic disorder, characterized by altered metabolism of macro-nutrients, such as fats, proteins, and carbohydrates. Diabetic retinopathy, diabetic cardiomyopathy, diabetic encephalopathy, diabetic periodontitis, and diabetic nephropathy are the prominent complications of diabetes. Inflammatory mediators are primarily responsible for these complications. Curcumin, a polyphenol derived from turmeric, is well known for its anti-oxidant, anti-inflammatory, and anti-apoptotic properties. The regulation of several signaling pathways effectively targets inflammatory mediators in diabetes. Curcumin’s anti-inflammatory and anti-oxidative activities against a wide range of molecular targets have been shown to have therapeutic potential for a variety of chronic inflammatory disorders, including diabetes. Curcumin’s biological examination has shown that it is a powerful anti-oxidant that stops cells from growing by releasing active free thiol groups at the target location. Curcumin is a powerful anti-inflammatory agent that targets inflammatory mediators in diabetes, and its resistant form leads to better therapeutic outcomes in diabetes complications. Moreover, Curcumin is an anti-oxidant and NF-B inhibitor that may be useful in treating diabetes. Curcumin has been shown to inhibit diabetes-related enzymes, such as a-glucosidase, aldose reductase and aldose reductase inhibitors. Through its anti-oxidant and anti-inflammatory effects, and its suppression of vascular endothelial development and nuclear transcription factors, curcumin has the ability to prevent, or reduce, the course of diabetic retinopathy. Curcumin improves insulin sensitivity by suppressing phosphorylation of ERK/JNK in HG-induced insulin-resistant cells and strengthening the PI3K-AKT-GSK3B signaling pathway. In the present article, we aimed to discuss the anti-inflammatory mechanisms of curcumin in diabetes regulated by various molecular signaling pathways.

Review of the Effects and Mechanism of Curcumin in the Treatment of Inflammatory Bowel Disease

Curcumin is extracted from the rhizomes of Curcuma longa L. It is now widely used in food processing, cosmetics, dyes, etc. Current researching indicates that curcumin has high medical value, including anti-inflammatory, antioxidant, anti-tumor, anti-apoptotic, anti-fibrosis, immune regulation and other effects, and can be used to treat a variety of diseases. Inflammatory bowel disease (IBD) is a nonspecific inflammatory disease of the intestine including Crohn’s disease (CD) and ulcerative colitis (UC). The drug treatment effect is often limited and accompanied by side effects. A large number of basic and clinical studies have shown that curcumin has the effect of treating IBD and also can maintain the remission of IBD. In this review, the research of curcumin on IBD in recent years is summarized in order to provide reference for further research and application of curcumin.

Benefits of Curcumin in the Vasculature: A Therapeutic Candidate for Vascular Remodeling in Arterial Hypertension and Pulmonary Arterial Hypertension?

Growing evidence suggests that hypertension is one of the leading causes of cardiovascular morbidity and mortality since uncontrolled high blood pressure increases the risk of myocardial infarction, aortic dissection, hemorrhagic stroke, and chronic kidney disease. Impaired vascular homeostasis plays a critical role in the development of hypertension-induced vascular remodeling. Abnormal behaviors of vascular cells are not only a pathological hallmark of hypertensive vascular remodeling, but also an important pathological basis for maintaining reduced vascular compliance in hypertension. Targeting vascular remodeling represents a novel therapeutic approach in hypertension and its cardiovascular complications. Phytochemicals are emerging as candidates with therapeutic effects on numerous pathologies, including hypertension. An increasing number of studies have found that curcumin, a polyphenolic compound derived from dietary spice turmeric, holds a broad spectrum of pharmacological actions, such as antiplatelet, anticancer, anti-inflammatory, antioxidant, and antiangiogenic effects. Curcumin has been shown to prevent or treat vascular remodeling in hypertensive rodents by modulating various signaling pathways. In the present review, we attempt to focus on the current findings and molecular mechanisms of curcumin in the treatment of hypertensive vascular remodeling. In particular, adverse and inconsistent effects of curcumin, as well as some favorable pharmacokinetics or pharmacodynamics profiles in arterial hypertension will be discussed. Moreover, the recent progress in the preparation of nano-curcumins and their therapeutic potential in hypertension will be briefly recapped. The future research directions and challenges of curcumin in hypertension-related vascular remodeling are also proposed. It is foreseeable that curcumin is likely to be a therapeutic agent for hypertension and vascular remodeling going forwards.

Improving Antibacterial Efficiency of Curcumin in Magnetic Polymeric Nanocomposites

In recent years, resistance to chemical antibiotics, as well as their side effects, has caused a necessity to utilize natural substances and herbal components with antibacterial effects. Curcumin, the major substance of Curcuma longa’s rhizome, was used as an antibacterial agent since ancient times. This work aimed to formulate a novel nanocomposite for the delivery of curcumin to overcome orthodox drugs resistance against bacteria and improve its efficacy. To fabricate targeting nanocomposites, first, Fe3O4 nanoparticles were synthesized followed by coating the obtained nanoparticles using sodium alginate containing curcumin. A 2 by 3 factorial design was tailored to predict the optimum formulation of nanocomposites. Characterization of nanocomposites including particle size, polydispersity index (PDI), zeta potential, entrapment efficiency, and drug loading was performed. The optimum formulation was analyzed by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier-transformed infrared spectroscopy (FT-IR), and in vitro release study at different pHs. Finally, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of samples against seven common bacteria were determined. Results showed that the optimized formulation contained 400 nm particles with the PDI and zeta potentials of 0.4 and − 58 mV, respectively. The optimized formulation with 70% entrapment efficiency reduced the MIC value 2 to 4 times in comparison with pure curcumin. Results also showed that polymer and drug concentrations can significantly affect entrapment efficiency. In conclusion, the current investigation demonstrated that this magnetic nanocomposite can be applied for the delivery of curcumin.

Graphical abstract

Botanical Interventions to Improve Glucose Control and Options for Diabetes Therapy

Diabetes mellitus is a major public health problem worldwide. This endocrine disease is clustered into distinct subtypes based on the route of development, with the most common forms associated with either autoimmunity (T1DM) or obesity (T2DM). A shared hallmark of both major forms of diabetes is a reduction in function (insulin secretion) or mass (cell number) of the pancreatic islet beta-cell. Diminutions in both mass and function are often present. A wide assortment of plants have been used historically to reduce the pathological features associated with diabetes. In this review, we provide an organized viewpoint focused around the phytochemicals and herbal extracts investigated using various preclinical and clinical study designs. In some cases, crude extracts were examined directly, and in others, purified compounds were explored for their possible therapeutic efficacy. A subset of these studies compared the botanical product with standard of care prescribed drugs. Finally, we note that botanical formulations are likely suspects for future drug discovery and refinement into class(es) of compounds that have either direct or adjuvant therapeutic benefit.

Dual-modified starch nanospheres encapsulated with curcumin by self-assembly: Structure, physicochemical properties and anti-inflammatory activity

Pullulanase debranching and subsequent hydroxypropylation were applied to prepare a series of dual-modified starches (Hydroxypropylated debranched starch, HPDS) with different degrees of hydroxypropyl substitution. Their structural and physicochemical properties varied with the degree of hydroxypropyl substitution, and all HPDS exhibited the ability to self-assemble into well-shaped nanospheres (100-150 nm, PDI < 0.2). These HPDS nanospheres were attempted to encapsulate curcumin with the aim of improving the bioavailability, solubility and stability of curcumin. Their structural characteristics, thermal stability, iodine staining, morphology, safety, encapsulation efficiency, in vitro gastrointestinal release behavior, and anti-inflammatory activity were evaluated. The results showed that curcumin could be effectively encapsulated into the HPDS nanospheres, and the encapsulation efficiency, water solubility and physical stability were positively correlated with the degree of hydroxypropyl substitution. After encapsulation, the water solubility and physical stability of curcumin could be increased up to 226-fold and 6-fold, respectively. The HPDS nanospheres also exhibited good safety (including hemolysis and cytotoxicity) and sustainable release of curcumin. Evaluation of anti-inflammatory activity showed that the activity of curcumin-encapsulated HPDS was enhanced by 170% compared to unencapsulated curcumin. These suggest that HPDS nanospheres encapsulation may be a more suitable option for the development of functional foods containing bioactive compounds.

Diet and redox state in maintaining skeletal muscle health and performance at high altitude

High altitude exposure leads to compromised physical performance with considerable weight loss. The major stressor at high altitude is hypobaric hypoxia which leads to disturbance in redox homeostasis. Oxidative stress is a well-known trigger for many high altitude illnesses and regulates several key signaling pathways under stressful conditions. Altered redox homeostasis is considered the prime culprit of high altitude linked skeletal muscle atrophy. Hypobaric hypoxia disturbs redox homeostasis through increased RONS production and compromised antioxidant system. Increased RONS disturbs the cellular homeostasis via multiple ways such as inflammation generation, altered protein anabolic pathways, redox remodeling of RyR1 that contributed to dysregulated calcium homeostasis, enhanced protein degradation pathways via activation calcium-regulated protein, calpain, and apoptosis. Ultimately, all the cellular signaling pathways aggregately result in skeletal muscle atrophy. Dietary supplementation of phytochemicals could become a safe and effective intervention to ameliorate skeletal muscle atrophy and enhance the physical performance of the personnel who are staying at high altitude regions. The present evidence-based review explores few dietary supplementations which regulate several signaling mechanisms and ameliorate hypobaric hypoxia induced muscle atrophy and enhances physical performance. However, a clinical research trial is required to establish proof-of-concept.

Curcumin nanoformulations to combat aging-related diseases

Aging increases the susceptibility to a diverse set of diseases and disorders, including neurodegeneration, cancer, diabetes, and arthritis. Natural compounds are currently being explored as alternative or complementary agents to treat or prevent aging-related malfunctions. Curcumin, a phytochemical isolated from the spice turmeric, has garnered great interest in recent years. With anti-oxidant, anti-inflammatory, anti-microbial, and other physiological activities, curcumin has great potential for health applications. However, the benefits of curcumin are restricted by its low bioavailability and stability in biological systems. Curcumin nanoformulations, or nano-curcumin, may overcome these limitations. This review discusses different forms of nano-curcumin that have been evaluated in vitro and in vivo to treat or prevent aging-associated health impairments. We describe current barriers for the routine use of curcumin nanoformulations in the clinic. Our review highlights outstanding questions and future work that is needed to ensure nano-curcumin is efficient and safe to lessen the burden of aging-related health problems.

Histone Acetyltransferases and Stem Cell Identity

Acetylation of histones is a key epigenetic modification involved in transcriptional regulation. The addition of acetyl groups to histone tails generally reduces histone-DNA interactions in the nucleosome leading to increased accessibility for transcription factors and core transcriptional machinery to bind their target sequences. There are approximately 30 histone acetyltransferases and their corresponding complexes, each of which affect the expression of a subset of genes. Because cell identity is determined by gene expression profile, it is unsurprising that the HATs responsible for inducing expression of these genes play a crucial role in determining cell fate. Here, we explore the role of HATs in the maintenance and differentiation of various stem cell types. Several HAT complexes have been characterized to play an important role in activating genes that allow stem cells to self-renew. Knockdown or loss of their activity leads to reduced expression and or differentiation while particular HATs drive differentiation towards specific cell fates. In this study we review functions of the HAT complexes active in pluripotent stem cells, hematopoietic stem cells, muscle satellite cells, mesenchymal stem cells, neural stem cells, and cancer stem cells.

Effect of eight-week curcumin supplementation with endurance training on glycemic indexes in middle age women with type 2 diabetes in Iran, A preliminary study

BACKGROUND AND AIMS

The purpose of this study was to determine the effects of curcumin supplementation & endurance training on glycemic indexes in middle-aged women with type 2 diabetes.

METHODS

40 middle-aged women with type 2 diabetes were randomly divided into four groups (control, curcumin, training & curcumin + training). Endurance training protocol included running on treadmill for eight weeks, three sessions per week and each session for 45-60 min, with a maximum intensity of 50-70% of MHR. The experimental groups received a supplementation of curcumin as a daily dose of 80 mg curcumin soft gel for 8 weeks while the control group was subjected to no supplementation or exercise during this period. One day before and one day after the eight-week experimental period, blood samples were taken from the subjects to measure the glycemic indexes, including fasting blood glucose, glycosylated hemoglobin, and serum insulin levels. T-test and two-way covariance analysis tests were used for analyzing the findings at a significant level of less than 0.05.

RESULTS

Eight weeks of curcumin supplementation and endurance training, whether done separately or simultaneously, significantly reduced fasting blood glucose, glycosylated hemoglobin and serum insulin levels (P < 0.05). The combination of curcumin supplementation and endurance training compared to the other two interventions caused a significant further decrease in these glycemic indexes (P < 0.05).

CONCLUSION

The findings of this study showed that eight weeks of curcumin supplementation and endurance training helped each other in improving the glycemic indexes of women with type 2 diabetes.

Hypoglycemic Activity of Curcuma mangga Val. Extract via Modulation of GLUT4 and PPAR-γ mRNA Expression in 3T3-L1 Adipocytes

Background

There would be over 600 million people living with diabetes by 2040 as predicted by the World Health Organization. Diabetes is characterized by raised blood sugar and insulin resistance. Insulin regulates the influx of glucose into the cell by upregulating the glucose transporter type 4 (GLUT4) expression on the plasma membrane. Besides, PPAR-γ also controls the metabolism of glucose in adipose tissues. Curcuma mangga Val., denoted as C. mangga, is a native Indonesian medicinal plant that has many beneficial effects, including an antidiabetic potential.

Purpose

In this research, we aimed to disclose the hypoglycemic activity of ethanol extract of C. mangga (EECM) in 3T3-L1 fibroblasts-derived adipocyte cells in regulating glucose uptake as confirmed by the GLUT4 and PPAR-γ gene expression.

Methods

The uptake of glucose was determined using radioactive glucose, while the gene expression of GLUT4, PPAR-γ, and β-actin was quantified using mRNA segregation and real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR).

Results

We discovered that EECM interventions (200 and 50 μg/mL) increased glucose uptake in lipid-laden 3T3-L1 cells by 14.75 and 8.86 fold compared to the control non-insulin, respectively (p < 0.05). At the same doses, they also increased GLUT4 mRNA expression by 8.41 and 11.18 fold compared to the control non-insulin, respectively (p < 0.05). In contrast, EECM interventions (200 and 50 μg/mL) showed lower levels of PPAR-γ mRNA expression compared to the control metformin, indicating the anti-adipogenic potentials of EECM.

Conclusion

EECM showed hypoglycemic activity in lipid-laden 3T3-L1 cells by improving glucose ingestion into the cells, which was mediated by increased GLUT4 expression and downregulated PPAR-γ expression.

Fabrication, structural characterization and functional attributes of polysaccharide-surfactant-protein ternary complexes for delivery of curcumin

In this study, the nanocomplexes as a novel delivery system for curcumin, were successfully fabricated using high methoxyl pectin (HMP), individual surfactants (rhamnolipid (Rha), tea saponin (TS) and ethyl lauroyl arginate hydrochloride (ELA)) and pea protein isolate (PPI). The optimum mass ratio between PPI and curcumin was 40:1. The HMP-Rha-PPI-Cur, HMP-TS-PPI-Cur and HMP-ELA-PPI-Cur complexes which had particle sizes of 453, 422 and 587 nm, exhibited encapsulation efficiencies of curcumin with 93.46, 92.05 and 86.73%, respectively. The analysis of FTIR revealed that HMP-surfactant-PPI-Cur complexes were formed mainly by hydrogen bonding and electrostatic attraction. XRD result showed that curcumin exhibited a non-crystallized state in the ternary complexes. Moreover, the curcumin within the HMP-Rha-PPI ternary complexes showed better stability under UV-light, thermal and simulated gastrointestinal conditions.

Lysine Acetyltransferase Inhibitors From Natural Sources

Acetylation of histone and non-histone protein lysine residues has been widely described as a critical modulator of several cell functions in humans. Lysine acetyltransferases (KATs) catalyse the transfer of acetyl groups on substrate proteins and are involved in multiple physiological processes such as cell signalling, metabolism, gene regulation, and apoptosis. Given the pivotal role of acetylation, the alteration of KATs enzymatic activity has been clearly linked to various cellular dysfunctions leading to several inflammatory, metabolic, neurological, and cancer diseases. Hence, the use KAT inhibitors (KATi) has been suggested as a potentially successful strategy to reverse or prevent these conditions. To date, only a few KATi have proven to be potential drug candidates, and there is still a keen interest in designing molecules showing drug-like properties from both pharmacodynamics and pharmacokinetics point of view. Increasing literature evidence has been highlighting natural compounds as a wide source of molecular scaffolds for developing therapeutic agents, including KATi. In fact, several polyphenols, catechins, quinones, and peptides obtained from natural sources (including nuts, oils, root extracts, and fungi metabolites) have been described as promising KATi. Here we summarize the features of this class of compounds, describing their modes of action, structure-activity relationships and (semi)-synthetic derivatives, with the aim of assisting the development of novel more potent, isoform selective and drug-like KATi.

Therapeutic Applications of Curcumin Nanomedicine Formulations in Cardiovascular Diseases

Cardiovascular diseases (CVD) compromises a group of heart and blood vessels disorders with high impact on human health and wellbeing. Curcumin (CUR) have demonstrated beneficial effects on these group of diseases that represent a global burden with a prevalence that continues increasing progressively. Pre- and clinical studies have demonstrated the CUR effects in CVD through its anti-hypercholesterolemic and anti-atherosclerotic effects and its protective properties against cardiac ischemia and reperfusion. However, the CUR therapeutic limitation is its bioavailability. New CUR nanomedicine formulations are developed to solve this problem. The present article aims to discuss different studies and approaches looking into the promising role of nanotechnology-based drug delivery systems to deliver CUR and its derivatives in CVD treatment, with an emphasis on their formulation properties, experimental evidence, bioactivity, as well as challenges and opportunities in developing these systems.

Silica-Lipid Hybrid Microparticles as Efficient Vehicles for Enhanced Stability and Bioaccessibility of Curcumin

Curcumin is an active ingredient with multiple functions, but its application is often restricted due to its poor water solubility, weak stability, and consequently low bioaccessibility. Based on this, the aim of this work is to develop a new vehicle to overcome these restrictions. Here we developed a curcumin-loaded nanoemulsion and then curcumin-loaded silica-lipid hybrid microparticles through emulsification and vacuum drying, respectively. The loading of curcumin in the nanoemulsion and microparticles was (0.30±0.02) and (0.67±0.02) %, respectively. FTIR and XRD analyses of microparticles revealed that curcumin was encapsulated in porous, amorphous silica. In vitro antioxidant activities showed that the encapsulation would not affect the antioxidant activity of curcumin. In vitro simulated digestion indicated that nanoemulsion and microparticles had higher curcumin bioaccessibility than the control group. The storage stability of microparticles remained the same during 6 weeks in the dark at 4, 25 and 40 °C. Moreover, the microparticles had a better chemical stability than nanoemulsion under the light. The cell viability was over 80% when the concentration of nanocarriers was less than 45 μg/mL. Hence, the microparticles could be a promising means to load curcumin and improve its solubility, light stability and bioaccessibility.

Molecular mechanisms of curcumin and its analogs in colon cancer prevention and treatment

Colorectal cancer remains to be the most prevalent malignancy in humans and 1.5 million men and women living in the United States are diagnosed with colorectal cancer, with a predicted 145,600 new cases to be diagnosed in 2019. Curcuminoids and its synthetic analogs are now of interest due to their bioactive attributes, especially their action as anticancer activity in various cancer cell line models. Several in vivo and in vitro studies have substantially proved their anticancer activities against colon cancer cell lines. Curcumin analogues like IND-4, FLLL, GO-Y030 and C086 have demonstrated to produce greater cytotoxicity when experimentally studied and study results from many have been suggested to be the same. Combination of curcumin with therapeutic cancer agents like tolfenamic acid, 5-fluorouracil, resveratrol and dasatinib showed improved cytotoxicity and chemotherapeutic effect. The results propose that employment of curcumin with novel drug delivery systems like liposome, micelles and nanoparticle have been performed which could improve the therapeutic efficacy against colon cancer. The present review highlights the mechanism of action, synergistic effect and novel delivery methods to improve the therapeutic potential of curcumin.

Histone acetyltransferase inhibitors: An overview in synthesis, structure-activity relationship and molecular mechanism

Acetylation, a key component in post-translational modification regulated by HATs and HDACs, is relevant to many crucial cellular contexts in organisms. Based on crucial pharmacophore patterns and the structure of targeted proteins, HAT inhibitors are designed and modified for higher affinity and better bioactivity. However, there are still some challenges, such as cell permeability, selectivity, toxicity and synthetic availability, which limit the improvement of HAT inhibitors. So far, only few HAT inhibitors have been approved for commercialization, indicating the urgent need for more successful and effective structure-based drug design and synthetic strategies. Here, we summarized three classes of HAT inhibitors based on their sources and structural scaffolds, emphasizing on their synthetic methods and structure-activity relationships and molecular mechanisms, hoping to facilitate the development and further application of HAT inhibitors.

Curcumin upregulates the Nrf2 system by repressing inflammatory signaling-mediated Keap1 expression in insulin-resistant conditions

Both oxidative stress and inflammation contribute to the development of insulin resistance (IR). Curcumin (Cur) not only has an anti-inflammatory effect but also has an antioxidative stress effect via the activation of NF-E2-related factor 2 (Nrf2). Since there is close cross-communication between inflammation and oxidative stress, we examined whether Cur could modulate Nrf2 function via its anti-inflammatory ability and investigated its underlying mechanism. In this study, we show that Cur inhibits inflammatory signaling and Kelch-like ECH-associated protein 1 (Keap1) expression, which is accompanied by the activation of the Nrf2 system. We further identified that the proinflammatory cytokine tumor necrosis factor alpha (TNFα) could stimulate Keap1 synthesis and increase Nrf2 polyubiquitination, but these effects could be significantly inhibited by Cur treatment. This study demonstrates that Cur-induced Nrf2 activation occurs through the inhibition of inflammatory signaling-mediated upregulation of Keap1, contributing to its beneficial effects on redox homeostasis and insulin sensitivity.

The effect of curcumin supplementation on anthropometric indices, insulin resistance and oxidative stress in patients with type 2 diabetes: a randomized, double-blind clinical trial

BACKGROUND

Diabetes mellitus is a common metabolic disorders in human and affect a lot of people around the world. Curcumin is a component of turmeric and in many studies therapeutic effects such as anti-hypertensive, anti-hyperlipidemia, anti-hyperglycemia for this substance are shown.

AIM

The aim of this study was to investigate the effect of curcumin supplementation on anthropometric indices glycemic control and oxidative stress in overweight patients with type 2 diabetes.

MATERIALS AND METHODS

In this randomized, double-blind, placebo-controlled trial, 53 participants with type 2 diabetes were divided randomly into the experimental and control groups to receive either 1500 mg curcumin or placebo capsule three times in a day for 10 weeks.

RESULT

Supplementation with curcumin in type 2 diabetes compare to placebo causes a significant changes in mean weight (- 0.64 ± 0.22 vs. 0.19 ± 0.37 p < 0.05), body mass index (BMI) (0.3 ± 0.03 vs. 0.1 ± 0 p < 0.05), waist circumference (WC) (- 1.2 ± 0.4 vs. - 0.43 ± 0.11 p < 0.05) and fasting blood sugar (FBS) (- 7 ± 2 vs. 3 ± 0.2 p < 0.05) but did not show any difference for hemoglobin A1c (HbA1c), insulin, malondialdehyde (MDA), total antioxidant capacity (TAC), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) and pancreatic B cell function (HOMA-B) at end of study.

CONCLUSION

This study indicated that daily administration of 1500 mg curcumin has positive effects in reducing fasting blood glucose and weight in patients with type 2 diabetes.Trial registration NCT02529982. Registered 19 August 2015, http://www.clinicaltrial.gov.

Macrophage plasticity, polarization and function in response to curcumin, a diet-derived polyphenol, as an immunomodulatory agent

Monocytes and macrophages are important cells of the innate immune system that have diverse functions, including defense against invading pathogens, removal of dead cells by phagocytosis, antigen presentation in the context of MHC class I and class II molecules, and production of various pro-inflammatory cytokines and chemokines such as IL-1β, IL-6, TNF-α and MCP-1. In addition, pro-inflammatory (M1) and anti-inflammatory (M2) macrophages clearly play important roles in the progression of several inflammatory diseases. Therefore, therapies that target macrophage polarization and function by either blocking their trafficking to sites of inflammation, or skewing M1 to M2 phenotype polarization may hold clinical promise in several inflammatory diseases. Dietary-derived polyphenols have potent natural anti-oxidative properties. Within this group of polyphenols, curcumin has been shown to suppress macrophage inflammatory responses. Curcumin significantly reduces co-stimulatory molecules and also inhibits MAPK activation and the translocation of NF-κB p65. Curcumin can also polarize/repolarize macrophages toward the M2 phenotype. Curcumin-treated macrophages have been shown to be highly efficient at antigen capture and endocytosis via the mannose receptor. These novel findings provide new perspectives for the understanding of the immunopharmacological role of curcumin, as well as its therapeutic potential for impacting macrophage polarization and function in the context of inflammation-related disease. However, the precise effects of curcumin on the migration, differentiation, polarization and immunostimulatory functions of macrophages remain unknown. Therefore, in this review, we summarized whether curcumin can influence macrophage polarization, surface molecule expression, cytokine and chemokine production and their underlying pathways in the prevention of inflammatory diseases.

The environmental pollutant, polychlorinated biphenyls, and cardiovascular disease: a potential target for antioxidant nanotherapeutics

Despite production having stopped in the 1970s, polychlorinated biphenyls (PCBs) represent persistent organic pollutants that continue to pose a serious human health risk. Exposure to PCBs has been linked to chronic inflammatory diseases, such as cardiovascular disease, type 2 diabetes, obesity, as well as hepatic disorders, endocrine dysfunction, neurological deficits, and many others. This is further complicated by the PCB's strong hydrophobicity, resulting in their ability to accumulate up the food chain and to be stored in fat deposits. This means that completely avoiding exposure is not possible, thus requiring the need to develop intervention strategies that can mitigate disease risks associated with exposure to PCBs. Currently, there is excitement in the use of nutritional compounds as a way of inhibiting the inflammation associated with PCBs, yet the suboptimal delivery and pharmacology of these compounds may not be sufficient in more acute exposures. In this review, we discuss the current state of knowledge of PCB toxicity and some of the antioxidant and anti-inflammatory nanocarrier systems that may be useful as an enhanced treatment modality for reducing PCB toxicity.

Concealed use of herbal and dietary supplements among Thai patients with type 2 diabetes mellitus

Background

Diabetes mellitus (DM) has been one of the most common chronic diseases that create great impacts on both morbidities and mortalities. Many patients who suffering from this disease seek for complementary and alternative medicine. The aim of this study was to determine the prevalence and related factors of herbal and dietary supplement (HDS) use in patients with DM type 2 at a single university hospital in Thailand.

Methods

A cross-sectional study was performed in 200 type 2 DM patients via face-to-face structured interviews using developed questionnaires comprised of demographic data, diabetes-specific information, details on HDS use, and medical adherence.

Results

From the endocrinology clinic, 61% of total patients reported HDS exposure and 28% were currently consuming. More than two-thirds of HDS users did not notify their physicians, mainly because of a lack of doctor concern; 73% of cases had no awareness of potential drug-herb interaction. The use of drumstick tree, turmeric and bitter gourd and holy mushroom were most frequently reported. The main reasons for HDS use were friend and relative suggestions and social media. Comparisons of demographic characteristics, medical adherence, and hemoglobin A1c among these non-HDS users, as well as current and former users, were not statistically significantly different.

Conclusions

This study revealed a great number of DM patients interested in HDS use. The use of HDS for glycemic control is an emerging public health concern given the potential adverse effects, drug interactions and benefits associated with its use. Health care professionals should aware of HDS use and hence incorporate this aspect into the clinical practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s40200-017-0317-3) contains supplementary material, which is available to authorized users.

Hyperglycemic memory in metabolism and cancer

Hyperglycemia is a hallmark of both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Recent evidence strongly suggests that prolonged exposure to hyperglycemia can epigenetically modify gene expression profiles in human cells and that this effect is sustained even after hyperglycemic control is therapeutically achieved; this phenomenon is called hyperglycemic memory. This metabolic memory effect contributes substantially to the pathology of various diabetic complications, such as diabetic retinopathy, hypertension, and diabetic nephropathy. Due to the metabolic memory in cells, diabetic patients suffer from various complications, even after hyperglycemia is controlled. With regard to this strong association between diabetes and cancer risk, cancer cells have emerged as key target cells of hyperglycemic memory in diabetic cancer patients. In this review, we will discuss the recent understandings of the molecular mechanisms underlying hyperglycemic memory in metabolism and cancer.

Nanomedicines for dysfunctional macrophage-associated diseases

Macrophages play vital functions in host inflammatory reaction, tissue repair, homeostasis and immunity. Dysfunctional macrophages have significant pathophysiological impacts on diseases such as cancer, inflammatory diseases (rheumatoid arthritis and inflammatory bowel disease), metabolic diseases (atherosclerosis, diabetes and obesity) and major infections like human immunodeficiency virus infection. In view of this common etiology in these diseases, targeting the recruitment, activation and regulation of dysfunctional macrophages represents a promising therapeutic strategy. With the advancement of nanotechnology, development of nanomedicines to efficiently target dysfunctional macrophages can strengthen the effectiveness of therapeutics and improve clinical outcomes. This review discusses the specific roles of dysfunctional macrophages in various diseases and summarizes the latest advances in nanomedicine-based therapeutics and theranostics for treating diseases associated with dysfunctional macrophages.

Phytobioactive compound-based nanodelivery systems for the treatment of type 2 diabetes mellitus - current status

Type 2 diabetes mellitus (T2DM) is a major chronic disease that is prevalent worldwide, and it is characterized by an increase in blood glucose, disturbances in the metabolism, and alteration in insulin secretion. Nowadays, food-based therapy has become an important treatment mode for type 2 diabetes, and phytobioactive compounds have gained an increasing amount of attention to this end because they have an effect on multiple biological functions, including the sustained secretion of insulin and regeneration of pancreatic islets cells. However, the poor solubility and lower permeability of these phyto products results in a loss of bioactivity during processing and oral delivery, leading to a significant reduction in the bioavailability of phytobioactive compounds to treat T2DM. Recently, nanotechnological systems have been developed for use as various types of carrier systems to improve the delivery of bioactive compounds and thus obtain a greater bioavailability. Furthermore, carrier systems in most nanodelivery systems are highly biocompatible, with nonimmunologic behavior, a high degree of biodegradability, and greater mucoadhesive strength. Therefore, this review focuses on the various types of nanodelivery systems that can be used for phytobioactive compounds in treating T2DM with greater antidiabetic effects. There is also additional focus on improving the effects of various phytobioactive compounds through nanotechnological delivery to ensure a highly efficient treatment of type 2 diabetes.

Immunosuppressive Effects of Natural α,β-Unsaturated Carbonyl-Based Compounds, and Their Analogs and Derivatives, on Immune Cells: A Review

The immune system is complex and pervasive as it functions to prevent or limit infections in the human body. In a healthy organism, the immune system and the redox balance of immune cells maintain homeostasis within the body. The failure to maintain the balance may lead to impaired immune response and either over activity or abnormally low activity of the immune cells resulting in autoimmune or immune deficiency diseases. Compounds containing α,β-unsaturated carbonyl-based moieties are often reactive. The reactivity of these groups is responsible for their diverse pharmacological activities, and the most important and widely studied include the natural compounds curcumin, chalcone, and zerumbone. Numerous studies have revealed the mainly immunosuppressive and anti-inflammatory activities of the aforesaid compounds. This review highlights the specific immunosuppressive effects of these natural α,β-unsaturated carbonyl-based compounds, and their analogs and derivatives on different types of immune cells of the innate (granulocytes, monocytes, macrophages, and dendritic cells) and adaptive (T cells, B cells, and natural killer cells) immune systems. The inhibitory effects of these compounds have been comprehensively studied on neutrophils, monocytes and macrophages but their effects on T cells, B cells, natural killer cells, and dendritic cells have not been well investigated. It is of paramount importance to continue generating experimental data on the mechanisms of action of α,β-unsaturated carbonyl-based compounds on immune cells to provide useful information for ensuing research to discover new immunomodulating agents.

Curcumin inhibits placental inflammation to ameliorate LPS-induced adverse pregnancy outcomes in mice via upregulation of phosphorylated Akt

INTRODUCTION

Excessive inflammation results in adverse pregnancy outcomes, including embryonic resorption, fetal growth restriction, and preeclampsia. This study investigated whether curcumin, a highly safe anti-inflammation drug, had protective effect on lipopolysaccharide (LPS)-treated pregnant mice.

METHOD

A mouse model of LPS-induced adverse pregnancy outcomes was generated by daily administering LPS from GD 13.5 to GD 16.5. Curcumin was given from GD 0.5. The effects of curcumin on maternal hypertension, proteinuria, pregnancy outcomes, as well as proinflammatory factors, chemokines, Akt, JNK, and P38 levels in placenta were examined.

RESULTS

Systolic blood pressure (156.6 ± 5.056 versus 125.5 ± 3.617 mmHg; P < 0.05) and proteinuria (22.36 ± 2.22 versus 12.70 ± 1.04 mg/L; P < 0.05) were decreased in the LPS+curcumin-treated group, as compared with the LPS-treated group. Curcumin also increased the number of live pups, fetal weight, and placental weight, while it decreased fetal resorption rate. Moreover, increased placental TNF-α, IL-1β, and IL-6 expressions in LPS-treated group were significantly suppressed after curcumin administration. Furthermore, decreased p-Akt level in placenta induced by LPS was improved by curcumin. Of note, the expression of p-Akt increased by curcumin was accompanied by the decreased chemokines MCP-1 and MIP-1 levels and fewer CD68-positive macrophages in the placenta.

CONCLUSION

Curcumin inhibited the expression of proinflammatory factors and macrophage infiltration in placenta and ameliorated LPS-induced adverse pregnancy outcomes in mice by inhibiting inflammation via upregulation of phosphorylated Akt.

The 11β-hydroxysteroid dehydrogenase type 1 inhibitor protects against the insulin resistance and hepatic steatosis in db/db mice

Glucocorticoids (GCs) metabolism is regulated by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). When GCs are present in excess, they can impair glucose-dependent insulin sensitivity. We have previously synthesized several curcumin analogues, of which four compounds were selective inhibitors of 11β-HSD1. Here, we present data supporting that the 11β-hydroxysteroid dehydrogenase type 1 inhibitor (H8) inhibits insulin resistance and ameliorates hepatic steatosis in db/db mice. We compared glucose and lipid metabolism in db/db mice with or without administration of H8, which significantly decreased fasting blood glucose levels and protected against insulin resistance and hepatic steatosis compared to when glucose and lipid metabolism were measured following curcumin administration. The hepatic enzyme was reduced significantly in the plasma samples from db/db mice which were treated with H8. Serum corticosterone (active) levels, which are regulated by 11β-HSD1 were reduced when mice received H8. H8 administration suppressed phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6-pase) expression, which are related to gluconeogenesis and enhanced glucose transporter 4 (GLUT4) protein content in liver. Treatment with H8 improved obesity and metabolic disorders, such as insulin resistance and hepatic steatosis by suppressing activity of 11β-HSD1, suggesting that H8 might be a beneficial drug for the treatment of obesity and Type-2 diabetes (T2D).

Curcumin directly inhibits the transport activity of GLUT1

Curcumin, a major ingredient in turmeric, has a long history of medicinal applications in a wide array of maladies including treatment for diabetes and cancer. Seemingly counterintuitive to the documented hypoglycemic effects of curcumin, however, a recent report indicates that curcumin directly inhibits glucose uptake in adipocytes. The major glucose transporter in adipocytes is GLUT4. Therefore, this study investigates the effects of curcumin in cell lines where the major transporter is GLUT1. We report that curcumin has an immediate inhibitory effect on basal glucose uptake in L929 fibroblast cells with a maximum inhibition of 80% achieved at 75 μM curcumin. Curcumin also blocks activation of glucose uptake by azide, glucose deprivation, hydroxylamine, or phenylarsine oxide. Inhibition does not increase with exposure time and the inhibitory effects reverse within an hour. Inhibition does not appear to involve a reaction between curcumin and the thiol side chain of a cysteine residue since neither prior treatment of cells with iodoacetamide nor curcumin with cysteine alters curcumin's inhibitory effects. Curcumin is a mixed inhibitor reducing the Vmax of 2DG transport by about half with little effect on the Km. The inhibitory effects of curcumin are not additive to the effects of cytochalasin B and 75 μM curcumin actually reduces specific cytochalasin B binding by 80%. Taken together, the data suggest that curcumin binds directly to GLUT1 at a site that overlaps with the cytochalasin B binding site and thereby inhibits glucose transport. A direct inhibition of GLUT proteins in intestinal epithelial cells would likely reduce absorption of dietary glucose and contribute to a hypoglycemic effect of curcumin. Also, inhibition of GLUT1 activity might compromise cancer cells that overexpress GLUT1 and be another possible mechanism for the documented anticancer effects of curcumin.

Potential effects of curcumin on peroxisome proliferator-activated receptor-γ in vitro and in vivo

Natural peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists are found in food and may be important for health through their anti-inflammatory properties. Curcumin (Cur) is a bright yellow spice, derived from the rhizome of Curcuma longa Linn. It has been shown to have many biological properties that appear to operate through diverse mechanisms. Some of these potentially beneficial effects of Cur are due to activation of the nuclear transcription factor PPAR-γ. It is reported (using in vitro and in vivo models) that Cur plays a potential role against several diseases. In this review article, we present the current literature on the effects of Cur on the modulation of inflammatory processes that are mediated through PPAR-γ.

Insulin-mimetic and anti-inflammatory potential of a vanadyl-Schiff base complex for its application against diabetes

Insulin-mimetic and anti-inflammatory potential of vanadium oxo complex (VOTP) enhances the GLUT4 translocation by inducing the phosphorylation of tyrosine moiety in insulin receptor substrate (IRS1).

Selected Phytochemicals and Culinary Plant Extracts Inhibit Fructose Uptake in Caco-2 Cells

This study compared the ability of nine culinary plant extracts containing a wide array of phytochemicals to inhibit fructose uptake and then explored the involvement of intestinal fructose transporters and phytochemicals for selected samples. The chemical signature was characterized by high performance liquid chromatography with mass spectrometry. Inhibition of [(14)C]-fructose uptake was tested by using human intestinal Caco-2 cells. Then, the relative contribution of the two apical-facing intestinal fructose transporters, GLUT2 and GLUT5, and the signature components for fructose uptake inhibition was confirmed in naive, phloretin-treated and forskolin-treated Caco-2 cells. HPLC/MS analysis of the chemical signature revealed that guava leaf contained quercetin and catechin, and turmeric contained curcumin, bisdemethoxycurcumin and dimethoxycurcumin. Similar inhibition of fructose uptake (by ~50%) was observed with guava leaf and turmeric in Caco-2 cells, but with a higher contribution of GLUT2 for turmeric and that of GLUT5 for guava leaf. The data suggested that, in turmeric, demethoxycurcumin specifically contributed to GLUT2-mediated fructose uptake inhibition, and curcumin did the same to GLUT5-mediated fructose uptake inhibition, but GLUT2 inhibition was more potent. By contrast, in guava leaf, catechin specifically contributed to GLUT5-mediated fructose uptake inhibition, and quercetin affected both GLUT5- and GLUT2-mediated fructose uptake inhibition, resulting in the higher contribution of GLUT5. These results suggest that demethoxycurcumin is an important contributor to GLUT2-mediated fructose uptake inhibition for turmeric extract, and catechin is the same to GLUT5-mediated fructose uptake inhibition for guava leaf extract. Quercetin, curcumin and bisdemethoxycurcumin contributed to both GLUT5- and GLUT2-mediated fructose uptake inhibition, but the contribution to GLUT5 inhibition was higher than the contribution to GLUT2 inhibition.

Therapeutic Applications of Curcumin Nanoformulations

Curcumin (diferuloylmethane) is a bioactive and major phenolic component of turmeric derived from the rhizomes of curcuma longa linn. For centuries, curcumin has exhibited excellent therapeutic benefits in various diseases. Owing to its anti-oxidant and anti-inflammatory properties, curcumin plays a significant beneficial and pleiotropic regulatory role in various pathological conditions including cancer, cardiovascular disease, Alzheimer's disease, inflammatory disorders, neurological disorders, and so on. Despite such phenomenal advances in medicinal applications, the clinical implication of native curcumin is hindered due to low solubility, physico-chemical instability, poor bioavailability, rapid metabolism, and poor pharmacokinetics. However, these issues can be overcome by utilizing an efficient delivery system. Active scientific research was initiated in 2005 to improve curcumin's pharmacokinetics, systemic bioavailability, and biological activity by encapsulating or by loading curcumin into nanoform(s) (nanoformulations). A significant number of nanoformulations exist that can be translated toward medicinal use upon successful completion of pre-clinical and human clinical trials. Considering this perspective, current review provides an overview of an efficient curcumin nanoformulation for a targeted therapeutic option for various human diseases. In this review article, we discuss the clinical evidence, current status, and future opportunities of curcumin nanoformulation(s) in the field of medicine. In addition, this review presents a concise summary of the actions required to develop curcumin nanoformulations as pharmaceutical or nutraceutical candidates.