Utility of curcumin for the treatment of diabetes mellitus: Evidence from preclinical and clinical studies

Epigenetic Orchestration of Neurodegenerative Disorders: A Possible Target for Curcumin as a Therapeutic

Epigenetic modulations play a major role in gene expression and thus are responsible for various physiological changes including age-associated neurological disorders. Neurodegenerative diseases such as Alzheimer's (AD), Parkinson's (PD), Huntington's disease (HD), although symptomatically different, may share common underlying mechanisms. Most neurodegenerative diseases are associated with increased oxidative stress, aggregation of certain proteins, mitochondrial dysfunction, inactivation/dysregulation of protein degradation machinery, DNA damage and cell excitotoxicity. Epigenetic modulations has been reported to play a significant role in onset and progression of neurodegenerative diseases by regulating these processes. Previous studies have highlighted the marked antioxidant and neuroprotective abilities of polyphenols such as curcumin, by increased activity of detoxification systems like superoxide dismutase (SOD), catalase or glutathione peroxidase. The role of curcumin as an epigenetic modulator in neurological disorders and neuroinflammation apart from other chronic diseases have also been reported by a few groups. Nonetheless, the evidences for the role of curcumin mediated epigenetic modulation in its neuroprotective ability are still limited. This review summarizes the current knowledge of the role of mitochondrial dysfunction, epigenetic modulations and mitoepigenetics in age-associated neurological disorders such as PD, AD, HD, Amyotrophic Lateral Sclerosis (ALS), and Multiple Sclerosis (MS), and describes the neuroprotective effects of curcumin in the treatment and/or prevention of these neurodegenerative diseases by regulation of the epigenetic machinery.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

The Golden Spice for Life: Turmeric with the Pharmacological Benefits of Curcuminoids Components, Including Curcumin, Bisdemethoxycurcumin, and Demethoxycurcumins

BACKGROUND

Turmeric (Curcuma longa L.), belonging to the Zingiberaceae family, is a perennial rhizomatous plant of tropical and subtropical regions. The three major chemical components responsible for the biological activities of turmeric are curcumin, demethoxycurcumin, and bisdemethoxycurcumin.

METHODS

The literature search included review articles, analytical studies, randomized control experiments, and observations, which have been gathered from various sources, such as Scopus, Google Scholar, PubMed, and ScienceDirect. A review of the literature was carried out using the keywords: turmeric, traditional Chinese medicine, traditional Iranian medicine, traditional Indian medicine, curcumin, curcuminoids, pharmaceutical benefits, turmerone, demethoxycurcumin, and bisdemethoxycurcumin. The main components of the rhizome of the leaf are α-turmerone, β-turmerone, and arturmerone.

RESULTS

The notable health benefits of turmeric are antioxidant activity, gastrointestinal effects, anticancer effects, cardiovascular and antidiabetic effects, antimicrobial activity, photoprotector activity, hepatoprotective and renoprotective effects, and appropriate for the treatment of Alzheimer's disease and inflammatory and edematic disorders.

DISCUSSION

Curcuminoids are phenolic compounds usually used as pigment spices with many health benefits, such as antiviral, antitumour, anti-HIV, anti-inflammatory, antiparasitic, anticancer, and antifungal effects. Curcumin, bisdemethoxycurcumin, and demethoxycurcumin are the major active and stable bioactive constituents of curcuminoids. Curcumin, which is a hydroponic polyphenol, and the main coloring agent in the rhizomes of turmeric, has anti-inflammatory, antioxidant, anti-cancer, and anticarcinogenic activities, as well as beneficial effects for infectious diseases and Alzheimer's disease. Bisdemethoxycurcumin possesses antioxidant, anti-cancer, and anti-metastasis activities. Demethoxycurcumin, which is another major component, has anti-inflammatory, antiproliferative, and anti-cancer activities and is the appropriate candidate for the treatment of Alzheimer's disease.

CONCLUSION

The goal of this review is to highlight the health benefits of turmeric in both traditional and modern pharmaceutical sciences by considering the important roles of curcuminoids and other major chemical constituents of turmeric.

A scientifically validated combination of garcinol, curcuminoids, and piperine for mild to moderate nonalcoholic steatohepatitis patients-results from a randomized, double-blind, placebo-controlled study

Background

Garcinol is a naturally occurring compound from the fruit rind of the Garcinia indica, with antioxidant, anti-inflammatory, and anticancer properties. Curcuminoids are the active molecule from the rhizome of Curcuma longa, studied extensively for its health benefits as an anti-inflammatory and antioxidant activities. Non-alcoholic steatohepatitis (NASH) is the progressive form of nonalcoholic steatohepatitis characterized by liver fat and inflammation.

Objective

To evaluate the clinical efficacy and safety of Garcinol, Curcuminoids and piperine (GCP) combination in patients with mild to moderate NASH in a randomized, double-blind, placebo-controlled study.

Methods

The patients received one tablet (450 mg) of GCP containing garcinol-50 mg, curcuminoids -250 mg and piperine 5 mg or a placebo (450 mg of microcrystalline cellulose) twice daily for 90 days. Changes in circulating aspartate aminotransferase (AST), alanine transaminase (ALT) levels, liver stiffness measurement (LSM), and controlled attenuation parameter (CAP) using Fibroscan were compared from baseline to day 90. Anthropometric parameters, serum levels of lipids, Interleukin (IL-6), hsCRP, and adiponectin were estimated. Safety was evaluated by laboratory parameters and by monitoring adverse events.

Results

Seventy-two patients were randomized and 63 (GCP = 32, Placebo = 31) completed the study. The mean age of the patients was 48.3 ± 8.7 years (36 males and 27 females). The mean reduction in AST (U/L) was 9.53 in GCP and 3.16 in placebo (p < 0.001) and that of ALT (U/L) was 13.47 in GCP and 7.43 in Placebo (p = 0.002). The liver stiffness and CAP scores showed a better reduction in GCP (0.56 kPa and 12.38 db/m) compared to placebo (0.064 kPa and 10.42 db/m) p < 0.05. Consequently, the noninvasive Fibroscan-AST (FAST) score reduction was also found to be significant in GCP compared to placebo. Additionally, body weight, lipid levels, hsCRP, and IL-6 in serum decreased, while adiponectin levels increased in GCP-supplemented participants compared to placebo. The combination of garcinol and curcuminoids was well tolerated with no significant changes in hematological and clinical laboratory parameters during the 90-day supplementation.

Conclusion

Our results suggest that GCP could be a possible supplement for the management of NASH.Clinical trial registration: https://clinicaltrials.gov/, identifier CTRI/2019/11/022147.

Biocompatible Anisole-Nonlinear PEG Core-Shell Nanogels for High Loading Capacity, Excellent Stability, and Controlled Release of Curcumin

Curcumin, a nontoxic and cheap natural medicine, has high therapeutic efficacy for many diseases, including diabetes and cancers. Unfortunately, its exceedingly low water-solubility and rapid degradation in the body severely limit its bioavailability. In this work, we prepare a series of biocompatible poly(vinyl anisole)@nonlinear poly(ethylene glycol) (PVAS@PEG) core-shell nanogels with different PEG gel shell thickness to provide high water solubility, good stability, and controllable sustained release of curcumin. The PVAS nanogel core is designed to attract and store curcumin molecules for high drug loading capacity and the hydrophilic nonlinear PEG gel shell is designed to offer water dispersibility and thermo-responsive drug release. The nanogels prepared are monodispersed in a spherical shape with clear core-shell morphology. The size and shell thickness of the nanogels can be easily controlled by changing the core-shell precursor feeding ratios. The optimized PVAS@PEG nanogels display a high curcumin loading capacity of 38.0 wt%. The nanogels can stabilize curcumin from degradation at pH = 7.4 and release it in response to heat within the physiological temperature range. The nanogels can enter cells effectively and exhibit negligible cytotoxicity to both the B16F10 and HL-7702 cells at a concentration up to 2.3 mg/mL. Such designed PVAS@PEG nanogels have great potential to be used for efficient drug delivery.

Curcumin: Overview of Extraction Methods, Health Benefits, and Encapsulation and Delivery Using Microemulsions and Nanoemulsions

Curcumin is the principal curcuminoid found in the rhizomes of turmeric. Due to its therapeutic action against cancer, depression, diabetes, some bacteria, and oxidative stress, it has been used widely in medicine since ancient times. Due to its low solubility, the human organism cannot completely absorb it. Advanced extraction technologies, followed by encapsulation in microemulsion and nanoemulsion systems, are currently being used to improve bioavailability. This review discusses the different methods available for curcumin extraction from plant material, methods for the identification of curcumin in the resulting extracts, its beneficial effects on human health, and the encapsulation techniques into small colloidal systems that have been used over the past decade to deliver this compound.

Neurological damages in COVID-19 patients: Mechanisms and preventive interventions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, causes coronavirus disease 2019 (COVID-19) which led to neurological damage and increased mortality worldwide in its second and third waves. It is associated with systemic inflammation, myocardial infarction, neurological illness including ischemic strokes (e.g., cardiac and cerebral ischemia), and even death through multi-organ failure. At the early stage, the virus infects the lung epithelial cells and is slowly transmitted to the other organs including the gastrointestinal tract, blood vessels, kidneys, heart, and brain. The neurological effect of the virus is mainly due to hypoxia-driven reactive oxygen species (ROS) and generated cytokine storm. Internalization of SARS-CoV-2 triggers ROS production and modulation of the immunological cascade which ultimately initiates the hypercoagulable state and vascular thrombosis. Suppression of immunological machinery and inhibition of ROS play an important role in neurological disturbances. So, COVID-19 associated damage to the central nervous system, patients need special care to prevent multi-organ failure at later stages of disease progression. Here in this review, we are selectively discussing these issues and possible antioxidant-based prevention therapies for COVID-19-associated neurological damage that leads to multi-organ failure.

Efficacy of the monocarbonyl curcumin analog C66 in the reduction of diabetes-associated cardiovascular and kidney complications

Curcumin is a polyphenolic compound derived from turmeric that has potential beneficial properties for cardiovascular and renal diseases and is relatively safe and inexpensive. However, the application of curcumin is rather problematic due to its chemical instability and low bioavailability. The experimental results showed improved chemical stability and potent pharmacokinetics of one of its analogs – (2E,6E)-2,6-bis[(2-trifluoromethyl)benzylidene]cyclohexanone (C66). There are several advantages of C66, like its synthetic accessibility, structural simplicity, improved chemical stability (in vitro and in vivo), presence of two reactive electrophilic centers, and good electron-accepting capacity. Considering these characteristics, we reviewed the literature on the application of C66 in resolving diabetes-associated cardiovascular and renal complications in animal models. We also summarized the mechanisms by which C66 is preventing the release of pro-oxidative and pro-inflammatory molecules in the priming and in activation stage of cardiomyopathy, renal fibrosis, and diabetic nephropathy. The cardiovascular protective effect of C66 against diabetes-induced oxidative damage is Nrf2 mediated but mainly dependent on JNK2. In general, C66 causes inhibition of JNK2, which reduces cardiac inflammation, fibrosis, oxidative stress, and apoptosis in the settings of diabetic cardiomyopathy. C66 exerts a powerful antifibrotic effect by reducing inflammation-related factors (MCP-1, NF-κB, TNF-α, IL-1β, COX-2, and CAV-1) and inducing the expression of anti-inflammatory factors (HO-1 and NEDD4), as well as targeting TGF-β/SMADs, MAPK/ERK, and PPAR-γ pathways in animal models of diabetic nephropathy. Based on the available evidence, C66 is becoming a promising drug candidate for improving cardiovascular and renal health.

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.

Pairing 3D-Printing with Nanotechnology to Manage Metabolic Syndrome

Introduction

This work was aimed to develop a Curcuma oil-based self-nanoemulsifying drug delivery system (SNEDDS) 3D-printed polypills containing glimepiride (GMD) and rosuvastatin (RSV) for treatment of dyslipidemia in patients with diabetes as a model for metabolic syndrome (MS).

Methods

Compartmentalized 3D printed polypills were prepared and studied in streptozotocin/poloxamer induced diabetic/dyslipidemic rats. The pharmacokinetic parameters of GMD and RSV in the prepared polypills were evaluated. Blood glucose level, lipid profile, antioxidant, and biochemical markers activities were investigated. Also, histopathological examination of the liver and pancreas was carried out. The atherosclerotic index, the area of islets of Langerhans, and liver steatosis lesion scores were calculated.

Results

The developed SNEDDS-loaded GMD/RSV polypills showed acceptable quality control characteristics with a high relative bioavailability of 217.16% and 224.28% for GMD and RSV, respectively, when compared with the corresponding non-SNEDDS pills. The prepared polypills showed dramatic lowering in blood glucose levels and substantial improvement in lipid profile and hepatic serum biomarkers as well as remarkable decrease in serum antioxidants in response to Poloxamer 407 intoxication. The prepared polypills decreased the risk of atherosclerosis and coronary disease by boosting the level of high-density lipoprotein and lowering both triglyceride and low-density lipoprotein. Microscopic examination showed normal hepatic sinusoids and high protection level with less detectable steatosis in the examined hepatocytes. Normal size pancreatic islets with apparently normal exocrine acini and pancreatic duct were also noticed.

Conclusion

This formulation strategy clearly shows the potential of the developed polypills in personalized medicine for treatment of patients with MS.

Evaluation of hypoglycemic therapeutics and nutritional supplementation for type 2 diabetes mellitus management: An insight on molecular approaches

OBJECTIVE

This review aims to summarize the current management of type 2 diabetes principles, including oral hypoglycemic agents, types of insulin administration, diet maintenance, and various molecular approaches.

METHODS

A literature search was conducted in different databases such as Scopus, ScienceDirect, Google Scholar, and Web of Science by using the following keywords: type-2 diabetes mellitus (T2DM), first-line and second-line treatment, oral hypoglycemic agents, insulin administration, diet/nutritional therapy, gene and stem cell therapy, and diabetic complications.

RESULTS

The first-line treatment of T2DM includes administering oral hypoglycemic agents (OHAs) and second-line treatment by insulin therapy and some OHAs like Sulfonylurea's (SU). The oral hypoglycemic or oral antidiabetic drugs have the function of lowering glucose in the blood. Insulin therapy is recommended for people with A1C levels > 7.0, and insulin administration is evolved drastically from the syringe, pump, pen, inhalation, insulin jet, and patch. The use of OHAs and insulin therapy during glycemic control has a severe effect on weight gain and other side effects. Hence, diet maintenance (macro and micronutrients) and nutritional therapy guidelines were also reviewed/recommended for safe T2DM management. Besides, the recent progress in molecular approaches that focuses on identifying new targets for T2DM (i.e.) consisting of gene therapy, stem cell therapy, and the modulation of insulin signaling pathways for the regulation of glucose storage and uptake also discussed.

CONCLUSION

The analysis of all these key factors is necessary to develop a potential agent to cure T2DM and suggest that a combination of therapies will pave the way for advanced management of T2DM.

Phytochemicals and Their Possible Mechanisms in Managing COVID-19 and Diabetes

For the writing of this manuscript, we searched information published from 2000 to 2021, through PubMed, Web of Science, Springer, and Science Direct. Focusing on the effects related to respiratory diseases, in addition to possible direct effects towards SARS-CoV-2, coupled with diabetes. Diabetes is a metabolic disease that is characterized by affecting the function of glucose, in addition to insulin insufficiency. This leads to patients with such pathologies as being at greater risk for developing multiple complications and increase exposure to viruses infections. This is the case of severe acute respiratory disease coronavirus 19 (SARS-CoV-2), which gave rise to coronavirus disease 2019 (COVID-19), declared an international public health emergency in March of 2020 Currently, several strategies have been applied in order to prevent the majority of the consequences of COVID-19, especially in patients with chronic diseases such as diabetes. Among the possible treatment options, we found that the use of phytochemical compounds has exhibited beneficial effects for the prevention and inhibition of infection by SARS-CoV-2, as well as for the improvement of the manifestations of diabetes.

Development of Aldose Reductase Inhibitors for the Treatment of Inflammatory Disorders and Cancer: Current Drug Design Strategies and Future Directions

Aldose Reductase (AR) is an enzyme that converts glucose to sorbitol during the polyol pathway of glucose metabolism. AR has been shown to be involved in the development of secondary diabetic complications due to its involvement in causing osmotic as well as oxidative stress. Various AR inhibitors have been tested for their use to treat secondary diabetic complications, such as retinopathy, neuropathy, and nephropathy in clinical studies. Recent studies also suggest the potential role of AR in mediating various inflammatory complications. Therefore, the studies on the development and potential use of AR inhibitors to treat inflammatory complications and cancer besides diabetes are currently on the rise. Further, genetic mutagenesis studies, computer modeling, and molecular dynamics studies have helped design novel and potent AR inhibitors. This review discussed the potential new therapeutic use of AR inhibitors in targeting inflammatory disorders and cancer besides diabetic complications. Further, we summarized studies on how AR inhibitors have been designed and developed for therapeutic purposes in the last few decades.

The Emerging Role of HDACs: Pathology and Therapeutic Targets in Diabetes Mellitus

Diabetes mellitus (DM) is one of the principal manifestations of metabolic syndrome and its prevalence with modern lifestyle is increasing incessantly. Chronic hyperglycemia can induce several vascular complications that were referred to be the major cause of morbidity and mortality in DM. Although several therapeutic targets have been identified and accessed clinically, the imminent risk of DM and its prevalence are still ascending. Substantial pieces of evidence revealed that histone deacetylase (HDAC) isoforms can regulate various molecular activities in DM via epigenetic and post-translational regulation of several transcription factors. To date, 18 HDAC isoforms have been identified in mammals that were categorized into four different classes. Classes I, II, and IV are regarded as classical HDACs, which operate through a Zn-based mechanism. In contrast, class III HDACs or Sirtuins depend on nicotinamide adenine dinucleotide (NAD+) for their molecular activity. Functionally, most of the HDAC isoforms can regulate β cell fate, insulin release, insulin expression and signaling, and glucose metabolism. Moreover, the roles of HDAC members have been implicated in the regulation of oxidative stress, inflammation, apoptosis, fibrosis, and other pathological events, which substantially contribute to diabetes-related vascular dysfunctions. Therefore, HDACs could serve as the potential therapeutic target in DM towards developing novel intervention strategies. This review sheds light on the emerging role of HDACs/isoforms in diabetic pathophysiology and emphasized the scope of their targeting in DM for constituting novel interventional strategies for metabolic disorders/complications.

Engineering 2D approaches fibrous platform incorporating turmeric and polyaniline nanoparticles to predict the expression of βIII-Tubulin and TREK-1 through qRT-PCR to detect neuronal differentiation of PC12 cells

The bioengineering electroactive construct of a nerve-guided conduit for repairing and restoring injured nerves is an exciting biomedical endeavor that has implications for the treatment of peripheral nerve injury. In this study, we report the development the polycaprolactone (PCL) nanofibrous substrate consisting of turmeric (TUR) and polyaniline nanoparticles (PANINPs) exhibits topological and biological features that mimics the natural extracellular matrix (ECM) for nerve cells. We evaluated the morphology of 2-dimensional (2D) fibrous substrates, and their ability of stem cell adhesion, growth and proliferation rate were influenced by use of various concentrations of turmeric in PCL-TUR substrates. The results showed that 0.62 wt% of TUR and 0.28 wt% of PANINPs in PCL nanofibers substrate exhibited the optimal cellular microenvironment to accelerate PC12 cellular activities. The in vitro experiments revealed that PCL-TUR@PANI substrates significantly stimulated the proliferation, differentiation, and spontaneous outgrowth and extension of neurites from the cells. The substrate has the capacity to respond directly to neuronal markers with significant upregulation of βIII-Tubulin and TREK-1 through myelination, and also trigger neurotrophic protein expression, which was confirmed via immunocytochemistry and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. This study provides a new technique to design substrate of nerve tissue-specific microenvironment for peripheral nerve cell regeneration and could offer promising biomaterials for in vivo peripheral nerve repair.

Current Trends in Drug Delivery System of Curcumin and its Therapeutic Applications

Curcumin is a poly phenolic compound extracted from turmeric. Over the past years, it has acquired significant interest among researchers due to its numerous pharmacological activities like anti- cancer, anti-alzheimer, anti-diabetic, anti-bacterial, anti-inflammatory and so on. However, the clinical use of curcumin is still obstructed due to tremendously poor bioavailability, rapid metabolism, lower gastrointestinal absorption, and low permeability through cell that makes its pharmacology thrilling. These issues have led to enormous surge of investigation to develop curcumin nano formulations which can overcome these restrictive causes. The scientists all across the universe are working on designing several drug delivery systems viz. liposomes, micelles, magnetic nano carriers, etc. for curcumin and its composites which not only improve its physiochemical properties but also enhanced its therapeutic applications. The review aims to systematically examine the treasure of information about the medicinal use of curcumin. This article delivers a general idea of the current study piloted to overwhelm the complications with the bioavailability of curcumin which have exhibited an enhanced biological activity than curcumin. This article explains the latest and detailed study of curcumin and its conjugates, its phytochemistry and biological perspectives and also proved curcumin as an efficient drug candidate for the treatment of numerous diseases. Recent advancements and futuristic viewpoints are also deliberated, which shall help researchers and foster commercial translations of improved nanosized curcumin combination for the treatment of various diseases.

Garcinia mangostana extract and curcumin ameliorate oxidative stress, dyslipidemia, and hyperglycemia in high fat diet-induced obese Wistar albino rats

The aim of this study was to explore the effects of Garcinia mangostana (mangosteen) and Curcuma longa independently and synergistically in modulating oxidative stress, dyslipidemia, and hyperglycemia commonly observed in high-fat diet-induced obesity in rodent models. Male albino Wistar rats were divided into eight experimental groups, fed on a normal diet or high-fat diet (HFD), then given mangosteen extract (400 mg /kg /day) and/or curcumin (80 mg/kg /day) for 6 weeks. Oxidative stress markers, glucose, and lipid fractions were measured in the sera. Mangosteen pericarp extract (MPE) induced a remarkable decrease in BMI (from 0.86 to 0.81 gm/cm²), while curcuma either alone or in combination was more effective, as treated rats recorded BMIs of 0.78 and 0.79 gm/cm², respectively. Regarding the antioxidant effects, MPE induced a significant increase of GSH in obese rats (123.86 ± 15.53 μg/ml vs 288.72 ± 121.37 μg/ml). As anti-atherogenic agents MPE demonstrate significant effect recorded higher level of HDL-C in treated animals, but ineefective as anti-dyslipidemic agent. Curcumin was more effective in reducing LDL-C levels in obese rats. Both extracts effectively reduced blood glucose. The present study demonstrated that MPE and curcumin were independently and synergistically effective in treating obesity-induced atherogenesis.

Curcumin reverses diabetic nephropathy in streptozotocin-induced diabetes in rats by inhibition of PKCβ/p66Shc axis and activation of FOXO-3a

This study investigated if the nephroprotective effect of Curcumin in streptozotocin-induced type 1 diabetes mellitus (DM) in rats involves downregulation/inhibition of p66Shc and examined the underlying mechanisms. Rats were divided into 4 groups (n = 12/group) as control, control + Curcumin (100 mg/kg), T1DM, and T1DM + Curcumin. Curcumin was administered orally to control or diabetic rats for 12 weeks daily. As compared to diabetic rats, Curcumin didn't affect either plasma glucose or insulin levels but significantly reduced serum levels of urea, blood urea nitrogen, and creatinine, and concurrently reduced albumin/protein urea and increased creatinine clearance. It also prevented the damage in renal tubules and mitochondria, mesangial cell expansion, the thickness of the basement membrane. Mechanistically, Curcumin reduced mRNA and protein levels of collagen I/III and transforming growth factor- β-1 (TGF-β1), reduced inflammatory cytokines levels, improved markers of mitochondrial function, and suppressed the release of cytochrome-c and the activation of caspase-3. In the kidneys of both control and diabetic rats, Curcumin reduced the levels of reactive oxygen species (ROS), increased mRNA levels of manganese superoxide dismutase (MnSOD) and gamma-glutamyl ligase, increased glutathione (GSH) and protein levels of Bcl-2 and MnSOD, and increased the nuclear levels of nuclear factor2 (Nrf2) and FOXO-3a. Besides, Curcumin reduced the nuclear activity of the nuclear factor-kappa B (NF-κB), downregulated protein kinase CβII (PKCβII), NADPH oxidase, and p66Shc, and decreased the activation of p66Shc. In conclusion, Curcumin prevents kidney damage in diabetic rats by activating Nrf2, inhibiting Nf-κB, suppressing NADPH oxidase, and downregulating/inhibiting PKCβII/p66Shc axis.

Phytochemicals as Potential Epidrugs in Type 2 Diabetes Mellitus

Type 2 diabetes Mellitus (T2DM) prevalence has significantly increased worldwide in recent years due to population age, obesity, and modern sedentary lifestyles. The projections estimate that 439 million people will be diabetic in 2030. T2DM is characterized by an impaired β-pancreatic cell function and insulin secretion, hyperglycemia and insulin resistance, and recently the epigenetic regulation of β-pancreatic cells differentiation has been underlined as being involved. It is currently known that several bioactive molecules, widely abundant in plants used as food or infusions, have a key role in histone modification and DNA methylation, and constituted potential epidrugs candidates against T2DM. In this sense, in this review the epigenetic mechanisms involved in T2DM and protein targets are reviewed, with special focus in studies addressing the potential use of phytochemicals as epidrugs that prevent and/or control T2DM in vivo and in vitro. As main findings, and although some controversial results have been found, bioactive molecules with epigenetic regulatory function, appear to be a potential replacement/complementary therapy of pharmacological hypoglycemic drugs, with minimal side effects. Indeed, natural epidrugs have shown to prevent or delay the T2DM development and the morbidity associated to dysfunction of blood vessels, eyes and kidneys due to sustained hyperglycemia in T2DM patients.

Effect of fluoxetine on the testes of adult albino rats and the possible protective role of curcumin

Fluoxetine (FLX) is extensively used for the treatment of a diversity of psychiatric disorders, mainly depression. However, it can adversely affect male fertility. This study was done to clarify the changes which take place in the testes after the oral administration of FLX and to evaluate the possible preventative role of curcumin. Seventy-six adult male albino rats were randomly divided into four equal groups. Control group: kept without any treatment. Curcumin group: received daily dose of curcumin (150 mg/kg body weight) through oral gavage for 8 weeks. FLX group. They were given daily dose of FLX (10 mg/kg body weight) given through oral gavage for 8 weeks. FLX and curcumin group. They were given FLX together with curcumin with the same previous doses through oral gavage daily for 8 weeks. By the end of the experiment, blood samples were collected for the biochemical study of testosterone. All the animals were anaesthetized by ether inhalation, and the testis specimens were dissected out and weighed. The specimens were subjected to histopathological, immunohistochemical, and morphometrical evaluation. FLX decreased serum testosterone, diminished both epithelial height and diameter of seminiferous tubules, increased collagen fiber deposition in testicular tissue and induced positive immune reaction to B-cell lymphoma-2-associated X protein. In the FLX and curcumin group, the FLX-induced changes were less remarkable. Exposure to FLX led to pronounced testicular alterations. Co-administration of curcumin with FLX ameliorated these changes.

Modulation of redox and insulin signaling underlie the anti-hyperglycemic and antioxidant effects of diphenyl diselenide in zebrafish

The organic selenium compound diphenyl diselenide (DD) has been recognized as an antioxidant and neuroprotective agent, exerting an anti-hyperglycemic effect in experimental models of diabetes. However, the precise mechanisms involved in the protection are unclear. Using the zebrafish (Danio rerio) as a model organism, here we investigated biomarkers underlying the protective effects of DD against hyperglycemia, targeting in a transcriptional approach the redox and insulin-signaling pathway. Fish were fed on a diet containing DD (3 mg/kg) for 74 days. In the last 14 days, they were exposed to a 111 mM glucose solution to induce a hyperglycemic state. DD reduced blood glucose levels as well as normalized the brain mRNA transcription of four insulin receptors-coding genes (Insra1, Insra2, Insrb1, Insrb2), which were down-regulated by glucose. DD alone caused an up-regulation of relative mRNA transcription in both Insra receptors and glucose transporter 3 genes. DD counteracted hyperglycemia-induced lipid peroxidation, protein and thiol depletion. Along with the decreased activity of antioxidant enzymes SOD and GPx, the brain of hyperglycemic fish presented a reduction in mRNA transcription of FoxO3A, FoxO3B, Nrf2, GPx3A, SOD1, and SOD2 genes. Besides normalizing the transcriptional levels, DD caused an up-regulation of relative mRNAs that encode Nrf2, FoxO1A, FOXO3A, GPx4A, PTP1B, AKT and SelP. Collectively, our findings suggest that the antioxidant and anti-hyperglycemic actions of DD in a zebrafish diabetes model are likely associated with the regulation of the oxidative stress resistance and the insulin-signaling pathway and that could be related to the modulation at mRNA level of two important transcription factors, Nrf2 and FoxO.

Investigation of binding interaction between human serum albumin with zirconium complex of curcumin and curcumin

The current study investigates the binding process of Zr(CUR) as a novel six-coordinate complex of zirconium with curcumin ligand and curcumin (CUR); as the main pharmacologically active ingredient of turmeric to human serum albumin (HSA); using fluorescence spectroscopy, infrared spectroscopy and molecular docking techniques. The fluorimetric results revealed that Zr(CUR) and CUR could effectively quench the endogenous fluorescence of HSA, formed a 1:1 complex, with a static quenching mechanism. The distance between donor (HSA) and acceptor (Zr(CUR) and CUR) were determined to be 3.15 nm for Zr(CUR) and 2.95 nm for CUR on the basis of the Forester's theory of non-radiative energy transfer. Results of the infrared absorption spectrum show that the secondary structure of HSA changes for both types. Molecular docking results indicated that for structure with minimum binding energy Zr(CUR) and CUR are in the position between IIA and IIIA. Also, a docking study showed that Zr(CUR) and CUR have several hydrogen bonds and Van der Waals contact with HSA.Communicated by Ramaswamy H. Sarma.

Involvement of TGF-β and Autophagy Pathways in Pathogenesis of Diabetes: A Comprehensive Review on Biological and Pharmacological Insights

Despite recent advancements in clinical drugs, diabetes treatment still needs further progress. As such, ongoing research has attempted to determine the precise molecular mechanisms of the disorder. Specifically, evidence supports that several signaling pathways play pivotal roles in the development of diabetes. However, the exact molecular mechanisms of diabetes still need to be explored. This study examines exciting new hallmarks for the strict involvement of autophagy and TGF-β signaling pathways in the pathogenesis of diabetes and the design of novel therapeutic strategies. Dysregulated autophagy in pancreatic β cells due to hyperglycemia, oxidative stress, and inflammation is associated with diabetes and accompanied by dysregulated autophagy in insulin target tissues and the progression of diabetic complications. Consequently, several therapeutic agents such as adiponectin, ezetimibe, GABA tea, geniposide, liraglutide, guava extract, and vitamin D were shown to inhibit diabetes and its complications through modulation of the autophagy pathway. Another pathway, TGF-β signaling pathway, appears to play a part in the progression of diabetes, insulin resistance, and autoimmunity in both type 1 and 2 diabetes and complications in diabetes. Subsequently, drugs that target TGF-β signaling, especially naturally derived ones such as resveratrol, puerarin, curcumin, hesperidin, and silymarin, as well as Propolis, Lycopus lucidus, and Momordica charantia extracts, may become promising alternatives to current drugs in diabetes treatment. This review provides keen insights into novel therapeutic strategies for the medical care of diabetes.

Curcumin, Alone or in Combination with Aminoguanidine, Increases Antioxidant Defenses and Glycation Product Detoxification in Streptozotocin-Diabetic Rats: A Therapeutic Strategy to Mitigate Glycoxidative Stress

Both oxidative stress and the exacerbated generation of advanced glycation end products (AGEs) have crucial roles in the onset and progression of diabetic complications. Curcumin has antioxidant and antidiabetic properties; its combination with compounds capable of preventing the advanced glycation events, such as aminoguanidine, is an interesting therapeutic option to counteract diabetic complications. This study is aimed at investigating the effects of treatments with curcumin or aminoguanidine, alone or in combination, on metabolic alterations in streptozotocin-diabetic rats; the focus was mainly on the potential of these bioactive compounds to oppose the glycoxidative stress. Curcumin (90 mg/kg) or aminoguanidine (50 and 100 mg/kg), alone or in combination, slightly decreased glycemia and the biomarkers of early protein glycation, but markedly decreased AGE levels (biomarkers of advanced glycation) and oxidative damage biomarkers in the plasma, liver, and kidney of diabetic rats. Some novel insights about the in vivo effects of these bioactive compounds are centered on the triggering of cytoprotective machinery. The treatments with curcumin and/or aminoguanidine increased the activities of the antioxidant enzymes (paraoxonase 1, superoxide dismutase, and catalase) and the levels of AGE detoxification system components (AGE-R1 receptor and glyoxalase 1). In addition, combination therapy between curcumin and aminoguanidine effectively prevented dyslipidemia in diabetic rats. These findings demonstrate the combination of curcumin (natural antioxidant) and aminoguanidine (prototype therapeutic agent with anti-AGE activity) as a potential complementary therapeutic option for use with antihyperglycemic agents, which may aggregate beneficial effects against diabetic complications.

Patterns of concomitant use of Ayurveda and conventional anti-diabetic formulations - Experiences at a tertiary care Ayurveda hospital, India

Background:

Majority of the population relies on traditional medicines for many of their health related problems. Particularly individuals with chronic illness like diabetes mellitus (DM) are more likely to simultaneously use herbal medicines. Many of such users believe that traditional medicines are natural and therefore safe, but this is a dangerous over simplification. Some herbal medicines may be associated with adverse effects, which include interactions with prescribed drugs. Information on such concomitant use of anti-diabetic drugs along with Ayurveda medicines is limited in Indian scenario.

Aims and objectives:

To survey the patterns of concomitant use of Ayurveda and conventional anti-diabetic drugs by diabetic patients attending an out-patient department of a tertiary care teaching hospital in New Delhi, India through a validated questionnaire.

Materials and methods:

This is a questionnaire-based survey, carried out after the approval of the Institutional Ethics Committee, subsequently registered at CTRI. A questionnaire to assess the pattern of concomitant use was developed; content was validated and pre-tested by a pilot study in 40 patients, further refined and used in the survey. The data was analyzed to evaluate the patterns of concomitant use of Ayurvedic and conventional anti-diabetic drugs.

Results:

About 95.9% of diabetic patients were taking herbo-mineral formulations concomitantly with conventional anti-diabetic drugs. Although 45.3% of diabetics were using Ayurveda interventions under the supervision of qualified AYUSH physicians, remaining involved in procuring the drugs over the counter (OTC) or from the local vendors. In majority of these instances, the use of Ayurveda formulations was not communicated with their physicians.

Conclusion:

The observations reveal that a majority of the diabetics (95.9%) were taking one or the other form of herbal preparations along with their conventional anti-diabetic drugs and about 44% among them were using these concomitantly. Thus, generating awareness on good practices of drug use seems to be essential.

Functional Foods: Product Development, Technological Trends, Efficacy Testing, and Safety

Functional foods is a very popular term in the social and scientific media; consequently, food producers have invested resources in the development of processed foods that may provide added functional benefits to consumers' well-being. Because of intrinsic regulation and end-of-use purposes in different countries, worldwide meanings and definitions of this term are still unclear. Hence, here we standardize this definition and propose a guideline to attest that some ingredients or foods truly deserve this special designation. Furthermore, focus is directed at the most recent studies and practical guidelines that can be used to develop and test the efficacy of potentially functional foods and ingredients. The most widespread functional ingredients, such as polyunsaturated fatty acids (PUFAs), probiotics/prebiotics/synbiotics, and antioxidants, and their technological means of delivery in food products are described. The review discusses the steps that food companies should take to ensure that their developed food product is truly functional.

Impact of curcumin treatment on diabetic albino rats

The current study was aimed to study the effect of curcumin on the expression levels of brain glucose transporter 1 protein (GLUT1) and femoral muscle glucose transporter 4 protein (GLUT4), in addition to study its possible therapeutic role in ameliorating insulin resistance and the metabolic disturbance in the obese and type 2 diabetic male albino Wistar rat model. Diabetes was induced by a high-fat (HF) diet with low dose streptozotocin (STZ). Curcumin was administered intragastrically for 8 weeks (80 mg/kg BW/day). The HF-diet group developed obesity, hyperglycemia, hyperinsulinemia, reduced liver glycogen content with significant dyslipidemia. In the diabetic control group, hyperglycemia and insulin resistance high calculated homeostasis model assessment (HOMA-IR-index score) were pronounced, with reductions in liver and muscle glycogen contents, concomitant with dyslipidemia and significantly elevated malondialdehyde levels in liver and pancreas. GLUT1 and GLUT4 were down-regulated in the obese and the diabetic control groups, respectively. Curcumin, showed glucose-lowering effect and decreased insulin resistance, dyslipidemia and malondialdehyde levels in both tissues, it increased liver & muscle glycogen contents, compared to the diabetic control. Curcumin significantly up-regulated GLUT4 gene expression, compared to the diabetic control group. In conclusions, these results indicate a therapeutic role of curcumin in improving the diabetic status, obesity and enhancing the expression of GLUT4 gene.

Curcumin combined with metformin decreases glycemia and dyslipidemia, and increases paraoxonase activity in diabetic rats

BACKGROUND

Combination of current antidiabetic agents with natural antioxidants to manage diabetes mellitus and its complications has appeared as an emerging trend. Curcumin, a yellow pigment isolated from Curcuma longa rhizomes, has gained attention due to its beneficial effects in controlling the disturbances observed in diabetes mellitus. The purpose of this study was to investigate if yoghurt enriched with curcumin and metformin, individually or as mixtures, ameliorates physiometabolic parameters, glycoxidative stress biomarkers, and paraoxonase 1 (PON 1) activity in diabetic rats.

METHODS

Streptozotocin-diabetic rats (6-week-old Wistar rats) were treated for 30 days with curcumin and metformin, isolated or as mixtures in yoghurt (10 rats/group). After treatments, the plasma levels of glucose, triacylglycerol, cholesterol, thiobarbituric acid reactive substances (TBARS, a biomarker of lipid oxidation), fluorescent advanced glycation end products (AGEs), and the activity of PON 1, an antioxidant enzyme were assessed. Data were analyzed using one-way analysis of variance (ANOVA) followed by Student-Newman-Keuls test.

RESULTS

Treatment of diabetic rats with curcumin or metformin alone decreased the plasma levels of glucose, triacylglycerol, cholesterol, TBARS, and fluorescent AGEs, as well as increased the activity of PON 1. The combination of metformin with curcumin further decreased dyslipidemia and TBARS levels in diabetic rats, indicating synergy, and maintained the high levels of PON 1.

CONCLUSION

These findings indicated that curcumin combined with metformin may act synergistically on dyslipidemia and oxidative stress, as well as increased PON 1 levels. Therefore, it might be a promising strategy for combating diabetic complications, mainly the cardiovascular events.