The antihyperglycemic effect of curcumin in high fat diet fed rats. Role of TNF-α and free fatty acids

Inhibition of HIV-1 infection with curcumin conjugated PEG-citrate dendrimer; a new nano formulation

BACKGROUND

Nano-drug delivery systems have become a promising approach to overcoming problems such as low solubility and cellular uptake of drugs. Along with various delivery devices, dendrimers are widely used through their unique features. PEG-citrate dendrimers are biocompatible and nontoxic, with the ability to improve drug solubility. Curcumin, a naturally occurring polyphenol, has multiple beneficial properties, such as antiviral activities. However, its optimum potential has been significantly hampered due to its poor water solubility, which leads to reduced bioavailability. So, the present study attempted to address this issue and investigate its antiviral effects against HIV-1.

METHOD

The G2 PEG-citrate dendrimer was synthesized. Then, curcumin was conjugated to it directly. FTIR, HNMR, DLS, and LCMS characterized the structure of products. The conjugate displayed an intense yellow color. In addition, increased aqueous solubility and cell permeability of curcumin were achieved based on flow cytometry results. So, it could be a suitable vehicle for improving the therapeutic applications of curcumin. Moreover, cell toxicity was assessed using XTT method. Ultimately, the SCR HIV system provided an opportunity to evaluate the level of HIV-1 inhibition by the curcumin-dendrimer conjugate using a p24 HIV ELISA kit.

RESULTS

The results demonstrated a 50% up to 90% inhibition of HIV proliferation at 12 μm and 60 μm, respectively. Inhibition of HIV-1 at concentrations much lower than CC50 (300 µM) indicates a high potential of curcumin-dendrimer conjugate against this virus.

CONCLUSION

Thereby, curcumin-dendrimer conjugate proves to be a promising tool to use in HIV-1 therapy.

Role of curcumin on beta-amyloid protein, tau protein, and biochemical and oxidative changes in streptozotocin-induced diabetic rats

Diabetes is one of the most common endocrine metabolic diseases and is associated with the accumulation of beta-amyloid plaques in the brain. Amyloid beta (Aβ) and abnormal tau proteins are effective in the development of Alzheimer's disease. The aim of this study is to investigate the therapeutic and protective effects of curcumin on beta-amyloid (Aβ) accumulation and tau protein expression levels, as well as biochemical and oxidative changes in streptozotocin-induced diabetes in rats. The study comprised five groups, each consisting of eight rats: control, diabetic, curcumin, curcumin during diabetic induction, and curcumin post-diabetic induction. Groups 2 and 4 were administered a single dose of 45 mg/kg streptozotocin on day 1, while group 5 received it on day 28. Curcumin was orally administered via gavage at a dose of 100 mg/kg/day for 35 days to the third, fourth, and fifth groups. At the end of the trial (day 35), blood sugar levels and insulin resistance were similar between the control and curcumin-treated groups but significantly higher in the diabetic groups (P < 0.05). The protective effect of curcumin is tested during induction and active diabetes. The results indicated that diabetic rats displayed increased levels of Aβ, tau protein, and total oxidant capacity (TOS) compared to the curcumin-treated groups. Additionally, the total antioxidant capacity (TAS) levels were lower in the diabetic rats (P < 0.05). Aβ protein levels are lower in both the serum and brain of rats with active diabetes and treated with curcumin compared to control rats (P > 0.05). In addition, serum TAS levels were higher in rats treated with curcumin following the induction of diabetes than pre-induction of diabetes (P > 0.05). The TOS levels in the serum were higher in the rats treated with curcumin during active diabetes compared to the rats treated prior to the induction of diabetes (P < 0.05). However, no significant difference was observed in the brain. The above results show that curcumin has an effect on reducing oxidative stress caused by diabetes and increasing antioxidant activity.

The Dose-Dependent Effect of Curcumin Supplementation on Inflammatory Response and Gut Microbiota Profile in High-Fat Fed C57BL/6 Mice

SCOPE

The prevalence of obesity has increased, with excessive consumption of high-fat foods being one of the primary causes. Curcumin, a polyphenol extracted from Curcuma longa L., exhibits anti-inflammatory activity.  The study aims to investigate the effects of curcumin supplementation in different doses on the biochemical profile, inflammatory response, and gut microbiota profile in mice that are fed with high-fat diet (HFD).

METHODS AND RESULTS

C57BL/6 male mice are fed a standard diet, or a HFD with or without different doses of curcumin (50, 250, and 500 mg kg-1 of body weight). Throughout the experimental period, food intake and body weight are assessed weekly. At euthanasia, blood, stool, and tissue samples are collected for biochemical, histological, and molecular analyses. Curcumin increases the IL-10 protein expression in the white adipose tissue. In the liver, there is a reduction in tumor necrosis factor alpha (TNF-α) and an increase in IL-10 gene expression. Also, curcumin promotes the growth of butyrogenic bacteria, such as Clostridium clusters IV and XIVa.

CONCLUSIONS

The findings suggest that curcumin has the potential to improve the inflammatory response and modulate healthy gut microbiota. Further studies are needed to clarify the role of curcumin as a preventive and effective strategy for obesity.

New Insights on Dietary Polyphenols for the Management of Oxidative Stress and Neuroinflammation in Diabetic Retinopathy

Diabetic retinopathy (DR) is a neurodegenerative and vascular pathology that is considered one of the leading causes of blindness worldwide, resulting from complications of advanced diabetes mellitus (DM). Current therapies consist of protocols aiming to alleviate the existing clinical signs associated with microvascular alterations limited to the advanced disease stages. In response to the low resolution and limitations of the DR treatment, there is an urgent need to develop more effective alternative therapies to optimize glycemic, vascular, and neuronal parameters, including the reduction in the cellular damage promoted by inflammation and oxidative stress. Recent evidence has shown that dietary polyphenols reduce oxidative and inflammatory parameters of various diseases by modulating multiple cell signaling pathways and gene expression, contributing to the improvement of several chronic diseases, including metabolic and neurodegenerative diseases. However, despite the growing evidence for the bioactivities of phenolic compounds, there is still a lack of data, especially from human studies, on the therapeutic potential of these substances. This review aims to comprehensively describe and clarify the effects of dietary phenolic compounds on the pathophysiological mechanisms involved in DR, especially those of oxidative and inflammatory nature, through evidence from experimental studies. Finally, the review highlights the potential of dietary phenolic compounds as a prophylactic and therapeutic strategy and the need for further clinical studies approaching the efficacy of these substances in DR management.

Regulation of Acetylation States by Nutrients in the Inhibition of Vascular Inflammation and Atherosclerosis

Atherosclerosis (AS) is a chronic metabolic disorder and primary cause of cardiovascular diseases, resulting in substantial morbidity and mortality worldwide. Initiated by endothelial cell stimulation, AS is characterized by arterial inflammation, lipid deposition, foam cell formation, and plaque development. Nutrients such as carotenoids, polyphenols, and vitamins can prevent the atherosclerotic process by modulating inflammation and metabolic disorders through the regulation of gene acetylation states mediated with histone deacetylases (HDACs). Nutrients can regulate AS-related epigenetic states via sirtuins (SIRTs) activation, specifically SIRT1 and SIRT3. Nutrient-driven alterations in the redox state and gene modulation in AS progression are linked to their protein deacetylating, anti-inflammatory, and antioxidant properties. Nutrients can also inhibit advanced oxidation protein product formation, reducing arterial intima-media thickness epigenetically. Nonetheless, knowledge gaps remain when it comes to understanding effective AS prevention through epigenetic regulation by nutrients. This work reviews and confirms the underlying mechanisms by which nutrients prevent arterial inflammation and AS, focusing on the epigenetic pathways that modify histones and non-histone proteins by regulating redox and acetylation states through HDACs such as SIRTs. These findings may serve as a foundation for developing potential therapeutic agents to prevent AS and cardiovascular diseases by employing nutrients based on epigenetic regulation.

Food Polyphenols and Type II Diabetes Mellitus: Pharmacology and Mechanisms

Type II diabetes mellitus and its related complications are growing public health problems. Many natural products present in our diet, including polyphenols, can be used in treating and managing type II diabetes mellitus and different diseases, owing to their numerous biological properties. Anthocyanins, flavonols, stilbenes, curcuminoids, hesperidin, hesperetin, naringenin, and phenolic acids are common polyphenols found in blueberries, chokeberries, sea-buckthorn, mulberries, turmeric, citrus fruits, and cereals. These compounds exhibit antidiabetic effects through different pathways. Accordingly, this review presents an overview of the most recent developments in using food polyphenols for managing and treating type II diabetes mellitus, along with various mechanisms. In addition, the present work summarizes the literature about the anti-diabetic effect of food polyphenols and evaluates their potential as complementary or alternative medicines to treat type II diabetes mellitus. Results obtained from this survey show that anthocyanins, flavonols, stilbenes, curcuminoids, and phenolic acids can manage diabetes mellitus by protecting pancreatic β-cells against glucose toxicity, promoting β-cell proliferation, reducing β-cell apoptosis, and inhibiting α-glucosidases or α-amylase. In addition, these phenolic compounds exhibit antioxidant anti-inflammatory activities, modulate carbohydrate and lipid metabolism, optimize oxidative stress, reduce insulin resistance, and stimulate the pancreas to secrete insulin. They also activate insulin signaling and inhibit digestive enzymes, regulate intestinal microbiota, improve adipose tissue metabolism, inhibit glucose absorption, and inhibit the formation of advanced glycation end products. However, insufficient data are available on the effective mechanisms necessary to manage diabetes.

Comparative effects of curcumin versus nano-curcumin on histological, immunohistochemical expression, histomorphometric, and biochemical changes to pancreatic beta cells and lipid profile of streptozocin induced diabetes in male Sprague-Dawley rats

Diabetes mellitus is a worldwide problem characterized by hyperglycemia as well as the damage of the microscopic structure of the beta cells of Langerhans pancreatic islets. In the present study, the histological, immunohistochemical, morphometric, and biochemical alterations to pancreatic beta cells in streptozocin (STZ)-induced diabetes were assessed in rats treated with curcumin (CU) (100 mg/kg/day) or nano-curcumin (nCU) (100 mg/kg/day) for 1 month. Twenty-four adult male Wistar albino rats were distributed into four groups: the nondiabetic control group, the diabetic untreated group, and two diabetic groups treated with CU or nCUR, respectively. Blood glucose, serum insulin levels, and lipid profile were measured. The pancreatic tissues were collected and processed into paraffin sections for histological and immunohistochemical examination, oxidative stress markers, and real-time PCR expression for pancreatic and duodenal homeobox 1 (PDX1). The insulin expression in beta cells was assessed using immunohistochemistry. Morphometrically, the percentage area of anti-insulin antibody reaction and the percentage area of islet cells were determined. STZ-induced deteriorating alteration in beta cells led to declines in the number of functioning beta cells and insulin immunoreactivity. In STZ-treated rats, CU and nCUR significantly reduced blood glucose concentration while increasing blood insulin level. It also caused a significant increase in the number of immunoreactive beta cells to the insulin expression and significant reduction of the immunoreactive beta cells to the caspase-3 expression. In conclusion, CU and nCUR could have a therapeutic role in the biochemical and microscopic changes in pancreatic beta cells in diabetes-induced rats through STZ administration with more bio-efficacy of nCUR.

Role of Turmeric and Curcumin in Prevention and Treatment of Chronic Diseases: Lessons Learned from Clinical Trials

Turmeric (Curcuma longa) has been used for thousands of years for the prevention and treatment of various chronic diseases. Curcumin is just one of >200 ingredients in turmeric. Almost 7000 scientific papers on turmeric and almost 20,000 on curcumin have been published in PubMed. Scientific reports based on cell culture or animal studies are often not reproducible in humans. Therefore, human clinical trials are the best indicators for the prevention and treatment of a disease using a given agent/drug. Herein, we conducted an extensive literature survey on PubMed and Scopus following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The keywords "turmeric and clinical trials" and "curcumin and clinical trials" were considered for data mining. A total of 148 references were found to be relevant for the key term "turmeric and clinical trials", of which 70 were common in both PubMed and Scopus, 44 were unique to PubMed, and 34 were unique to Scopus. Similarly, for the search term "curcumin and clinical trials", 440 references were found to be relevant, of which 70 were unique to PubMed, 110 were unique to Scopus, and 260 were common to both databases. These studies show that the golden spice has enormous health and medicinal benefits for humans. This Review will extract and summarize the lessons learned about turmeric and curcumin in the prevention and treatment of chronic diseases based on clinical trials.

Role of Fenugreek, Cinnamon, Curcuma longa, Berberine and Momordica charantia in Type 2 Diabetes Mellitus Treatment: A Review

Type 2 diabetes mellitus (T2DM) is a complex disease that has become a major global health concern. Given the efficacy of antidiabetic drugs, pharmacological therapy is considered the first-line treatment of T2DM; however, due to their potential side effects and high costs, new and cost-effective treatments with minimal side effects are needed. Medicinal plants have been used for centuries as part of traditional medicine to treat T2DM. Among these, fenugreek, cinnamon, Curcuma longa, berberine, and Momordica charantia have demonstrated different degrees of hypoglycemic activity in clinical studies and animal models. Therefore, the aim of this review is to synthesize the mechanisms of action of five medicinal plants, as well as the experimental and clinical evidence of their hypoglycemic activity from the published literature.

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.

New Advances in Metabolic Syndrome, from Prevention to Treatment: The Role of Diet and Food

The definition of metabolic syndrome (MetS) has undergone several changes over the years due to the difficulty in establishing universal criteria for it. Underlying the disorders related to MetS is almost invariably a pro-inflammatory state related to altered glucose metabolism, which could lead to elevated cardiovascular risk. Indeed, the complications closely related to MetS are cardiovascular diseases (CVDs) and type 2 diabetes (T2D). It has been observed that the predisposition to metabolic syndrome is modulated by complex interactions between human microbiota, genetic factors, and diet. This review provides a summary of the last decade of literature related to three principal aspects of MetS: (i) the syndrome's definition and classification, pathophysiology, and treatment approaches; (ii) prediction and diagnosis underlying the biomarkers identified by means of advanced methodologies (NMR, LC/GC-MS, and LC, LC-MS); and (iii) the role of foods and food components in prevention and/or treatment of MetS, demonstrating a possible role of specific foods intake in the development of MetS.

Role of potential bioactive metabolites from traditional Chinese medicine for type 2 diabetes mellitus: An overview

Type 2 diabetes mellitus (T2DM) is a metabolic disease with persistent hyperglycemia primarily caused by insulin resistance (IR). The number of diabetic patients globally has been rising over the past decades. Although significant progress has been made in treating diabetes mellitus (DM), existing clinical drugs for diabetes can no longer fully meet patients when they face complex and huge clinical treatment needs. As a traditional and effective medical system, traditional Chinese medicine (TCM) has a unique understanding of diabetes treatment and has developed many classic and practical prescriptions targeting DM. With modern medicine and pharmacy advancements, researchers have discovered that various bioactive metabolites isolated from TCM show therapeutic on DM. Compared with existing clinical drugs, these bioactive metabolites demonstrate promising prospects for treating DM due to their excellent biocompatibility and fewer adverse reactions. Accordingly, these valuable metabolites have attracted the interest of researchers worldwide. Despite the abundance of research works and specialized-topic reviews published over the past years, there is a lack of updated and systematic reviews concerning this fast-growing field. Therefore, in this review, we summarized the bioactive metabolites derived from TCM with the potential treatment of T2DM by searching several authoritative databases such as PubMed, Web of Science, Wiley Online Library, and Springer Link. For the convenience of readers, the content is divided into four parts according to the structural characteristics of these valuable compounds (flavonoids, terpenoids, alkaloids, and others). Meanwhile, the detailed mechanism and future directions of these promising compounds curing DM are also summarized in the related sections. We hope this review inspires increasingly valuable and significant research focusing on potential bioactive metabolites from TCM to treat DM in the future.

Accumulation of Advanced Glycation End-Products in the Body and Dietary Habits

The formation of advanced glycation end-products (AGE) in tissues is a physiological process; however, excessive production and storage are pathological and lead to inflammation. A sedentary lifestyle, hypercaloric and high-fructose diet and increased intake of processed food elements contribute to excessive production of compounds, which are created in the non-enzymatic multi-stage glycation process. The AGE’s sources can be endogenous and exogenous, mainly due to processing food at high temperatures and low moisture, including grilling, roasting, and frying. Accumulation of AGE increases oxidative stress and initiates various disorders, leading to the progression of atherosclerosis, cardiovascular disease, diabetes and their complications. Inborn defensive mechanisms, recovery systems, and exogenous antioxidants (including polyphenols) protect from excessive AGE accumulation. Additionally, numerous products have anti-glycation properties, occurring mainly in fruits, vegetables, herbs, and spices. It confirms the role of diet in the prevention of civilization diseases.

Curcumin Remedies Testicular Function and Spermatogenesis in Male Mice with Low-Carbohydrate-Diet-Induced Metabolic Dysfunction

Increasing reports on the significance of dietary patterns in reproduction have arisen from both animal and human studies, suggesting an interactive association between nutrition and male fertility. The aim of this study was to investigate the effects of curcumin supplementation on low-carbohydrate-diet-induced metabolic dysfunction, testicular antioxidant capacity, apoptosis, inflammation and spermatogenesis in male mice. Male C57BL/6 mice were fed a normal diet (AIN-93M group, n = 12) and a low-carbohydrate diet for 12 weeks (LC group, fed with low-carbohydrate diet, n = 48), and mice randomly chosen from the LC group were later fed their original diet (LC group, n = 12). This diet was changed to AIN-93M feed (LC/AIN-93M group, n = 12), a ketogenic diet (LC/KD group, n = 12), or a ketogenic diet treated with curcumin supplementation for the final 6 weeks (LC/KDCu group, n = 12). A poor sperm morphology and mean testicular biopsy score (MTBS) were observed in the LC and LC/KD groups, but they were eliminated by the normal diet or ketogenic diet with curcumin. The LC group exhibited a lower testicular testosterone level and a lower 17β-HSD activity and protein expression. This also enhanced apoptosis protein expressions in testis tissue, including Bax/BCl₂, cleaved caspase 3, PARP and NF-κB. Meanwhile, we found a statistically significant increase in lipid peroxidation and decreased superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase levels in the LC group. Our study indicated that a replacement of a normal diet or ketogenic diet supplemented with curcumin attenuated poor semen quality and reduced testosterone levels by the LC diet by reducing oxidative stress.

An update on molecular mechanisms of curcumin effect on diabetes

Owing to its prevalent nature, diabetes mellitus has become one of the most serious endocrine illnesses affecting a patient's quality of life due to the manifestation of side effects such as cardiovascular diseases, retinopathy, neuropathy, and nephropathy. Curcumin ((1E, 6E) 21, 7-bis (4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione), a major compound of turmeric, has been used in conventional medicine because of its safe nature and cost-effectiveness to meliorate diabetes and its comorbidities. These effects have also been observed in rodent models of diabetes resulting in a reduction of glycemia and blood lipids. Both the preventive and therapeutic activities of this compound are due to its antioxidant and anti-inflammatory characteristics. Furthermore, preclinical outcomes and clinical investigation demonstrate that the use of curcumin neutralizes insulin resistance, obesity, and hyperglycemia. Despite the many benefits of curcumin, its two limiting factors, solubility and bioavailability, remain a challenge for researchers; therefore, several methods such as drug formulation, nano-drug delivery, and the use of curcumin analogs have been developed to deliver curcumin and increase its bioavailability. PRACTICAL APPLICATIONS: The rise of people with type 2 diabetes has become a major concern at the global healthcare level. The best diabetes treatments today are anti-diabetic drug administration, lifestyle-related interventions (such as healthy eating and daily physical activity), arterial pressure detection, and fat control. The polyphenol curcumin, found in turmeric, can promote health by acting on a variety of cellular signaling pathways. This review article discusses curcumin and its role in the treatment of diabetes.

Zingiberaceae plants/curcumin consumption and multiple health outcomes: An umbrella review of systematic reviews and meta-analyses of randomized controlled trials in humans

This umbrella review is to recapitulate and grade the available evidence of associations between consumption of Zingiberaceae plants/curcumin (Cur) and multiple health-related outcomes. This study included 161 meta-analyses of randomized controlled trials in 76 articles with 67 unique health outcomes. Data on heterogeneity and publication bias are considered to assess the quality of evidence. Based on the different impact of Zingiberaceae plants/Cur on human health, the advantages outweigh the disadvantages. Zingiberaceae plants/Cur can mainly improve metabolic syndrome, non-alcoholic fatty liver disease, cardiovascular disease, and some chronic inflammatory diseases, likewise, obviously relief the pain of osteoarthritis and related diseases. Ginger supplements have been shown to improve vomiting during pregnancy and to relieve nausea and vomiting caused by chemotherapy and surgery. The surgery is any type of surgery, including laparoscopic surgery, gynecological surgery and mixed surgery. Beneficial associations were found with Cur intervention in gastrointestinal, neurological and oral diseases. Zingiberaceae plants/Cur are generally safe and favorable for multiple health outcomes in humans. High-quality research is further needed to prove the observed associations.

Improvement of Glycaemia and Endothelial Function by a New Low-Dose Curcuminoid in an Animal Model of Type 2 Diabetes

Curcumin has been suggested as a promising treatment for metabolic diseases, but the high doses required limit its therapeutic use. In this study, a new curcuminoid is synthesised to increase curcumin anti-inflammatory and antioxidant potential and to achieve hypoglycaemic and protective vascular effects in type 2 diabetic rats in a lower dose. In vitro, the anti-inflammatory effect was determined through the Griess reaction, and the antioxidant activity through ABTS and TBARS assays. In vivo, Goto-Kakizaki rats were treated for 2 weeks with the equimolar dose of curcumin (40 mg/kg/day) or curcuminoid (52.4 mg/kg/day). Fasting glycaemia, insulin tolerance, plasma insulin, insulin signalling, serum FFA, endothelial function and several markers of oxidative stress were evaluated. Both compounds presented a significant anti-inflammatory effect. Moreover, the curcuminoid had a marked hypoglycaemic effect, accompanied by higher GLUT4 levels in adipose tissue. Both compounds increased NO-dependent vasorelaxation, but only the curcuminoid exacerbated the response to ascorbic acid, consistent with a higher decrease in vascular oxidative and nitrosative stress. SOD1 and GLO1 levels were increased in EAT and heart, respectively. Altogether, these data suggest that the curcuminoid developed here has more pronounced effects than curcumin in low doses, improving the oxidative stress, endothelial function and glycaemic profile in type 2 diabetes.

Effects of turmeric (Curcuma longa) and its constituent (curcumin) on the metabolic syndrome: An updated review

Metabolic syndrome (MS) involves people with the following risk factors: obesity, hypertension, high glucose level and hyperlipidemia. It can increase the risk of heart disease, stroke and type 2 diabetes mellitus. The prevalence of MS in the world's adult population is about 20%-25%. Today, there is much care to use medicinal plants. Turmeric (Curcuma longa) as well as curcumin which is derived from the rhizome of the plant, has been shown beneficial effects on different components of MS. Thus, the purpose of this manuscript was to introduce different in vitro, in vivo and human studies regarding the effect of turmeric and its constituent on MS. Moreover, different mechanisms of action by which this plant overcomes MS have been introduced. Based on studies, turmeric and its bioactive component, curcumin, due to their anti-inflammatory and antioxidant properties, have antidiabetic effects through increasing insulin release, antihyperlipidemic effects by increasing fatty acid uptake, anti-obesity effects by decreasing lipogenesis, and antihypertensive effects by increasing nitric oxide. According to several in vivo, in vitro and human studies, it can be concluded that turmeric or curcumin has important values as a complementary therapy in MS. However, more clinical trials should be done to confirm these effects.

Curcumin in Retinal Diseases: A Comprehensive Review from Bench to Bedside

Recent evidence in basic science is leading to a growing interest in the possible role of curcumin in treating retinal diseases. Curcumin has been demonstrated to be able to modulate gene transcription and reduce ganglion cell apoptosis, downgrade VEGF, modulate glucose levels and decrease vascular dysfunction. So far, the use of curcumin has been limited by poor bioavailability; to overcome this issue, different types of carriers have been used. Multiple recent studies disclosed the efficacy of using curcumin in treating different retinal conditions. The aim of this review is to comprehensively review and discuss the role of curcumin in retinal diseases from bench to bedside.

Utilizing the underutilized plant resources for development of life style foods: Putting nutrigenomics to use

Sufficient amount of minerals, vitamins, and proteins in human diet play indispensable role in maintaining the active metabolism for better human health. All the essential nutrients that are requisite for an individual's survival are acquired from plants as well as animals. Micronutrients and macronutrients directly influence the metabolic pathways and their deficiencies play a substantial role in development of manifold disorders. In addition to environmental factors, quality and quantity of foods are key factors in maintaining the human health. Transition from healthy to diseased state is concurrent with the pattern of gene expression that is largely influenced by nutrition and environment. A combined approach to study the influence of nutrition on expression of numerous genes can be well explored through nutrigenomic studies. Nutrigenomics includes studies wherein applied genomics is used to investigate nutritional science to understand the compartmentalization of genes that influence the cause of diet-related complications. This review describes the role of underutilized crops as frontline foods to circumvent the health complications through the nutrigenomic studies. Further dynamics of nutrigenomic tools to study the impact of nutrition on the changing pattern of genome stability and gene expression for developing precise safety measures against wide range of health ailments linked to metabolic networks. Additionally, this review provides detailed information on nutrigenomic studies undertaken to unravel the potential of underutilized crops to augment the human health and to carry the agronomic/genomic approaches to enhance nutritional profile of underutilized crops to overcome diet-related disorders.

The Effects of Curcumin Plus Piperine Supplementation in Patients with Acute Myocardial Infarction: A Randomized, Double-Blind, and Placebo-Controlled Trial

BACKGROUND

Acute myocardial infarction (AMI) is a leading cause of death and disability worldwide. Previous investigations have demonstrated that curcumin has a cardioprotective effect and may improve myocardial injury. So this study was performed to assess whether supplementation with curcumin could diminish myocardial injury following AMI.

METHODS

To conduct this randomized, double-blinded, and placebo-controlled clinical trial, seventy-two patients with acute myocardial infarction, aged 18-75 years, were enrolled and randomly divided into the active intervention and control groups. The active intervention group (n = 38) received curcumin capsules with piperine supplement (500 mg/day, 95% curcuminoids) for 8 weeks, whereas the control group (n = 34) received a placebo capsule. At the baseline and end of the study, ejection fraction was assessed, and blood samples were taken from all patients to measure the levels of cardiac troponin I(cTnI), lipid profile, FBG, HbA1C, liver enzymes, renal function parameters, and electrolytes.

RESULTS

In this trial, curcumin supplementation significantly reduced the levels of HbA1C (-0.3 ± 2.2 vs. +1.1 ± 1.3, P = 0.002), LDL (-10.3 ± 20.7 vs. +0.2 ± 22.5, P = 0.039), ALT (-10.2 ± 28.5 vs. +7.3 ± 39.2, P = 0.029), and ALP (+6.4 ± 39.5 vs. +38.0 ± 69.0, P = 0.018) compared to the placebo group. Moreover, the serum concentration of HDL significantly improved in comparison with the placebo group (+4.5 ± 8.9 vs. -1.6 ± 7.7, P = 0.002). However, no substantial difference was perceived between the groups regarding the ejection fraction and serum levels of cTnI, FBG, renal function parameters, and electrolytes.

CONCLUSION

Our results indicated that daily intake of 500 mg of curcumin capsules with piperine supplement for 8 weeks modified lipid profile, liver enzymes, and glycemic status, but did not have any effect on ejection fraction and serum concentration of cardiac troponin I, renal function parameters, and electrolytes in acute myocardial infarction patients.

The Multifaceted Actions of Curcumin in Obesity

Obesity remains a pervasive health concern worldwide with concomitant comorbidities such as cardiovascular diseases, diabetes, inflammation, and other metabolic disorders. A wealth of data validates dietary and lifestyle modifications such as restricting caloric intake and increasing physical activity to slow the obesity development. Recently, the advent of phytochemicals such as curcumin, the active ingredient in turmeric, has attracted considerable research interest in tracking down their possible effects in protection against obesity and obesity-related comorbidities. According to the existing literature, curcumin may regulate lipid metabolism and suppress chronic inflammation interacting with white adipose tissue, which plays a central role in the complications associated with obesity. Curcumin also inhibits the differentiation of adipocyte and improves antioxidant properties. In the present review, we sought to deliberate the possible effects of curcumin in downregulating obesity and curtailing the adverse health effects of obesity.

Effects of High-fat Diet and Chronic Mild Stress on Depression-like Behaviors and Levels of Inflammatory Cytokines in the Hippocampus and Prefrontal Cortex of Rats

Obesity and depression tend to co-occur, and obese patients with chronic low-grade inflammation have a higher risk of developing depression. However, mechanisms explaining these connections have not been fully elucidated. Here, an animal model of comorbid obesity and depression induced by high-fat diet (HFD) combined with chronic unpredictable mild stress (CUMS) was used, and sucrose preference, open field, elevated plus maze and Morris water maze tests were used to detected depression-and anxiety-like behaviors and spatial memory. The levels of inflammatory cytokines and NF-κB and microglial activation in the hippocampus and prefrontal cortex were examined in the study. Our results revealed that the comorbidity group exhibited the most severe depression-like behavior. Obesity but unstressed rats had the highest serum lipid levels among groups. The HFD and CUMS alone and combination of them increased levels of IL-1β, IL-6 and TNF-α in the hippocampus and prefrontal cortex, which was significantly related to depression-like behaviors. Further, NF-κB protein and mRNA levels and microglial activation in the hippocampus and prefrontal cortex significantly increased in stressed, obese and comorbid groups, with animals in comorbid group having the highest NF-κB mRNA levels in the hippocampus and level of NF-κB proteins in the prefrontal cortex, and the highest microglial activation in both brain areas. The study concluded that HFD and CUMS alone and combination induce depression-like symptoms, abnormal serum lipid levels, microglial activation and increased inflammatory cytokines in the brain, effects that are possibly mediated by TLR4-NF-κB signaling.

ε-Viniferin, a promising natural oligostilbene, ameliorates hyperglycemia and hyperlipidemia by activating AMPK in vivo

ε-Viniferin (VNF), a naturally occurring oligostilbene (a resveratrol dimer), is mainly found in grapes and red wines. However, unlike resveratrol, the biological activity of VNF has not been widely studied. This study was conducted to investigate the beneficial effects of VNF on hyperglycemia and hyperlipidemia and further to reveal the underlying mechanism. The ameliorative effects of VNF in high-fat-diet and streptozotocin-induced type 2 diabetic rats were assessed physiologically, biochemically and histologically after oral administration of VNF (30 mg kg-1 and 60 mg kg-1) for 8 weeks. Western blotting and immunohistochemistry experiments were performed to determine the effects of VNF on the AMPK phosphorylation levels in the livers of diabetic rats. Molecular docking and molecular dynamics simulation were further performed to study the molecular-level interaction between VNF and AMPK. Meanwhile, the protective effects of VNF on the liver and kidney were also evaluated. The results showed that the VNF treatment caused a significant decrease in the concentrations of fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), and low density lipoprotein-cholesterol (LDL-C), and improved the glucose tolerance of diabetic rats. In addition, the liver and kidney damage indices such as alanine aminotransferase (ALT), aspartate aminotransaminase (AST), creatinine (CR), and blood urea nitrogen (BUN) were also lowered and improved. Moreover, VNF could increase the AMPK activation and attenuate histopathological changes in the liver of diabetic rats. The molecular docking and molecular dynamics simulation results revealed for the first time that VNF bound to the hinge region between the α- and β-units of AMPK and interacted with the active site of AMPK. In conclusion, VNF can effectively improve hyperglycemia and hyperlipidemia and exhibit protective effects on the liver and kidney functions. The underlying mechanism of VNF in hyperglycemia and hyperlipidemia may be related to the activation of AMPK in vivo. Our findings indicate that VNF is a potentially useful natural agent for the treatment of metabolic diseases, especially type 2 diabetes and hyperlipidemia.

Curcumin prevents obesity by targeting TRAF4-induced ubiquitylation in m6 A-dependent manner

Obesity has become a major health problem that has rapidly prevailed over the past several decades worldwide. Curcumin, a natural polyphenolic compound present in turmeric, has been shown to have a protective effect on against obesity and metabolic diseases. However, its underlying mechanism remains largely unknown. Here, we show that the administration of curcumin significantly prevents HFD-induced obesity and decreases the fat mass of the subcutaneous inguinal WAT (iWAT) and visceral epididymal WAT (eWAT) in mice. Mechanistically, curcumin inhibits adipogenesis by reducing the expression of AlkB homolog 5 (ALKHB5), an m6 A demethylase, which leads to higher m6 A-modified TNF receptor-associated factor 4 (TRAF4) mRNA. TRAF4 mRNA with higher m6 A level is recognized and bound by YTHDF1, leading to enhanced translation of TRAF4. TRAF4, acting as an E3 RING ubiquitin ligase, promotes degradation of adipocyte differentiation regulator PPARγ by a ubiquitin-proteasome pathway thereby inhibiting adipogenesis. Thus, m6 A-dependent TRAF4 expression upregulation by ALKBH5 and YTHDF1 contributes to curcumin-induced obesity prevention. Our findings provide mechanistic insights into how m6 A is involved in the anti-obesity effect of curcumin.

Impact of curcumin on fatty acid metabolism

Free fatty acids (FFAs) and fatty acid synthesis (FAS) activity have significantly contributed to disease states such as insulin resistance, obesity, type 2 diabetes, myocardial infarction, blood pressure, and several types of cancer. Currently, several treatment options are available for patients with these conditions. Due to safety concerns, adverse effects, limited efficacy, and low tolerability associated with many medications, the identification of novel agents with less toxicity and a more favorable outcome is warranted. Curcumin is a phenolic compound derived from the turmeric plant with various biological activities, including anticarcinogenic, antioxidant, antiinflammatory, and hypolipidemic properties. PubMed, Scopus, and Web of Science were searched up to February 2020 for studies that demonstrated the efficacy and mechanisms of curcumin action on FFAs, FAS, and β-oxidation activity, as well as the desaturation system. Most of the evidence is in-vivo and in-vitro studies that demonstrate that curcumin possesses regulatory properties on FFAs levels through its effects on FAS and β-oxidation activity as well as desaturation system, which could improve insulin resistance, obesity, and other FFAs-related disorders. The present study provides a review of the existing in-vitro, in-vivo, and clinical evidence on the effect of curcumin on FFAs and FAS activity, β-oxidation, and desaturation system.

Obesity-Associated Inflammation: Does Curcumin Exert a Beneficial Role?

Curcumin is a lipophilic polyphenol, isolated from the plant turmeric of Curcuma longa. Curcuma longa has always been used in traditional medicine in Asian countries because it is believed to have numerous health benefits. Nowadays it is widely used as spice component and in emerging nutraceutical food worldwide. Numerous studies have shown that curcumin possesses, among others, potential anti-inflammatory properties. Obesity represents a main risk factor for several chronic diseases, including type 2 diabetes, cardiovascular disease, and some types of cancer. The establishment of a low-grade chronic inflammation, both systemically and locally in adipose tissue, occurring in obesity most likely represents a main factor in the pathogenesis of chronic diseases. The molecular mechanisms responsible for the onset of the obesity-associated inflammation are different from those involved in the classic inflammatory response caused by infections and involves different signaling pathways. The inflammatory process in obese people is triggered by an inadequate intake of nutrients that produces quantitative and qualitative alterations of adipose tissue lipid content, as well as of various molecules that act as endogenous ligands to activate immune cells. In particular, dysfunctional adipocytes secrete inflammatory cytokines and chemokines, the adipocytokines, able to recruit immune cells into adipose tissue, amplifying the inflammatory response also at systemic level. This review summarizes the most recent studies focused at elucidating the molecular targets of curcumin activity responsible for its anti-inflammatory properties in obesity-associated inflammation and related pathologies.

The Influence of Plant Extracts and Phytoconstituents on Antioxidant Enzymes Activity and Gene Expression in the Prevention and Treatment of Impaired Glucose Homeostasis and Diabetes Complications

Diabetes is a complex metabolic disorder resulting either from insulin resistance or an impaired insulin secretion. Prolonged elevated blood glucose concentration, the key clinical sign of diabetes, initiates an enhancement of reactive oxygen species derived from glucose autoxidation and glycosylation of proteins. Consequently, chronic oxidative stress overwhelms cellular endogenous antioxidant defenses and leads to the acute and long-standing structural and functional changes of macromolecules resulting in impaired cellular functioning, cell death and organ dysfunction. The oxidative stress provoked chain of pathological events over time cause diabetic complications such as nephropathy, peripheral neuropathy, cardiomyopathy, retinopathy, hypertension, and liver disease. Under diabetic conditions, accompanying genome/epigenome and metabolite markers alterations may also affect glucose homeostasis, pancreatic β-cells, muscle, liver, and adipose tissue. By providing deeper genetic/epigenetic insight of direct or indirect dietary effects, nutrigenomics offers a promising opportunity to improve the quality of life of diabetic patients. Natural plant extracts, or their naturally occurring compounds, were shown to be very proficient in the prevention and treatment of different pathologies associated with oxidative stress including diabetes and its complications. Considering that food intake is one of the crucial components in diabetes’ prevalence, progression and complications, this review summarizes the effect of the major plant secondary metabolite and phytoconstituents on the antioxidant enzymes activity and gene expression under diabetic conditions.

Natural Bioactive Compounds Useful in Clinical Management of Metabolic Syndrome

Metabolic syndrome (MetS) is a clinical manifestation characterized by a plethora of comorbidities, including hyperglycemia, abdominal obesity, arterial hypertension, and dyslipidemia. All MetS comorbidities participate to induce a low-grade inflammation state and oxidative stress, typical of this syndrome. MetS is related to an increased risk of cardiovascular diseases and early death, with an important impact on health-care costs. For its clinic management a poly-pharmaceutical therapy is often required, but this can cause side effects and reduce the patient's compliance. For this reason, finding a valid and alternative therapeutic strategy, natural and free of side effects, could represent a useful tool in the fight the MetS. In this context, the use of functional foods, and the assumption of natural bioactive compounds (NBCs), could exert beneficial effects on body weight, blood pressure and glucose metabolism control, on endothelial damage, on the improvement of lipid profile, on the inflammatory state, and on oxidative stress. This review focuses on the possible beneficial role of NBCs in the prevention and in the clinical management of MetS and its comorbidities.

Plant terpenes on treating cardiovascular and metabolic disease: a review

The use of medicinal plants as a therapy alternative is old as human existence itself. Nowadays, the search for effective molecules for chronic diseases treatments has increased. The cardiometabolic disorders still the main cause of death worldwide and plants may offer potential pharmacological innovative approaches to treat and prevent diseases. In the range of plant molecules are inserted the terpenes, which constituent essential elements with several pharmacological characteristics and applications, including cardiovascular and metabolic properties. Thus, the aim of the present review is to update the terpenes use on chronic disorders such as obesity, diabetes, hypertension and vascular conditions. The review includes a brief terpenes description based on the scientific literature in addition to data collected from secondary sources such as books and conference proceedings. We concluded that terpenes could act as adjuvant or main alternative treatment (when started earlier) to improve cardiometabolic diseases, contributing to reduce side effects of conventional drugs, in addition to preserving ethnopharmacological knowledge.

The Effect of Curcumin Supplementation on Pulse Wave Velocity in Patients with Metabolic Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial

Cardiovascular disease is a leading cause of death in many societies. Arterial stiffness is an initial sign of structural and functional changes in the arterial wall. Pulse wave velocity (PWV) is the gold standard for non-invasive evaluation of aortic stiffness and a modifiable cardiovascular risk factor. Curcumin is a major component of turmeric with known anti-inflammatory and anti-oxidative effects. Since arterial stiffness is affected by inflammation and oxidative stress, it may be improved by curcumin supplementation. The purpose of this clinical trial was to investigate the potential effects of curcumin on improving arterial stiffness in patients with metabolic syndrome. This placebo-controlled, double-blind, randomized clinical trial was conducted among metabolic syndrome patients. Sixty-six eligible individuals were randomly assigned to active intervention or control groups. The active intervention group received curcumin supplement at a dose of 500 mg daily for 12 weeks, whereas the control group received placebo capsule. Physical activity, daily dietary energy intake, anthropometric body composition, and biochemical hemodynamic and arterial stiffness parameters were evaluated at baseline and at the end of the study. Body weight decreased significantly in the curcumin group compared to placebo. Also, curcumin intervention improved PWV, which remained significant after adjustment for potential confounding factors (p = 0.011). The current clinical trial demonstrated that daily intake of 500 mg of curcumin for 12 weeks can lead to the improvement of arterial stiffness and weight management among subjects with metabolic syndrome.

Medicinal plants utilized in Thai Traditional Medicine for diabetes treatment: Ethnobotanical surveys, scientific evidence and phytochemicals

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes mellitus remains the most lethal metabolic disease of contemporaneous times and despite the therapeutic arsenal currently available, research on new antidiabetic agents remains a priority. In recent years, the revitalization of Thai Traditional Medicine (TTM) became a clear priority for the Thai government, and many efforts have been undertaken to accelerate research on herbal medicines and their use in medical services in various hospitals. Additionally, and particularly in rural areas, treatment of diabetes and associated symptomatology frequently relies on herbal preparations recommended by practitioners of TTM. In the current work, medicinal plants used in Thailand for treating diabetes, as well as their hypoglycaemic pharmacological evidences and potential therapeutic use for diabetes-related complications were reviewed.

MATERIALS AND METHODS

Ethnopharmacological information on the plant materials used in TTM for diabetes treatment was collected through literature search in a range of scientific databases using the search terms: diabetes, folk medicine, Thailand medicinal plants, traditional medicine. Information regarding scientific evidence on the antidiabetic effects of surveyed species was obtained considering not only the most common taxonomic designation, but also taxonomic synonyms, and including the keywords 'diabetes' and 'hypoglycaemic effect'.

RESULTS

A total of 183 species known to be used for diabetes management in TTM were reviewed, with 30% of them still lacking experimental evidences to support claims regarding the mechanisms and phytochemicals underlying their antidiabetic properties. Moreover, a total of 46 bioactives displaying effective antidiabetic effects have been isolated from 24 species, their underlying mechanism(s) of action being fully or partially disclosed.

CONCLUSIONS

We deliver the most extensive survey dealing with the ethnomedicinal knowledge of Thai medicinal plants utilized on diabetes management. We are certain that the current review will spark further research on Thai plants for the development of new standardized phytomedicines through drug discovery programmes.

Effects of Curcumin in a Mouse Model of Very High Fat Diet-Induced Obesity

Worldwide rates of Western-diet-induced obesity epidemics are growing dramatically. Being linked with numerous comorbidities and complications, including cardiovascular disease, type 2 diabetes, cancer, chronic inflammation, and osteoarthritis (OA), obesity represents one of the most threatening challenges for modern healthcare. Mouse models are an invaluable tool for investigating the effects of diets and their bioactive components against high fat diet (HFD)-induced obesity and its comorbidities. During recent years, very high fat diets (VHFDs), providing 58–60% kcal fat, have become a popular alternative to more traditional HFDs, providing 40–45% total kcal fat, due to the faster induction of obesity and stronger metabolic responses. This project aims to investigate if the 60% fat VHFD is suitable to evaluate the protective effects of curcumin in diet-induced obesity and osteoarthritis. B6 male mice, prone to diet-induced metabolic dysfunction, were supplemented with VHFD without or with curcumin for 13 weeks. Under these experimental conditions, feeding mice a VHFD for 13 weeks did not result in expected robust manifestations of the targeted pathophysiologic conditions. Supplementing the diet with curcumin, in turn, protected the animals against obesity without significant changes in white adipocyte size, glucose clearance, and knee cartilage integrity. Additional research is needed to optimize diet composition, curcumin dosage, and duration of dietary interventions to establish the VHFD-induced obesity for evaluating the effects of curcumin on metabolic dysfunctions related to obesity and osteoarthritis.

Acupuncture attenuates the development of diabetic peripheral neuralgia by regulating P2X4 expression and inflammation in rat spinal microglia

Diabetic peripheral neuropathy (DPN) is a chronic microvascular complication of diabetes. The purpose of this study is to find the underlying mechanism for the effects of acupuncture in DPN rats. Rats were rendered diabetic with a single injection of 35 mg/kg streptozotocin (STZ). These STZ-diabetic rats were treated with acupuncture for 20 min once daily. The therapeutic efficacy of acupuncture was assessed using mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) evaluations. After 14 days treatment, acupuncture markedly reduced the pathological injury in STZ-diabetic rats. Moreover, it significantly down-regulated P2X4 and OX42 expression along with the reduced levels of inflammatory factors (CXCR3, TNF-α, IL-1β, IL-6), GSP and lipid metabolisms in the spinal cord of the DPN rats. Acupuncture could relieve DPN in rats by regulating P2X4 expression and inflammation in spinal microglia.

Selected Indonesian Medicinal Plants for the Management of Metabolic Syndrome: Molecular Basis and Recent Studies

Increased prevalence of metabolic syndrome (MetS) in the world influences quality of health in all respective countries, including Indonesia. Data from Indonesian Family Life Survey reported in 2019 showed that the prevalence of MetS in Indonesia currently is 21.66%, estimated with the provincial incidence ranging up to 50%; additionally, the most common components of MetS discovered in Indonesia were poor high-density lipoprotein (HDL) cholesterol and hypertension. Management treatment of MetS involves a combination of lifestyle changes and pharmacological interventions to decrease cerebrovascular disease. Various natural substances have been shown to govern any cardiovascular or metabolic disorders through different mechanisms, such as triggering anti-inflammation, lipid profile correction, sensitization of insulin reception, or blood glucose control. In Indonesia, the utilization of natural compounds is part of the nation's culture. The community widely uses them; even though in general, their effectiveness and safety have not been thoroughly assessed by rigorous clinical trials. Scientific evidence suggested that cinnamon, mangosteen, and curcumin, as well as their derived components possess a broad spectrum of pharmacological activity. In this review, an enormous potential of cinnamon, mangosteen, and curcumin, which originated and are commonly used in Indonesia, could be treated against MetS, such as diabetes, hyperlipidemia, hypertension, and obesity. The findings suggested that cinnamon, mangosteen, curcumin and their derivatives may reflect areas of promise in the management of MetS.

Curcumin inhibits alloxan-induced pancreatic islet cell damage via antioxidation and antiapoptosis

The present study elucidates the possible protective effects of curcumin on β-cells damaged by oxidative stress and its significance in controlling diabetes mellitus in in vitro experiments. Pancreatic islet (RIN-m5F) cells were treated with 25 mmol/L alloxan (AXN) to induce cell damage and the protective effects of curcumin were observed. The results showed that curcumin significantly promoted the cellular activity of AXN-treated RIN-m5F cells, decreased the ratio of apoptosis, downregulated the level of malondialdehyde, upregulated the levels of superoxide dismutase and reactive oxygen species, increased the expression of Bcl-2, cleaved caspase-3, and cleaved PARP1, and decreased the expression of Bax in AXN-treated cells. These results suggest that curcumin inhibits AXN-induced damage in RIN-m5F cells via antioxidative and antiapoptotic mechanisms.

The Underlying Mechanisms of Curcumin Inhibition of Hyperglycemia and Hyperlipidemia in Rats Fed a High-Fat Diet Combined With STZ Treatment

Curcumin is the main secondary metabolite of Curcuma longa and other Curcuma spp, and has been reported to have some potential in preventing and treating some physiological disorders. This study investigated the effect of curcumin in inhibiting high-fat diet and streptozotocin (STZ)-induced hyperglycemia and hyperlipidemia in rats. Twenty-six male Sprague-Dawley (SD) rats (170–190 g) were randomly divided into a standard food pellet diet group (Control group), a high-fat diet and streptozotocin group (HF + STZ group), and a high-fat diet combined with curcumin and STZ group (HF + Cur + STZ group). Compared with the HF + STZ group, the HF + Cur + STZ group exhibited significantly reduced fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), alanine aminotransferase (AST), and aspartate transaminase (ALT) levels, as well as liver coefficients. In the livers of these rats, the expression of malondialdehyde (MDA) and Bax was downregulated, whereas that of superoxide dismutase (SOD) and Bcl-2 was upregulated. Moreover, the liver histology of these rats was improved and resembled that of the control rats. These results suggest that curcumin prevents high-fat diet and STZ-induced hyperglycemia and hyperlipidemia, mainly via anti-oxidant and anti-apoptotic mechanisms in the liver.

Shared pathways for neuroprogression and somatoprogression in neuropsychiatric disorders

Activated immune-inflammatory, oxidative and nitrosative stress (IO&NS) pathways and consequent mitochondrial aberrations are involved in the pathophysiology of psychiatric disorders including major depression, bipolar disorder and schizophrenia. They offer independent and shared contributions to pathways underpinning medical comorbidities including insulin resistance, metabolic syndrome, obesity and cardiovascular disease - herein conceptualized as somatoprogression. This narrative review of human studies aims to summarize relationships between IO&NS pathways, neuroprogression and somatoprogression. Activated IO&NS pathways, implicated in the neuroprogression of psychiatric disorders, affect the pathogenesis of comorbidities including insulin resistance, dyslipidaemia, obesity and hypertension, and by inference, metabolic syndrome. These conditions activate IO&NS pathways, exacerbating neuroprogression in psychiatric disorders. The processes whereby proinflammatory cytokines, nitrosative and endoplasmic reticulum stress, NADPH oxidase isoforms, PPARγ inactivation, SIRT1 deficiency and intracellular signalling pathways impact lipid metabolism and storage are considered. Through associations between body mass index, chronic neuroinflammation and FTO expression, activation of IO&NS pathways arising from somatoprogression may contribute to neuroprogression. Early evidence highlights the potential of adjuvants targeting IO&NS pathways for treating somatoprogression and neuroprogression.

Mechanics insights of curcumin in myocardial ischemia: Where are we standing?

Cardiovascular disorders are known as one of the main health problems which are associated with mortality worldwide. Myocardial ischemia (MI) is improper blood supply to myocardium which leads from serious complications to life-threatening problems like AMI, atherosclerosis, hypertension, cardiac-hypertrophy as well as diabetic associated complications as diabetic atherosclerosis/cardiomyopathy/hypertension. Despite several efforts, the current therapeutic platforms are not related with significant results. Hence, it seems, developing novel therapies are required. In this regard, increasing evidences indicated, curcumin (CRC) acts as cardioprotective agent. Given that CRC and its analogs exert their cardioprotective effects via affecting on a variety of cardiovascular diseases-related mechanisms (i.e., Inflammation, and oxidative stress). Herein, for first time, we have highlighted the protective impacts of CRC against MI. This review might be a steppingstone for further investigation into the clinical implications of the CRC against MI. Furthermore, it pulls in light of a legitimate concern for scientific community, seeking novel techniques and characteristic dynamic biopharmaceuticals for use against myocardial ischemia.

Curcumin and Type 2 Diabetes Mellitus: Prevention and Treatment

Type 2 diabetes mellitus (T2DM) is an ensemble of metabolic diseases that has reached pandemic dimensions all over the world. The multifactorial nature of the pathology makes patient management, which includes lifelong drug therapy and lifestyle modification, extremely challenging. It is well known that T2DM is a preventable disease, therefore lowering the incidence of new T2DM cases could be a key strategy to reduce the global impact of diabetes. Currently, there is growing evidence on the efficacy of the use of medicinal plants supplements for T2DM prevention and management. Among these medicinal plants, curcumin is gaining a growing interest in the scientific community. Curcumin is a bioactive molecule present in the rhizome of the Curcuma longa plant, also known as turmeric. Curcumin has different pharmacological and biological effects that have been described by both in vitro and in vivo studies, and include antioxidant, cardio-protective, anti-inflammatory, anti-microbial, nephro-protective, anti-neoplastic, hepato-protective, immunomodulatory, hypoglycaemic and anti-rheumatic effects. In animal models, curcumin extract delays diabetes development, improves β-cell functions, prevents β-cell death, and decreases insulin resistance. The present review focuses on pre-clinical and clinical trials on curcumin supplementation in T2DM and discusses the peculiar mechanisms by which curcumin might ameliorate diabetes management.

Resveratrol-mediated glycemic regulation is blunted by curcumin and is associated to modulation of gut microbiota

The polyphenols resveratrol (RSV) and curcumin (Cur) are phytoalexines and natural antibiotics with numerous pharmacological functions and metabolic impacts. Recent evidences show a broad control of gut microbiota by polyphenols which could influence glycemic regulation. The aim of this work is to estimate the respective effect of RSV and Cur alone or in association on the control of glycemia and on gut microbiota. A 5-week chronic treatment of hyperglycemic mice with RSV and/or Cur resulted in a differential effect on glucose tolerance test and modified gut microbiome. We precisely identified groups of bacteria representing a specific signature of the glycemic effect of RSV. Inferred metagenomic analysis and metabolic pathway prediction showed that the sulfur and branched-chain amino-acid (BCAA) metabolic activities are tightly correlated with the efficacy of RSV for the control of glycaemia. The impact on BCAA metabolism was further validated by serum metabolomics analysis. Altogether, we show that polyphenols specifically impact gut microbiota and corresponding metabolic functions which could be responsible for their therapeutic role.

Danzhi Jiangtang Capsule Mediates NIT-1 Insulinoma Cell Proliferation and Apoptosis by GLP-1/Akt Signaling Pathway

Objective

This study aimed to investigate the effects of Danzhi Jiangtang Capsule (DJC) on the proliferation and apoptosis functions of NIT-1 pancreatic β-cells exposed to high-glucose load through GLP-1 activated Akt/ FoxO1 signaling pathway.

Methods

Cellular apoptosis of NIT-1 pancreatic β-cells was induced by culturing in medium with 33.3mmol/L high glucose (HG). Then low-dose DJC (HG +LD), high-dose DJC (HG +HD), high-dose DJC+ GLP-1 inhibition (HG +HD +GI), and high-dose DJC+AKT inhibition (HG +HD+AI) were added, respectively. Cellular proliferation was accessed by cell counting kit (CCK-8) and cellular apoptosis was measured by Annexin V-FITC/PI staining. The protein levels of phosphorylated phosphatidylinositol-3-kinase (p-PI3K), phosphorylated AKT (p-AKT), phosphorylated Forkhead box protein O1 (p-FoxO1), and cleaved caspase-3 were detected by Western blotting. The mRNA expression of pancreatic duodenal homeobox-1 (PDX-1), CyclinD1, Bcl-2, and insulin was tested by Q-PCR.

Results

Comparing to HG group, (HG+HD) group showed a significantly increased cellular proliferation. The apoptosis of NIT-1 cells also was obviously reduced, with downregulated cleaved caspase-3 protein level and upregulated PDX-1, CyclinD1, and Bcl-2 mRNA levels (P<0.05). Additionally, (HG+HD) group manifested increased insulin mRNA expression; the protein levels of p-PI3K and p-AKT were markedly increased and p-FoxO1 was decreased. All of the above therapeutic effects by DJC intervention had been reversed by GLP-1 inhibition in (HG+HD+GI) group or AKT inhibition in (HG+HD+AI) group.

Conclusion

DJC was able to attenuate the toxicity of high-glucose load in NIT-1 pancreatic β-cells, ascribed to the improvement of cellular proliferation and apoptosis by GLP-1/Akt signaling pathway. This study could supply a new mechanism of DJC effects on type 2 diabetes mellitus (T2DM) treatment.

PID1 alters the antilipolytic action of insulin and increases lipolysis via inhibition of AKT/PKA pathway activation

Purpose

The aim of this study was to investigate the effect of phosphotyrosine interaction domain containing 1 (PID1) on the insulin-induced activation of the AKT (protein kinase B)/protein kinase A (PKA)/hormone-sensitive lipase (HSL) pathway and lipolysis.

Methods

Sprague–Dawley rats were fed either chow or a high-fat diet (HFD). The levels of insulin, glycerol, free fatty acids (FFAs) and PID1 mRNA expression were measured in the 2 groups. Furthermore, we examined the role of PID1 in the regulation of the AKT/PKA/HSL cascade and lipolysis in the 3T3-L1 cell line.

Results

Adipose tissue from HFD rats exhibited elevated PID1 expression, which showed a positive correlation with insulin levels and lipolysis. In 3T3-L1 adipocytes, we found that the antilipolytic effect of insulin is mediated by AKT and that phosphorylated AKT results in the promotion of PDE3B expression, the dephosphorylation of PKA and HSL and the suppression of glycerol release. However, overexpression of PID1 and treatment with 1 μM isoproterenol and 100 nM insulin for 24 h resulted in an increased release of glycerol and a noticeable inhibition of AKT phosphorylation, PDE3B expression and the phosphorylation of PKA/HSL in 3T3-L1 cells. In contrast, knockdown of PID1 and treatment with the above reagents inhibited lipolysis and activated the phosphorylation of AKT, which resulted in the dephosphorylation of PKA and HSL.

Conclusions

Our findings indicate that PID1 in adipose tissue increases lipolysis by altering the antilipolytic action of insulin. This suggests that PID1 may represent a new therapeutic target to ameliorate adipocyte lipolysis and hence improve insulin sensitivity.

Metabolic benefits of curcumin supplementation in patients with metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials

The finding of studies on the effect of curcumin extract on metabolic factor in patients with metabolic syndrome has had arguable results. This systematic review with meta-analysis of randomized controlled trials (RCT) aimed to analyze the effect of curcumin/turmeric on metabolic factors in patients with metabolic syndrome. The PICO strategy was used to establish the guiding question of this review. Several databases for RCT were searched until September 2018. Of the 144 articles initially identified, seven trials met the eligibility criteria. A random-effects model with a mean weight difference (WMD) and a 95% confidence interval was performed for quantitative data synthesis. Pooled estimates of WMD were calculated between intervention and control groups using random-effects model in the presence of high level of heterogeneity between the studies. The results showed significant improvement of fasting blood glucose (p = 0.01), triglycerides (p < 0.001), high-density lipoprotein cholesterol (p = 0.003), and diastolic blood pressure (p = 0.007) levels. Curcumin was not associated with a significant change in waist circumference measurement (p = 0.6) and systolic blood pressure level (p = 0.269). Curcumin supplementation improves some components of metabolic syndrome.

Effect of turmeric on glycemic status, lipid profile, hs-CRP, and total antioxidant capacity in hyperlipidemic type 2 diabetes mellitus patients

Diabetes mellitus is the most common metabolic disorder worldwide. This study examined the effect of turmeric supplementation on glycemic status, lipid profile, hs-CRP and total antioxidant capacity in hyperlipidemic type 2 diabetic patients. In this double-blind, randomized clinical trial, 80 hyperlipidemic type 2 diabetic patients were divided into turmeric (2,100 mg powdered rhizome of turmeric daily) and placebo groups for 8 weeks. Body weight, fasting plasma glucose, hemoglobin A1c (HbA1c), serum insulin, triglyceride (TG), total cholesterol, low density lypoprotein cholesterol (LDL-c), high density lypoprotein cholesterol, apolipoprotein A1, apolipoprotein B, high sensitivity C-reactive protein (hs-CRP), and total antioxidant capacity were measured before and after intervention. Statistical analysis was carried out using paired and independent t and chi-square tests. Seventy five patients completed the study. The turmeric group showed significant decreases in body weight, TG, and LDL-c compared with baseline (p value < 0.05). Body mass index, TG, and total cholesterol decreased significantly in the turmeric group compared with the placebo group (p value < 0.05). No significant changes were observed in other parameters between the two groups after intervention (p value < 0.05). Turmeric improved some fractions of lipid profile and decreased body weight in hyperlipidemic patients with type 2 diabetes. It had no significant effect on glycemic status, hs-CRP, and total antioxidant capacity in these patients.

A pilot study of the effect of phospholipid curcumin on serum metabolomic profile in patients with non-alcoholic fatty liver disease: a randomized, double-blind, placebo-controlled trial

BACKGROUND/OBJECTIVES

Curcumin, a natural polyphenol compound in the spice turmeric, has been found to have potent anti-oxidative and anti-inflammatory activity. Curcumin may treat non-alcoholic fatty liver disease (NAFLD) through its beneficial effects on biomarkers of oxidative stress (OS) and inflammation, which are considered as two feature of this disease. However, the effects of curcumin on NAFLD have been remained poorly understood. This investigation evaluated the effects of administrating curcumin on metabolic status in NAFLD patients.

SUBJECTS/METHODS

Fifty-eight NAFLD patients participated in a randomized, double-blind, placebo-controlled parallel design of study. The subjects were allocated randomly into two groups, which either received 250 mg phospholipid curcumin or placebo, one capsule per day for a period of 8 weeks. Fasting blood samples were taken from each subject at the start and end of the study period. Subsequently, metabolomics analysis was performed for serum samples using NMR.

RESULTS

Compared with the placebo, supplementing phospholipid curcumin resulted in significant decreases in serum including 3- methyl-2-oxovaleric acid, 3-hydroxyisobutyrate, kynurenine, succinate, citrate, α-ketoglutarate, methylamine, trimethylamine, hippurate, indoxyl sulfate, chenodeoxycholic acid, taurocholic acid, and lithocholic acid. This profile of metabolic biomarkers could distinguish effectively NAFLD subjects who were treated with curcumin and placebo groups, achieving value of 0.99 for an area under receiver operating characteristic curve (AUC).

CONCLUSIONS

Characterizing the serum metabolic profile of the patients with NAFLD at the end of the intervention using NMR-based metabolomics method indicated that the targets of curcumin treatment included some amino acids, TCA cycle, bile acids, and gut microbiota.